:root {
  color-scheme: dark;
  --bg: #080a14; --card: #11141f; --card-2: #171a29; --text: #e9ebf7; --muted: #8e94b0; --line: #23263a; --line-2: #2d3150;
  --primary: #6d5ef0; --primary-2: #5a3fd0; --accent: #8b93ff; --input: #1a1d2d;
  --ok: #3ddc97; --warn: #ffb454; --bad: #ff6b81;
  --ok-bg: rgba(61, 220, 151, .13); --warn-bg: rgba(255, 180, 84, .14); --bad-bg: rgba(255, 107, 129, .14);
  --radius: 16px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; background: var(--bg); }
body {
  margin: 0; min-height: 100vh; padding-bottom: 92px; color: var(--text);
  font: 16px/1.45 Inter, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background:
    radial-gradient(60rem 30rem at 85% -10%, rgba(124, 77, 255, .22), transparent 60%),
    radial-gradient(50rem 28rem at 0% -5%, rgba(59, 91, 219, .25), transparent 60%),
    radial-gradient(50rem 22rem at 50% 108%, rgba(20, 184, 166, .16), transparent 65%),
    linear-gradient(rgba(255, 255, 255, .025) 1px, transparent 1px) 0 0 / 44px 44px,
    linear-gradient(90deg, rgba(255, 255, 255, .025) 1px, transparent 1px) 0 0 / 44px 44px,
    var(--bg);
  background-attachment: fixed;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1 { font-size: 1.5rem; margin: 0 0 .9rem; letter-spacing: -.01em; }
h2 { font-size: 1.05rem; margin: 0 0 .7rem; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.right { text-align: right; }
.nowrap { white-space: nowrap; }

.topbar { background: rgba(13, 15, 26, .8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 10; }
.topbar .in { max-width: 980px; margin: 0 auto; padding: .65rem 1rem; display: flex; align-items: center; gap: .9rem; }
.brand { font-weight: 700; color: var(--text); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.brand:hover { text-decoration: none; }
.topbar a.tl, .topbar button.tl { color: var(--muted); font-size: .9rem; background: none; border: 0; padding: .25rem; cursor: pointer; font-family: inherit; }
.topbar a.tl:hover, .topbar button.tl:hover { color: var(--text); text-decoration: none; }
.topbar form { margin: 0; }

.wrap { max-width: 980px; margin: 0 auto; padding: 1.1rem 1rem; }
.card {
  background: linear-gradient(180deg, rgba(23, 26, 41, .85), rgba(17, 20, 31, .92));
  border: 1px solid var(--line); border-radius: 20px; padding: 1.1rem; margin-bottom: 1rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .25);
}
.card > :last-child { margin-bottom: 0; }
details.card summary { cursor: pointer; }

.bottomnav { position: fixed; bottom: 0; left: 0; right: 0; background: rgba(13, 15, 26, .9); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-top: 1px solid var(--line); display: flex; justify-content: space-around; padding: .35rem .25rem calc(.35rem + env(safe-area-inset-bottom)); z-index: 20; }
.bottomnav a { flex: 1; text-align: center; color: var(--muted); font-size: .68rem; padding: .25rem 0; min-width: 0; }
.bottomnav a:hover { text-decoration: none; color: var(--text); }
.bottomnav a .ic { display: block; font-size: 1.35rem; line-height: 1.3; }
.bottomnav a.active { color: var(--accent); font-weight: 600; }
.bottomnav a.cta .ic { background: linear-gradient(135deg, #8b6cff, var(--primary-2)); color: #fff; width: 3.1rem; height: 3.1rem; line-height: 3.1rem; border-radius: 50%; margin: -1.4rem auto .1rem; box-shadow: 0 6px 18px rgba(109, 94, 240, .55); font-size: 1.5rem; }
.bottomnav a.cta span.lb { color: var(--accent); font-weight: 600; }

.btn, button.btn { display: inline-block; background: linear-gradient(135deg, #7c6bff, var(--primary-2)); color: #fff; border: 0; border-radius: 12px; padding: .7rem 1.1rem; font: inherit; font-weight: 600; cursor: pointer; text-align: center; min-height: 44px; box-shadow: 0 4px 14px rgba(109, 94, 240, .3); }
.btn:hover { filter: brightness(1.1); text-decoration: none; }
.btn.secondary { background: var(--card-2); color: var(--text); border: 1px solid var(--line-2); box-shadow: none; }
.btn.secondary:hover { border-color: var(--primary); }
.btn.danger { background: linear-gradient(135deg, #ff6b81, #d6335a); }
.btn.block { display: block; width: 100%; }
.btn.sm { padding: .4rem .75rem; min-height: 36px; font-size: .9rem; }

label { display: block; font-size: .85rem; color: var(--muted); margin: .7rem 0 .25rem; }
input, select, textarea { width: 100%; font: inherit; padding: .65rem .8rem; border: 1px solid var(--line-2); border-radius: 12px; background: var(--input); color: var(--text); min-height: 44px; }
input::placeholder, textarea::placeholder { color: #6a7090; }
input:focus, select:focus, textarea:focus { outline: none; border-color: #6b74e8; box-shadow: 0 0 0 3px rgba(107, 116, 232, .28); }
input[type=checkbox], input[type=radio] { accent-color: var(--primary); }
.row { display: grid; gap: .75rem; }
@media (min-width: 640px) { .row.two { grid-template-columns: 1fr 1fr; } .row.three { grid-template-columns: repeat(3, 1fr); } }

.stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: .75rem; margin-bottom: 1rem; }
@media (min-width: 720px) { .stats { grid-template-columns: repeat(4, 1fr); } }
.stat { background: var(--card-2); border: 1px solid var(--line); border-radius: 16px; padding: .9rem; }
.stat .v { font-size: 1.4rem; font-weight: 700; letter-spacing: -.01em; }
.stat .l { color: var(--muted); font-size: .8rem; }
.stat.ok .v { color: var(--ok); } .stat.warn .v { color: var(--warn); }

.bar { height: 8px; background: var(--line); border-radius: 99px; overflow: hidden; margin-top: .5rem; }
.bar > i { display: block; height: 100%; background: linear-gradient(90deg, #6d5ef0, var(--ok)); }

.flash { background: var(--ok-bg); color: var(--ok); border: 1px solid rgba(61, 220, 151, .3); border-radius: 12px; padding: .7rem 1rem; margin-bottom: 1rem; }
.error { background: var(--bad-bg); color: var(--bad); border: 1px solid rgba(255, 107, 129, .3); border-radius: 12px; padding: .7rem 1rem; margin-bottom: 1rem; }

.chips { display: flex; gap: .5rem; overflow-x: auto; padding: .1rem .1rem .6rem; margin: 0 -.1rem; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
.chips::-webkit-scrollbar { display: none; }
.chip { flex: 0 0 auto; padding: .45rem .9rem; border-radius: 99px; border: 1px solid var(--line-2); background: var(--card-2); color: var(--text); font: inherit; font-size: .9rem; min-height: 38px; display: inline-flex; align-items: center; cursor: pointer; }
.chip:hover { text-decoration: none; border-color: var(--primary); }
.chip.on { background: linear-gradient(135deg, #7c6bff, var(--primary-2)); border-color: transparent; color: #fff; font-weight: 600; }

table { width: 100%; border-collapse: collapse; }
th, td { padding: .6rem .5rem; text-align: left; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { font-size: .75rem; text-transform: uppercase; letter-spacing: .05em; color: var(--accent); font-weight: 600; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
.scroll { overflow-x: auto; }

.list { list-style: none; margin: 0; padding: 0; }
.list li { display: flex; align-items: center; gap: .75rem; padding: .7rem 0; border-bottom: 1px solid var(--line); }
.list li:last-child { border-bottom: 0; }
.list .grow { flex: 1; min-width: 0; }
.list .grow b, .list .grow span { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.badge { display: inline-block; font-size: .72rem; font-weight: 600; padding: .15rem .55rem; border-radius: 99px; background: rgba(139, 147, 255, .16); color: var(--accent); }
.badge.ok { background: var(--ok-bg); color: var(--ok); } .badge.warn { background: var(--warn-bg); color: var(--warn); } .badge.bad { background: var(--bad-bg); color: var(--bad); }

.chart { display: flex; align-items: flex-end; gap: 3px; height: 130px; padding-top: 1rem; }
.chart .col { flex: 1; min-width: 3px; background: linear-gradient(180deg, #8b93ff, #4b3fb8); border-radius: 4px 4px 0 0; opacity: .75; }
.chart .col:hover { opacity: 1; }
.chart-axis { display: flex; justify-content: space-between; font-size: .75rem; color: var(--muted); margin-top: .3rem; }

.att-row { display: flex; align-items: center; gap: .6rem; padding: .55rem 0; border-bottom: 1px solid var(--line); }
.att-row:last-child { border-bottom: 0; }
.att-row .nm { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.seg { display: inline-flex; border: 1px solid var(--line-2); border-radius: 12px; overflow: hidden; }
.seg input { position: absolute; opacity: 0; width: 0; min-height: 0; }
.seg label { margin: 0; padding: .55rem .8rem; font-size: .85rem; color: var(--muted); cursor: pointer; background: var(--input); min-width: 44px; text-align: center; }
.seg input:checked + label.p { background: var(--ok); color: #062014; font-weight: 700; }
.seg input:checked + label.a { background: var(--bad); color: #2b0610; font-weight: 700; }
.seg input:checked + label.l { background: var(--warn); color: #2b1a02; font-weight: 700; }
.seg input:focus-visible + label { outline: 2px solid var(--accent); outline-offset: -2px; }

.login { max-width: 380px; margin: 12vh auto 0; padding: 1rem; }
.login h1 { text-align: center; font-size: 1.8rem; }
.kv { display: grid; grid-template-columns: 8.5rem 1fr; gap: .35rem .75rem; margin: 0; }
.kv dt { color: var(--muted); } .kv dd { margin: 0; font-weight: 500; }

@media print {
  html, body { background: #fff !important; color: #000; }
  .topbar, .bottomnav, .noprint { display: none !important; }
}

.hero { text-align: center; padding: 1.6rem .5rem 1.2rem; }
.hero .eyebrow { color: var(--accent); font-size: .8rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; margin: 0 0 .4rem; }
.hero h1 { font-size: 2rem; margin: 0 0 .4rem; }
.hero .tagline { color: var(--muted); font-size: 1.05rem; margin: 0; }
.about { white-space: pre-line; margin: 0; }
.tags { display: flex; flex-wrap: wrap; gap: .5rem; }
.tag { padding: .35rem .8rem; border-radius: 99px; background: rgba(139, 147, 255, .14); color: var(--accent); font-size: .9rem; font-weight: 600; }
.actions { display: flex; flex-wrap: wrap; gap: .6rem; }
.actions .btn { flex: 1 1 9rem; }
.hero .logo { display: block; margin: 0 auto .9rem; border-radius: 24px; box-shadow: 0 10px 34px rgba(109, 94, 240, .5); }

.eyebrow { color: var(--accent); font-size: .8rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; margin: 0 0 .4rem; }
.center { text-align: center; }
.wrap.narrow { max-width: 460px; }
.s-brand { display: flex; align-items: center; gap: .7rem; justify-content: center; font-weight: 700; margin: .4rem 0 1.2rem; }
.s-brand img { border-radius: 12px; box-shadow: 0 4px 16px rgba(109, 94, 240, .45); }
body.student-app { padding-bottom: 2rem; }
.bigbtn { font-size: 1.25rem; padding: 1.1rem 1rem; min-height: 64px; }
.status-icon { width: 4rem; height: 4rem; line-height: 4rem; border-radius: 50%; margin: 0 auto; font-size: 1.8rem; background: var(--card-2); color: var(--muted); }
.status-icon.ok { background: var(--ok-bg); color: var(--ok); }
.status-icon.bad { background: var(--bad-bg); color: var(--bad); }
.code { font-size: 2.2rem; font-weight: 800; letter-spacing: .3em; color: var(--accent); margin-top: .2rem; }
.pin-big { font-size: 3rem; font-weight: 800; letter-spacing: .35em; color: var(--accent); text-align: center; margin: .6rem 0; }
@media print {
  .pin-card { break-inside: avoid; border: 1px solid #999 !important; background: #fff !important; box-shadow: none !important; color: #000 !important; }
  .pin-card .muted, .pin-card td, .pin-card th { color: #000 !important; }
}

.pre { white-space: pre-line; margin: .3rem 0; }
.lesson .lesson-head { display: flex; align-items: center; gap: .4rem; flex-wrap: wrap; }
.homework { margin-top: .6rem; padding: .6rem .8rem; border-left: 3px solid var(--warn); background: var(--warn-bg); border-radius: 0 10px 10px 0; }