:root {
  --paper: #f7f8f3;
  --panel: #ffffff;
  --ink: #14241e;
  --muted: #68766e;
  --line: #dbe3dc;
  --soft: #eef3ed;
  --green: #235c49;
  --deep: #143d32;
  --orange: #b86b3b;
  --accent: #5c8c73;
  --accent-rgb: 92, 140, 115;
  --danger: #a45443;
  --success: #427a5b;
  font-family: 'Avenir Next', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body { min-width: 320px; min-height: 100vh; margin: 0; background: radial-gradient(circle at 82% 3%, rgba(var(--accent-rgb), .08), transparent 25%), var(--paper); }
button, textarea, input, select { font: inherit; }
button:focus-visible, a:focus-visible, textarea:focus-visible, input:focus-visible, [tabindex="-1"]:focus-visible { outline: 3px solid #174b3b; outline-offset: 3px; }

.course-loader { position: fixed; inset: 0; z-index: 100; display: flex; align-items: center; justify-content: center; gap: 12px; color: #69766f; background: var(--paper); font-size: 14px; }
.course-loader span { width: 34px; height: 34px; border: 3px solid #dbe3dc; border-top-color: var(--green); border-radius: 50%; animation: spin .8s linear infinite; }
.course-ready .course-loader { display: none; }
@keyframes spin { to { transform: rotate(360deg); } }

.course-topbar { position: sticky; top: 0; z-index: 30; height: 68px; display: grid; grid-template-columns: 190px minmax(0, 1fr) 210px auto; align-items: center; gap: 16px; padding: 0 max(28px,calc((100vw - 1280px)/2)); border-bottom: 1px solid var(--line); background: rgba(248, 249, 244, .94); backdrop-filter: blur(16px); }
.brand { display: flex; align-items: center; gap: 9px; color: var(--deep); text-decoration: none; }
.brand i { width: 31px; height: 31px; display: grid; place-items: center; border-radius: 10px; color: var(--deep); background: #f1ad6b; font-style: normal; transform: rotate(-4deg); }
.course-meta { display: grid; gap: 2px; min-width: 0; }
.course-meta span { color: var(--orange); font-size: 11px; font-weight: 700; letter-spacing: .14em; }
.course-meta b { overflow: hidden; font-size: 14px; text-overflow: ellipsis; white-space: nowrap; }
.top-progress { justify-self:end; display: flex; align-items: center; gap: 10px; }
.top-progress > i { width: 190px; height: 6px; overflow: hidden; border-radius: 8px; background: #dfe5df; }
.top-progress em { display: block; width: 6.25%; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--orange), var(--accent)); transition: width .35s ease; }
.top-progress span { min-width: 45px; color: #5f6d65; font-size: 12px; }
.dashboard-link { justify-self: end; color: #647169; font-size: 13px; text-decoration: none; }
.dashboard-link:hover { color: var(--green); }

.course-main { display: grid; grid-template-columns: 300px minmax(0, 1fr); min-height: calc(100vh - 68px); }
.course-rail { position: sticky; top: 68px; height: calc(100vh - 68px); display: flex; flex-direction: column; padding: 25px 18px 18px; border-right: 1px solid var(--line); background: #edf1eb; }
.course-rail-head { display: flex; align-items: center; gap: 11px; padding: 0 8px 19px; }
.course-rail-head > span { width: 43px; height: 43px; display: grid; flex: 0 0 auto; place-items: center; border-radius: 13px; color: white; background: var(--green); font: 700 20px Georgia, 'Songti SC', serif; }
.course-rail-head > div { display: grid; gap: 3px; min-width: 0; }
.course-rail-head em { overflow: hidden; color: var(--orange); font-size: 9px; font-style: normal; font-weight: 800; letter-spacing: .08em; text-overflow: ellipsis; white-space: nowrap; }
.course-rail-head b { overflow: hidden; font-size: 14px; text-overflow: ellipsis; white-space: nowrap; }
.course-rail-head small { color: #9a6943; font-size: 11px; }
.rail-caption { display: flex; justify-content: space-between; padding: 10px 9px 9px; border-top: 1px solid rgba(104, 123, 112, .14); color: #66736c; font-size: 11px; }
.rail-caption span { color: #8d9791; }
#course-rail-nav { flex: 1; display: grid; align-content: start; gap: 5px; min-height: 0; padding: 0 3px 8px 0; overflow-y: auto; scrollbar-color: #c4d0c7 transparent; scrollbar-width: thin; }
.rail-phase { padding: 12px 10px 3px; color: var(--orange); font-size: 10px; font-weight: 700; letter-spacing: .11em; text-transform: uppercase; }
.rail-step { width: 100%; display: grid; grid-template-columns: 31px 1fr auto; align-items: center; gap: 9px; padding: 9px 10px; border: 0; border-radius: 10px; color: #5d6b63; background: transparent; text-align: left; cursor: pointer; transition: .18s ease; }
.rail-step > span { width: 29px; height: 29px; display: grid; place-items: center; border: 1px solid #c8d2ca; border-radius: 9px; font-size: 11px; }
.rail-step > b { overflow: hidden; font-size: 12px; font-weight: 600; text-overflow: ellipsis; white-space: nowrap; }
.rail-step > i { width: 7px; height: 7px; border-radius: 50%; background: #c8d0ca; font-size: 0; font-style: normal; }
.rail-step:hover:not(.locked) { background: rgba(255, 255, 255, .62); }
.rail-step.active { color: white; background: var(--green); box-shadow: 0 7px 17px rgba(35, 92, 73, .15); }
.rail-step.active > span { border-color: rgba(255, 255, 255, .3); background: rgba(255, 255, 255, .1); }
.rail-step.active > i { background: #f3b675; box-shadow: 0 0 0 4px rgba(255, 255, 255, .1); }
.rail-step.complete > span { color: white; border-color: var(--accent); background: var(--accent); }
.rail-step.complete > i { background: var(--accent); }
.rail-step.locked { opacity: .42; cursor: not-allowed; }
.points-note { display: flex; gap: 8px; margin-top: 9px; padding: 12px; border-radius: 11px; color: #736959; background: #f8efe1; }
.points-note span { color: #bd7040; }
.points-note p { margin: 0; font-size: 11px; line-height: 1.6; }

.course-content { width: 100%; max-width: 1040px; margin: 0 auto; padding: 42px clamp(30px, 5vw, 70px) 90px; }
.course-layer-map { position: relative; margin: 0 0 22px; padding: 22px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .1); border-radius: 20px; color: white; background: radial-gradient(circle at 90% 0, rgba(var(--accent-rgb), .46), transparent 36%), linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px), #173f34; background-size: auto, 26px 26px, 26px 26px, auto; box-shadow: 0 24px 60px rgba(20, 61, 50, .14); }
.course-layer-map::after { position: absolute; top: -48px; right: -34px; width: 160px; height: 160px; border: 1px solid rgba(255, 255, 255, .09); border-radius: 50%; content: ''; pointer-events: none; }
.course-layer-heading { position: relative; z-index: 1; display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 17px; }
.course-layer-heading > div > span { color: #efb576; font-size: 9px; font-weight: 800; letter-spacing: .17em; }
.course-layer-heading h2 { margin: 5px 0 0; font: 700 22px/1.25 Georgia, 'Songti SC', serif; }
.course-layer-heading > p { display: grid; justify-items: end; gap: 3px; margin: 0; text-align: right; }
.course-layer-heading > p b { color: #f4c28d; font-size: 11px; }
.course-layer-heading > p small { color: rgba(255, 255, 255, .56); font-size: 10px; }
.course-layer-map ol { position: relative; z-index: 1; display: grid; grid-template-columns: 2fr 4fr 2fr; gap: 8px; margin: 0; padding: 0; list-style: none; }
.course-layer-map li { min-width: 0; min-height: 84px; display: grid; grid-template-columns: 30px minmax(0, 1fr); align-content: center; gap: 7px 10px; padding: 13px; border: 1px solid rgba(255, 255, 255, .12); border-radius: 13px; background: rgba(5, 28, 22, .46); opacity: .54; transition: opacity .2s ease, transform .2s ease, border-color .2s ease; }
.course-layer-map li > i { width: 28px; height: 28px; display: grid; grid-row: 1 / 3; place-items: center; border: 1px solid rgba(255, 255, 255, .2); border-radius: 8px; color: #efb576; font-size: 9px; font-style: normal; font-weight: 800; }
.course-layer-map li > span { min-width: 0; display: grid; gap: 3px; }
.course-layer-map li > span b { font-size: 12px; }
.course-layer-map li > span small { overflow: hidden; color: rgba(255, 255, 255, .58); font-size: 9px; line-height: 1.45; text-overflow: ellipsis; white-space: nowrap; }
.course-layer-map li > em { grid-column: 2; color: rgba(255, 255, 255, .42); font-size: 9px; font-style: normal; }
.course-layer-map li.active { border-color: rgba(239, 181, 118, .72); background: linear-gradient(140deg, rgba(var(--accent-rgb), .46), rgba(7, 32, 25, .74)); box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .06), 0 12px 30px rgba(4, 24, 18, .2); opacity: 1; transform: translateY(-2px); }
.course-layer-map li.active > i { color: #173f34; border-color: #efb576; background: #efb576; }
.course-layer-map li.active > span small, .course-layer-map li.active > em { color: rgba(255, 255, 255, .76); }
.lifecycle-lanes { position: relative; z-index: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 10px; }
.lifecycle-lanes > div { display: grid; grid-template-columns: 105px minmax(0, 1fr) auto; align-items: center; gap: 10px; min-height: 48px; padding: 10px 13px; border-radius: 11px; }
.lifecycle-lanes span { font-size: 9px; font-weight: 800; letter-spacing: .08em; }
.lifecycle-lanes b { overflow: hidden; font-size: 10px; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }
.lifecycle-lanes small { font-size: 9px; white-space: nowrap; }
.training-lane { color: #ffe7cc; border: 1px solid rgba(239, 181, 118, .34); background: rgba(184, 107, 59, .2); }
.training-lane small { color: #f5bd82; }
.inference-lane { color: #dff4ea; border: 1px solid rgba(142, 205, 177, .3); background: rgba(50, 121, 91, .2); }
.inference-lane small { color: #9dd1b5; }
.scope-note { display: flex; gap: 14px; margin: 0 0 30px; padding: 14px 16px; border: 1px solid #e5c8a8; border-radius: 13px; color: #705d4d; background: #fff4e7; font-size: 12px; line-height: 1.75; }
.scope-note b { flex: 0 0 auto; color: #a55f32; }
.course-onboarding { margin: 0 0 34px; padding: 25px; border: 1px solid rgba(var(--accent-rgb), .24); border-radius: 20px; background: linear-gradient(145deg, rgba(var(--accent-rgb), .1), rgba(255, 255, 255, .82)); }
.onboarding-heading > span { color: var(--orange); font-size: 10px; font-weight: 700; letter-spacing: .16em; }
.onboarding-heading h2 { margin: 7px 0 8px; font: 700 24px/1.35 Georgia, 'Songti SC', serif; }
.onboarding-heading p { max-width: 780px; margin: 0; color: #56665d; font-size: 13px; line-height: 1.75; }
.onboarding-grid { display: grid; grid-template-columns: 1.2fr 1fr 1fr; gap: 10px; margin-top: 18px; }
.onboarding-grid article { min-height: 125px; padding: 15px; border: 1px solid rgba(var(--accent-rgb), .15); border-radius: 13px; background: rgba(255, 255, 255, .72); }
.onboarding-grid span { display: block; margin-bottom: 7px; color: var(--green); font-size: 10px; font-weight: 700; letter-spacing: .08em; }
.onboarding-grid p, .onboarding-grid ul { margin: 0; padding: 0; color: #647169; font-size: 11px; line-height: 1.75; }
.onboarding-grid ul { padding-left: 17px; }
.detail-lesson { animation: rise .32s ease; }
@keyframes rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.lesson-heading { display: flex; align-items: center; justify-content: space-between; gap: 15px; }
.lesson-heading > div { display: flex; align-items: center; gap: 10px; }
.eyebrow { color: var(--orange); font-size: 11px; font-weight: 700; letter-spacing: .16em; }
.phase-chip, .step-state { padding: 5px 9px; border-radius: 999px; font-size: 11px; }
.phase-chip { color: var(--green); background: #e5efe8; }
.step-state { color: #87634c; background: #f7eadc; }
.step-state.passed { color: #416450; background: #e6f1e9; }
.detail-lesson > h1 { max-width: 800px; margin: 14px 0 13px; font: 700 clamp(32px, 4.4vw, 48px)/1.3 Georgia, 'Songti SC', serif; letter-spacing: -.045em; text-wrap: balance; }
.lead { max-width: 820px; margin: 0 0 23px; color: var(--muted); font-size: 16px; line-height: 1.85; }
.scenario-card { display: grid; grid-template-columns: 135px 1fr; align-items: start; gap: 15px; margin: -5px 0 13px; padding: 15px 18px; border: 1px solid #dfd9ce; border-radius: 13px; background: #fbf8f1; }
.scenario-card span { color: #9a5d36; font-size: 11px; font-weight: 700; letter-spacing: .06em; }
.scenario-card p { margin: 0; color: #5d665f; font-size: 13px; line-height: 1.72; }
.objective-card { display: grid; grid-template-columns: 135px 1fr; align-items: center; gap: 15px; padding: 15px 18px; border: 1px solid rgba(var(--accent-rgb), .27); border-radius: 13px; background: rgba(var(--accent-rgb), .07); }
.objective-card span { color: var(--green); font-size: 11px; font-weight: 700; letter-spacing: .06em; }
.objective-card p { margin: 0; color: #52625a; font-size: 13px; line-height: 1.7; }
.concept-bridge { display: grid; grid-template-columns: minmax(0, 1fr) 220px; gap: 10px; margin-top: 11px; }
.concept-bridge article { padding: 14px 17px; border: 1px solid #d9e3df; border-radius: 13px; background: #f8fbfa; }
.concept-bridge article:last-child { background: rgba(var(--accent-rgb), .08); }
.concept-bridge article > span { display: block; margin-bottom: 6px; color: #577069; font-size: 10px; font-weight: 700; letter-spacing: .06em; }
.concept-bridge p { margin: 0; color: #5c6b63; font-size: 12px; line-height: 1.7; }
#step-terms { display: flex; flex-wrap: wrap; gap: 6px; }
#step-terms span { padding: 6px 9px; border-radius: 999px; color: white; background: var(--accent); font-size: 11px; font-weight: 700; }

.detail-section, .animation-section, .lab-section { margin-top: 34px; }
.section-title-row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.section-title-row > div { display: flex; align-items: center; gap: 10px; }
.section-title-row span { width: 27px; height: 27px; display: grid; place-items: center; border-radius: 8px; color: white; background: var(--green); font-size: 11px; }
.section-title-row h2 { margin: 0; font: 700 20px Georgia, 'Songti SC', serif; }
.section-title-row small { color: #66736c; font-size: 11px; }
.detail-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 11px; }
.detail-card { position: relative; min-height: 150px; padding: 18px; overflow: hidden; border: 1px solid var(--line); border-radius: 15px; background: rgba(255, 255, 255, .72); }
.detail-card::after { position: absolute; right: -17px; bottom: -29px; width: 75px; height: 75px; border-radius: 50%; background: rgba(var(--accent-rgb), .07); content: ''; }
.detail-card > span { color: var(--orange); font-size: 10px; font-weight: 700; letter-spacing: .1em; }
.detail-card h3 { margin: 10px 0 6px; font-size: 14px; }
.detail-card p { margin: 0; color: #66736c; font-size: 12px; line-height: 1.72; }

.animation-instruction { margin: -3px 0 13px; color: #637169; font-size: 12px; line-height: 1.7; }
.step-animation { overflow: hidden; border: 1px solid #c9d7cf; border-radius: 20px; background: #173f34; box-shadow: 0 22px 48px rgba(23, 63, 52, .13); }
.animation-toolbar { min-height: 54px; display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 9px 11px 9px 17px; border-bottom: 1px solid #d9e2dc; background: #f7f9f5; }
.animation-mode { display: flex; align-items: center; gap: 9px; color: #496058; font-size: 11px; font-weight: 700; letter-spacing: .03em; }
.animation-mode > i { position: relative; width: 19px; height: 19px; display: grid; flex: 0 0 auto; place-items: center; border-radius: 7px; color: white; background: var(--green); font-size: 9px; font-style: normal; }
.animation-mode > i::after { content: '→'; }
.step-animation[data-animation-kind="compare"] .animation-mode > i::after { content: '⇄'; }
.step-animation[data-animation-kind="loop"] .animation-mode > i::after { content: '↻'; }
.step-animation[data-animation-kind="branch"] .animation-mode > i::after { content: '◇'; }
.step-animation[data-animation-kind="stack"] .animation-mode > i::after { content: '↓'; }
.step-animation[data-animation-kind="gate"] .animation-mode > i::after { content: '⊣'; }
.step-animation[data-animation-kind="feedback"] .animation-mode > i::after { content: '↗'; }
.step-animation[data-animation-kind="transform"] .animation-mode > i::after { content: '⇒'; }
.animation-mode > i::before { position: absolute; inset: -4px; border: 1px solid rgba(var(--accent-rgb), .45); border-radius: 9px; content: ''; animation: animation-mode-pulse 2.4s ease-out infinite; }
.animation-controls { display: flex; gap: 6px; }
.animation-controls button { min-height: 34px; display: inline-flex; align-items: center; gap: 6px; padding: 6px 10px; border: 1px solid #d2ddd6; border-radius: 9px; color: #52645b; background: white; cursor: pointer; font-size: 10px; }
.animation-controls button:hover:not(:disabled) { color: var(--green); border-color: #aebfb4; background: #edf3ee; }
.animation-controls button:disabled { opacity: .58; cursor: default; }
.animation-controls button > span { width: 15px; color: var(--orange); font-size: 11px; text-align: center; }
.animation-controls button > b { font-weight: 700; }
.animation-canvas { position: relative; min-height: 410px; overflow: hidden; padding: 31px; background: radial-gradient(circle at 10% 0, rgba(240, 177, 112, .16), transparent 27%), radial-gradient(circle at 90% 100%, rgba(var(--accent-rgb), .3), transparent 32%), linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px), #173f34; background-size: auto, auto, 28px 28px, 28px 28px, auto; }
.animation-canvas::after { position: absolute; top: -28%; left: -18%; width: 34%; height: 160%; border-right: 1px solid rgba(245, 183, 116, .34); background: linear-gradient(90deg, transparent, rgba(245, 183, 116, .08), transparent); content: ''; transform: skewX(-12deg); animation: animation-sweep 7.2s ease-in-out infinite; pointer-events: none; }
.step-animation[data-animation-kind="gate"] .animation-canvas::after { width: 18%; border-right-color: rgba(244, 190, 126, .7); background: linear-gradient(90deg, transparent, rgba(244, 190, 126, .15)); }
.step-animation[data-animation-kind="feedback"] .animation-canvas::after { width: 46%; border-right-color: rgba(154, 205, 178, .5); background: linear-gradient(90deg, transparent, rgba(154, 205, 178, .12), transparent); }
.animation-ambient { position: absolute; inset: 0; overflow: hidden; pointer-events: none; }
.animation-ambient i { position: absolute; display: block; border: 1px solid rgba(255, 255, 255, .09); border-radius: 50%; animation: animation-orbit 7.2s ease-in-out infinite; }
.animation-ambient i:nth-child(1) { top: 22px; right: 8%; width: 74px; height: 74px; }
.animation-ambient i:nth-child(2) { right: 22%; bottom: 26px; width: 22px; height: 22px; animation-delay: -2.4s; }
.animation-ambient i:nth-child(3) { bottom: 34px; left: 6%; width: 48px; height: 48px; animation-delay: -4.8s; }
.animation-principle { position: relative; z-index: 2; display: grid; grid-template-columns: 52px minmax(0, 1fr) auto; align-items: center; gap: 13px; margin-bottom: 21px; padding: 14px 16px; border: 1px solid rgba(255, 255, 255, .14); border-radius: 13px; background: rgba(7, 28, 23, .62); }
.animation-principle > span { color: #efb576; font-size: 10px; font-weight: 800; letter-spacing: .12em; }
.animation-principle > p { margin: 0; color: rgba(255, 255, 255, .9); font-size: 12px; line-height: 1.65; }
.animation-principle > small { padding: 5px 8px; border: 1px solid rgba(255, 255, 255, .14); border-radius: 999px; color: rgba(255, 255, 255, .58); font-size: 9px; white-space: nowrap; }
.animation-example-heading { position: relative; z-index: 2; display: flex; align-items: baseline; gap: 11px; margin: 0 2px 12px; }
.animation-example-heading > span { flex: 0 0 auto; color: #efb576; font-size: 9px; font-weight: 800; letter-spacing: .13em; }
.animation-example-heading > b { min-width: 0; color: rgba(255, 255, 255, .88); font-size: 12px; line-height: 1.45; }
.animation-track { position: relative; z-index: 2; min-height: 126px; display: grid; align-items: center; isolation: isolate; }
.animation-node { position: relative; z-index: 3; min-width: 0; min-height: 112px; display: grid; align-content: start; padding: 15px 15px 14px; overflow: hidden; border: 1px solid rgba(255, 255, 255, .2); border-radius: 14px; background: rgba(248, 251, 246, .93); opacity: .43; transform: translateY(3px) scale(.985); animation: animation-node-cycle 7.2s linear infinite; animation-delay: var(--animation-delay); }
.animation-node::after { position: absolute; right: -24px; bottom: -35px; width: 88px; height: 88px; border: 1px solid rgba(var(--accent-rgb), .18); border-radius: 50%; background: rgba(var(--accent-rgb), .08); content: ''; }
.animation-node > span { position: relative; z-index: 1; width: 27px; height: 27px; display: grid; place-items: center; margin-bottom: 10px; border-radius: 8px; color: white; background: var(--green); font-size: 10px; font-weight: 700; }
.animation-node > small { position: relative; z-index: 1; overflow: hidden; color: var(--orange); font-size: 9px; font-weight: 800; letter-spacing: .08em; text-overflow: ellipsis; white-space: nowrap; }
.animation-node > b { position: relative; z-index: 1; display: -webkit-box; margin-top: 5px; overflow: hidden; color: #263b33; font-size: 12px; line-height: 1.48; -webkit-box-orient: vertical; -webkit-line-clamp: 2; }
.animation-link { position: relative; z-index: 3; height: 26px; display: grid; place-items: center; color: #f2bd83; }
.animation-link > i { position: absolute; right: 5px; left: 5px; height: 1px; overflow: hidden; background: rgba(255, 255, 255, .18); }
.animation-link > span { position: relative; z-index: 2; width: 24px; height: 24px; display: grid; place-items: center; border: 1px solid rgba(255, 255, 255, .15); border-radius: 50%; background: #173f34; font-size: 11px; }
.animation-link::after { position: absolute; z-index: 3; left: 5px; width: 7px; height: 7px; border-radius: 50%; background: #f2b878; box-shadow: 0 0 0 5px rgba(242, 184, 120, .12); content: ''; opacity: 0; animation: animation-link-cycle 7.2s linear infinite; animation-delay: var(--animation-delay); }
.animation-signal { position: absolute; z-index: 4; top: 50%; left: 16%; width: 9px; height: 9px; border: 2px solid #173f34; border-radius: 50%; background: #f3b879; box-shadow: 0 0 0 6px rgba(243, 184, 121, .15); opacity: 0; transform: translate(-50%, -50%); animation: animation-signal-cycle 7.2s ease-in-out infinite; }
.animation-ornament { position: absolute; z-index: 1; pointer-events: none; animation: animation-ornament-breathe 7.2s ease-in-out infinite; }
.animation-ornament i, .animation-ornament span { position: absolute; display: block; box-sizing: border-box; }

/* Eight kinds use eight actual diagram geometries; the content schema stays identical. */
.animation-layout-linear { grid-template-columns: minmax(0, 1fr) 46px minmax(0, 1fr) 46px minmax(0, 1fr); }
.animation-visual-flow .animation-node { border-radius: 10px; }
.animation-ornament-route { top: 50%; right: 5%; left: 5%; height: 1px; border-top: 1px dashed rgba(242, 184, 120, .28); }
.animation-ornament-route i { top: -4px; width: 8px; height: 8px; border: 1px solid rgba(242, 184, 120, .55); border-radius: 50%; background: #173f34; }
.animation-ornament-route i:nth-child(1) { left: 0; }
.animation-ornament-route i:nth-child(2) { left: calc(50% - 4px); }
.animation-ornament-route i:nth-child(3) { right: 0; }
.animation-ornament-route span { top: -2px; left: 12%; width: 16%; height: 3px; border-radius: 999px; background: rgba(242, 184, 120, .38); }

.animation-layout-split { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: auto auto; gap: 18px 42px; padding: 9px 22px 0; }
.animation-layout-split .animation-node-1 { grid-column: 1; grid-row: 1; }
.animation-layout-split .animation-node-2 { grid-column: 1 / 3; grid-row: 2; width: 58%; min-height: 92px; justify-self: center; }
.animation-layout-split .animation-node-3 { grid-column: 2; grid-row: 1; }
.animation-layout-split .animation-link, .animation-layout-split .animation-signal { display: none; }
.animation-visual-compare .animation-node-1 { border-top: 3px solid #f2b878; }
.animation-visual-compare .animation-node-3 { border-top: 3px solid #8fc4aa; }
.animation-visual-compare .animation-node-2 { border-radius: 999px; text-align: center; }
.animation-ornament-balance { top: 25px; left: 50%; width: 108px; height: 126px; transform: translateX(-50%); }
.animation-ornament-balance span { top: 8px; bottom: 0; left: 50%; width: 1px; background: linear-gradient(#f2b878, rgba(242, 184, 120, .12)); }
.animation-ornament-balance i:nth-child(1) { top: 8px; left: 0; width: 100%; height: 1px; background: rgba(242, 184, 120, .55); }
.animation-ornament-balance i:nth-child(2), .animation-ornament-balance i:nth-child(3) { top: 1px; width: 15px; height: 15px; border: 2px solid #efb576; border-radius: 50%; background: #173f34; }
.animation-ornament-balance i:nth-child(2) { left: -7px; }
.animation-ornament-balance i:nth-child(3) { right: -7px; }

.animation-layout-cycle { grid-template-columns: repeat(3, minmax(0, 1fr)); grid-template-rows: 118px 118px; gap: 24px 34px; padding: 0 40px; }
.animation-layout-cycle .animation-node-1 { grid-column: 2; grid-row: 1; }
.animation-layout-cycle .animation-node-2 { grid-column: 3; grid-row: 2; }
.animation-layout-cycle .animation-node-3 { grid-column: 1; grid-row: 2; }
.animation-layout-cycle .animation-link, .animation-layout-cycle .animation-signal { display: none; }
.animation-visual-loop .animation-node { min-height: 104px; border-radius: 50% 50% 18px 18px; text-align: center; }
.animation-ornament-cycle { top: 9%; right: 14%; bottom: 3%; left: 14%; border: 2px solid rgba(143, 196, 170, .33); border-radius: 50%; }
.animation-ornament-cycle::after { position: absolute; top: 2px; right: 14%; color: #efb576; font-size: 20px; content: '↻'; transform: rotate(18deg); }
.animation-ornament-cycle i { width: 9px; height: 9px; border: 2px solid #efb576; border-radius: 50%; background: #173f34; }
.animation-ornament-cycle i:nth-child(1) { top: -5px; left: calc(50% - 5px); }
.animation-ornament-cycle i:nth-child(2) { right: 3%; bottom: 18%; }
.animation-ornament-cycle i:nth-child(3) { bottom: 18%; left: 3%; }
.animation-ornament-cycle span { inset: 20%; border: 1px dashed rgba(255, 255, 255, .12); border-radius: 50%; }

.animation-layout-fork { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: 116px 122px; gap: 48px 58px; padding: 0 48px; }
.animation-layout-fork .animation-node-1 { grid-column: 1 / 3; grid-row: 1; width: 48%; justify-self: center; }
.animation-layout-fork .animation-node-2 { grid-column: 1; grid-row: 2; }
.animation-layout-fork .animation-node-3 { grid-column: 2; grid-row: 2; }
.animation-layout-fork .animation-link, .animation-layout-fork .animation-signal { display: none; }
.animation-visual-branch .animation-node-1 { border-radius: 14px 14px 32px 32px; }
.animation-visual-branch .animation-node-2, .animation-visual-branch .animation-node-3 { border-left: 3px solid #8fc4aa; }
.animation-ornament-fork { top: 100px; right: 24%; left: 24%; height: 72px; }
.animation-ornament-fork span { top: 0; left: 50%; width: 1px; height: 31px; background: rgba(242, 184, 120, .62); }
.animation-ornament-fork i:nth-child(1) { top: 30px; right: 0; left: 0; height: 1px; background: rgba(242, 184, 120, .62); }
.animation-ornament-fork i:nth-child(2), .animation-ornament-fork i:nth-child(3) { top: 30px; width: 1px; height: 42px; background: linear-gradient(rgba(242, 184, 120, .62), rgba(143, 196, 170, .2)); }
.animation-ornament-fork i:nth-child(2) { left: 0; }
.animation-ornament-fork i:nth-child(3) { right: 0; }

.animation-layout-tower { grid-template-columns: minmax(0, 430px); justify-content: center; padding: 0 13%; }
.animation-layout-tower .animation-link { width: 36px; height: 34px; justify-self: center; }
.animation-layout-tower .animation-link > i { top: 3px; bottom: 3px; left: 50%; width: 1px; height: auto; }
.animation-layout-tower .animation-link > span { transform: rotate(90deg); }
.animation-layout-tower .animation-link::after, .animation-layout-tower .animation-signal { display: none; }
.animation-visual-stack .animation-node { min-height: 92px; border-radius: 8px; box-shadow: 0 8px 0 rgba(7, 28, 23, .2); }
.animation-ornament-levels { inset: -3px 8%; border-right: 1px solid rgba(143, 196, 170, .25); border-left: 1px solid rgba(143, 196, 170, .25); }
.animation-ornament-levels i { right: 0; left: 0; height: 1px; border-top: 1px dashed rgba(143, 196, 170, .2); }
.animation-ornament-levels i:nth-child(1) { top: 15%; }
.animation-ornament-levels i:nth-child(2) { top: 50%; }
.animation-ornament-levels i:nth-child(3) { bottom: 15%; }
.animation-ornament-levels span { top: 0; bottom: 0; left: calc(50% - 3px); width: 6px; background: linear-gradient(transparent, rgba(242, 184, 120, .18), transparent); }

.animation-layout-checkpoint { grid-template-columns: minmax(0, 1fr) 48px minmax(128px, .7fr) 48px minmax(0, 1fr); }
.animation-visual-gate .animation-node-2 { min-height: 152px; align-content: center; border: 2px solid #efb576; border-radius: 10px; background: #f7ead8; text-align: center; }
.animation-visual-gate .animation-node-2 > span { margin-right: auto; margin-left: auto; }
.animation-ornament-checkpoint { top: -12px; bottom: -12px; left: 50%; width: 176px; border-right: 1px solid rgba(242, 184, 120, .45); border-left: 1px solid rgba(242, 184, 120, .45); background: repeating-linear-gradient(135deg, transparent 0 11px, rgba(242, 184, 120, .06) 11px 17px); transform: translateX(-50%); }
.animation-ornament-checkpoint i { right: -7px; left: -7px; height: 1px; background: rgba(242, 184, 120, .36); }
.animation-ornament-checkpoint i:nth-child(1) { top: 12%; }
.animation-ornament-checkpoint i:nth-child(2) { top: 50%; }
.animation-ornament-checkpoint i:nth-child(3) { bottom: 12%; }
.animation-ornament-checkpoint span { top: 7px; left: 50%; width: 42px; height: 6px; border-radius: 999px; background: #efb576; transform: translateX(-50%); }

.animation-layout-curve { grid-template-columns: repeat(3, minmax(0, 1fr)); grid-template-rows: 118px 118px; gap: 28px 34px; padding: 0 34px; }
.animation-layout-curve .animation-node-1 { grid-column: 1; grid-row: 2; }
.animation-layout-curve .animation-node-2 { grid-column: 2; grid-row: 1; }
.animation-layout-curve .animation-node-3 { grid-column: 3; grid-row: 2; }
.animation-layout-curve .animation-link, .animation-layout-curve .animation-signal { display: none; }
.animation-visual-feedback .animation-node-2 { border-top: 3px solid #efb576; border-radius: 30px 30px 10px 10px; }
.animation-visual-feedback .animation-node-1, .animation-visual-feedback .animation-node-3 { min-height: 102px; }
.animation-ornament-curve { inset: 11% 8% 2%; }
.animation-ornament-curve i:nth-child(1), .animation-ornament-curve i:nth-child(2) { bottom: 35%; width: 40%; height: 2px; background: linear-gradient(90deg, rgba(143, 196, 170, .12), rgba(143, 196, 170, .65)); }
.animation-ornament-curve i:nth-child(1) { left: 8%; transform: rotate(-24deg); transform-origin: right; }
.animation-ornament-curve i:nth-child(2) { right: 8%; transform: rotate(24deg); transform-origin: left; }
.animation-ornament-curve i:nth-child(3) { right: 8%; bottom: 0; left: 8%; height: 46%; border-bottom: 2px dashed rgba(242, 184, 120, .45); border-left: 2px dashed rgba(242, 184, 120, .45); border-radius: 0 0 0 70%; }
.animation-ornament-curve span { bottom: 41%; left: calc(8% - 5px); width: 10px; height: 10px; border-bottom: 2px solid #efb576; border-left: 2px solid #efb576; transform: rotate(45deg); }

.animation-layout-morph { grid-template-columns: minmax(0, 1fr) 50px minmax(138px, .75fr) 50px minmax(0, 1fr); }
.animation-visual-transform .animation-node-1 { border-radius: 5px; }
.animation-visual-transform .animation-node-2 { width: 142px; min-height: 142px; aspect-ratio: 1; align-content: center; justify-self: center; border: 2px solid #efb576; border-radius: 50%; background: #f8efe1; text-align: center; }
.animation-visual-transform .animation-node-2 > span { margin-right: auto; margin-left: auto; border-radius: 50%; }
.animation-visual-transform .animation-node-3 { border-radius: 30px; }
.animation-ornament-morph { top: 50%; left: 50%; width: 188px; height: 188px; border: 1px dashed rgba(242, 184, 120, .38); border-radius: 50%; transform: translate(-50%, -50%); }
.animation-ornament-morph i { border: 1px solid rgba(143, 196, 170, .28); border-radius: 50%; }
.animation-ornament-morph i:nth-child(1) { inset: 10px; }
.animation-ornament-morph i:nth-child(2) { inset: 23px; }
.animation-ornament-morph i:nth-child(3) { inset: 36px; }
.animation-ornament-morph span { top: 50%; left: -10px; width: calc(100% + 20px); height: 1px; background: linear-gradient(90deg, transparent, rgba(242, 184, 120, .55), transparent); }
.animation-caption-stack { position: relative; z-index: 2; min-height: 112px; display: grid; margin-top: 17px; }
.animation-caption-card { position: relative; grid-area: 1 / 1; display: grid; grid-template-columns: 135px minmax(0, 1fr); align-content: center; column-gap: 17px; padding: 17px 19px; border: 1px solid rgba(255, 255, 255, .12); border-radius: 13px; background: rgba(7, 28, 23, .72); opacity: 0; transform: translateY(8px); animation: animation-caption-cycle 7.2s linear infinite; animation-delay: var(--animation-delay); }
.animation-caption-card > span { grid-column: 1; grid-row: 1 / 3; align-self: center; color: #efb576; font-size: 10px; font-weight: 800; letter-spacing: .07em; }
.animation-caption-card > b { grid-column: 2; color: white; font-size: 13px; line-height: 1.45; }
.animation-caption-card > p { grid-column: 2; margin: 5px 0 0; color: rgba(255, 255, 255, .68); font-size: 11px; line-height: 1.65; }
.animation-transcript { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; margin: -1px !important; overflow: hidden !important; clip: rect(0, 0, 0, 0) !important; white-space: nowrap !important; border: 0 !important; }
.step-animation.is-paused .animation-mode > i::before,
.step-animation.is-paused .animation-canvas::after,
.step-animation.is-paused .animation-ambient i,
.step-animation.is-paused .animation-ornament,
.step-animation.is-paused .animation-node,
.step-animation.is-paused .animation-link::after,
.step-animation.is-paused .animation-signal,
.step-animation.is-paused .animation-caption-card { animation-play-state: paused; }
.step-animation.is-restarting .animation-mode > i::before,
.step-animation.is-restarting .animation-canvas::after,
.step-animation.is-restarting .animation-ambient i,
.step-animation.is-restarting .animation-ornament,
.step-animation.is-restarting .animation-node,
.step-animation.is-restarting .animation-link::after,
.step-animation.is-restarting .animation-signal,
.step-animation.is-restarting .animation-caption-card { animation: none !important; }
.step-animation.prefers-reduced-motion .animation-canvas::after,
.step-animation.prefers-reduced-motion .animation-ambient,
.step-animation.prefers-reduced-motion .animation-signal,
.step-animation.prefers-reduced-motion .animation-link::after,
.step-animation.prefers-reduced-motion .animation-mode > i::before { display: none; }
.step-animation.prefers-reduced-motion .animation-ornament { animation: none; }
.step-animation.prefers-reduced-motion .animation-node { opacity: 1; transform: none; animation: none; }
.step-animation.prefers-reduced-motion .animation-caption-stack { gap: 8px; min-height: 0; }
.step-animation.prefers-reduced-motion .animation-caption-card { grid-area: auto; opacity: 1; transform: none; animation: none; }

@keyframes animation-mode-pulse { 0% { opacity: .8; transform: scale(.78); } 70%, 100% { opacity: 0; transform: scale(1.28); } }
@keyframes animation-node-cycle { 0%, 27% { border-color: rgba(242, 184, 120, .92); opacity: 1; transform: translateY(-4px) scale(1); box-shadow: 0 12px 28px rgba(4, 23, 18, .22), 0 0 0 3px rgba(242, 184, 120, .1); } 32%, 96% { border-color: rgba(255, 255, 255, .2); opacity: .43; transform: translateY(3px) scale(.985); box-shadow: none; } 100% { border-color: rgba(242, 184, 120, .92); opacity: 1; transform: translateY(-4px) scale(1); box-shadow: 0 12px 28px rgba(4, 23, 18, .22), 0 0 0 3px rgba(242, 184, 120, .1); } }
@keyframes animation-link-cycle { 0%, 20% { left: 5px; opacity: 0; } 24% { opacity: 1; } 31% { left: calc(100% - 12px); opacity: 0; } 32%, 100% { left: 5px; opacity: 0; } }
@keyframes animation-signal-cycle { 0%, 21% { left: 16%; opacity: 0; } 25% { opacity: 1; } 32% { left: 50%; opacity: 0; } 33%, 54% { left: 50%; opacity: 0; } 58% { opacity: 1; } 65% { left: 84%; opacity: 0; } 66%, 100% { left: 16%; opacity: 0; } }
@keyframes animation-caption-cycle { 0%, 27% { opacity: 1; transform: translateY(0); } 32%, 96% { opacity: 0; transform: translateY(8px); } 100% { opacity: 1; transform: translateY(0); } }
@keyframes animation-sweep { 0%, 10% { left: -35%; opacity: 0; } 24% { opacity: 1; } 72% { opacity: .8; } 90%, 100% { left: 112%; opacity: 0; } }
@keyframes animation-orbit { 0%, 100% { opacity: .35; transform: translate3d(0, 0, 0) scale(.92); } 50% { opacity: .8; transform: translate3d(-10px, 8px, 0) scale(1.08); } }
@keyframes animation-ornament-breathe { 0%, 100% { opacity: .58; } 50% { opacity: 1; } }

.lab-section { padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: rgba(255, 255, 255, .8); box-shadow: 0 18px 50px rgba(44, 66, 55, .05); }
.lab-instruction { margin: -2px 0 18px; color: #637169; font-size: 13px; line-height: 1.7; }
.lab-shell { min-height: 220px; }
.lab-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 14px; padding: 10px 12px; border-radius: 10px; color: #6e786f; background: #eff3ee; font-size: 11px; }
.lab-toolbar b { color: var(--green); letter-spacing: .06em; }
.lab-action { min-height: 42px; padding: 10px 16px; border: 0; border-radius: 10px; color: white; background: var(--green); cursor: pointer; font-size: 12px; font-weight: 700; }
.lab-action:hover { background: var(--deep); }
.lab-action.secondary { color: var(--green); border: 1px solid #cbd8cf; background: white; }
.lab-action.secondary:hover { background: #eef4ef; }
.lab-feedback { min-height: 73px; margin-top: 14px; padding: 14px 16px; border-radius: 12px; color: #59675f; background: #eff3ee; font-size: 12px; line-height: 1.75; white-space: pre-wrap; }
.lab-feedback b { display: block; margin-bottom: 3px; color: var(--ink); font-size: 13px; }
.lab-feedback.error { color: #7e493c; background: #fff0eb; }
.lab-feedback.success { color: #416450; background: #e9f3ec; }

.choice-grid, .multi-grid { display: grid; gap: 9px; }
.choice-option, .multi-option { width: 100%; display: grid; grid-template-columns: 30px 1fr; align-items: center; gap: 11px; padding: 12px; border: 1px solid #d8dfd9; border-radius: 11px; color: #59675f; background: #fbfcf9; text-align: left; cursor: pointer; transition: .16s; }
.choice-option > i, .multi-option > i { width: 27px; height: 27px; display: grid; place-items: center; border-radius: 8px; color: #66736c; background: #edf1ec; font-size: 11px; font-style: normal; }
.choice-option b, .multi-option b { display: block; color: #405048; font-size: 13px; }
.choice-option small, .multi-option small { display: block; margin-top: 3px; color: #68766e; font-size: 11px; line-height: 1.5; }
.choice-option:hover, .multi-option:hover { border-color: var(--accent); transform: translateY(-1px); }
.choice-option.selected, .multi-option.selected { border-color: var(--accent); background: rgba(var(--accent-rgb), .1); }
.choice-option.wrong { border-color: #dc9e8d; background: #fff2ed; }
.choice-option.correct { border-color: #75a386; background: #eaf4ed; }
.multi-actions, .order-actions, .builder-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 13px; }

.order-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 13px; }
.order-column { min-height: 185px; padding: 13px; border: 1px dashed #cdd7cf; border-radius: 12px; background: #f6f8f4; }
.order-column > span { display: block; margin-bottom: 9px; color: #869089; font-size: 10px; font-weight: 700; letter-spacing: .08em; }
.order-list { display: grid; gap: 7px; }
.order-empty { padding: 16px 8px; color: #66736c; font-size: 11px; text-align: center; }
.order-item { width: 100%; display: grid; grid-template-columns: 25px 1fr; align-items: center; gap: 8px; padding: 9px; border: 1px solid #d9e0da; border-radius: 9px; color: #59675f; background: white; text-align: left; cursor: pointer; }
.order-item > i { width: 23px; height: 23px; display: grid; place-items: center; border-radius: 7px; color: var(--green); background: #eaf1eb; font-size: 10px; font-style: normal; }
.order-item b { font-size: 12px; }
.order-item small { display: block; color: #68766e; font-size: 10px; }
.order-item:disabled { opacity: .4; cursor: default; }

.inspect-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; }
.inspect-card { min-height: 112px; padding: 14px; border: 1px solid #d9e0da; border-radius: 12px; color: #526159; background: #fafbf8; text-align: left; cursor: pointer; }
.inspect-card span { color: var(--orange); font-size: 10px; font-weight: 700; }
.inspect-card b { display: block; margin: 6px 0 4px; font-size: 13px; }
.inspect-card p { max-height: 0; margin: 0; overflow: hidden; color: #76827a; font-size: 11px; line-height: 1.65; opacity: 0; transition: .2s ease; }
.inspect-card.revealed { border-color: var(--accent); background: rgba(var(--accent-rgb), .08); }
.inspect-card.revealed p { max-height: 120px; opacity: 1; }

.match-layout { display: grid; grid-template-columns: 1fr 44px 1fr; align-items: start; gap: 9px; }
.match-column { display: grid; gap: 8px; }
.match-column > span { margin-bottom: 2px; color: #66736c; font-size: 10px; font-weight: 700; }
.match-arrow { display: grid; place-items: center; min-height: 130px; color: #9aa49e; }
.match-button { min-height: 46px; padding: 10px; border: 1px solid #d7ded8; border-radius: 10px; color: #59675f; background: #fbfcf9; text-align: left; cursor: pointer; font-size: 11px; line-height: 1.45; }
.match-button.selected { color: var(--green); border-color: var(--accent); background: rgba(var(--accent-rgb), .09); }
.match-button.matched { color: #4c715c; border-color: #9bbca6; background: #e9f3ec; cursor: default; }
.match-button.wrong { border-color: #d79987; background: #fff0eb; }

.builder-input label { display: block; margin-bottom: 7px; color: #5b6961; font-size: 12px; font-weight: 600; }
.builder-input textarea { width: 100%; min-height: 86px; padding: 12px; border: 1px solid #d4ddd5; border-radius: 10px; outline: none; color: #415048; background: #fbfcf9; resize: vertical; }
.builder-input textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(var(--accent-rgb), .1); }
.builder-parts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin-top: 11px; }
.builder-part { display: flex; align-items: flex-start; gap: 8px; padding: 10px; border-radius: 9px; color: #65736b; background: #eff3ee; font-size: 11px; line-height: 1.5; cursor: pointer; }
.builder-part input { margin-top: 2px; accent-color: var(--green); }
.builder-preview { min-height: 84px; margin-top: 12px; padding: 13px; border-left: 3px solid var(--accent); border-radius: 0 10px 10px 0; color: #65736b; background: rgba(var(--accent-rgb), .07); font-size: 11px; line-height: 1.7; white-space: pre-wrap; }

.range-controls { display: grid; gap: 12px; }
.range-control { display: grid; grid-template-columns: 150px minmax(120px, 1fr) minmax(92px, auto); align-items: center; gap: 12px; padding: 11px 12px; border-radius: 11px; background: #f1f4ef; }
.range-control label { color: #5d6b63; font-size: 11px; font-weight: 600; }
.range-control input { width: 100%; accent-color: var(--green); }
.range-control output { color: var(--green); font-size: 12px; font-weight: 700; text-align: right; }
.range-metrics { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; margin-top: 12px; }
.range-metric { display: grid; gap: 4px; min-height: 66px; place-content: center; padding: 10px; border-radius: 10px; background: #eef3ed; text-align: center; }
.range-metric span { color: #66736c; font-size: 10px; }
.range-metric b { color: #34463d; font-size: 15px; }

.takeaway-box { display: grid; grid-template-columns: 90px 1fr; gap: 14px; margin-top: 22px; padding: 17px; border-left: 3px solid var(--orange); border-radius: 0 12px 12px 0; color: #6e6258; background: #f8eee2; }
.takeaway-box span { color: #a9623a; font-size: 11px; font-weight: 700; }
.takeaway-box p { margin: 0; font-size: 12px; line-height: 1.75; }
.learning-bridge { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 11px; margin-top: 12px; }
.learning-bridge article { padding: 16px 17px; border: 1px solid var(--line); border-radius: 13px; background: rgba(255, 255, 255, .74); }
.learning-bridge span { display: block; margin-bottom: 7px; color: var(--green); font-size: 10px; font-weight: 700; letter-spacing: .08em; }
.learning-bridge article:last-child span { color: #a9623a; }
.learning-bridge p { margin: 0; color: #66736c; font-size: 12px; line-height: 1.75; }
.lesson-actions { display: flex; justify-content: space-between; gap: 12px; margin-top: 28px; }
.primary-next, .secondary-button { min-height: 47px; padding: 0 18px; border-radius: 11px; cursor: pointer; font-size: 13px; font-weight: 700; }
.primary-next { min-width: 230px; border: 0; color: white; background: var(--green); }
.primary-next:disabled { color: #98a29c; background: #dfe4df; cursor: not-allowed; }
.primary-next:not(:disabled):hover { background: var(--deep); }
.secondary-button { border: 1px solid #d3ddd5; color: #647169; background: transparent; }
.secondary-button:hover:not(:disabled) { color: var(--green); background: white; }
.secondary-button:disabled { opacity: .35; cursor: default; }

.course-complete { margin-top: 28px; padding: 38px 30px; border-radius: 20px; color: white; background: linear-gradient(145deg, #235442, #143c32); text-align: center; box-shadow: 0 22px 50px rgba(19, 57, 46, .18); }
.course-complete > div { width: 48px; height: 48px; display: grid; place-items: center; margin: 0 auto 12px; border-radius: 50%; color: var(--green); background: #f1b171; font-size: 23px; }
.course-complete > span { color: #f0b174; font-size: 11px; letter-spacing: .17em; }
.course-complete h2 { margin: 10px 0; font: 700 25px Georgia, 'Songti SC', serif; }
.course-complete p { max-width: 620px; margin: 0 auto; color: rgba(255, 255, 255, .62); font-size: 12px; line-height: 1.75; }
.complete-actions { display: flex; justify-content: center; gap: 10px; margin-top: 18px; }
.complete-actions a, .complete-actions button { min-height: 42px; padding: 10px 15px; border: 0; border-radius: 9px; color: var(--deep); background: #f0b170; font-size: 12px; font-weight: 700; text-decoration: none; cursor: pointer; }
.complete-actions button { color: white; border: 1px solid rgba(255, 255, 255, .25); background: rgba(255, 255, 255, .08); }

.course-error { max-width: 720px; margin: 100px auto; padding: 30px; border: 1px solid #e5c8a8; border-radius: 16px; background: #fff4e7; text-align: center; }
.course-error h1 { font: 700 28px Georgia, 'Songti SC', serif; }
.course-error p { color: #725f50; line-height: 1.7; }
.course-error a { color: var(--green); }

@media (max-width: 980px) {
  .course-topbar { grid-template-columns: 150px minmax(0, 1fr) 190px auto; padding: 0 18px; }
  .course-main { grid-template-columns: 260px minmax(0, 1fr); }
  .detail-grid { grid-template-columns: 1fr; }
  .onboarding-grid { grid-template-columns: 1fr; }
  .concept-bridge { grid-template-columns: 1fr; }
  .learning-bridge { grid-template-columns: 1fr; }
  .detail-card { min-height: 0; }
  .lifecycle-lanes > div { grid-template-columns: 1fr; gap: 3px; }
  .lifecycle-lanes b { white-space: normal; }
}

@media (max-width: 780px) {
  .course-topbar { height: 60px; grid-template-columns: 1fr auto auto; }
  .course-meta, .top-progress { display: none; }
  .course-main { display: block; }
  .course-rail { position: sticky; top: 60px; z-index: 20; width: 100%; height: 58px; display: block; padding: 7px 12px; overflow-x: auto; border-right: 0; border-bottom: 1px solid var(--line); scrollbar-width: none; }
  .course-rail::-webkit-scrollbar { display: none; }
  .course-rail-head, .rail-caption, .points-note, .rail-phase { display: none; }
  #course-rail-nav { width: max-content; display: flex; gap: 6px; overflow: visible; }
  .rail-step { width: 43px; height: 43px; display: block; padding: 7px; }
  .rail-step > span { width: 29px; height: 29px; }
  .rail-step > b, .rail-step > i { display: none; }
  .course-content { padding: 30px 20px 70px; }
  .course-layer-map { padding: 18px; }
  .course-layer-heading { align-items: flex-start; }
  .course-layer-map ol { grid-template-columns: 1fr; }
  .course-layer-map li { min-height: 68px; }
  .course-layer-map li > span small { white-space: normal; }
  .lifecycle-lanes { grid-template-columns: 1fr; }
  .scope-note { display: grid; }
  .detail-lesson > h1 { font-size: 34px; }
  .lesson-heading { align-items: flex-start; }
  .lesson-heading > div { align-items: flex-start; flex-direction: column; gap: 6px; }
  .scenario-card, .objective-card { grid-template-columns: 1fr; gap: 5px; }
  .animation-toolbar { align-items: flex-start; padding: 11px 12px 11px 15px; }
  .animation-mode { min-height: 34px; }
  .animation-canvas { min-height: 0; padding: 21px; }
  .animation-principle { grid-template-columns: 1fr auto; gap: 7px 10px; }
  .animation-principle > p { grid-column: 1 / 3; grid-row: 2; }
  .animation-principle > small { grid-column: 2; grid-row: 1; }
  .animation-example-heading { align-items: flex-start; }
  .animation-track { min-height: 0; grid-template-columns: 1fr; }
  .animation-node { min-height: 96px; }
  .animation-link { width: 34px; height: 35px; justify-self: center; }
  .animation-link > i { top: 3px; bottom: 3px; left: 50%; width: 1px; height: auto; }
  .animation-link > span { transform: rotate(90deg); }
  .animation-link::after, .animation-signal { display: none; }
  .animation-layout-linear, .animation-layout-tower, .animation-layout-checkpoint, .animation-layout-morph { grid-template-columns: 1fr; grid-template-rows: none; padding: 0; }
  .animation-ornament-route { top: 4%; right: auto; bottom: 4%; left: 50%; width: 1px; height: auto; border-top: 0; border-left: 1px dashed rgba(242, 184, 120, .28); }
  .animation-ornament-route i { top: auto; left: -4px; }
  .animation-ornament-route i:nth-child(1) { top: 0; }
  .animation-ornament-route i:nth-child(2) { top: calc(50% - 4px); }
  .animation-ornament-route i:nth-child(3) { right: auto; bottom: 0; }
  .animation-ornament-route span { top: 12%; left: -1px; width: 3px; height: 16%; }
  .animation-layout-split { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: auto auto; gap: 14px; padding: 0; }
  .animation-layout-split .animation-node-2 { width: 78%; }
  .animation-visual-compare .animation-node-2 { border-radius: 22px; }
  .animation-ornament-balance { top: 22px; width: 70px; height: 112px; }
  .animation-layout-cycle { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: auto auto; gap: 28px 14px; padding: 0 4px; }
  .animation-layout-cycle .animation-node-1 { grid-column: 1 / 3; width: 68%; justify-self: center; }
  .animation-layout-cycle .animation-node-2 { grid-column: 2; }
  .animation-layout-cycle .animation-node-3 { grid-column: 1; }
  .animation-visual-loop .animation-node { border-radius: 24px 24px 12px 12px; }
  .animation-ornament-cycle { top: 6%; right: 4%; bottom: 1%; left: 4%; }
  .animation-layout-fork { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: auto auto; gap: 38px 14px; padding: 0; }
  .animation-layout-fork .animation-node-1 { width: 68%; }
  .animation-ornament-fork { top: 96px; right: 25%; left: 25%; height: 58px; }
  .animation-layout-curve { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: auto auto; gap: 28px 14px; padding: 0 4px; }
  .animation-layout-curve .animation-node-1 { grid-column: 1; }
  .animation-layout-curve .animation-node-2 { grid-column: 1 / 3; width: 68%; justify-self: center; }
  .animation-layout-curve .animation-node-3 { grid-column: 2; }
  .animation-ornament-curve { inset: 8% 2% 0; }
  .animation-visual-gate .animation-node-2 { min-height: 110px; border-right-width: 5px; border-left-width: 5px; }
  .animation-ornament-checkpoint { top: 31%; right: -7px; bottom: 31%; left: -7px; width: auto; border: 0; border-top: 1px solid rgba(242, 184, 120, .45); border-bottom: 1px solid rgba(242, 184, 120, .45); transform: none; }
  .animation-ornament-checkpoint i { display: none; }
  .animation-ornament-checkpoint span { top: 50%; left: 3px; width: 6px; height: 40px; transform: translateY(-50%); }
  .animation-visual-transform .animation-node-2 { width: 82%; min-height: 112px; aspect-ratio: auto; border-radius: 999px; }
  .animation-ornament-morph { width: 178px; height: 178px; }
  .animation-caption-stack { min-height: 0; }
  .animation-caption-card { grid-template-columns: 1fr; align-content: center; gap: 5px; }
  .animation-caption-card > span, .animation-caption-card > b, .animation-caption-card > p { grid-column: 1; grid-row: auto; }
  .lab-section { padding: 18px; }
  .order-layout, .match-layout { grid-template-columns: 1fr; }
  .match-arrow { min-height: 18px; transform: rotate(90deg); }
  .range-control { grid-template-columns: 1fr 65px; }
  .range-control label { grid-column: 1 / 3; }
}

@media (max-width: 520px) {
  .dashboard-link { font-size: 0; }
  .dashboard-link::after { font-size: 12px; content: '返回主页'; }
  .scope-note { font-size: 11px; }
  .course-layer-heading { display: grid; }
  .course-layer-heading > p { justify-items: start; text-align: left; }
  .course-layer-map li { grid-template-columns: 30px minmax(0, 1fr) auto; }
  .course-layer-map li > em { grid-column: 3; grid-row: 1 / 3; align-self: center; }
  .detail-lesson > h1 { font-size: 30px; }
  .lead { font-size: 14px; }
  .section-title-row small { display: none; }
  .animation-instruction { font-size: 11px; }
  .animation-toolbar { align-items: center; }
  .animation-mode > span { max-width: 135px; line-height: 1.4; }
  .animation-controls button { width: 35px; justify-content: center; padding: 6px; }
  .animation-controls button > b { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); }
  .inspect-grid, .builder-parts, .range-metrics { grid-template-columns: 1fr; }
  .lesson-actions { flex-direction: column-reverse; }
  .primary-next, .secondary-button { width: 100%; }
  .complete-actions { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .detail-lesson, .course-loader span, .top-progress em { animation: none; transition: none; }
  .animation-canvas::after, .animation-ambient, .animation-signal, .animation-link::after, .animation-mode > i::before { display: none; }
  .animation-ornament { animation: none; }
  .animation-node { border-color: rgba(255, 255, 255, .35); opacity: 1; transform: none; animation: none; }
  .animation-caption-stack { gap: 8px; min-height: 0; }
  .animation-caption-card { grid-area: auto; opacity: 1; transform: none; animation: none; }
}