:root {
  --bg: #f5f6f8; --surface: #fff; --ink: #14202e; --muted: #5d6b7a; --line: #e3e7ec;
  --brand: #0f5f73; --brand-2: #e8f3f5; --accent: #f2a541; --ok: #1f8a4c; --ok-bg: #e7f5ec;
  --bad: #c0392b; --bad-bg: #fbeaea; --warn-bg: #fff4e0; --radius: 12px;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Inter, system-ui, -apple-system, "Segoe UI", sans-serif; background: var(--bg); color: var(--ink); line-height: 1.55; font-size: 15px; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
h1 { font-size: 1.7rem; line-height: 1.25; margin: .2em 0 .4em; font-weight: 800; }
h2 { font-size: 1.2rem; margin: 0 0 .6em; }
h3 { font-size: 1.05rem; margin: 0 0 .4em; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 16px; }
.main { padding-top: 24px; padding-bottom: 48px; min-height: 70vh; }
.muted { color: var(--muted); } .small { font-size: .86rem; } .nowrap { white-space: nowrap; }
.center { text-align: center; } .pad { padding: 32px 0; } .pad-t { padding-top: 16px; }
.inline { display: inline; } .right { margin-left: auto; } .grow { flex: 1; min-width: 0; }
.narrow { max-width: 720px; margin-left: auto; margin-right: auto; }

/* Header */
.top { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 10; }
.top-in { display: flex; align-items: center; gap: 16px; height: 62px; }
.logo { display: flex; align-items: center; gap: 8px; font-weight: 800; font-size: 1.1rem; color: var(--ink); }
.logo:hover { text-decoration: none; }
.logo-mark { width: 32px; height: 32px; border-radius: 9px; background: var(--brand); color: #fff; display: grid; place-items: center; }
.top-search { flex: 1; max-width: 340px; }
.top-search input { width: 100%; }
.nav { display: flex; align-items: center; gap: 16px; margin-left: auto; }
.nav a { color: var(--ink); font-weight: 600; font-size: .93rem; }
.nav-admin { color: var(--brand) !important; }
.nav-user { font-size: .88rem; color: var(--muted); }
.nav-t, .nav-btn { display: none; }

/* Forms */
input, select, textarea { font: inherit; padding: 9px 11px; border: 1px solid var(--line); border-radius: 8px; background: #fff; color: var(--ink); width: 100%; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--brand-2); border-color: var(--brand); }
input[type=checkbox], input[type=radio] { width: auto; }
textarea.mono { font-family: ui-monospace, Consolas, monospace; font-size: .9rem; }
label { display: block; font-weight: 600; font-size: .9rem; margin-bottom: 12px; }
label > input, label > select, label > textarea { margin-top: 5px; font-weight: 400; }
label.check { display: flex; gap: 8px; align-items: flex-start; font-weight: 500; }
label.check input { margin-top: 4px; }
.row2, .row3 { display: grid; gap: 12px; grid-template-columns: 1fr 1fr; }
.row3 { grid-template-columns: 1fr 1fr 1fr; }
.btn { display: inline-block; background: var(--brand); color: #fff; border: 0; border-radius: 9px; padding: 10px 18px; font: inherit; font-weight: 700; cursor: pointer; text-align: center; }
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn-sm { padding: 6px 12px; font-size: .86rem; }
.btn-lg { padding: 13px 28px; font-size: 1.05rem; }
.btn-block { display: block; width: 100%; margin-bottom: 8px; }
.btn-ghost { background: var(--brand-2); color: var(--brand); }
.btn-danger { background: var(--bad); }
.btns { display: flex; gap: 8px; flex-wrap: wrap; }
.linkbtn { background: none; border: 0; color: var(--brand); cursor: pointer; font: inherit; padding: 0; }
.linkbtn:hover { text-decoration: underline; }
.danger { color: var(--bad) !important; }

/* Blocks */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; margin-bottom: 16px; }
.flash { padding: 12px 16px; border-radius: 10px; margin-bottom: 16px; font-weight: 500; }
.flash ul { margin: 6px 0 0; padding-left: 20px; }
.flash-ok { background: var(--ok-bg); color: var(--ok); }
.flash-err { background: var(--bad-bg); color: var(--bad); }
.flash-warn { background: var(--warn-bg); color: #8a5a00; }
.empty { padding: 28px; text-align: center; color: var(--muted); background: var(--surface); border: 1px dashed var(--line); border-radius: var(--radius); margin-bottom: 16px; }
.info-box { background: var(--brand-2); color: var(--brand); padding: 10px 12px; border-radius: 8px; font-weight: 600; margin: 8px 0; }
.ok-box { background: var(--ok-bg); color: var(--ok); padding: 8px 12px; border-radius: 8px; font-weight: 700; margin-bottom: 10px; }
.tag { display: inline-block; font-size: .74rem; font-weight: 700; padding: 2px 8px; border-radius: 999px; background: var(--brand-2); color: var(--brand); vertical-align: middle; }
.tag-trial { background: #fff1d6; color: #9a5b00; }
.tag-ok { background: var(--ok-bg); color: var(--ok); }
.tag-warn { background: var(--warn-bg); color: #8a5a00; }
.role-admin { background: #2b2d42; color: #fff; } .role-teacher { background: #e4e9ff; color: #3341a8; }
.crumbs { font-size: .86rem; color: var(--muted); margin-bottom: 6px; }
.page-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; margin-bottom: 8px; }
.sec-title { margin-top: 28px; }
.prose { white-space: pre-line; }
.help { background: var(--bg); border-radius: 8px; padding: 10px 14px; margin-bottom: 12px; }
.help summary { cursor: pointer; font-weight: 600; }
.help pre { background: #fff; padding: 10px; border-radius: 6px; overflow-x: auto; }

/* Home */
.hero { background: linear-gradient(120deg, #0f5f73, #13405a); color: #fff; border-radius: 18px; padding: 44px 36px; margin-bottom: 8px; }
.hero h1 { font-size: 2.1rem; max-width: 640px; }
.hero p { max-width: 640px; opacity: .9; }
.hero-search { display: flex; gap: 8px; max-width: 520px; margin-top: 18px; }
.hero-search input { border: 0; }
.hero .btn { background: var(--accent); color: #2a1a00; }
.grid { display: grid; gap: 16px; }
.cats { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.courses { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.cat-card { display: flex; flex-direction: column; gap: 4px; margin: 0; color: var(--ink); border-left: 4px solid var(--brand); }
.cat-card:hover, .course-card:hover, .my-course:hover { box-shadow: 0 6px 18px rgba(20, 32, 46, .08); text-decoration: none; }
.course-card { padding: 0; overflow: hidden; margin: 0; color: var(--ink); display: flex; flex-direction: column; }
.cc-cover { height: 120px; background: linear-gradient(135deg, #0f5f73, #3b8ea5); background-size: cover; background-position: center; position: relative; }
.cc-cover.type-test { background-color: #7a4e9c; background-image: linear-gradient(135deg, #5b3a8a, #9a6bc2); }
.cc-cover.type-video { background-image: linear-gradient(135deg, #b5552f, #e39150); }
.cc-cover .badge { position: absolute; left: 12px; bottom: 10px; background: rgba(255,255,255,.92); color: var(--ink); font-size: .74rem; font-weight: 700; padding: 3px 9px; border-radius: 999px; }
.cc-body { padding: 14px 16px; display: flex; flex-direction: column; gap: 2px; flex: 1; }
.cc-meta { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: auto; padding-top: 10px; font-size: .84rem; color: var(--muted); }
.price { margin-left: auto; color: var(--ink); }
.my-course { color: var(--ink); margin: 0; }
.chips { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.chip { background: var(--surface); border: 1px solid var(--line); padding: 6px 14px; border-radius: 999px; color: var(--ink); font-weight: 600; font-size: .9rem; }
.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.filters input { flex: 2; min-width: 200px; } .filters select { flex: 1; min-width: 140px; width: auto; }

/* Course */
.course-head { display: grid; grid-template-columns: 1fr 280px; gap: 24px; }
.ch-side { border-left: 1px solid var(--line); padding-left: 24px; }
.price-big { font-size: 1.6rem; font-weight: 800; margin-bottom: 12px; }
.tags { display: flex; gap: 6px; }
.chapter h3 { margin-bottom: 8px; }
.items { list-style: none; margin: 0; padding: 0; }
.items li { display: flex; align-items: center; gap: 10px; padding: 9px 4px; border-top: 1px solid var(--line); flex-wrap: wrap; }
.items li:first-child { border-top: 0; }
.items .ico { width: 26px; height: 26px; border-radius: 50%; background: var(--brand-2); color: var(--brand); display: grid; place-items: center; font-size: .8rem; flex: none; }
.items li.locked { color: var(--muted); } .items li.locked .ico { background: var(--bg); color: var(--muted); }
.lock { margin-left: auto; }
.progress { height: 8px; background: var(--line); border-radius: 99px; overflow: hidden; margin: 6px 0; }
.progress span { display: block; height: 100%; background: var(--ok); }
.progress.sm { height: 6px; width: 110px; }
.video { position: relative; padding-top: 56.25%; border-radius: var(--radius); overflow: hidden; background: #000; margin-bottom: 16px; }
.video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.lesson-nav { display: flex; justify-content: space-between; gap: 12px; margin-top: 16px; flex-wrap: wrap; }
.big-ico { font-size: 3rem; }
.facts { padding-left: 20px; }

/* Test */
.test-bar { position: sticky; top: 62px; z-index: 5; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 16px; display: flex; gap: 16px; align-items: center; margin-bottom: 16px; }
.timer { margin-left: auto; font-weight: 800; font-size: 1.2rem; font-variant-numeric: tabular-nums; background: var(--brand-2); color: var(--brand); padding: 4px 12px; border-radius: 8px; }
.timer-low { background: var(--bad-bg); color: var(--bad); }
.question .q-num { font-weight: 700; color: var(--muted); font-size: .86rem; margin-bottom: 6px; }
.q-head { display: flex; justify-content: space-between; }
.q-text { font-weight: 600; white-space: pre-line; margin-bottom: 10px; }
.q-img { max-width: 100%; max-height: 360px; border-radius: 8px; margin-bottom: 10px; }
.opts { display: grid; gap: 8px; }
.opt { display: flex; gap: 10px; align-items: center; padding: 10px 12px; border: 1px solid var(--line); border-radius: 9px; font-weight: 500; margin: 0; cursor: pointer; }
.opts.compact .opt { padding: 6px 10px; cursor: default; }
label.opt:hover { border-color: var(--brand); }
label.opt:has(input:checked) { border-color: var(--brand); background: var(--brand-2); }
.opt-l { width: 24px; height: 24px; border-radius: 6px; background: var(--bg); display: grid; place-items: center; font-weight: 700; font-size: .8rem; flex: none; }
.opt-right { border-color: var(--ok); background: var(--ok-bg); }
.opt-wrong { border-color: var(--bad); background: var(--bad-bg); }
.q-ok { border-left: 4px solid var(--ok); } .q-bad { border-left: 4px solid var(--bad); }
.explain { margin-top: 10px; background: var(--bg); padding: 10px 12px; border-radius: 8px; white-space: pre-line; }
.result-head { display: flex; gap: 24px; align-items: center; }
.score-ring { --p: 0; width: 110px; height: 110px; border-radius: 50%; flex: none; display: grid; place-items: center;
  background: conic-gradient(var(--ok) calc(var(--p) * 1%), var(--line) 0); }
.score-ring span { width: 84px; height: 84px; border-radius: 50%; background: #fff; display: grid; place-items: center; font-weight: 800; font-size: 1.3rem; }

/* Auth */
.auth { max-width: 420px; margin: 24px auto; }

/* Teacher / admin */
.cols { display: grid; grid-template-columns: 1fr 360px; gap: 24px; align-items: start; }
.ch-edit { display: flex; gap: 8px; align-items: center; margin-bottom: 8px; }
.ch-edit input { width: auto; }
.ch-edit .grow { flex: 1; }
.w-num { width: 70px !important; }
.items.edit li { font-size: .93rem; }
.ch-actions { display: flex; gap: 8px; align-items: center; margin-top: 10px; }
.danger-zone summary { cursor: pointer; color: var(--bad); font-weight: 600; }
.stats { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; margin: 12px 0 8px; }
.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; }
.stat b { display: block; font-size: 1.5rem; }
.stat span { color: var(--muted); font-size: .84rem; }
.tbl-wrap { padding: 0; overflow-x: auto; }
.tbl { width: 100%; border-collapse: collapse; font-size: .9rem; }
.tbl th { text-align: left; font-size: .78rem; text-transform: uppercase; letter-spacing: .03em; color: var(--muted); background: var(--bg); }
.tbl th, .tbl td { padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.tbl tr:last-child td { border-bottom: 0; }
.tbl tr.dim td { opacity: .5; }
.tbl-filter { max-width: 320px; margin-bottom: 10px; }
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 16px; overflow-x: auto; }
.tabs a { padding: 9px 14px; color: var(--muted); font-weight: 600; border-bottom: 2px solid transparent; white-space: nowrap; }
.tabs a.on { color: var(--brand); border-color: var(--brand); }
.log { list-style: none; margin: 0; padding: 0; }
.log li { padding: 7px 0; border-top: 1px solid var(--line); font-size: .9rem; }
.log li:first-child { border-top: 0; }
.pager { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 12px; }
.pager a { padding: 5px 11px; border: 1px solid var(--line); border-radius: 7px; background: #fff; }
.pager a.on { background: var(--brand); color: #fff; }
.cat-admin { padding: 12px 16px; }
.cat-row { display: flex; gap: 8px; align-items: center; }
.cat-row form.ch-edit { margin: 0; }
.cat-top input[name=name] { font-weight: 700; }
.subs { padding-left: 32px; margin-top: 6px; display: grid; gap: 6px; }
.form h2 { margin-top: 0; }

.foot { border-top: 1px solid var(--line); padding: 20px 0; color: var(--muted); font-size: .85rem; background: var(--surface); }

@media (max-width: 860px) {
  .course-head, .cols { grid-template-columns: 1fr; }
  .ch-side { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-top: 16px; }
  .top-search { display: none; }
  .nav-btn { display: block; margin-left: auto; font-size: 1.5rem; cursor: pointer; }
  .nav { display: none; position: absolute; top: 62px; left: 0; right: 0; background: #fff; flex-direction: column; align-items: stretch; padding: 12px 16px; border-bottom: 1px solid var(--line); gap: 12px; }
  .nav-t:checked ~ .nav { display: flex; }
  .row2, .row3 { grid-template-columns: 1fr; }
  .hero { padding: 28px 20px; } .hero h1 { font-size: 1.6rem; }
  h1 { font-size: 1.4rem; }
  .result-head { flex-direction: column; align-items: flex-start; }
}
.nav a.btn { color: #fff; }