/* Trading academy — styles.
 *
 * DESIGN-RULES.md: solid backgrounds only. No grid, no dot-grid, no mesh, no noise,
 * no gradients. The chart is the one place with visual complexity and it earns that by
 * carrying real data; everything around it stays flat so the candles are the only thing
 * competing for attention.
 *
 * Sentence case everywhere. No exclamation marks. tabular-nums on every number that is
 * read down a column.
 */

:root {
  --bg: #ffffff;
  --surface: #f6f7f9;
  --surface-2: #eef0f4;
  --line: #e2e5ea;
  --line-strong: #ccd1d9;
  --ink: #12151a;
  --ink-2: #4a5260;
  --ink-3: #79818f;
  --accent: #1d4ed8;
  --accent-ink: #ffffff;
  --ok: #15803d;
  --warn: #b45309;
  --bad: #b91c1c;
  --locked: #8b93a1;

  --badge-verified-bg: #dcfce7;  --badge-verified-ink: #14532d;
  --badge-measured-bg: #dbeafe;  --badge-measured-ink: #1e3a8a;
  --badge-mech-bg: #ede9fe;      --badge-mech-ink: #4c1d95;
  --badge-std-bg: #f1f3f6;       --badge-std-ink: #3f4653;
  --badge-folk-bg: #fee2e2;      --badge-folk-ink: #7f1d1d;

  --chart-bg: #ffffff;
  --chart-rule: #eef0f4;
  --chart-axis: #79818f;
  --chart-up: #15803d;
  --chart-down: #b91c1c;
  --chart-zone: #1d4ed8;
  --chart-answer: #15803d;
  --chart-user: #b45309;
  --chart-liq: #b91c1c;
  --chart-level: #79818f;
  --chart-marker: #1d4ed8;
  --chart-hidden: #ccd1d9;

  --radius: 10px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1116;
    --surface: #161a21;
    --surface-2: #1d222b;
    --line: #252b35;
    --line-strong: #333a46;
    --ink: #e8eaee;
    --ink-2: #a8b0bd;
    --ink-3: #7b8391;
    --accent: #5b8def;
    --accent-ink: #0e1116;
    --ok: #4ade80;
    --warn: #fbbf24;
    --bad: #f87171;
    --locked: #5a626f;

    --badge-verified-bg: #14321f; --badge-verified-ink: #86efac;
    --badge-measured-bg: #16243f; --badge-measured-ink: #93c5fd;
    --badge-mech-bg: #241a3d;     --badge-mech-ink: #c4b5fd;
    --badge-std-bg: #1d222b;      --badge-std-ink: #a8b0bd;
    --badge-folk-bg: #3b1616;     --badge-folk-ink: #fca5a5;

    --chart-bg: #0e1116;
    --chart-rule: #1c222b;
    --chart-axis: #7b8391;
    --chart-up: #4ade80;
    --chart-down: #f87171;
    --chart-zone: #5b8def;
    --chart-answer: #4ade80;
    --chart-user: #fbbf24;
    --chart-liq: #f87171;
    --chart-level: #7b8391;
    --chart-marker: #5b8def;
    --chart-hidden: #333a46;
  }
}

:root[data-theme="dark"] {
  --bg: #0e1116; --surface: #161a21; --surface-2: #1d222b;
  --line: #252b35; --line-strong: #333a46;
  --ink: #e8eaee; --ink-2: #a8b0bd; --ink-3: #7b8391;
  --accent: #5b8def; --accent-ink: #0e1116;
  --ok: #4ade80; --warn: #fbbf24; --bad: #f87171; --locked: #5a626f;
  --badge-verified-bg: #14321f; --badge-verified-ink: #86efac;
  --badge-measured-bg: #16243f; --badge-measured-ink: #93c5fd;
  --badge-mech-bg: #241a3d;     --badge-mech-ink: #c4b5fd;
  --badge-std-bg: #1d222b;      --badge-std-ink: #a8b0bd;
  --badge-folk-bg: #3b1616;     --badge-folk-ink: #fca5a5;
  --chart-bg: #0e1116; --chart-rule: #1c222b; --chart-axis: #7b8391;
  --chart-up: #4ade80; --chart-down: #f87171; --chart-zone: #5b8def;
  --chart-answer: #4ade80; --chart-user: #fbbf24; --chart-liq: #f87171;
  --chart-level: #7b8391; --chart-marker: #5b8def; --chart-hidden: #333a46;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------------------------------------------------------------- app shell */

.app { display: flex; min-height: 100vh; }

.side {
  width: 264px; flex: 0 0 264px;
  background: var(--surface);
  border-right: 1px solid var(--line);
  padding: 20px 0;
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
}

.brand { padding: 0 20px 16px; border-bottom: 1px solid var(--line); margin-bottom: 12px; }
.brand h1 { font-size: 15px; margin: 0; font-weight: 650; letter-spacing: -0.01em; }
.brand p { font-size: 12px; color: var(--ink-3); margin: 3px 0 0; }

.nav { padding: 0 10px; }
.nav a {
  display: flex; align-items: center; gap: 9px;
  padding: 8px 10px; border-radius: 8px;
  color: var(--ink-2); font-size: 14px; font-weight: 500;
}
.nav a:hover { background: var(--surface-2); text-decoration: none; }
.nav a.on { background: var(--accent); color: var(--accent-ink); }
.nav .sep { height: 1px; background: var(--line); margin: 10px 12px; }

.main { flex: 1; min-width: 0; padding: 32px 40px 80px; max-width: 920px; }

.topbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 24px; }
.topbar h2 { margin: 0; font-size: 24px; letter-spacing: -0.02em; font-weight: 650; }
.topbar .sub { color: var(--ink-3); font-size: 14px; margin-top: 2px; }

/* ------------------------------------------------------------------ pieces */

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}
.card + .card { margin-top: 12px; }

.grid { display: grid; gap: 12px; }
.grid.two { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid.three { grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); }

.badge {
  display: inline-block; padding: 2px 8px; border-radius: 999px;
  font-size: 11px; font-weight: 650; letter-spacing: 0.01em;
  background: var(--badge-std-bg); color: var(--badge-std-ink);
  white-space: nowrap;
}
.badge.verified { background: var(--badge-verified-bg); color: var(--badge-verified-ink); }
.badge.measured { background: var(--badge-measured-bg); color: var(--badge-measured-ink); }
.badge.mechanical { background: var(--badge-mech-bg); color: var(--badge-mech-ink); }
.badge.folklore { background: var(--badge-folk-bg); color: var(--badge-folk-ink); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 7px;
  min-height: 40px; padding: 0 16px;
  border-radius: 8px; border: 1px solid var(--line-strong);
  background: var(--surface-2); color: var(--ink);
  font-family: inherit; font-size: 14px; font-weight: 600;
  cursor: pointer;
}
.btn:hover { border-color: var(--ink-3); }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn.primary:hover { filter: brightness(1.08); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn.sm { min-height: 32px; padding: 0 11px; font-size: 13px; }

.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.spacer { flex: 1; }

.num, .stat b, table td.num, .mono { font-variant-numeric: tabular-nums; font-family: var(--mono); }

.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; }
.stat span { display: block; font-size: 12px; color: var(--ink-3); margin-bottom: 4px; }
.stat b { font-size: 21px; font-weight: 650; letter-spacing: -0.01em; }
.stat.ok b { color: var(--ok); } .stat.bad b { color: var(--bad); } .stat.warn b { color: var(--warn); }

.bar { height: 5px; background: var(--surface-2); border-radius: 999px; overflow: hidden; }
.bar i { display: block; height: 100%; background: var(--accent); }

/* ------------------------------------------------------------------- tiers */

.tier { border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); margin-bottom: 12px; overflow: hidden; }
.tier > header { display: flex; align-items: center; gap: 14px; padding: 16px 20px; cursor: pointer; }
.tier > header:hover { background: var(--surface-2); }
.tier .no { width: 30px; height: 30px; flex: 0 0 30px; border-radius: 8px; background: var(--surface-2); color: var(--ink-2); display: grid; place-items: center; font-weight: 700; font-size: 13px; font-variant-numeric: tabular-nums; }
.tier.open-t .no { background: var(--accent); color: var(--accent-ink); }
.tier h3 { margin: 0; font-size: 16px; font-weight: 620; }
.tier .blurb { font-size: 13px; color: var(--ink-3); margin-top: 2px; }
.tier.locked { opacity: 0.72; }
.tier .lock { font-size: 12px; color: var(--locked); font-weight: 600; }
.tier ol { list-style: none; margin: 0; padding: 0 0 8px; border-top: 1px solid var(--line); }
.tier li { display: block; margin: 0; padding: 0; }
.tier .lesson-link { display: flex; align-items: center; gap: 12px; padding: 9px 20px 9px 64px; font-size: 14px; color: inherit; text-decoration: none; width: 100%; box-sizing: border-box; }
.tier a.lesson-link:hover { background: var(--surface-2); }
.tier li .n { color: var(--ink-3); font-variant-numeric: tabular-nums; font-size: 12px; width: 18px; }
.tier li .t { flex: 1; color: var(--ink); }
.tier li.read .t::after { content: '  ✓'; color: var(--ok); font-weight: 700; }
.tier li .m { color: var(--ink-3); font-size: 12px; font-variant-numeric: tabular-nums; }

.gate { background: var(--surface-2); border-top: 1px solid var(--line); padding: 12px 20px; font-size: 13px; color: var(--ink-2); }
.gate b { color: var(--ink); }

/* ------------------------------------------------------------------ lesson */

.lesson { max-width: 74ch; }
.lesson h2 { font-size: 19px; margin: 32px 0 10px; letter-spacing: -0.01em; }
.lesson h3 { font-size: 16px; margin: 24px 0 8px; }
.lesson p { margin: 0 0 14px; color: var(--ink); }
.lesson ul, .lesson ol { margin: 0 0 14px; padding-left: 22px; }
.lesson li { margin-bottom: 5px; }
.lesson hr { border: 0; border-top: 1px solid var(--line); margin: 28px 0; }
.lesson code { background: var(--surface-2); padding: 1px 5px; border-radius: 4px; font-family: var(--mono); font-size: 0.88em; }
.lesson pre.code { background: var(--surface); border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px; overflow-x: auto; font-size: 13px; line-height: 1.5; }
.lesson pre.code code { background: none; padding: 0; }
.lesson blockquote { margin: 18px 0; padding: 12px 18px; border-left: 3px solid var(--accent); background: var(--surface); border-radius: 0 8px 8px 0; }
.lesson blockquote p:last-child { margin-bottom: 0; }
.tw { overflow-x: auto; margin: 0 0 16px; }
.lesson table { border-collapse: collapse; width: 100%; font-size: 14px; }
.lesson th, .lesson td { border: 1px solid var(--line); padding: 7px 11px; text-align: left; vertical-align: top; }
.lesson th { background: var(--surface-2); font-weight: 620; }
.lesson td.num { text-align: right; }
.checklist { list-style: none; padding-left: 0; }
.checklist li.check { display: flex; gap: 9px; align-items: flex-start; }
.checklist .box { width: 15px; height: 15px; flex: 0 0 15px; margin-top: 4px; border: 1.5px solid var(--line-strong); border-radius: 4px; }
.checklist .box.on { background: var(--ok); border-color: var(--ok); }
.reveal { border: 1px solid var(--line); border-radius: 8px; padding: 10px 14px; margin: 0 0 14px; background: var(--surface); }
.reveal summary { cursor: pointer; font-weight: 600; }

/* ------------------------------------------------------------------- drill */

.chartwrap { background: var(--chart-bg); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
canvas.chart { display: block; width: 100%; height: 420px; touch-action: none; }

.opts { display: flex; gap: 8px; flex-wrap: wrap; }
.opt { flex: 1; min-width: 110px; min-height: 48px; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--surface); color: var(--ink); font: inherit; font-weight: 600; cursor: pointer; }
.opt:hover { border-color: var(--accent); }
.opt.sel { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.opt.right { background: var(--ok); border-color: var(--ok); color: #fff; }
.opt.wrong { background: var(--bad); border-color: var(--bad); color: #fff; }

.ev { display: flex; gap: 9px; align-items: flex-start; padding: 9px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); cursor: pointer; font-size: 14px; margin-bottom: 7px; }
.ev.sel { border-color: var(--accent); background: var(--surface-2); }
.ev .box { width: 15px; height: 15px; flex: 0 0 15px; margin-top: 4px; border: 1.5px solid var(--line-strong); border-radius: 4px; }
.ev.sel .box { background: var(--accent); border-color: var(--accent); }
.ev.miss { border-color: var(--warn); }

.feedback { border-radius: var(--radius); padding: 14px 16px; margin-top: 12px; border: 1px solid var(--line); background: var(--surface); }
.feedback.ok { border-color: var(--ok); }
.feedback.no { border-color: var(--bad); }
.feedback h4 { margin: 0 0 6px; font-size: 14px; }
.feedback p { margin: 0 0 6px; font-size: 14px; color: var(--ink-2); }
.feedback p:last-child { margin-bottom: 0; }

input[type="text"], input[type="email"], input[type="number"], textarea, select {
  background: var(--bg); color: var(--ink);
  border: 1px solid var(--line-strong); border-radius: 8px;
  padding: 9px 11px; font: inherit; font-size: 14px; width: 100%;
}
input[type="number"], input.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
textarea { min-height: 150px; resize: vertical; line-height: 1.5; }
label.f { display: block; font-size: 12px; color: var(--ink-3); margin-bottom: 4px; font-weight: 600; }

.empty { text-align: center; padding: 48px 20px; color: var(--ink-3); }
.note { font-size: 13px; color: var(--ink-3); }

/* ------------------------------------------------------------ enrollment & auth */

.student-tag {
  display: none;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  color: var(--ink-2);
  margin-top: 8px;
  padding: 4px 8px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.student-tag.active { display: flex; }
.student-tag .dot {
  width: 6px; height: 6px; border-radius: 999px;
  background: var(--ok); flex: 0 0 6px;
}
.student-tag .email-text {
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}

.enroll-wrap {
  max-width: 480px;
  margin: 32px auto 60px;
}
.enroll-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
}
.enroll-card h3 {
  margin: 0 0 6px;
  font-size: 19px;
  font-weight: 650;
  letter-spacing: -0.01em;
}
.enroll-card p.intro {
  margin: 0 0 20px;
  font-size: 14px;
  color: var(--ink-2);
  line-height: 1.5;
}
.otp-input {
  font-size: 24px !important;
  font-weight: 700;
  letter-spacing: 6px;
  text-align: center;
  font-family: var(--mono) !important;
  font-variant-numeric: tabular-nums;
  padding: 10px 14px !important;
}
.enroll-feedback {
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 13px;
  margin-top: 14px;
  line-height: 1.4;
}
.enroll-feedback.err {
  border: 1px solid var(--bad);
  background: var(--surface-2);
  color: var(--bad);
}
.enroll-feedback.ok {
  border: 1px solid var(--ok);
  background: var(--surface-2);
  color: var(--ok);
}
.email-badge {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 6px;
  margin-bottom: 18px;
  font-size: 13px;
  color: var(--ink-2);
}
.email-badge b {
  color: var(--ink);
  font-family: var(--mono);
  font-weight: 600;
}
.enroll-divider {
  display: flex;
  align-items: center;
  text-align: center;
  margin: 18px 0;
  color: var(--ink-3);
  font-size: 12px;
}
.enroll-divider::before,
.enroll-divider::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid var(--line);
}
.enroll-divider span {
  padding: 0 10px;
}
.btn.text {
  background: transparent;
  border: 0;
  color: var(--accent);
  padding: 2px 6px;
  min-height: auto;
  font-size: 12px;
  cursor: pointer;
}
.btn.text:hover {
  text-decoration: underline;
}
.btn.full {
  width: 100%;
}

/* ----------------------------------------------------------------- mobile */

@media (max-width: 860px) {
  .app { flex-direction: column; }
  .side { width: 100%; flex: none; height: auto; position: static; border-right: 0; border-bottom: 1px solid var(--line); padding: 14px 0; }
  .nav { display: flex; gap: 6px; overflow-x: auto; padding: 0 16px; }
  .nav .sep { display: none; }
  /* 44px minimum tap target — the desktop 38px fails on a phone */
  .nav a { white-space: nowrap; min-height: 44px; padding: 0 14px; }
  .brand { padding: 0 16px 12px; }
  .main { padding: 20px 16px 64px; }
  .topbar h2 { font-size: 20px; }
  canvas.chart { height: 320px; }
  .tier li { padding-left: 20px; }

  /* 44px minimum on every control that a thumb has to hit. The desktop sizes
   * (40px buttons, 32px small buttons, 42px inputs and rows) all fail on a phone,
   * and they failed identically in WebKit and Chromium — layout, not engine. */
  .btn, .btn.sm { min-height: 44px; }
  input[type="text"], input[type="email"], input[type="number"], select { min-height: 44px; }
  .ev { min-height: 44px; align-items: center; padding: 11px 12px; }
  .opt { min-height: 48px; }
  /* Links sitting in a row act as controls, so give them a target. Prose links
   * inside .lesson stay inline text and are deliberately excluded. */
  .card .row > a:not(.btn) { min-height: 44px; display: flex; align-items: center; }
}