/* platå · vocab-SR · headpage-v2 visual style */
:root {
  --bg: oklch(0.18 0.02 150);
  --bg-elev: oklch(0.22 0.025 150);
  --surface: oklch(0.25 0.03 150);
  --fg: oklch(0.94 0.015 80);
  --muted: oklch(0.66 0.02 80);
  --border: oklch(0.36 0.02 150);
  --accent: oklch(0.72 0.16 55);
  --accent-soft: oklch(0.72 0.16 55 / 0.18);
  --good: oklch(0.78 0.16 145);
  --bad: oklch(0.66 0.20 25);
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 0 oklch(0.10 0.02 150), 0 8px 24px oklch(0.10 0.02 150 / 0.4);
  --display-stack: "Fraunces", ui-serif, Georgia, serif;
  --body-stack: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono-stack: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { color-scheme: dark; }
body {
  background: radial-gradient(ellipse at top, oklch(0.22 0.03 150) 0%, var(--bg) 50%, oklch(0.14 0.02 150) 100%) fixed;
  color: var(--fg);
  font-family: var(--body-stack);
  font-size: 16px; line-height: 1.5;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
  min-height: 100dvh;
}

.app { max-width: 720px; margin: 0 auto; padding: 24px 20px 64px; display: flex; flex-direction: column; gap: 18px; }

.hdr { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.brand { display: flex; align-items: baseline; gap: 8px; text-decoration: none; color: var(--fg); font-family: var(--display-stack); font-weight: 600; letter-spacing: -0.01em; font-size: 20px; }
.brand-mark { color: var(--accent); font-size: 22px; line-height: 1; }
.brand-sep { color: var(--muted); font-weight: 400; }
.brand-sub { font-family: var(--body-stack); font-size: 13px; color: var(--muted); font-weight: 500; letter-spacing: 0.02em; }
.brand-sub .ver { font-family: var(--mono-stack); font-size: 11px; opacity: 0.7; margin-left: 4px; }
.hdr-actions { display: flex; gap: 4px; }
.icon-btn { width: 36px; height: 36px; background: transparent; color: var(--muted); border: 1px solid var(--border); border-radius: var(--radius-sm); font-family: var(--mono-stack); font-size: 16px; cursor: pointer; transition: color 120ms, background 120ms, border-color 120ms; }
.icon-btn:hover { color: var(--fg); background: var(--bg-elev); border-color: var(--accent); }

.stats { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; }
.stat { background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 10px 8px; text-align: center; display: flex; flex-direction: column; gap: 2px; }
.stat-num { font-family: var(--display-stack); font-size: 22px; font-weight: 600; color: var(--fg); line-height: 1; letter-spacing: -0.01em; }
.stat-label { font-family: var(--body-stack); font-size: 11px; color: var(--muted); letter-spacing: 0.04em; text-transform: uppercase; }

.pickers { display: flex; flex-direction: column; gap: 10px; padding: 14px; background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); }
.picker-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.picker-label { font-family: var(--mono-stack); font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; min-width: 64px; }
.chip-group { display: flex; gap: 6px; flex-wrap: wrap; }
.chip { background: transparent; color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 6px 14px; font-family: var(--body-stack); font-size: 13px; font-weight: 500; cursor: pointer; transition: color 120ms, background 120ms, border-color 120ms; }
.chip:hover { color: var(--fg); border-color: oklch(0.50 0.03 150); }
.chip[aria-selected="true"] { background: var(--accent-soft); color: var(--accent); border-color: var(--accent); }

.plan-context-card {
  padding: 16px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  display: grid;
  gap: 8px;
}
.plan-context-card.completed { border-left-color: var(--good); background: oklch(0.78 0.16 145 / 0.08); }
.plan-context-card .eyebrow {
  margin: 0;
  font-family: var(--mono-stack);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}
.plan-context-card h3 { margin: 0; font-family: var(--display-stack); font-size: 22px; line-height: 1.14; color: var(--fg); }
.plan-context-card p { margin: 0; color: var(--muted); line-height: 1.55; }
.plan-context-meta { display: flex; flex-wrap: wrap; gap: 6px; }
.plan-context-meta span {
  padding: 3px 8px;
  border: 1px solid var(--border);
  border-radius: 999px;
  font-family: var(--mono-stack);
  font-size: 11px;
  color: var(--accent);
}
.plan-context-link { color: var(--fg); font-weight: 700; text-decoration-color: var(--accent); text-underline-offset: 4px; }

.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px 24px; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 18px; min-height: 280px; }
.prompt-meta { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
#prompt-counter { font-family: var(--mono-stack); font-size: 13px; color: var(--muted); }
.meta-pill { font-family: var(--mono-stack); font-size: 11px; color: var(--muted); background: var(--bg-elev); padding: 4px 10px; border-radius: 999px; letter-spacing: 0.04em; }
.prompt { font-family: var(--display-stack); font-size: clamp(28px, 6vw, 38px); font-weight: 500; letter-spacing: -0.015em; color: var(--fg); margin: 0; line-height: 1.15; }
.prompt-hint { font-family: var(--body-stack); font-size: 13px; color: var(--muted); margin: 0; margin-top: -8px; font-style: italic; }
.answer-form { display: flex; gap: 8px; }
.answer-input { flex: 1; background: var(--bg); color: var(--fg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 14px; font-family: var(--mono-stack); font-size: 17px; outline: none; transition: border-color 120ms, background 120ms; }
.answer-input:focus { border-color: var(--accent); background: var(--bg-elev); }
.answer-input.correct { border-color: var(--good); background: oklch(0.78 0.16 145 / 0.08); }
.answer-input.wrong { border-color: var(--bad); background: oklch(0.66 0.20 25 / 0.08); }

.btn { font-family: var(--body-stack); font-size: 14px; font-weight: 500; padding: 12px 18px; border-radius: var(--radius-sm); border: 1px solid transparent; cursor: pointer; transition: background 120ms, color 120ms, border-color 120ms; }
.btn-primary { background: var(--accent); color: oklch(0.18 0.02 150); border-color: var(--accent); font-weight: 600; }
.btn-primary:hover { background: oklch(0.78 0.16 55); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-ghost { background: transparent; color: var(--fg); border-color: var(--border); }
.btn-ghost:hover { background: var(--bg-elev); border-color: var(--accent); }

.feedback { font-family: var(--body-stack); font-size: 14px; padding: 12px 14px; border-radius: var(--radius-sm); border: 1px solid var(--border); }
.feedback.good { color: var(--good); background: oklch(0.78 0.16 145 / 0.10); border-color: oklch(0.78 0.16 145 / 0.4); }
.feedback.bad { color: var(--bad); background: oklch(0.66 0.20 25 / 0.10); border-color: oklch(0.66 0.20 25 / 0.4); }
.feedback .correct-answer { font-family: var(--mono-stack); color: var(--fg); background: var(--bg); padding: 1px 6px; border-radius: 4px; margin-left: 4px; }
.feedback .alt { color: var(--muted); font-size: 12px; margin-top: 4px; }
.feedback .next-hint { color: var(--muted); font-size: 12px; margin-top: 6px; font-style: italic; }

.hidden { display: none !important; }

.summary-title { font-family: var(--display-stack); font-size: 28px; font-weight: 600; margin: 0; color: var(--fg); letter-spacing: -0.015em; }
.summary-line { margin: 0; color: var(--muted); font-size: 15px; }
.summary-line strong { color: var(--fg); font-weight: 600; font-family: var(--display-stack); font-size: 17px; }
.summary-acc { margin-top: 4px; }
.summary-mistakes { list-style: none; margin: 0; padding: 12px 14px; background: var(--bg-elev); border-radius: var(--radius-sm); border: 1px solid var(--border); display: flex; flex-direction: column; gap: 6px; max-height: 220px; overflow-y: auto; }
.summary-mistakes li { font-family: var(--mono-stack); font-size: 13px; color: var(--muted); }
.summary-mistakes li .given { color: var(--bad); text-decoration: line-through; }
.summary-mistakes li .right { color: var(--good); margin-left: 8px; }
.summary-mistakes li.empty { color: var(--muted); font-style: italic; font-family: var(--body-stack); }
.next-step-slot { display: block; }
.next-step-card {
  padding: 16px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.next-step-card.repeat { border-left-color: var(--bad); }
.next-step-card.enough { border-left-color: var(--good); }
.next-step-card .eyebrow {
  margin: 0;
  font-family: var(--mono-stack);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}
.next-step-card h3 {
  margin: 0;
  font-family: var(--display-stack);
  font-size: 22px;
  line-height: 1.14;
  color: var(--fg);
}
.next-step-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}
.next-step-card .next-step-meta {
  font-family: var(--mono-stack);
  font-size: 12px;
  color: var(--accent);
}
.next-step-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 2px; }
.next-step-card .link-button { text-decoration: none; }
.summary-actions { display: flex; gap: 8px; flex-wrap: wrap; }

.ftr { margin-top: 12px; padding-top: 16px; border-top: 1px solid var(--border); font-size: 12px; color: var(--muted); text-align: center; }
.ftr p { margin: 4px 0; }
.ftr a { color: var(--accent); text-decoration: none; }
.ftr a:hover { text-decoration: underline; }
.ftr-meta { font-family: var(--mono-stack); font-size: 11px; opacity: 0.7; }

@media (max-width: 540px) {
  .app { padding: 16px 14px 48px; gap: 14px; }
  .card { padding: 20px 16px; }
  .stats { grid-template-columns: repeat(5, 1fr); gap: 4px; }
  .stat { padding: 8px 4px; }
  .stat-num { font-size: 18px; }
  .stat-label { font-size: 10px; }
  .brand-sub { display: none; }
}

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition: none !important; } }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}