/* ============================================================
   Educatone — Lesson page
   ============================================================ */
.content { max-width: 1240px; }
.crumbs { display: flex; align-items: center; gap: 8px; font-size: 13.5px; color: var(--text-muted); margin-bottom: var(--space-5); flex-wrap: wrap; }
.crumbs a:hover { color: var(--text-soft); } .crumbs svg { width: 15px; height: 15px; } .crumbs .cur { color: var(--text-soft); font-weight: 600; }

.lesson-grid { display: grid; grid-template-columns: 1fr 320px; gap: var(--space-8); align-items: start; }

/* ---- Lesson header ---- */
.lh { margin-bottom: var(--space-6); }
.lh__eyebrow { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; color: var(--color-primary); }
.lh h1 { font-size: 28px; font-weight: 800; letter-spacing: -.03em; line-height: 1.15; margin-top: 8px; }
.lh__meta { display: flex; align-items: center; gap: var(--space-4); margin-top: var(--space-4); color: var(--text-soft); font-size: 14px; flex-wrap: wrap; }
.lh__meta .d { width: 4px; height: 4px; border-radius: 50%; background: var(--border-strong); }
.lh__meta span { display: inline-flex; align-items: center; gap: 6px; }
.lh__meta svg { width: 16px; height: 16px; }

/* ---- Tabs ---- */
.tabs-bar { display: flex; gap: 4px; background: var(--surface); border: 1px solid var(--border); padding: 5px; border-radius: var(--r-md); margin-bottom: var(--space-6); box-shadow: var(--shadow-xs); position: sticky; top: calc(var(--header-h) + 8px); z-index: 20; }
.tab-btn { flex: 1; border: none; background: transparent; height: 46px; border-radius: var(--r-sm); font-size: 14.5px; font-weight: 600; color: var(--text-soft); display: inline-flex; align-items: center; justify-content: center; gap: 8px; transition: all var(--dur) var(--ease); }
.tab-btn svg { width: 18px; height: 18px; }
.tab-btn:hover { color: var(--text); background: var(--surface-2); }
.tab-btn.is-active { background: var(--color-primary); color: #fff; box-shadow: var(--shadow-primary); }
.tab-btn .pill { font-size: 11px; font-weight: 700; padding: 2px 7px; border-radius: var(--r-full); background: var(--surface-2); color: var(--text-soft); }
.tab-btn.is-active .pill { background: rgba(255,255,255,.25); color: #fff; }

.tab-panel { display: none; }
.tab-panel.is-active { display: block; animation: fade .25s var(--ease); }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---- Video ---- */
.video { position: relative; aspect-ratio: 16/9; border-radius: var(--r-lg); overflow: hidden; background: linear-gradient(135deg, #1E1B4B, #4338CA); display: grid; place-items: center; box-shadow: var(--shadow-md); }
.video::after { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 50% 45%, rgba(255,255,255,.12), transparent 60%); }
.video__play { width: 84px; height: 84px; border-radius: 50%; background: rgba(255,255,255,.16); backdrop-filter: blur(6px); border: 1px solid rgba(255,255,255,.3); display: grid; place-items: center; cursor: pointer; z-index: 1; transition: transform var(--dur) var(--ease), background var(--dur); }
.video__play:hover { transform: scale(1.06); background: rgba(255,255,255,.26); }
.video__play svg { width: 34px; height: 34px; color: #fff; margin-left: 4px; }
.video__bar { position: absolute; left: 0; right: 0; bottom: 0; padding: var(--space-4) var(--space-5); display: flex; align-items: center; gap: var(--space-4); color: #fff; z-index: 1; background: linear-gradient(transparent, rgba(0,0,0,.45)); }
.video__bar .line { flex: 1; height: 5px; border-radius: 99px; background: rgba(255,255,255,.3); overflow: hidden; }
.video__bar .line > span { display: block; height: 100%; width: 32%; background: #fff; border-radius: 99px; }
.video__bar small { font-size: 12.5px; font-variant-numeric: tabular-nums; }

/* ---- Article content ---- */
.article { margin-top: var(--space-8); font-size: 16px; line-height: 1.7; color: var(--text); }
.article h2 { font-size: 22px; font-weight: 800; letter-spacing: -.02em; margin: var(--space-8) 0 var(--space-4); }
.article h3 { font-size: 18px; font-weight: 700; margin: var(--space-6) 0 var(--space-3); }
.article p { margin-bottom: var(--space-4); color: var(--text); }
.article p strong { color: var(--text); font-weight: 600; }
.article ul { margin: 0 0 var(--space-4) var(--space-5); color: var(--text); }
.article li { margin-bottom: 8px; }
.article a { color: var(--color-primary); font-weight: 600; }
.article a:hover { text-decoration: underline; }
.code { background: #1E1B2E; color: #E4E4F0; border-radius: var(--r-md); padding: var(--space-5); font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace; font-size: 13.5px; line-height: 1.7; overflow-x: auto; margin: 0 0 var(--space-4); }
.code .k { color: #C4B5FD; } .code .s { color: #86EFAC; } .code .c { color: #6B7280; }
.callout { display: flex; gap: var(--space-4); background: var(--color-primary-soft); border: 1px solid #C7D2FE; border-radius: var(--r-md); padding: var(--space-5); margin: 0 0 var(--space-4); }
.callout svg { width: 22px; height: 22px; color: var(--color-primary-hover); flex-shrink: 0; }
.callout b { color: var(--color-primary-hover); } .callout p { margin: 4px 0 0; color: #3730A3; }

/* ---- Attachments ---- */
.attachments { margin-top: var(--space-8); }
.attachments h3 { font-size: 15px; font-weight: 700; margin-bottom: var(--space-4); }
.attach { display: flex; align-items: center; gap: var(--space-4); padding: var(--space-4); border: 1px solid var(--border); border-radius: var(--r-md); margin-bottom: 10px; transition: border-color var(--dur), background var(--dur); }
.attach:hover { border-color: var(--border-strong); background: var(--surface-2); }
.attach__ico { width: 42px; height: 42px; border-radius: 10px; background: var(--color-danger-soft); color: #B91C1C; display: grid; place-items: center; flex-shrink: 0; }
.attach__ico.xls { background: var(--color-success-soft); color: #15803D; }
.attach__ico.zip { background: var(--color-warning-soft); color: #B45309; }
.attach__info { flex: 1; min-width: 0; } .attach__info b { font-size: 14px; font-weight: 600; display: block; } .attach__info small { color: var(--text-muted); font-size: 12.5px; }

/* ---- Bottom actions ---- */
.lesson-actions { display: flex; align-items: center; justify-content: space-between; gap: var(--space-4); margin-top: var(--space-10); padding-top: var(--space-6); border-top: 1px solid var(--border); flex-wrap: wrap; }

/* ---- Homework ---- */
.hw-box { }
.hw-head { display: flex; align-items: flex-start; gap: var(--space-4); margin-bottom: var(--space-6); }
.hw-head__ico { width: 48px; height: 48px; border-radius: 13px; background: var(--color-warning-soft); color: #B45309; display: grid; place-items: center; flex-shrink: 0; }
.hw-head h2 { font-size: 22px; font-weight: 800; letter-spacing: -.02em; }
.hw-head p { color: var(--text-soft); margin-top: 4px; font-size: 14.5px; }
.hw-status { margin-left: auto; }

.task { background: var(--surface-2); border-radius: var(--r-md); padding: var(--space-5) var(--space-6); margin-bottom: var(--space-6); }
.task h3 { font-size: 16px; font-weight: 700; margin-bottom: var(--space-3); }
.task ol { margin: 0 0 0 var(--space-5); color: var(--text-soft); } .task li { margin-bottom: 8px; }
.task .req { display: flex; gap: var(--space-6); margin-top: var(--space-5); flex-wrap: wrap; font-size: 13.5px; }
.task .req span { display: inline-flex; align-items: center; gap: 7px; color: var(--text-soft); } .task .req svg { width: 16px; height: 16px; color: var(--color-primary); }

.hw-label { font-size: 14px; font-weight: 700; margin-bottom: var(--space-3); }
.textarea { width: 100%; min-height: 130px; padding: var(--space-4); font-family: inherit; font-size: 15px; line-height: 1.6; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-md); resize: vertical; }
.textarea:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 4px var(--color-primary-ring); }
.hw-submitted { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border); font-size: 14px; color: var(--text); }
.hw-submitted p { margin: 4px 0; line-height: 1.55; }
.hw-file { display: inline-flex; align-items: center; gap: 6px; margin: 6px 8px 0 0; padding: 7px 12px; border: 1px solid var(--border); border-radius: 9px; font-size: 13px; font-weight: 600; color: var(--color-primary-hover); background: var(--surface-2); }
.hw-file:hover { background: var(--color-primary-soft); }

.dropzone { margin-top: var(--space-5); border: 2px dashed var(--border-strong); border-radius: var(--r-md); padding: var(--space-8); text-align: center; cursor: pointer; transition: border-color var(--dur), background var(--dur); }
.dropzone:hover { border-color: var(--color-primary); background: var(--color-primary-soft); }
.dropzone svg { width: 34px; height: 34px; color: var(--text-muted); margin: 0 auto 10px; }
.dropzone b { font-size: 14.5px; } .dropzone small { display: block; color: var(--text-muted); font-size: 13px; margin-top: 4px; }

/* ---- Test ---- */
.test-head { display: flex; align-items: center; gap: var(--space-4); margin-bottom: var(--space-6); }
.test-head__ico { width: 48px; height: 48px; border-radius: 13px; background: #EDE9FE; color: #6D28D9; display: grid; place-items: center; flex-shrink: 0; }
.test-head h2 { font-size: 22px; font-weight: 800; letter-spacing: -.02em; }
.test-head p { color: var(--text-soft); margin-top: 4px; font-size: 14.5px; }
.test-progress { margin-bottom: var(--space-6); }
.test-progress .meta { display: flex; justify-content: space-between; font-size: 13px; margin-bottom: 8px; color: var(--text-soft); }
.test-progress .bar { height: 8px; border-radius: 99px; background: var(--surface-2); overflow: hidden; }
.test-progress .bar > span { display: block; height: 100%; background: var(--color-primary); border-radius: 99px; transition: width var(--dur) var(--ease); }

.q { padding: var(--space-6); margin-bottom: var(--space-5); }
.q__num { font-size: 12.5px; font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: .05em; }
.q__title { font-size: 17px; font-weight: 700; margin: 8px 0 var(--space-5); line-height: 1.4; }
.opt { display: flex; align-items: center; gap: var(--space-4); padding: var(--space-4) var(--space-5); border: 1.5px solid var(--border); border-radius: var(--r-md); margin-bottom: 10px; cursor: pointer; transition: border-color var(--dur), background var(--dur); }
.opt:hover { border-color: var(--border-strong); background: var(--surface-2); }
.opt__mark { width: 24px; height: 24px; border-radius: 50%; border: 2px solid var(--border-strong); flex-shrink: 0; display: grid; place-items: center; transition: all var(--dur); }
.opt__mark svg { width: 14px; height: 14px; color: #fff; opacity: 0; }
.opt input { position: absolute; opacity: 0; pointer-events: none; }
.opt__text { font-size: 15px; font-weight: 500; }
.opt:has(input:checked) { border-color: var(--color-primary); background: var(--color-primary-soft); }
.opt:has(input:checked) .opt__mark { border-color: var(--color-primary); background: var(--color-primary); }
.opt:has(input:checked) .opt__mark svg { opacity: 1; }
/* graded */
.opt.correct { border-color: var(--color-success); background: var(--color-success-soft); }
.opt.correct .opt__mark { border-color: var(--color-success); background: var(--color-success); }
.opt.correct .opt__mark svg { opacity: 1; }
.opt.wrong { border-color: var(--color-danger); background: var(--color-danger-soft); }
.opt.wrong .opt__mark { border-color: var(--color-danger); background: var(--color-danger); }
.opt.wrong .opt__mark svg { opacity: 1; }

.test-result { text-align: center; padding: var(--space-10) var(--space-6); }
.test-result__ring { width: 120px; height: 120px; border-radius: 50%; margin: 0 auto var(--space-5); position: relative; display: grid; place-items: center; background: conic-gradient(var(--color-success) 80%, var(--surface-2) 0); }
.test-result__ring::before { content: ""; position: absolute; width: 94px; height: 94px; border-radius: 50%; background: var(--surface); }
.test-result__ring b { position: relative; font-size: 30px; font-weight: 800; }
.test-result h2 { font-size: 24px; font-weight: 800; }
.test-result p { color: var(--text-soft); margin: 8px auto var(--space-6); max-width: 42ch; }
.test-result .btns { display: flex; gap: var(--space-3); justify-content: center; flex-wrap: wrap; }

/* ---- Right rail: lesson list ---- */
.lesson-rail { display: flex; flex-direction: column; gap: var(--space-5); position: sticky; top: calc(var(--header-h) + var(--space-5)); }
.rail-card { padding: var(--space-5); }
.rail-card__head { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-4); }
.rail-card__head b { font-size: 15px; font-weight: 700; } .rail-card__head small { font-size: 12.5px; color: var(--text-muted); }
.rl { display: flex; flex-direction: column; gap: 3px; }
.rl__item { display: flex; align-items: center; gap: 11px; padding: 10px; border-radius: var(--r-md); font-size: 14px; transition: background var(--dur); }
.rl__item:hover { background: var(--surface-2); }
.rl__item.active { background: var(--color-primary-soft); }
.rl__item.active .rl__t { color: var(--color-primary-hover); font-weight: 700; }
.rl__ico { width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; flex-shrink: 0; }
.rl__ico svg { width: 14px; height: 14px; }
.rl__ico.done { background: var(--color-success-soft); color: #15803D; }
.rl__ico.active { background: var(--color-primary); color: #fff; }
.rl__ico.lock { background: var(--surface-2); color: var(--text-muted); }
.rl__t { flex: 1; min-width: 0; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.rl__item.lock .rl__t { color: var(--text-muted); }

.next-card { padding: var(--space-5); }
.next-card small { font-size: 12.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; color: var(--text-muted); }
.next-card b { display: block; font-size: 15.5px; font-weight: 700; margin: 8px 0 var(--space-4); line-height: 1.3; }

@media (max-width: 1080px) {
  .lesson-grid { grid-template-columns: 1fr; }
  .lesson-rail { position: static; order: 2; }
  .tabs-bar { position: static; }
}
@media (max-width: 640px) {
  .lh h1 { font-size: 23px; }
  .tab-btn { font-size: 0; gap: 0; height: 44px; }
  .tab-btn svg { width: 20px; height: 20px; }
  .tab-btn .pill { font-size: 11px; }
  .lesson-actions .btn { flex: 1; }
}

/* ---- GetCourse-import lesson design (class-based; keeps the BLOCKS JSON small) ---- */
.article .gc-lead { font-size: 17px; color: var(--text-soft); line-height: 1.7; margin: 0 0 20px; border-left: 3px solid #C7D2FE; padding-left: 15px; }
.article .gc-h3 { font-size: 19px; font-weight: 750; letter-spacing: -.02em; margin: 26px 0 13px; color: var(--text); display: flex; align-items: center; gap: 11px; }
.article > .gc-h3:first-child { margin-top: 4px; }
.article .gc-h3::before { content: ""; flex: none; width: 4px; height: 20px; border-radius: 2px; background: var(--color-primary); }
.article .gc-ih { font-weight: 750; font-size: 16.5px; color: var(--text); margin: 22px 0 9px; letter-spacing: -.01em; line-height: 1.4; }
.article .gc-sub { font-weight: 700; font-size: 15px; color: var(--text); margin: 18px 0 6px; }
.article hr.gc-hr { height: 1px; background: var(--border); margin: 30px 0 0; border: 0; }
.article ul.gc-ul, .article ul.gc-ulp { list-style: none; margin: 16px 0; padding: 0; }
.article ul.gc-ul { padding: 15px 18px; background: #F8FAFC; border: 1px solid var(--border); border-radius: 12px; }
.article ul.gc-ulp { margin: 10px 0; }
.article ul.gc-ul > li, .article ul.gc-ulp > li { position: relative; padding-left: 24px; margin: 0 0 9px; line-height: 1.6; color: var(--text); }
.article ul.gc-ul > li:last-child, .article ul.gc-ulp > li:last-child { margin-bottom: 0; }
.article ul.gc-ul > li::before, .article ul.gc-ulp > li::before { content: ""; position: absolute; left: 3px; top: 9px; width: 7px; height: 7px; border-radius: 50%; background: var(--color-primary); }
.article .gc-box { border-radius: 12px; padding: 13px 16px; margin: 16px 0; border: 1px solid; border-left-width: 4px; color: var(--text); }
.article .gc-box__l { display: flex; align-items: center; gap: 7px; margin-bottom: 6px; font-weight: 700; font-size: 12px; letter-spacing: .05em; text-transform: uppercase; }
.article .gc-box__l svg { flex: none; }
.article .gc-box > p:last-child, .article .gc-box ul:last-child { margin-bottom: 0; }
.article .gc-box ul.gc-ul { background: rgba(255,255,255,.5); }
.article .gc-warn   { background: #FEF3C7; border-color: #FDE68A; border-left-color: #D97706; }
.article .gc-warn   .gc-box__l { color: #B45309; } .article .gc-warn   .gc-box__l svg { color: #D97706; }
.article .gc-danger { background: #FEE2E2; border-color: #FECACA; border-left-color: #DC2626; }
.article .gc-danger .gc-box__l { color: #B91C1C; } .article .gc-danger .gc-box__l svg { color: #DC2626; }
.article .gc-info   { background: #EEF2FF; border-color: #C7D2FE; border-left-color: #4F46E5; }
.article .gc-info   .gc-box__l { color: #3730A3; } .article .gc-info   .gc-box__l svg { color: #4F46E5; }
.article .gc-ok     { background: #DCFCE7; border-color: #BBF7D0; border-left-color: #16A34A; }
.article .gc-ok     .gc-box__l { color: #15803D; } .article .gc-ok     .gc-box__l svg { color: #16A34A; }
.article .gc-btnwrap { text-align: center; margin: 16px 0; }
.article a.gc-btn { display: inline-block; background: var(--color-primary); color: #fff; font-weight: 600; font-size: 15px; padding: 12px 26px; border-radius: 10px; text-decoration: none; box-shadow: 0 2px 8px rgba(79,70,229,.28); }
.article a.gc-btn:hover { background: var(--color-primary-hover); text-decoration: none; }
.article .gc-num { display: flex; gap: 10px; align-items: center; margin: 16px 0 6px; }
.article .gc-num > b { flex: none; width: 25px; height: 25px; border-radius: 50%; background: var(--color-primary); color: #fff; font-weight: 700; font-size: 13px; display: flex; align-items: center; justify-content: center; }