/* Zero Academy — Paper Editorial + Claude accent
   Палитра наследует academy.smolnikov.pro, акцент --claude #d97757 (Anthropic orange) */
:root {
  --claude: #d97757;
  --claude-deep: #b85c3e;
  --ink: #1a1612;
  --ink2: #5a5147;
  --ink3: #8a8175;
  --rule: #d9cfba;
  --paper: #f5f0e6;
  --paper2: #ede6d4;
  --paper3: #e0d6bc;
  --light: #f3e7df;
  --ok: #3d6b2e;
  --err: #9a3324;
  --term-bg: #1e1b18;
  --term-fg: #e8e2d5;
  --term-green: #8fce6b;
  --term-dim: #8a8175;
  --serif: 'Newsreader', Georgia, serif;
  --display: 'Instrument Serif', Georgia, serif;
  --sans: 'IBM Plex Sans', system-ui, sans-serif;
  --mono: 'IBM Plex Mono', 'SF Mono', Menlo, monospace;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--serif);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.6;
  font-size: 18px;
}
a { color: var(--claude-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* ---- masthead ---- */
.masthead {
  border-bottom: 2px solid var(--ink);
  background: var(--paper);
  position: sticky; top: 0; z-index: 50;
}
.masthead-in {
  max-width: 1100px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { font-family: var(--display); font-size: 28px; color: var(--ink); letter-spacing: .3px; }
.brand b { color: var(--claude-deep); font-weight: 400; }
.masthead nav { display: flex; gap: 20px; font-family: var(--sans); font-size: 14px; text-transform: uppercase; letter-spacing: .5px; }

/* ---- wrap ---- */
.wrap { max-width: 1100px; margin: 0 auto; padding: 32px 24px 80px; }
.narrow { max-width: 720px; }

/* ---- buttons ---- */
.btn {
  display: inline-block; font-family: var(--sans); font-size: 15px; font-weight: 500;
  padding: 12px 24px; border: 2px solid var(--ink); background: var(--ink); color: var(--paper);
  cursor: pointer; min-height: 44px; letter-spacing: .3px; transition: transform .05s;
}
.btn:hover { background: var(--claude-deep); border-color: var(--claude-deep); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn-ghost { background: transparent; color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--paper); }
.btn:disabled { opacity: .4; cursor: not-allowed; }
.btn-accent { background: var(--claude); border-color: var(--claude); color: #fff; }
.btn-accent:hover { background: var(--claude-deep); border-color: var(--claude-deep); }

/* ---- hero (landing) ---- */
.hero { padding: 64px 0 40px; border-bottom: 1px solid var(--rule); }
.hero h1 { font-family: var(--display); font-size: clamp(40px, 7vw, 76px); line-height: 1.02; margin: 0 0 20px; font-weight: 400; }
.hero .lead { font-size: 22px; color: var(--ink2); max-width: 620px; margin: 0 0 28px; }
.kicker { font-family: var(--sans); text-transform: uppercase; letter-spacing: 2px; font-size: 13px; color: var(--claude-deep); margin-bottom: 16px; }

/* ---- dashboard levels ---- */
.levels { display: grid; gap: 0; margin-top: 8px; border-top: 1px solid var(--rule); }
.level-row {
  display: grid; grid-template-columns: 64px 1fr auto; gap: 20px; align-items: center;
  padding: 22px 8px; border-bottom: 1px solid var(--rule); text-decoration: none; color: var(--ink);
}
.level-row:hover { background: var(--paper2); text-decoration: none; }
.level-num { font-family: var(--display); font-size: 40px; color: var(--claude); line-height: 1; }
.level-row.locked .level-num { color: var(--ink3); }
.level-meta h3 { font-family: var(--serif); font-weight: 600; font-size: 21px; margin: 0 0 4px; }
.level-meta .sub { font-family: var(--sans); font-size: 13px; color: var(--ink3); text-transform: uppercase; letter-spacing: .5px; }
.level-prog { font-family: var(--sans); font-size: 13px; color: var(--ink2); text-align: right; min-width: 90px; }
.level-bar { height: 4px; background: var(--paper3); margin-top: 6px; width: 90px; }
.level-bar > i { display: block; height: 100%; background: var(--claude); }
.lock-ico { color: var(--ink3); font-size: 18px; }

/* ---- lesson list (inside level) ---- */
.lesson-list { border-top: 1px solid var(--rule); }
.lesson-link {
  display: flex; align-items: center; gap: 14px; padding: 16px 8px;
  border-bottom: 1px solid var(--rule); color: var(--ink); text-decoration: none;
}
.lesson-link:hover { background: var(--paper2); text-decoration: none; }
.lesson-link .n { font-family: var(--mono); font-size: 13px; color: var(--ink3); min-width: 44px; }
.lesson-link .t { flex: 1; }
.lesson-link .done { color: var(--ok); }
.lesson-link .dur { font-family: var(--sans); font-size: 12px; color: var(--ink3); }

/* ---- lesson player ---- */
.lesson-top {
  position: sticky; top: 0; z-index: 40; background: var(--paper); border-bottom: 1px solid var(--rule);
}
.lesson-top-in { max-width: 760px; margin: 0 auto; padding: 10px 24px; display: flex; align-items: center; gap: 14px; font-family: var(--sans); font-size: 13px; }
.lesson-top .crumb { color: var(--ink3); flex: 1; text-transform: uppercase; letter-spacing: .5px; }
.lesson-top a { color: var(--ink2); }
.progress-track { height: 4px; background: var(--paper3); }
.progress-track > i { display: block; height: 100%; background: var(--claude); transition: width .3s; }

.player { max-width: 760px; margin: 0 auto; padding: 40px 24px 120px; }
.section { animation: fade .25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.sec-tag { font-family: var(--sans); text-transform: uppercase; letter-spacing: 2px; font-size: 12px; color: var(--claude-deep); margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
.sec-tag .ico { font-size: 15px; }
.section h2 { font-family: var(--display); font-weight: 400; font-size: 34px; line-height: 1.1; margin: 0 0 18px; }
.section p { margin: 0 0 16px; }

.analogy { border-left: 3px solid var(--claude); background: var(--paper2); padding: 16px 20px; margin: 20px 0; font-style: italic; color: var(--ink2); }
.analogy::before { content: '💡 '; font-style: normal; }
.key-points { list-style: none; padding: 0; margin: 24px 0; counter-reset: kp; }
.key-points li { position: relative; padding: 10px 0 10px 44px; border-top: 1px solid var(--rule); counter-increment: kp; }
.key-points li::before { content: counter(kp); position: absolute; left: 0; top: 8px; width: 28px; height: 28px; background: var(--ink); color: var(--paper); font-family: var(--sans); font-size: 14px; display: grid; place-items: center; }

/* ---- code tabs ---- */
.code-tabs { margin: 20px 0; border: 1px solid var(--ink); }
.code-tabbar { display: flex; background: var(--paper2); border-bottom: 1px solid var(--ink); font-family: var(--sans); font-size: 13px; }
.code-tabbar button { border: 0; background: transparent; padding: 10px 16px; cursor: pointer; font-family: var(--sans); color: var(--ink2); border-right: 1px solid var(--rule); }
.code-tabbar button.active { background: var(--ink); color: var(--paper); }
.code-body { margin: 0; padding: 18px 20px; font-family: var(--mono); font-size: 14px; line-height: 1.55; background: var(--term-bg); color: var(--term-fg); overflow-x: auto; white-space: pre; }

/* ---- quiz / options ---- */
.opts { display: grid; gap: 10px; margin: 8px 0 20px; }
.opt {
  display: flex; align-items: center; gap: 12px; padding: 14px 18px; border: 2px solid var(--rule);
  background: var(--paper); cursor: pointer; font-size: 17px; text-align: left; font-family: var(--serif);
}
.opt:hover { border-color: var(--ink3); }
.opt .key { font-family: var(--mono); font-size: 13px; width: 22px; height: 22px; border: 1px solid var(--ink3); display: grid; place-items: center; flex: none; color: var(--ink2); }
.opt.sel { border-color: var(--ink); }
.opt.correct { border-color: var(--ok); background: #eef3e8; }
.opt.wrong { border-color: var(--err); background: #f6ebe9; }

/* ---- fill ---- */
.fill-prompt { font-size: 22px; margin: 12px 0 18px; }
.fill-prompt .blank { display: inline-block; min-width: 90px; border-bottom: 2px solid var(--claude); }
.fill-input { font-family: var(--mono); font-size: 18px; padding: 12px 16px; border: 2px solid var(--ink); background: var(--paper); width: 100%; max-width: 320px; }

/* ---- sort / match ---- */
.sort-grid { display: grid; gap: 16px; margin: 16px 0; }
.sort-pool { display: flex; flex-wrap: wrap; gap: 10px; }
.chip { padding: 10px 16px; border: 2px solid var(--ink); background: var(--paper); cursor: pointer; font-family: var(--sans); font-size: 15px; }
.chip.sel { background: var(--claude); border-color: var(--claude); color: #fff; }
.chip.placed { opacity: .5; }
.ord-num { font-family: var(--mono); font-size: 12px; color: var(--claude-deep); font-weight: 600; }
.chip.sel .ord-num { color: #fff; }
.cats { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.cat { border: 2px dashed var(--rule); padding: 14px; min-height: 90px; }
.cat h4 { font-family: var(--sans); font-size: 13px; text-transform: uppercase; letter-spacing: .5px; margin: 0 0 10px; color: var(--ink2); }
.cat.ok { border-color: var(--ok); border-style: solid; }
.cat .chip { cursor: default; margin-bottom: 8px; display: block; }

.match-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.match-col { display: grid; gap: 10px; }
.match-item { padding: 14px 16px; border: 2px solid var(--rule); background: var(--paper); cursor: pointer; font-size: 16px; }
.match-item.sel { border-color: var(--claude); background: var(--light); }
.match-item.matched { border-color: var(--ok); background: #eef3e8; cursor: default; }

/* ---- feedback ---- */
.feedback { padding: 14px 18px; margin: 16px 0; border-left: 3px solid var(--ink3); background: var(--paper2); font-size: 16px; }
.feedback.ok { border-color: var(--ok); }
.feedback.no { border-color: var(--err); }

/* ---- terminal ---- */
.term-wrap { display: grid; grid-template-columns: 1fr; gap: 14px; margin: 18px 0; }
.term-wrap.has-fs { grid-template-columns: 1fr 220px; }
.term { background: var(--term-bg); border-radius: 8px; overflow: hidden; font-family: var(--mono); font-size: 14px; }
.term-bar { background: #2c2824; padding: 8px 12px; display: flex; align-items: center; gap: 7px; }
.term-bar i { width: 12px; height: 12px; border-radius: 50%; display: block; }
.term-bar .r { background: #ff5f57; } .term-bar .y { background: #febc2e; } .term-bar .g { background: #28c840; }
.term-bar span { color: var(--term-dim); font-size: 12px; margin-left: 8px; }
.term-body { padding: 14px; min-height: 160px; max-height: 360px; overflow-y: auto; color: var(--term-fg); line-height: 1.5; white-space: pre-wrap; word-break: break-word; }
.term-line .prompt { color: var(--term-green); }
.term-line .cmd { color: var(--term-fg); }
.term-out { color: var(--term-dim); }
.term-inrow { display: flex; align-items: center; padding: 0 14px 14px; }
.term-inrow .prompt { color: var(--term-green); font-family: var(--mono); font-size: 14px; white-space: nowrap; }
.term-input { flex: 1; background: transparent; border: 0; outline: 0; color: var(--term-fg); font-family: var(--mono); font-size: 14px; padding: 4px 6px; }
.palette { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 10px; }
.palette .pcmd { font-family: var(--mono); font-size: 12px; background: var(--paper2); border: 1px solid var(--rule); padding: 3px 8px; color: var(--ink2); }
.fs-tree { background: var(--paper2); border: 1px solid var(--rule); padding: 12px; font-family: var(--mono); font-size: 13px; }
.fs-tree h4 { font-family: var(--sans); font-size: 11px; text-transform: uppercase; letter-spacing: .5px; color: var(--ink3); margin: 0 0 8px; }
.fs-node { padding: 2px 0 2px 14px; color: var(--ink2); }
.fs-node.dir { color: var(--ink); font-weight: 600; }
.try-hint { font-family: var(--sans); font-size: 13px; color: var(--ink3); margin-top: 8px; }

/* ---- challenge ---- */
.challenge-brief { border: 2px solid var(--ink); padding: 18px 20px; margin: 16px 0; background: var(--paper2); }
.hints details { margin: 8px 0; font-family: var(--sans); font-size: 14px; }
.hints summary { cursor: pointer; color: var(--claude-deep); }

/* ---- complete screen ---- */
.complete { text-align: center; padding: 40px 0; }
.complete .big { font-family: var(--display); font-size: 56px; margin: 0 0 8px; }
.complete .stats { display: flex; justify-content: center; gap: 32px; margin: 28px 0; font-family: var(--sans); }
.complete .stat .v { font-size: 32px; font-family: var(--display); color: var(--claude-deep); }
.complete .stat .l { font-size: 12px; text-transform: uppercase; letter-spacing: 1px; color: var(--ink3); }

.actionbar { position: sticky; bottom: 0; background: var(--paper); border-top: 1px solid var(--rule); padding: 16px 24px; display: flex; justify-content: center; gap: 12px; }

/* ---- footer ---- */
.foot { border-top: 2px solid var(--ink); margin-top: 40px; padding: 24px; text-align: center; font-family: var(--sans); font-size: 13px; color: var(--ink3); }

/* ---- mobile ---- */
@media (max-width: 720px) {
  body { font-size: 17px; }
  .term-wrap.has-fs { grid-template-columns: 1fr; }
  .fs-tree { order: -1; }
  .cats, .match-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 40px; }
  .complete .stats { gap: 18px; }
  .masthead nav { display: none; }
}