.lesson-studio, .lesson-page { --lesson-blue: #1378bd; --lesson-ink: #153957; --lesson-sky: #e7f4ff; --lesson-line: #cce1f1; }
.lesson-studio { max-width: 1420px; margin: 0 auto; padding: clamp(16px, 3vw, 34px) 0 60px; color: var(--lesson-ink); }
.lesson-studio-head { display: flex; justify-content: space-between; align-items: end; gap: 20px; margin-bottom: 24px; }
.lesson-eyebrow, .lesson-edit-kicker { display: inline-block; color: #1477ad; font-size: .76rem; font-weight: 850; letter-spacing: .12em; text-transform: uppercase; }
.lesson-studio h1 { margin: 5px 0 8px; font-size: clamp(2rem, 4vw, 3.2rem); letter-spacing: -.04em; }
.lesson-studio-head p { margin: 0; max-width: 650px; line-height: 1.5; color: #526e84; }
.lesson-generation-reminder { display: flex; align-items: center; flex-wrap: wrap; gap: 10px 18px; margin: -5px 0 22px; padding: 15px 18px; border: 1px solid #a9d6e8; border-radius: 13px; background: #eaf8ff; color: #174764; }
.lesson-generation-reminder strong { flex: 1 1 100%; font-size: .96rem; }
.lesson-generation-reminder span { flex: 1 1 390px; font-size: .83rem; line-height: 1.45; }
.lesson-generation-reminder button { min-height: 37px; padding: 8px 12px; background: #1477ad; font-size: .8rem; }
.lesson-count { flex: 0 0 auto; padding: 9px 14px; border-radius: 100px; background: #d9f3e8; color: #116344; font-size: .85rem; font-weight: 800; }
.lesson-studio-grid { display: grid; grid-template-columns: minmax(290px, .9fr) minmax(380px, 1.1fr); gap: 18px; align-items: start; }
.lesson-editor-card { padding: clamp(18px, 2vw, 26px); border: 1px solid var(--lesson-line); border-radius: 18px; background: #fff; box-shadow: 0 8px 28px rgba(29, 79, 118, .055); }
.lesson-editor-card h2 { margin: 0 0 8px; font-size: 1.18rem; letter-spacing: -.02em; }
.lesson-editor-card p { line-height: 1.5; }
.lesson-step-list { display: grid; gap: 9px; margin-top: 18px; }
.lesson-step-item { display: flex; align-items: center; gap: 10px; border: 1px solid #dbe7ef; border-radius: 12px; background: #f9fcff; }
.lesson-step-item.is-selected { border-color: #39a2d5; background: #eaf7ff; box-shadow: 0 0 0 2px #d6f0fc; }
.lesson-step-select { flex: 1; display: grid; gap: 3px; min-height: 69px; padding: 11px 13px; text-align: left; background: transparent; color: var(--lesson-ink); }
.lesson-step-select:hover { background: transparent; }
.lesson-step-select strong { font-size: .88rem; }
.lesson-step-select small { color: #617e92; font-size: .72rem; }
.lesson-step-actions { display: flex; align-items: center; gap: 3px; padding-right: 9px; }
.lesson-step-actions label { display: grid; place-items: center; min-width: 30px; }
.lesson-step-actions input { width: 19px; height: 19px; accent-color: #1477ad; }
.lesson-step-actions button { min-width: 28px; min-height: 30px; padding: 0; border: 1px solid #cde0ed; background: #fff; color: #21556f; }
.lesson-step-actions button:hover { background: #dff2ff; }
.lesson-edit { display: grid; gap: 12px; }
.lesson-edit > label { display: grid; gap: 5px; color: #35536a; font-size: .82rem; font-weight: 750; }
.lesson-edit input[type="text"], .lesson-edit input:not([type]), .lesson-edit textarea { width: 100%; padding: 10px 12px; border: 1px solid #bcd2e2; border-radius: 9px; background: #fff; color: #16394d; font-weight: 450; line-height: 1.4; }
.lesson-edit textarea { resize: vertical; }
.lesson-edit-divider { height: 1px; margin: 6px 0 2px; background: #dae7ef; }
.lesson-options { display: grid; gap: 7px; margin: 0; padding: 11px; border: 1px solid #d4e6f0; border-radius: 10px; }
.lesson-options legend { padding: 0 5px; font-size: .8rem; font-weight: 750; }
.lesson-options label { display: flex; gap: 8px; align-items: center; }
.lesson-options input[type="checkbox"] { width: 19px; height: 19px; flex: 0 0 19px; accent-color: #1477ad; }
.lesson-fill-keys { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.lesson-fill-keys label { display: grid; gap: 5px; color: #35536a; font-size: .82rem; font-weight: 750; }
.lesson-fill-keys input { padding: 10px 12px; border: 1px solid #bcd2e2; border-radius: 9px; }
.lesson-hint { color: #668092; font-size: .83rem; }
.lesson-publish-row { padding: 13px; border-radius: 10px; background: #eaf7ff; }
.lesson-switch { display: flex; align-items: center; gap: 9px; font-weight: 760; }
.lesson-switch input { width: 20px; height: 20px; accent-color: #1477ad; }
.lesson-editor-actions, .lesson-share-actions { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.lesson-editor-actions button, .lesson-share-actions button { background: #1477ad; }
#lesson-save-status { color: #177453; font-size: .82rem; }
.lesson-share, .lesson-responses { margin-top: 18px; }
.lesson-share { display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.lesson-finalize { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-top: 18px; border-color: #9dd8c1; background: #f4fcf8; }
.lesson-finalize > div:first-child { max-width: 650px; }
.lesson-finalize h2 { margin: 5px 0 6px; }
.lesson-finalize p { margin: 0; color: #526f67; }
.lesson-finalize-actions { display: grid; justify-items: start; gap: 8px; flex: 0 0 auto; }
.lesson-finalize-actions button { min-height: 46px; background: #137a61; }
#lesson-finalize-status { max-width: 280px; color: #9b3b2d; font-size: .8rem; font-weight: 750; }
.lesson-share { margin: 12px 0 20px; }
.lesson-student-url { display: block; max-width: 100%; padding: 10px 12px; border: 1px solid #d4e6ef; border-radius: 8px; background: #f5faff; color: #095f8a; overflow-wrap: anywhere; font-size: .85rem; }
.lesson-share-actions .lesson-unpublish { background: #eef3f6; color: #45677a; }
#lesson-pdf-status { color: #a32923; font-size: .82rem; font-weight: 700; }
.lesson-share p { margin: 0; color: #61798b; }
.lesson-share-copy { display: grid; gap: 12px; max-width: 680px; }
.lesson-qr-card { display: grid; justify-items: center; gap: 6px; flex: 0 0 auto; padding: 10px; border: 1px solid #c9e2ee; border-radius: 13px; background: #fff; }
.lesson-qr-card img { display: block; width: 210px; height: 210px; image-rendering: crisp-edges; }
.lesson-qr-card span { color: #39647b; font-size: .76rem; font-weight: 800; }
.lesson-link { display: inline-flex; align-items: center; min-height: 42px; padding: 0 14px; border: 1px solid #8fc3dd; border-radius: 7px; background: #e8f6ff; color: #075c8d; font-weight: 750; text-decoration: none; }
.lesson-responses h2 span { margin-left: 4px; padding: 3px 9px; border-radius: 99px; background: #e6f3fc; font-size: .82rem; }
.lesson-response-heading { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.lesson-response-heading button { min-height: 34px; font-size: .78rem; }
.lesson-responses details { margin-top: 9px; border: 1px solid #d6e6f0; border-radius: 9px; }
.lesson-responses summary { display: flex; justify-content: space-between; gap: 12px; padding: 12px; cursor: pointer; }
.lesson-responses time { color: #6a8190; font-size: .8rem; }
.lesson-response-body { padding: 0 14px 12px; }
.lesson-response-body p { margin: 8px 0; font-size: .88rem; }
.lesson-response-step { padding: 10px 0; border-top: 1px solid #e0edf3; }
.lesson-response-step ol { margin: 8px 0 0; padding-left: 22px; }
.lesson-response-step li { margin: 7px 0; line-height: 1.45; }
.lesson-response-step li span { display: block; color: #547084; }
.lesson-response-step li strong { display: block; font-weight: 650; }
.lesson-loading { max-width: 700px; margin: 8vh auto; padding: 30px; text-align: center; color: #31566f; }

.lesson-page { min-height: 100vh; background: radial-gradient(circle at 12% 2%, #dcf5ff, transparent 34%), #f3f8fc; color: var(--lesson-ink); }
.lesson-page.is-clipboard-locked { -webkit-user-select: none; user-select: none; }
.lesson-page.is-clipboard-locked input, .lesson-page.is-clipboard-locked textarea { -webkit-user-select: text; user-select: text; }
#lesson-clipboard-notice { position: fixed; right: 18px; bottom: 18px; z-index: 1001; max-width: min(340px, calc(100vw - 36px)); padding: 12px 16px; border-radius: 10px; background: #173d58; color: #fff; box-shadow: 0 9px 28px #0b2d4650; font-size: .86rem; font-weight: 750; line-height: 1.4; }
.lesson-topbar { display: flex; justify-content: space-between; gap: 10px; align-items: center; min-height: 60px; padding: 10px clamp(18px, 4vw, 50px); background: #103955; color: #fff; }
.lesson-topbar span { color: #c8e8f8; font-size: .86rem; }
.lesson-topbar.is-student { position: sticky; top: 0; z-index: 30; box-shadow: 0 4px 14px #0a2b4130; }
.lesson-topbar-identity { display: flex; align-items: center; justify-content: flex-end; gap: 16px; min-width: 0; }
.lesson-topbar-topic { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lesson-student-name { max-width: min(38ch, 48vw); padding: 7px 12px; border: 1px solid #73b5d4; border-radius: 9px; background: #1a5577; color: #fff; font-size: .9rem; line-height: 1.25; text-align: right; overflow-wrap: anywhere; }
.lesson-player { max-width: 920px; margin: 0 auto; padding: 26px 18px 70px; }
.lesson-preview-workspace { display: grid; grid-template-columns: 268px minmax(0, 1fr); align-items: start; gap: 20px; width: min(1500px, 100%); margin: 0 auto; padding: 0 18px 45px; }
.lesson-preview-workspace .lesson-player { grid-column: 2; grid-row: 1; width: 100%; max-width: none; min-width: 0; padding: 26px 0 40px; }
.lesson-preview-pages { grid-column: 1; grid-row: 1; position: sticky; top: 15px; max-height: calc(100vh - 30px); overflow: auto; margin-top: 26px; padding: 14px; border: 1px solid #c8e1ee; border-radius: 17px; background: #fff; box-shadow: 0 12px 32px #17486612; }
.lesson-preview-pages-head { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.lesson-preview-pages h2 { margin: 0; color: #123b59; font-size: 1.12rem; }
.lesson-preview-pages-head span, .lesson-preview-pages > p { color: #698596; font-size: .74rem; }
.lesson-preview-pages > p { margin: 5px 0 13px; }
.lesson-preview-page-list { display: grid; gap: 9px; }
.lesson-preview-start-tile, .lesson-preview-page-item { width: 100%; border: 1px solid #cbdfe9; border-radius: 11px; background: #f6fbfe; }
.lesson-preview-start-tile { display: flex; align-items: center; gap: 10px; min-height: 72px; padding: 9px; color: #21475e; text-align: left; }
.lesson-preview-start-tile > span:last-child { display: grid; min-width: 0; }
.lesson-preview-start-tile small { overflow: hidden; color: #5e7a8b; text-overflow: ellipsis; white-space: nowrap; }
.lesson-preview-page-item { display: grid; grid-template-columns: minmax(0, 1fr) 28px; gap: 5px; padding: 7px; }
.lesson-preview-start-tile.is-active, .lesson-preview-page-item.is-active { border: 2px solid #168bc1; background: #e9f7ff; }
.lesson-preview-page-item.is-hidden { opacity: .7; }
.lesson-preview-page-select { display: grid; grid-template-columns: 22px minmax(0, 1fr); gap: 6px; min-width: 0; padding: 0; border: 0; background: transparent; color: #173f5b; text-align: left; }
.lesson-preview-page-number { display: grid; place-items: center; width: 23px; height: 23px; border-radius: 6px; background: #d8effa; color: #1173a4; font-size: .72rem; font-weight: 850; }
.lesson-preview-page-thumb { display: grid; align-content: start; gap: 3px; min-height: 88px; overflow: hidden; padding: 7px; border: 1px solid #d8e8ef; border-radius: 7px; background: #fff; }
.lesson-preview-page-thumb.is-board { background: #fff8e8; }
.lesson-preview-page-thumb small { color: #1582b4; font-size: .52rem; font-weight: 850; letter-spacing: .07em; }
.lesson-preview-page-thumb strong { overflow: hidden; font-size: .72rem; line-height: 1.15; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.lesson-preview-page-thumb > span { overflow: hidden; color: #688092; font-size: .6rem; line-height: 1.25; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; }
.lesson-preview-page-thumb img { width: 100%; height: 42px; object-fit: contain; }
.lesson-preview-page-name { grid-column: 2; overflow: hidden; font-size: .69rem; font-weight: 800; text-overflow: ellipsis; white-space: nowrap; }
.lesson-preview-page-actions { display: grid; align-content: start; gap: 4px; }
.lesson-preview-page-actions button { min-width: 25px; min-height: 25px; padding: 0; border: 1px solid #c5dce8; border-radius: 5px; background: #fff; color: #245a78; font-size: .86rem; }
.lesson-preview-page-actions button[data-preview-delete] { color: #a73333; }
.lesson-preview-page-actions button:disabled { opacity: .35; cursor: default; }
.lesson-preview-page-actions button[data-preview-show] { writing-mode: vertical-rl; min-height: 65px; padding: 4px; font-size: .59rem; }
.lesson-preview-page-actions span { color: #8a7650; font-size: .52rem; writing-mode: vertical-rl; }
.lesson-preview-add { display: grid; gap: 7px; margin-top: 16px; padding-top: 13px; border-top: 1px solid #dcebf2; }
.lesson-preview-add label { font-size: .76rem; font-weight: 800; }
.lesson-preview-add select { width: 100%; min-height: 35px; border: 1px solid #bad4e3; border-radius: 7px; background: #fff; color: #173f5b; }
.lesson-preview-add button { min-height: 37px; padding: 6px 8px; background: #1477ad; font-size: .74rem; }
#lesson-preview-pages-status { min-height: 0; color: #9f372b; font-weight: 700; }
@media (max-width: 950px) { .lesson-preview-workspace { display: flex; flex-direction: column-reverse; gap: 0; } .lesson-preview-workspace .lesson-player { padding-top: 10px; } .lesson-preview-pages { position: static; width: 100%; max-height: none; margin-top: 14px; } .lesson-preview-page-list { display: flex; overflow-x: auto; padding-bottom: 7px; } .lesson-preview-start-tile, .lesson-preview-page-item { flex: 0 0 178px; } .lesson-preview-add { grid-template-columns: 1fr auto; align-items: end; } .lesson-preview-add label { grid-column: 1 / -1; } }
.lesson-progress { display: flex; align-items: center; gap: 13px; margin-bottom: 18px; font-size: .78rem; font-weight: 800; color: #407187; }
.lesson-progress > div { flex: 1; height: 9px; border-radius: 99px; background: #d2e7f2; overflow: hidden; }
.lesson-progress i { display: block; height: 100%; background: linear-gradient(90deg, #28b5db, #1377b0); transition: width .3s; }
.lesson-hero, .lesson-player-card { padding: clamp(22px, 5vw, 48px); border: 1px solid #cfe3f0; border-radius: 24px; background: #fff; box-shadow: 0 20px 55px rgba(18, 71, 110, .08); }
.lesson-hero { text-align: center; }
.lesson-hero h1, .lesson-player-card h1 { margin: 8px 0 14px; font-size: clamp(2rem, 5vw, 3.5rem); line-height: 1.06; letter-spacing: -.045em; }
.lesson-hero p { max-width: 610px; margin: 12px auto; color: #4d6c80; line-height: 1.6; }
.lesson-hero-visual { display: flex; justify-content: center; align-items: center; gap: clamp(10px, 3vw, 28px); margin: 26px auto; padding: 20px; border-radius: 19px; background: linear-gradient(120deg, #e4f5ff, #fff0c7); font-size: clamp(1.5rem, 5vw, 3rem); }
.lesson-hero-lamp { filter: drop-shadow(0 0 14px #ffc33b); }
.lesson-hero label { display: grid; gap: 7px; max-width: 340px; margin: 26px auto 13px; font-weight: 750; text-align: left; }
.lesson-hero input { min-height: 46px; padding: 9px 12px; border: 1px solid #a9c9db; border-radius: 8px; }
.lesson-name-fields { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; max-width: 580px; margin: 20px auto 12px; }
.lesson-name-fields label { width: 100%; max-width: none; margin: 0; }
.lesson-name-fields input { width: 100%; min-width: 0; }
.lesson-hero button, .lesson-navigation button { min-height: 48px; background: #1477ad; }
.lesson-card-kicker { color: #1685b8; font-size: .77rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
.lesson-reading { max-width: 760px; margin: 0 0 20px; font-size: clamp(1.04rem, 2vw, 1.22rem); line-height: 1.7; }
.lesson-reading p { margin: 0 0 1.05em; white-space: pre-wrap; }
.lesson-reading p:last-child { margin-bottom: 0; }
.lesson-page-intro.has-side-image { display: grid; grid-template-columns: minmax(0, 1fr) minmax(250px, 28%); align-items: start; gap: clamp(20px, 3vw, 40px); }
.lesson-page-copy { min-width: 0; }
.lesson-page-intro.has-side-image .lesson-page-copy h1 { overflow-wrap: anywhere; }
.lesson-page-images { display: grid; gap: 12px; margin: 18px 0 24px; }
.lesson-page-intro.has-side-image .lesson-page-images { margin: 0; }
.lesson-page-images .lesson-figure { margin: 0; }
.lesson-page-images img { width: 100%; max-height: 360px; object-fit: contain; }
@media (max-width: 720px) { .lesson-page-intro.has-side-image { grid-template-columns: 1fr; } .lesson-page-intro.has-side-image .lesson-page-images { max-width: 460px; margin: 0 0 22px; } }
.lesson-board-text p, .lesson-notebook span { white-space: pre-wrap; }
.lesson-circuit { display: flex; align-items: center; flex-wrap: wrap; justify-content: center; gap: 0; margin: 24px 0; padding: 25px; border-radius: 16px; background: #e9f6fd; }
.lesson-battery, .lesson-bulb-symbol { display: grid; place-items: center; width: 75px; height: 75px; border: 4px solid #184b6d; border-radius: 50%; background: #fff; color: #184b6d; font-size: 1.5rem; font-weight: 800; }
.lesson-battery small { font-size: .55rem; }
.lesson-bulb-symbol { font-size: 2.1rem; }
.lesson-wire { width: min(14vw, 105px); height: 5px; background: #184b6d; }
.lesson-caption { flex: 0 0 100%; margin-top: 17px; text-align: center; font-weight: 760; }
.lesson-visual-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 24px 0; }
.lesson-concept-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(185px, 1fr)); gap: 12px; margin: 24px 0; }
.lesson-concept-card { border: 1px solid #b9dfea; border-radius: 16px; background: linear-gradient(145deg, #e8f8ff, #fff); padding: 18px; box-shadow: 0 7px 18px #1748660d; }
.lesson-concept-card > span { display: inline-block; color: #087eae; font-weight: 900; margin-bottom: 10px; }
.lesson-concept-card strong { display: block; color: #123b59; font-size: 1.1rem; }
.lesson-concept-card p { margin: 8px 0 0; line-height: 1.5; }
.lesson-compare-chart { border: 1px solid #b9dfea; border-radius: 17px; overflow: hidden; margin: 24px 0; box-shadow: 0 8px 20px #1748660d; }
.lesson-chart-head, .lesson-chart-row { display: grid; grid-template-columns: minmax(95px, .8fr) repeat(2, minmax(0, 1.3fr)); }
.lesson-chart-head { background: #153d59; color: white; }
.lesson-chart-head > *, .lesson-chart-row > * { padding: 13px 15px; border-right: 1px solid #d6e9f0; }
.lesson-chart-head > * { border-color: #567489; }
.lesson-chart-row:nth-child(odd) { background: #eef8fc; }
.lesson-chart-row b { color: #104f70; }
.lesson-chart-row span { line-height: 1.45; }
@media (max-width: 600px) { .lesson-chart-head, .lesson-chart-row { grid-template-columns: minmax(67px, .75fr) repeat(2, minmax(0, 1.25fr)); font-size: .83rem; } .lesson-chart-head > *, .lesson-chart-row > * { padding: 10px 7px; overflow-wrap: anywhere; } }
.lesson-compare-chart.is-proscons .lesson-chart-head strong:first-of-type { background: #137a69; }
.lesson-compare-chart.is-proscons .lesson-chart-head strong:last-of-type { background: #9a6235; }
.lesson-visual-editor { background: #f2faff; padding: 18px; border: 1px solid #c9e3ee; border-radius: 14px; margin: 16px 0; }
.lesson-visual-editor h3 { margin: 0 0 5px; }
.lesson-visual-editor p { margin: 0 0 12px; color: #49677a; }
.lesson-visual-editor textarea { width: 100%; }
.lesson-read-check-editor { margin: 18px 0; padding: 18px; border: 1px solid #b4dce9; border-radius: 14px; background: #f0faff; }
.lesson-read-check-editor h3 { margin: 0 0 5px; color: #124965; }
.lesson-read-check-editor p { margin: 0 0 14px; color: #527289; }
.lesson-read-check-editor label { display: grid; gap: 7px; margin: 10px 0; font-weight: 750; }
.lesson-read-check-editor select { width: 100%; min-height: 42px; padding: 8px; border: 1px solid #accfdf; border-radius: 8px; background: white; }
.lesson-extra-checks { margin: 19px 0; padding: 18px; border: 1px solid #bfdcea; border-radius: 14px; background: #f4fbff; }
.lesson-extra-checks h3 { margin: 0 0 5px; color: #124965; }
.lesson-extra-checks > p { margin: 0 0 14px; color: #527289; font-size: .88rem; }
.lesson-extra-check-list { display: grid; gap: 12px; }
.lesson-extra-check-card { min-width: 0; padding: 14px; border: 1px solid #cee5ef; border-radius: 12px; background: #fff; }
.lesson-extra-check-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-bottom: 10px; }
.lesson-extra-check-head button { min-height: 34px; padding: 6px 10px; font-size: .76rem; }
.lesson-extra-check-card > label { display: grid; gap: 6px; font-weight: 750; }
.lesson-extra-check-card textarea { width: 100%; min-height: 70px; }
.lesson-extra-check-card select { width: 100%; min-height: 42px; margin-top: 6px; padding: 8px 10px; border: 1px solid #accfdf; border-radius: 8px; background: #fff; color: #16394d; }
.lesson-extra-check-card .lesson-fill-keys { margin-top: 12px; }
.lesson-extra-check-card .lesson-options { margin-top: 12px; }
.lesson-answer-guide { display: grid; gap: 10px; margin: 14px 0; padding: 15px; border: 1px solid #c7dfeb; border-radius: 12px; background: #fff; }
.lesson-answer-guide > strong { color: #124965; }
.lesson-answer-guide > p { margin: 0; color: #527289; font-size: .84rem; }
.lesson-answer-guide label { display: grid; gap: 6px; margin: 0; font-weight: 700; }
.lesson-answer-guide textarea { width: 100%; min-height: 68px; }
.lesson-guide-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.lesson-guide-actions button { min-height: 38px; }
.lesson-guide-actions span { color: #527289; font-size: .82rem; }
.lesson-extra-check-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.lesson-extra-check-actions button { min-height: 40px; }
.lesson-extra-check-actions button:disabled { opacity: .55; cursor: not-allowed; }
.lesson-visual-grid > img { width: 100%; height: 280px; object-fit: contain; border: 1px solid #d8eaf3; border-radius: 15px; background: #e0efff; }
.lesson-filament { position: relative; display: flex; flex-direction: column; align-items: center; justify-content: center; height: 280px; border-radius: 15px; background: radial-gradient(circle at 50% 44%, #fff2b0, #d9f2ff 68%); overflow: hidden; }
.lesson-glass { position: relative; display: block; width: 125px; height: 135px; border: 5px solid #35718d; border-radius: 60px 60px 43px 43px; background: rgba(255, 255, 255, .48); box-shadow: 0 0 30px #ffcf57; }
.lesson-thread { position: absolute; left: 40px; top: 62px; width: 35px; height: 20px; border: 5px solid #fba62b; border-bottom: 0; border-radius: 50% 50% 0 0; box-shadow: 0 0 20px 9px #ffb938; animation: lesson-glow 2s ease-in-out infinite alternate; }
.lesson-base { width: 60px; height: 29px; border-radius: 4px 4px 12px 12px; background: repeating-linear-gradient(#6f8b9d 0 5px, #b0c7d2 5px 9px); }
.lesson-rays { position: absolute; top: 22px; left: 30%; color: #f4aa21; font-size: 2.8rem; animation: lesson-glow 1.6s infinite alternate; }
.lesson-filament small { margin-top: 12px; font-size: .74rem; font-weight: 760; text-align: center; }
@keyframes lesson-glow { from { opacity: .45; filter: brightness(.9); } to { opacity: 1; filter: brightness(1.35); } }
@media (prefers-reduced-motion: reduce) { .lesson-thread, .lesson-rays { animation: none; } }
.lesson-figure { margin: 22px 0; padding: 14px; border-radius: 16px; background: #eaf5fc; text-align: center; }
.lesson-figure img { display: block; max-width: 100%; max-height: 350px; margin: auto; object-fit: contain; }
.lesson-activity { margin-top: 26px; padding: clamp(16px, 3vw, 24px); border: 1px solid #bde1f2; border-radius: 16px; background: #f2fbff; }
.lesson-activity + .lesson-activity { margin-top: 14px; }
.lesson-question-number { display: block; margin-bottom: 12px; color: #1176a6; font-size: .82rem; letter-spacing: .04em; text-transform: uppercase; }
.lesson-activity > label, .lesson-multi legend { margin-bottom: 11px; font-size: 1.03rem; font-weight: 800; }
.lesson-activity textarea { display: block; width: 100%; margin-top: 10px; padding: 12px; border: 1px solid #accbdc; border-radius: 10px; line-height: 1.5; resize: vertical; }
.lesson-fill { font-size: 1.1rem; line-height: 2.4; }
.lesson-fill input { width: 67px; height: 40px; margin: 0 5px; padding: 3px 7px; border: 2px dashed #7db4d1; border-radius: 7px; background: #fff; text-align: center; font-weight: 850; }
.lesson-chips { display: flex; flex-wrap: wrap; gap: 9px; }
.lesson-chips button { flex: 1 1 140px; min-height: 38px; background: #d4edfa; color: #175e85; cursor: pointer; }
.lesson-multi { display: grid; gap: 9px; }
.lesson-multi .lesson-question-number { margin-bottom: 0; }
.lesson-multi-choices { display: grid; gap: 9px; min-width: 0; margin: 0; padding: 0; border: 0; }
.lesson-multi-choices legend { padding: 0; }
.lesson-multi label { display: flex; align-items: center; gap: 12px; min-height: 48px; padding: 9px 12px; border: 1px solid #c9e1ed; border-radius: 9px; background: #fff; cursor: pointer; }
.lesson-multi input { width: 20px; height: 20px; accent-color: #1477ad; }
.lesson-truefalse { padding: 16px 20px; }
.lesson-truefalse .lesson-question-number { margin-bottom: 8px; }
.lesson-truefalse-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.lesson-truefalse-statement { flex: 1; min-width: 0; margin: 0; font-size: 1.03rem; font-weight: 800; line-height: 1.4; }
.lesson-truefalse-options { display: flex; flex: 0 0 auto; gap: 9px; }
.lesson-truefalse-options label { min-height: 42px; padding: 7px 13px; font-weight: 750; white-space: nowrap; }
.lesson-truefalse-options label:has(input[value="true"]) { border-color: #a8d9bb; background: #eaf8ef; color: #176b43; }
.lesson-truefalse-options label:has(input[value="false"]) { border-color: #e8b5b5; background: #fff0f0; color: #a33030; }
.lesson-truefalse-options input[value="true"] { accent-color: #198754; }
.lesson-truefalse-options input[value="false"] { accent-color: #c43d3d; }
.lesson-truefalse-options label:has(input[value="true"]:checked) { border-color: #198754; background: #d6f2e1; box-shadow: 0 0 0 2px #b4e3c7; }
.lesson-truefalse-options label:has(input[value="false"]:checked) { border-color: #c43d3d; background: #ffe2e2; box-shadow: 0 0 0 2px #f1bbbb; }
@media (max-width: 700px) { .lesson-truefalse-row { align-items: stretch; flex-direction: column; gap: 12px; } .lesson-truefalse-options { width: 100%; } .lesson-truefalse-options label { flex: 1; justify-content: center; } }
.lesson-error, #lesson-error { min-height: 20px; color: #a32923; font-size: .85rem; font-weight: 700; }
.lesson-time-gate { margin: 18px 0 0; color: #527187; font-size: .82rem; font-weight: 700; text-align: right; }
.lesson-time-gate.is-ready { color: #16724c; }
.lesson-session-overlay { position: fixed; inset: 0; z-index: 1000; display: grid; place-items: center; padding: 20px; background: rgba(15, 42, 65, .68); }
.lesson-session-overlay > div { max-width: 480px; padding: 28px; border-radius: 18px; background: #fff; color: #173d58; text-align: center; box-shadow: 0 20px 60px rgba(0, 0, 0, .2); }
.lesson-session-overlay strong { font-size: 1.3rem; }
.lesson-session-overlay p { margin-bottom: 0; line-height: 1.5; }
#lesson-start:disabled, #lesson-next:disabled, #lesson-done:disabled { background: #a5bdcb; color: #244c62; cursor: not-allowed; box-shadow: none; }
.lesson-navigation { display: flex; justify-content: space-between; gap: 12px; margin-top: 25px; }
.lesson-navigation .secondary { background: #e5eff5; color: #25536b; }
.lesson-notebook { display: grid; grid-template-columns: minmax(0, 1fr) minmax(160px, 230px); align-items: center; gap: 24px; margin: 20px 0; padding: 16px 24px; border-left: 6px solid #f0ad30; border-radius: 12px; background: #fff4d7; line-height: 1.5; }
.lesson-notebook-copy { display: grid; align-content: center; gap: 7px; min-width: 0; }
.lesson-notebook-illustration { display: block; width: 100%; max-width: 230px; height: auto; justify-self: end; }
@media (max-width: 700px) { .lesson-notebook { grid-template-columns: 1fr; gap: 4px; } .lesson-notebook-illustration { width: min(190px, 65%); justify-self: center; } }
.lesson-notebook strong { font-size: 1.12rem; }
.lesson-board-images { display: grid; gap: 20px; }
.lesson-board-images figure { position: relative; margin: 0; padding: 15px; border: 1px solid #b8d7e9; border-radius: 15px; background: #e1f0fd; text-align: center; }
.lesson-board-images figure span { position: absolute; top: 10px; left: 10px; display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: #1378bd; color: #fff; font-weight: 850; }
.lesson-board-images img { display: block; max-width: 100%; max-height: 450px; margin: auto; object-fit: contain; }
.lesson-next { margin: 23px 0 0; padding: 12px; border-radius: 8px; background: #e4f4ff; font-weight: 800; }
.lesson-feedback { margin-top: 16px; padding: 13px; border-radius: 8px; background: #edf8f2; color: #276849; }
.lesson-complete-page .lesson-player { display: grid; place-items: center; min-height: calc(100vh - 70px); }
.lesson-complete-card { width: min(100%, 760px); padding: clamp(28px, 5vw, 56px); border: 1px solid #cce1f1; border-radius: 24px; background: #fff; box-shadow: 0 16px 45px rgba(24, 77, 111, .09); text-align: center; }
.lesson-complete-icon { display: grid; place-items: center; width: 70px; height: 70px; margin: 0 auto 20px; border-radius: 50%; background: #d9f3e8; color: #126b4c; font-size: 2rem; font-weight: 900; }
.lesson-complete-card h1 { margin: 8px 0 16px; color: #153957; font-size: clamp(2.2rem, 6vw, 3.5rem); }
.lesson-complete-status { display: inline-block; margin: 0; padding: 10px 16px; border-radius: 100px; background: #e8f5ff; color: #17587b; font-weight: 750; }
.lesson-complete-card .lesson-feedback { margin-top: 26px; padding: 20px; text-align: left; line-height: 1.55; }
.lesson-complete-motto { margin-top: 28px; padding: 22px 24px; border-radius: 16px; background: #eef8f3; color: #126b4c; }
.lesson-complete-motto span { font-size: .8rem; font-weight: 850; letter-spacing: .13em; }
.lesson-complete-motto p { margin: 10px 0 0; font-size: clamp(1.15rem, 2.5vw, 1.45rem); font-weight: 800; line-height: 1.45; }
@media (max-width: 850px) { .lesson-studio-grid { grid-template-columns: 1fr; } .lesson-share { align-items: start; flex-direction: column; } }
@media (max-width: 600px) { .lesson-topbar { font-size: .82rem; } .lesson-topbar span { display: none; } .lesson-student-name { max-width: 55vw; font-size: .8rem; } .lesson-player { padding: 16px 11px 48px; } .lesson-hero, .lesson-player-card { padding: 22px 17px; border-radius: 16px; } .lesson-name-fields { grid-template-columns: 1fr; } .lesson-visual-grid { grid-template-columns: 1fr; } .lesson-visual-grid > img { height: 240px; } .lesson-navigation { flex-wrap: wrap; } .lesson-navigation button { flex: 1 1 180px; } .lesson-studio-head { align-items: start; flex-direction: column; } }

/* Reusable topic workspace */
.lesson-overview .lesson-studio-head h1 { max-width: 800px; }
.lesson-create { display: grid; grid-template-columns: minmax(230px, .75fr) minmax(480px, 1.25fr); gap: 20px; align-items: center; }
.lesson-create p { margin: 0; color: #5c788a; }
.lesson-create form { display: grid; grid-template-columns: 1.2fr .85fr auto; gap: 12px; align-items: end; }
.lesson-create label, .lesson-source label, .lesson-step-core label, .lesson-board-editor label { display: grid; gap: 6px; min-width: 0; color: #31546a; font-size: .84rem; font-weight: 760; }
.lesson-create label span, .lesson-source label span, .lesson-step-core label span { color: #7b8f9c; font-size: .75rem; font-weight: 550; }
.lesson-create input, .lesson-create select, .lesson-source input, .lesson-source select, .lesson-source textarea, .lesson-step-core input { min-height: 43px; border: 1px solid #bcd2e2; border-radius: 9px; color: #16394d; font-weight: 450; }
.lesson-create button { min-height: 43px; white-space: nowrap; }
#lesson-create-status { grid-column: 2; min-height: 0; margin: 0; color: #b42318; font-size: .82rem; }
.lesson-class-filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0 0; }
.lesson-class-filters button { display: flex; flex: 1 1 78px; align-items: center; justify-content: center; gap: 7px; min-height: 49px; padding: 8px 10px; border: 1px solid var(--class-accent, #b8d4e6); border-radius: 10px; background: var(--class-soft, #fff); color: var(--class-accent, #19445e); font-size: .94rem; font-weight: 800; white-space: nowrap; }
.lesson-class-filters button:hover { border-color: var(--class-accent, #1378bd); background: var(--class-soft, #eaf6ff); box-shadow: 0 2px 8px rgba(18, 68, 98, .12); }
.lesson-class-filters button.is-active { border-color: var(--class-accent, #126fa9); background: var(--class-accent, #126fa9); color: #fff; box-shadow: 0 3px 9px rgba(18, 68, 98, .2); }
.lesson-class-filters button:focus-visible { outline: 3px solid #183b56; outline-offset: 2px; }
.lesson-filter-count { display: grid; place-items: center; min-width: 23px; height: 23px; padding: 0 5px; border-radius: 99px; background: #fff; color: var(--class-accent, #416b84); font-size: .74rem; }
.lesson-class-filters button.is-active .lesson-filter-count { background: #fff; color: var(--class-accent, #126fa9); }
:is(.lesson-class-filters button[data-topic-class-filter="5a"], .lesson-class-filters button[data-topic-class-filter="5b"], .lesson-topic-card[data-topic-class="5a"], .lesson-topic-card[data-topic-class="5b"]) { --class-accent: #70409a; --class-soft: #f1eafa; }
:is(.lesson-class-filters button[data-topic-class-filter="6a"], .lesson-class-filters button[data-topic-class-filter="6b"], .lesson-topic-card[data-topic-class="6a"], .lesson-topic-card[data-topic-class="6b"]) { --class-accent: #006f73; --class-soft: #e2f5f3; }
:is(.lesson-class-filters button[data-topic-class-filter="7a"], .lesson-class-filters button[data-topic-class-filter="7b"], .lesson-topic-card[data-topic-class="7a"], .lesson-topic-card[data-topic-class="7b"]) { --class-accent: #126fa9; --class-soft: #e6f3fd; }
:is(.lesson-class-filters button[data-topic-class-filter="8a"], .lesson-class-filters button[data-topic-class-filter="8b"], .lesson-topic-card[data-topic-class="8a"], .lesson-topic-card[data-topic-class="8b"]) { --class-accent: #8a5b00; --class-soft: #fff1d8; }
:is(.lesson-class-filters button[data-topic-class-filter="9a"], .lesson-class-filters button[data-topic-class-filter="9b"], .lesson-topic-card[data-topic-class="9a"], .lesson-topic-card[data-topic-class="9b"]) { --class-accent: #a53265; --class-soft: #fce9f0; }
:is(.lesson-class-filters button[data-topic-class-filter="10a"], .lesson-class-filters button[data-topic-class-filter="10b"], .lesson-topic-card[data-topic-class="10a"], .lesson-topic-card[data-topic-class="10b"]) { --class-accent: #246b3e; --class-soft: #e6f5e9; }
.lesson-overview-title { display: flex; align-items: baseline; gap: 14px; margin: 30px 0 14px; }
.lesson-overview-title h2 { margin: 0; font-size: 1.3rem; }
.lesson-overview-title span { color: #638093; font-size: .85rem; }
#lesson-overview-status { min-height: 0; margin: 0 0 10px; color: #31647d; font-size: .84rem; font-weight: 700; }
#lesson-overview-status:empty { display: none; }
.lesson-topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); gap: 14px; }
.lesson-empty-topics { grid-column: 1 / -1; margin: 0; padding: 24px; border: 1px dashed #bad4e4; border-radius: 12px; color: #617e92; }
.lesson-empty-topics[hidden], .lesson-topic-card[hidden] { display: none; }
.lesson-topic-card { display: grid; grid-template-rows: 1fr auto; gap: 5px; min-height: 215px; padding: 19px; border: 1px solid #c9deeb; border-radius: 16px; background: #fff; color: #163b55; text-align: left; box-shadow: 0 8px 22px rgba(20, 67, 102, .045); }
.lesson-topic-card:hover { background: #f4fbff; border-color: #6cbbdd; transform: translateY(-2px); }
.lesson-topic-open { display: grid; justify-items: start; align-content: start; gap: 8px; width: 100%; min-height: 0; padding: 0; border: 0; background: transparent; color: inherit; text-align: left; }
.lesson-topic-open:hover { background: transparent; }
.lesson-topic-open:focus-visible, .lesson-topic-delete:focus-visible, .lesson-topic-transfer:focus-visible { outline: 3px solid #1687be; outline-offset: 3px; }
.lesson-topic-card-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 6px; }
.lesson-topic-transfer { min-height: 32px; padding: 5px 8px; border: 1px solid #b9d9e9; border-radius: 7px; background: #eff8fd; color: #126087; font-size: .74rem; font-weight: 800; }
.lesson-topic-transfer:hover { background: #ddf0fa; }
.lesson-topic-card-actions .lesson-topic-delete { margin-left: auto; }
.lesson-topic-delete { justify-self: end; min-height: 32px; padding: 5px 9px; border: 1px solid #ecc9c5; border-radius: 7px; background: #fff4f2; color: #a32925; font-size: .76rem; font-weight: 800; }
.lesson-topic-delete:hover { background: #ffe5e0; }
.lesson-transfer-dialog { width: min(460px, calc(100% - 28px)); max-height: calc(100vh - 32px); padding: 25px; border: 1px solid #b9d9e9; border-radius: 16px; background: #fff; color: #173d58; box-shadow: 0 20px 60px rgba(15, 42, 65, .2); }
.lesson-transfer-dialog::backdrop { background: rgba(15, 42, 65, .55); }
.lesson-transfer-dialog h2 { margin: 0 0 11px; font-size: 1.3rem; overflow-wrap: anywhere; }
.lesson-transfer-dialog p { margin: 0 0 16px; line-height: 1.5; }
.lesson-transfer-dialog label { display: grid; gap: 7px; font-weight: 800; }
.lesson-transfer-dialog select { width: 100%; min-height: 44px; padding: 8px 10px; border: 1px solid #b9d9e9; border-radius: 8px; background: #fff; color: #173d58; }
#lesson-transfer-note { margin-top: 15px; color: #36637c; font-size: .86rem; }
#lesson-transfer-error { min-height: 18px; color: #a32925; font-size: .82rem; font-weight: 750; }
.lesson-transfer-actions { display: flex; justify-content: flex-end; flex-wrap: wrap; gap: 9px; }
.lesson-transfer-actions button { min-height: 40px; }
.lesson-topic-card-head { display: flex; width: 100%; align-items: start; justify-content: space-between; gap: 8px; }
.lesson-topic-class { max-width: calc(100% - 51px); padding: 5px 8px; border-radius: 7px; background: var(--class-soft, #e7f3fb); color: var(--class-accent, #175678); font-size: .72rem; font-weight: 850; overflow-wrap: anywhere; }
.lesson-topic-mark { display: grid; place-items: center; width: 43px; height: 43px; border-radius: 11px; background: linear-gradient(135deg, #d5f2ff, #fff0c6); color: #1677a9; font-size: 1.25rem; font-weight: 900; }
.lesson-topic-card strong { font-size: 1.08rem; overflow-wrap: anywhere; }
.lesson-topic-card small { color: #688193; }
.lesson-topic-open > b { margin-top: 5px; color: #0c70a4; font-size: .84rem; }
.lesson-topic-meta { display: flex; flex-wrap: wrap; gap: 6px; }
.lesson-topic-meta span { padding: 4px 7px; border-radius: 6px; background: #edf4f9; color: #4d7187; font-size: .7rem; font-weight: 750; }
.lesson-topic-meta .is-published { background: #dcf4e8; color: #16714d; }
.lesson-editor-head { align-items: end; }
.lesson-editor-head > div { display: flex; flex-direction: column; align-items: flex-start; }
.lesson-back-link { display: flex; align-items: center; width: fit-content; min-height: 44px; margin: 0 0 9px; padding: 7px 0; background: transparent; color: #116b99; font-size: 1.12rem; font-weight: 900; }
.lesson-back-link:hover { background: transparent; color: #0c4f7a; text-decoration: underline; }
.lesson-section-heading { display: flex; align-items: start; gap: 13px; margin: 0 0 18px; }
.lesson-section-heading h2 { margin: 0 0 5px; font-size: 1.23rem; }
.lesson-section-heading p { margin: 0; color: #607e90; font-size: .86rem; }
.lesson-section-number { display: grid; place-items: center; width: 35px; height: 35px; flex: 0 0 35px; border-radius: 10px; background: #dff3ff; color: #0876af; font-size: .83rem; font-weight: 900; }
.lesson-source-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 13px; }
.lesson-source-grid label, .lesson-source-bottom label { display: grid; gap: 6px; }
.lesson-optional { margin: 16px 0; border: 1px solid #d8e6ee; border-radius: 11px; background: #f8fbfd; }
.lesson-optional summary { padding: 11px 14px; color: #176d9a; font-size: .85rem; font-weight: 800; cursor: pointer; }
.lesson-optional summary span { color: #7893a3; font-weight: 550; }
.lesson-optional .lesson-source-grid { padding: 0 14px 14px; }
.lesson-source-bottom { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(220px, .65fr); gap: 14px; }
.lesson-source-bottom textarea { min-height: 130px; resize: vertical; }
.lesson-upload { display: grid; align-content: center; justify-items: start; gap: 8px; padding: 16px; border: 2px dashed #a8cee2; border-radius: 11px; background: #f0f9ff; }
.lesson-upload strong, .lesson-upload small { display: block; }
.lesson-upload small { margin-top: 4px; color: #6d8594; font-size: .75rem; }
.lesson-upload-button { display: inline-flex !important; align-items: center; justify-content: center; width: fit-content; min-height: 37px; padding: 7px 12px; border-radius: 8px; background: #1378ad; color: white !important; cursor: pointer; font-size: .81rem !important; font-weight: 800 !important; }
.lesson-upload-button:hover { background: #0c628f; }
.lesson-upload-button input { position: absolute; width: 1px; height: 1px; padding: 0; opacity: 0; }
.lesson-link-form { display: grid; grid-template-columns: 1fr auto; gap: 6px; width: 100%; padding-top: 11px; border-top: 1px solid #bddded; }
.lesson-link-form strong { grid-column: 1 / -1; font-size: .78rem; }
.lesson-link-form input[name="name"] { grid-column: 1 / -1; }
.lesson-link-form input { width: 100%; min-width: 0; min-height: 34px; padding: 6px 9px; font-size: .74rem; }
.lesson-link-form button { min-height: 34px; padding: 5px 10px; font-size: .73rem; white-space: nowrap; }
#lesson-upload-status { color: #177453; font-size: .78rem; }
.lesson-resource-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 9px; margin-top: 15px; }
.lesson-resource-card { display: flex; align-items: center; gap: 9px; min-width: 0; padding: 8px; border: 1px solid #d4e5ee; border-radius: 10px; background: #fff; }
.lesson-resource-card img, .lesson-pdf-icon { display: grid; place-items: center; width: 46px; height: 46px; flex: 0 0 46px; border-radius: 7px; background: #e2f3ff; object-fit: cover; color: #0c71a4; font-size: .72rem; font-weight: 900; }
.lesson-resource-card div { display: grid; gap: 2px; min-width: 0; flex: 1; }
.lesson-resource-card strong { overflow: hidden; color: #204861; font-size: .78rem; text-overflow: ellipsis; white-space: nowrap; }
.lesson-resource-card small { color: #7890a0; font-size: .68rem; }
.lesson-resource-card a { color: #0c70a4; font-size: .72rem; font-weight: 780; }
.lesson-resource-card button { width: 25px; min-height: 25px; padding: 0; background: #f8e7e7; color: #a12222; }
.lesson-empty-material { margin: 14px 0 0; color: #7390a0; font-size: .82rem; }
.lesson-generate { margin-top: 18px; border-color: #a9d6e8; background: linear-gradient(145deg, #fff, #f2faff); }
.lesson-generate h3 { margin: 18px 0 9px; color: #234b62; font-size: .88rem; }
.lesson-focus-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.lesson-focus-grid label, .lesson-source-choices label { display: flex; align-items: center; gap: 9px; min-width: 0; padding: 10px; border: 1px solid #cfe2ec; border-radius: 9px; background: white; color: #315c72; cursor: pointer; font-size: .81rem; font-weight: 700; }
.lesson-focus-grid label:has(input:checked), .lesson-source-choices label:has(input:checked) { border-color: #2b9dc7; background: #e7f7fd; }
.lesson-focus-grid input, .lesson-source-choices input { width: 17px; height: 17px; flex: 0 0 17px; accent-color: #147cad; }
.lesson-source-choices { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 8px; }
.lesson-source-choices span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lesson-generation-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 13px; margin-top: 20px; }
.lesson-generation-actions button { min-height: 45px; background: #127bac; }
#lesson-generate-status { color: #28647e; font-size: .83rem; font-weight: 700; }
.lesson-generation-note { margin: 11px 0 0; color: #668899; font-size: .78rem; }
.lesson-is-processing { overflow: hidden; }
.lesson-processing-layer { position: fixed; inset: 0; z-index: 10000; display: grid; place-items: center; padding: 20px; background: rgba(9, 37, 61, .72); }
.lesson-processing-card { width: min(100%, 480px); padding: clamp(24px, 5vw, 38px); border-radius: 22px; background: #fff; color: #183e58; text-align: center; box-shadow: 0 24px 70px rgba(0, 20, 41, .28); }
.lesson-processing-card:focus { outline: none; }
.lesson-processing-card h2 { margin: 20px 0 10px; font-size: clamp(1.45rem, 4vw, 1.85rem); }
.lesson-processing-card p { margin: 0 0 13px; line-height: 1.5; }
.lesson-processing-hint { color: #5e788a; font-weight: 700; }
.lesson-processing-time { display: inline-block; margin-top: 8px; padding: 7px 12px; border-radius: 999px; background: #eaf7ff; color: #176d99; font-size: .85rem; font-weight: 800; }
.lesson-processing-spinner { display: inline-block; width: 62px; height: 62px; border: 6px solid #d7eef9; border-top-color: #137eaf; border-radius: 50%; animation: lesson-processing-spin .8s linear infinite; }
@keyframes lesson-processing-spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .lesson-processing-spinner { animation-duration: 2.5s; } }
.lesson-preview-section { margin-top: 18px; }
.lesson-preview-frame { display: block; width: 100%; height: 650px; margin-top: 15px; border: 1px solid #cbdde8; border-radius: 14px; background: #fff; }
.lesson-preview-banner { padding: 14px 18px; border-bottom: 1px solid #e6d19b; background: #fff7e6; color: #523d1c; }
.lesson-preview-banner-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; width: min(1500px, 100%); margin: 0 auto; }
.lesson-preview-banner-heading { display: flex; align-items: center; gap: 14px; min-width: 0; }
.lesson-preview-stage { display: grid; place-items: center; width: 54px; height: 54px; flex: 0 0 54px; border-radius: 14px; background: #f4dcaa; color: #5d4219; font-size: .86rem; font-weight: 900; }
.lesson-preview-banner-copy strong { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; font-size: 1.05rem; line-height: 1.25; }
.lesson-preview-draft { padding: 3px 8px; border: 1px solid #dfb55f; border-radius: 999px; color: #705019; font-size: .72rem; font-weight: 800; }
.lesson-preview-banner-copy p { margin: 4px 0 0; color: #705b38; font-size: .82rem; line-height: 1.4; }
.lesson-preview-banner-actions { display: flex; align-items: center; gap: 10px; flex: 0 0 auto; }
.lesson-preview-banner-actions a, .lesson-preview-banner-actions button { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 9px 14px; border-radius: 9px; font-size: .83rem; font-weight: 800; line-height: 1.25; text-decoration: none; }
.lesson-preview-banner-actions a { border: 1px solid #bca270; background: #fffdf7; color: #68491b; }
.lesson-preview-banner-actions a:hover { background: #fff1cc; }
.lesson-preview-banner-actions button { background: #805617; color: #fff; }
.lesson-preview-banner-actions :is(a, button):focus-visible { outline: 3px solid #167eb0; outline-offset: 3px; }
@media (max-width: 850px) { .lesson-preview-banner-inner { align-items: stretch; flex-direction: column; gap: 12px; } .lesson-preview-banner-actions { justify-content: flex-end; } }
@media (max-width: 520px) { .lesson-preview-banner { padding: 13px 12px; } .lesson-preview-stage { width: 44px; height: 44px; flex-basis: 44px; } .lesson-preview-banner-actions { display: grid; grid-template-columns: 1fr 1fr; } .lesson-preview-banner-actions :is(a, button) { width: 100%; padding: 9px; text-align: center; } }

/* Keep the creation flow to one decision at a time. */
.lesson-studio-stages { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px; margin: 0 0 18px; }
.lesson-studio-stages button { display: flex; align-items: center; justify-content: center; gap: 8px; min-height: 47px; padding: 8px 10px; border: 1px solid #c6dfed; border-radius: 10px; background: #f5faff; color: #37647d; font-size: .83rem; font-weight: 800; }
.lesson-studio-stages button b { display: grid; place-items: center; width: 24px; height: 24px; flex: 0 0 24px; border-radius: 50%; background: #d8edf8; color: #126d9d; }
.lesson-studio-stages button.is-current { border-color: #218abd; background: #e4f5fe; color: #0c5d87; }
.lesson-studio-stages button:disabled { opacity: .48; cursor: not-allowed; }
.lesson-studio-material :is(.lesson-generate, .lesson-after-create, .lesson-preview-section, .lesson-finalize, .lesson-idea-section, .lesson-flow-heading, .lesson-studio-grid, .lesson-share, .lesson-responses),
.lesson-studio-create :is(.lesson-source, .lesson-after-material, .lesson-generation-reminder, .lesson-preview-section, .lesson-finalize, .lesson-idea-section, .lesson-flow-heading, .lesson-studio-grid, .lesson-share, .lesson-responses),
.lesson-studio-edit :is(.lesson-source, .lesson-after-material, .lesson-generate, .lesson-after-create, .lesson-generation-reminder) { display: none; }
.lesson-stage-actions { display: flex; justify-content: flex-end; margin: 16px 0; }
.lesson-stage-actions button { min-height: 46px; }
.lesson-stage-actions button.secondary { background: #e5eff5; color: #25536b; }
.lesson-field-help { margin: -5px 0 11px; color: #607e90; font-size: .87rem; }
.lesson-free-goals, .lesson-board-guide label { display: grid; gap: 7px; color: #31546a; font-size: .87rem; font-weight: 760; }
.lesson-free-goals { margin: 20px 0; }
.lesson-free-goals span, .lesson-board-guide h3 span { color: #778c99; font-size: .78rem; font-weight: 550; }
.lesson-free-goals textarea, .lesson-board-guide textarea { width: 100%; min-height: 100px; padding: 12px; border: 1px solid #bcd2e2; border-radius: 9px; background: #fff; color: #16394d; font: inherit; font-weight: 450; resize: vertical; }
.lesson-board-guide { display: grid; gap: 12px; margin: 22px 0; padding: 18px; border: 1px solid #eed490; border-radius: 13px; background: #fffaf0; }
.lesson-board-guide h3, .lesson-board-guide p { margin: 0; }
.lesson-board-guide p { color: #6a7280; font-size: .87rem; line-height: 1.5; }
.lesson-guide-heading { display: block; margin: 2px 0 9px; color: #31546a; font-size: .84rem; }
.lesson-board-guide-files { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 12px; }
.lesson-guide-card { min-width: 0; padding: 8px; border: 2px solid #e3d5ad; border-radius: 12px; background: #fff; }
.lesson-guide-card:has(input:checked) { border-color: #1284b3; background: #ecf9ff; box-shadow: 0 0 0 2px #d3eff9; }
.lesson-board-guide-files .lesson-guide-card label { display: grid; gap: 8px; max-width: none; padding: 0; border: 0; background: transparent; cursor: pointer; }
.lesson-guide-preview { display: grid; place-items: center; height: 142px; overflow: hidden; border-radius: 8px; background: #f1f6f9; }
.lesson-guide-preview img { width: 100%; height: 100%; object-fit: contain; }
.lesson-guide-pdf { display: grid; place-items: center; width: 66px; height: 84px; border-radius: 7px; background: #e0edf6; color: #215d7b; font-weight: 900; }
.lesson-guide-choice { display: flex; align-items: flex-start; gap: 8px; min-height: 37px; color: #173e57; font-size: .77rem; overflow-wrap: anywhere; }
.lesson-guide-choice input { width: 19px; height: 19px; flex: 0 0 19px; margin-top: 1px; accent-color: #1378ad; }
.lesson-guide-card > a { display: inline-block; margin: 4px 0 1px 27px; color: #126d9a; font-size: .75rem; font-weight: 760; }
#lesson-guide-status { display: block; margin-top: 8px; color: #a13f2f; font-size: .78rem; font-weight: 750; }
@media (max-width: 650px) { .lesson-studio-stages { grid-template-columns: repeat(2, minmax(0, 1fr)); } .lesson-studio-stages button { justify-content: flex-start; } }
@media (max-width: 760px) { .lesson-finalize { align-items: stretch; flex-direction: column; } .lesson-finalize-actions { width: 100%; } .lesson-finalize-actions button { width: 100%; } }
.lesson-preview-edit-trigger { display: block; width: fit-content; min-height: 38px; margin: 0 0 18px auto; padding: 7px 14px; border: 1px solid #a5cddb; border-radius: 9px; background: #e8f7fd; color: #0e6087; font-size: .85rem; font-weight: 800; }
.lesson-hero .lesson-preview-edit-trigger { margin-left: auto; }
.lesson-preview-top-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; align-items: center; gap: 10px; margin: 0 0 18px; }
.lesson-preview-top-actions .lesson-preview-edit-trigger { margin: 0; }
.lesson-preview-save-top { min-height: 38px; padding: 7px 14px; border: 1px solid #126f9b; border-radius: 9px; background: #147eb0; color: #fff; font-size: .85rem; font-weight: 800; }
.lesson-preview-top-actions button:disabled { opacity: .65; cursor: default; }
.lesson-direct-edit { outline: 2px dashed #0b9aca; outline-offset: 5px; border-radius: 5px; background: #f1fbff; cursor: text; }
.lesson-direct-edit:focus { outline: 3px solid #087bad; background: #fff; }
.lesson-preview-edit-panel { margin: 26px 0; padding: clamp(16px, 3vw, 25px); border: 2px solid #6dbfd8; border-radius: 17px; background: #f2fbff; text-align: left; }
.lesson-preview-edit-panel h2 { margin: 0 0 6px; color: #163d59; font-size: 1.35rem; }
.lesson-preview-edit-panel > p { margin: 0 0 18px; color: #527187; font-size: .93rem; }
.lesson-preview-edit-panel label { display: grid; gap: 6px; margin: 12px 0; color: #1b4c68; font-weight: 750; }
.lesson-preview-edit-panel textarea, .lesson-preview-edit-panel input:not([type="checkbox"]):not([type="file"]) { width: 100%; min-width: 0; padding: 10px 12px; border: 1px solid #a8cbda; border-radius: 9px; background: #fff; color: #123b59; font: inherit; }
.lesson-preview-edit-panel textarea { resize: vertical; }
.lesson-preview-edit-columns { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.lesson-preview-edit-group { margin: 18px 0; padding-top: 12px; border-top: 1px solid #cde7ef; }
.lesson-preview-edit-group h3 { margin: 0; }
.lesson-preview-options label { display: flex; align-items: center; gap: 10px; }
.lesson-preview-media { margin: 18px 0; padding: 12px; border: 1px solid #bddce7; border-radius: 12px; }
.lesson-preview-media legend { padding: 0 5px; font-weight: 850; }
.lesson-preview-media label:not(.lesson-preview-upload) { display: flex; align-items: center; gap: 10px; margin: 6px 0; padding: 7px; border-radius: 8px; background: #fff; }
.lesson-preview-media img { width: 48px; height: 42px; object-fit: contain; }
.lesson-preview-media .lesson-image-position-label, .lesson-preview-media .lesson-image-prompt-label { display: grid; gap: 6px; background: transparent; font-weight: 800; }
.lesson-preview-media :is(select, input[type="text"], input:not([type])) { width: 100%; }
.lesson-preview-media #lesson-preview-generate-image { margin-top: 8px; }
.lesson-preview-upload { padding: 12px; border: 2px dashed #82bfd5; border-radius: 10px; background: #fff; cursor: pointer; }
.lesson-preview-upload input { width: 100%; }
.lesson-preview-edit-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 9px; margin-top: 18px; }
.lesson-preview-edit-actions button { min-height: 43px; }
.lesson-preview-edit-actions span { color: #aa3f27; font-weight: 700; }
@media (max-width: 600px) { .lesson-preview-edit-columns { grid-template-columns: 1fr; } }
.lesson-idea-section { margin-top: 18px; }
.lesson-ideas { display: grid; grid-template-columns: repeat(4, 1fr); gap: 9px; }
.lesson-ideas button { display: grid; justify-items: start; align-content: start; gap: 4px; min-height: 132px; padding: 12px; border: 1px solid #d3e6ef; border-radius: 10px; background: #f5fbff; color: #234b62; text-align: left; }
.lesson-ideas button:hover { background: #e5f6ff; border-color: #7dc4e1; }
.lesson-ideas button > span { font-size: 1.3rem; color: #167dae; }
.lesson-ideas strong { font-size: .83rem; }
.lesson-ideas small { color: #698596; font-size: .71rem; line-height: 1.3; }
.lesson-ideas b { align-self: end; margin-top: auto; color: #0874aa; font-size: .72rem; }
.lesson-flow-heading { margin: 28px 0 14px; }
.lesson-step-item.is-board { border-color: #f0d487; background: #fffaed; }
.lesson-add-steps { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin-top: 16px; }
.lesson-add-steps span { flex: 0 0 100%; color: #6e8999; font-size: .77rem; font-weight: 800; }
.lesson-add-steps button { min-height: 31px; padding: 5px 9px; border: 1px solid #bddce9; background: #edf8fd; color: #18698f; font-size: .74rem; }
.lesson-add-steps button:hover { background: #d8f1fb; }
.lesson-step-core { display: grid; grid-template-columns: 1fr 170px; gap: 10px; }
.lesson-step-core input { min-width: 0; width: 100%; }
.lesson-board-editor { padding: 13px; border: 1px solid #efcf72; border-radius: 11px; background: #fff9e9; }
.lesson-board-editor p { margin: 8px 0 0; color: #8a6c28; font-size: .75rem; }
.lesson-board-rich-field > strong { display: block; margin: 0 0 8px; color: #1b4c68; font-size: .9rem; }
.lesson-board-rich { overflow: hidden; border: 1px solid #a8cbda; border-radius: 11px; background: #fff; }
.lesson-board-rich-toolbar { display: flex; align-items: center; flex-wrap: wrap; gap: 6px; padding: 8px; border-bottom: 1px solid #d6e8f0; background: #f5fafe; }
.lesson-board-rich-toolbar button { display: inline-flex; align-items: center; justify-content: center; min-width: 40px; min-height: 40px; padding: 5px 9px; border: 1px solid #b7d3e0; border-radius: 8px; background: #fff; color: #183c57; font-size: 1rem; cursor: pointer; }
.lesson-board-rich-toolbar button:hover, .lesson-board-rich-toolbar button:focus-visible { border-color: #1877a3; outline: 2px solid #a1d7ef; }
.lesson-board-rich-toolbar .lesson-board-color { padding: 5px; }
.lesson-board-color span { display: block; width: 23px; height: 23px; border-radius: 50%; background: var(--swatch); }
.lesson-board-rich-divider { width: 1px; height: 28px; margin: 0 3px; background: #cbdfe9; }
.lesson-board-custom-color { display: inline-flex !important; align-items: center; gap: 6px !important; margin: 0 !important; color: #31546a; font-size: .8rem; font-weight: 700; }
.lesson-board-custom-color input[type="color"], .lesson-preview-edit-panel .lesson-board-custom-color input[type="color"] { width: 42px; height: 40px; min-width: 42px; padding: 3px; border: 1px solid #b7d3e0; border-radius: 8px; background: #fff; cursor: pointer; }
.lesson-board-rich-content { min-height: 220px; max-height: 460px; overflow: auto; padding: 14px 16px; color: #173b57; font-size: 1rem; font-weight: 400; line-height: 1.6; white-space: pre-wrap; overflow-wrap: anywhere; }
.lesson-board-rich-content:focus { outline: 3px solid #b3e1f4; outline-offset: -3px; }
.lesson-board-rich-content:empty::before { content: attr(data-placeholder); color: #718a9a; }
.lesson-board-rich-content div { min-height: 1.6em; }
.lesson-board-rich-content > .lesson-board-edit-part { color: #a87310; font-size: .84rem; font-weight: 800; text-transform: uppercase; }
.lesson-board-rich-content > .lesson-board-edit-heading { font-weight: 850; }
.lesson-board-rich-content > .lesson-board-edit-subheading { font-weight: 400; }
.lesson-board-rich-content strong { font-weight: 800; }
.lesson-board-rich-status { display: block; min-height: 1.3em; padding: 0 12px 6px; color: #426b80; font-size: .75rem; }
.lesson-board-editor .lesson-board-rich-status { margin: 0; }
.lesson-preview-edit-panel .lesson-board-rich-field { margin: 14px 0; }
.lesson-step-media { display: grid; gap: 8px; padding: 13px; border: 1px solid #d5e8f1; border-radius: 11px; background: #f7fbfe; }
.lesson-step-media > strong { font-size: .84rem; }
.lesson-step-media > p { margin: 0; color: #718b9b; font-size: .74rem; }
.lesson-attachment-list { display: grid; gap: 6px; max-height: 170px; overflow-y: auto; }
.lesson-attachment-list label { display: flex; align-items: center; gap: 7px; padding: 5px; border-radius: 5px; background: #fff; color: #335970; font-size: .76rem; }
.lesson-attachment-list input { width: 18px; height: 18px; flex: 0 0 18px; accent-color: #1477ad; }
.lesson-step-resources { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 13px; margin: 18px 0; }
.lesson-step-resources .lesson-figure { margin: 0; }
.lesson-step-resources .lesson-figure img { max-height: 320px; }
.lesson-pdf-card { display: flex; align-items: center; gap: 13px; min-height: 80px; padding: 15px; border: 1px solid #b9d9e9; border-radius: 11px; background: #ecf8ff; color: #145c84; text-decoration: none; }
.lesson-pdf-card b { display: grid; place-items: center; width: 48px; height: 48px; flex: 0 0 48px; border-radius: 7px; background: #1378ad; color: #fff; font-size: .78rem; }
.lesson-pdf-card span { display: grid; gap: 3px; overflow-wrap: anywhere; font-weight: 800; }
.lesson-pdf-card small { font-weight: 500; }
.lesson-board-text { margin: 22px 0; padding: clamp(20px, 4vw, 30px); border: 1px solid #efd991; border-radius: 15px; background: #fffdf5; }
.lesson-board-text > span { color: #a87310; font-size: .73rem; font-weight: 900; letter-spacing: .15em; }
.lesson-board-text h2 { margin: 8px 0 20px; padding-bottom: 8px; border-bottom: 3px solid #d7a84b; color: #173d58; font-size: clamp(1.55rem, 3vw, 2.05rem); font-weight: 900; }
.lesson-board-section + .lesson-board-section { margin-top: 24px; padding-top: 18px; border-top: 1px solid #e9dbb9; }
.lesson-board-part { display: inline-block; margin-bottom: 8px; color: #a87310; font-size: .75rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
.lesson-board-section h3 { margin: 0 0 12px; color: #183c57; font-size: clamp(1.12rem, 2.2vw, 1.35rem); font-weight: 850; line-height: 1.35; }
.lesson-board-section p { margin: 0 0 10px; font-size: clamp(1.02rem, 2vw, 1.18rem); line-height: 1.55; }
.lesson-board-section .lesson-board-subheading { font-weight: 400; }
.lesson-board-section ol, .lesson-board-section ul { display: grid; gap: 9px; margin: 0 0 10px; padding-left: 1.85rem; }
.lesson-board-section li { padding-left: 4px; font-size: clamp(1.02rem, 2vw, 1.18rem); line-height: 1.48; }
.lesson-board-section li::marker { color: #096f9c; font-weight: 850; }
.lesson-filament { margin: 15px 0; }
.lesson-read-done { margin-top: 20px; padding: 13px; border-radius: 9px; background: #edf8fd; color: #366d89; font-weight: 720; }
.lesson-date-note { padding: 7px 10px; border-radius: 8px; background: #f1f8fd; font-size: .82rem; }
.lesson-chips button { max-width: 100%; overflow-wrap: anywhere; }
.lesson-fill input { min-width: 90px; width: min(38vw, 155px); font-size: .86rem; }
@media (max-width: 1100px) { .lesson-create { grid-template-columns: 1fr; } #lesson-create-status { grid-column: 1; } .lesson-ideas, .lesson-focus-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 850px) { .lesson-create form { grid-template-columns: 1fr 1fr; } .lesson-create form button { grid-column: 1 / -1; } .lesson-source-bottom { grid-template-columns: 1fr; } }
@media (max-width: 600px) { .lesson-create form, .lesson-source-grid, .lesson-step-core { grid-template-columns: 1fr; } .lesson-ideas { grid-template-columns: 1fr 1fr; } .lesson-ideas button { min-height: 120px; } .lesson-overview-title { display: block; } .lesson-editor-card { padding: 16px; } .lesson-studio { padding: 16px 10px 45px; } .lesson-step-resources { grid-template-columns: 1fr; } .lesson-focus-grid { grid-template-columns: 1fr 1fr; } .lesson-preview-frame { height: 560px; } }