/* ─────────────────────────────────────────────
   StillRead-inspired palette · Light mode
   Editorial serif + clean sans
   ───────────────────────────────────────────── */

:root {
  /* Surfaces */
  --bg-base: #faf9fc;
  --bg-surface: #ffffff;
  --bg-sunken: #f3f3f7;
  --bg-hover: #ede8f0;

  /* Rose / plum accents (lifted from StillRead light) */
  --accent: #785561;
  --accent-ink: #563742;
  --accent-soft: #fed1df;
  --accent-tint: rgba(254, 209, 223, 0.50);
  --accent-tint-strong: rgba(254, 209, 223, 0.80);
  --accent-wash: #fdf1f5;

  /* Ink */
  --text-primary: #2f3337;
  --text-secondary: #5c5f64;
  --text-tertiary: #8a8a92;
  --text-on-accent: #fff7f7;

  /* Lines */
  --border: rgba(176, 178, 184, 0.32);
  --border-strong: rgba(120, 85, 97, 0.30);
  --border-soft: rgba(176, 178, 184, 0.18);

  /* Status */
  --success: #3a8a3a;
  --success-wash: rgba(58, 138, 58, 0.08);
  --warning: #b77d2a;
  --warning-wash: rgba(183, 125, 42, 0.10);
  --error: #a8364b;

  /* Metrics */
  --radius: 14px;
  --radius-sm: 10px;
  --radius-lg: 20px;
  --shadow-card: 0 1px 0 rgba(120, 85, 97, 0.04), 0 8px 24px rgba(60, 50, 55, 0.04);
  --shadow-elev: 0 1px 0 rgba(120, 85, 97, 0.06), 0 18px 48px rgba(60, 50, 55, 0.08);

  /* Type */
  --font-serif: "Source Serif 4", "Source Serif Pro", ui-serif, Georgia, "Times New Roman", serif;
  --font-sans: "Inter Tight", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --font-zh: "Noto Serif TC", var(--font-serif);

  /* Density (tweakable) */
  --pad-card: 28px;
  --pad-row: 18px;
  --gap-stack: 28px;
}

:root[data-density="compact"] {
  --pad-card: 18px;
  --pad-row: 12px;
  --gap-stack: 18px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }

body {
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-zh), var(--font-sans);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  line-height: 1.55;
}

.mono { font-family: var(--font-mono); font-feature-settings: "ss01"; }
.sans { font-family: var(--font-sans); }
.serif { font-family: var(--font-zh), var(--font-serif); }

/* ── App shell ─────────────────────────────── */
.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky; top: 0; z-index: 30;
  background: rgba(250, 249, 252, 0.82);
  backdrop-filter: saturate(1.4) blur(18px);
  -webkit-backdrop-filter: saturate(1.4) blur(18px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: 1240px; margin: 0 auto;
  padding: 14px 32px;
  display: flex; align-items: center; gap: 20px;
}
.brand {
  display: flex; align-items: baseline; gap: 10px;
  font-family: var(--font-serif);
  font-size: 20px; font-weight: 600; letter-spacing: -0.015em;
  color: var(--accent-ink);
}
.brand .brand-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  display: inline-block;
  transform: translateY(-2px);
}
.brand .sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-tertiary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-left: 12px;
  border-left: 1px solid var(--border);
}

.nav {
  display: flex; align-items: center; gap: 4px;
  font-family: var(--font-sans);
  font-size: 13px;
}
.nav button {
  background: transparent; border: none; cursor: pointer;
  padding: 7px 14px; border-radius: 9999px;
  color: var(--text-secondary);
  font: inherit;
  transition: background .18s, color .18s;
}
.nav button:hover { background: var(--bg-hover); color: var(--text-primary); }
.nav button.active {
  background: var(--accent-tint);
  color: var(--accent-ink);
}
.topbar-controls {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 12px;
}
.lang-seg {
  display: inline-flex;
  align-items: center;
  background: var(--bg-sunken);
  border-radius: 9999px;
  padding: 3px;
  gap: 2px;
}
.lang-seg button {
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 5px 11px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-tertiary);
  border-radius: 9999px;
  transition: background .15s, color .15s;
  min-width: 32px;
}
.lang-seg button:hover { color: var(--text-primary); }
.lang-seg button.active {
  background: var(--bg-surface);
  color: var(--accent-ink);
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}
.participant-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0;
  text-transform: none;
  color: var(--accent-ink);
  background: var(--accent-tint);
  padding: 2px 4px 2px 9px;
  border-radius: 999px;
  border-left: none;
}
.participant-chip .round-badge {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  padding: 1px 6px;
  border-radius: 999px;
  background: var(--bg-surface);
  color: var(--accent);
  border: 1px solid var(--accent);
}
.participant-chip .switch-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: none;
  background: transparent;
  color: var(--accent-ink);
  cursor: pointer;
  font-size: 14px;
  line-height: 1;
  padding: 0;
  opacity: 0.55;
  transition: opacity .15s, background .15s;
}
.participant-chip .switch-btn:hover {
  background: var(--accent-soft);
  opacity: 1;
}

/* ── Main canvas ──────────────────────────── */
.canvas {
  flex: 1;
  max-width: 1240px;
  width: 100%;
  margin: 0 auto;
  padding: 40px 32px 80px;
}
.canvas-compact { padding: 18px 32px 18px; }

/* ── View header (above each screen) ──────── */
.view-head {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 24px; margin-bottom: 32px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 22px;
}
.view-head .eyebrow {
  font-family: var(--font-mono); font-size: 10.5px;
  color: var(--text-tertiary);
  letter-spacing: 0.12em; text-transform: uppercase;
  margin-bottom: 8px;
}
.view-head h1 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 34px;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--text-primary);
}
.view-head h1 em {
  color: var(--accent);
  font-style: italic;
  font-weight: 400;
}
.view-head .lede {
  max-width: 380px;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ── Card primitives ──────────────────────── */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.callout {
  border: 1px solid var(--border-strong);
  background: var(--accent-wash);
  color: var(--accent-ink);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 13px;
  line-height: 1.6;
  display: flex; align-items: flex-start; gap: 12px;
}
.callout .tag {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  background: var(--accent);
  color: var(--text-on-accent);
  padding: 3px 8px;
  border-radius: 999px;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ── Buttons ──────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font-sans);
  font-size: 13px; font-weight: 500;
  padding: 9px 16px;
  border-radius: 9999px;
  border: 1px solid var(--border);
  background: var(--bg-surface);
  color: var(--text-primary);
  cursor: pointer;
  transition: background .18s, border-color .18s, color .18s, transform .08s;
  white-space: nowrap;
}
.btn:hover { background: var(--bg-hover); }
.btn:active { transform: translateY(1px); }
.btn[disabled] { opacity: 0.4; cursor: not-allowed; }

.btn-primary {
  background: var(--accent);
  color: var(--text-on-accent);
  border-color: var(--accent);
}
.btn-primary:hover { background: var(--accent-ink); border-color: var(--accent-ink); }

.btn-ghost { border-color: transparent; background: transparent; color: var(--text-secondary); }
.btn-ghost:hover { background: var(--bg-hover); color: var(--text-primary); }

.btn-icon {
  width: 32px; height: 32px; padding: 0;
  border-radius: 9999px;
}

/* ── Tweaks panel ─────────────────────────── */
.tweaks-panel {
  position: fixed; right: 24px; bottom: 24px;
  width: 280px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-elev);
  padding: 18px;
  font-family: var(--font-sans);
  font-size: 13px;
  z-index: 60;
}
.tweaks-panel h4 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 15px;
  margin-bottom: 14px;
  color: var(--accent-ink);
  display: flex; align-items: center; justify-content: space-between;
}
.tweaks-panel h4 .tag {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  color: var(--text-tertiary);
  background: var(--bg-sunken);
  padding: 3px 8px;
  border-radius: 999px;
  text-transform: uppercase;
}
.tweak-row { margin-bottom: 14px; }
.tweak-row:last-child { margin-bottom: 0; }
.tweak-row .label {
  font-size: 11px;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-family: var(--font-mono);
  margin-bottom: 6px;
}
.seg {
  display: grid; grid-template-columns: 1fr 1fr;
  background: var(--bg-sunken);
  border-radius: 9999px;
  padding: 3px;
  gap: 2px;
}
.seg button {
  background: transparent; border: none; cursor: pointer;
  padding: 6px 10px;
  font: inherit;
  font-size: 12px;
  color: var(--text-secondary);
  border-radius: 9999px;
  transition: background .15s, color .15s;
}
.seg button.active {
  background: var(--bg-surface);
  color: var(--accent-ink);
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}

/* ── Subdued type helpers ─────────────────── */
.muted { color: var(--text-secondary); }
.dim { color: var(--text-tertiary); }
.kbd {
  font-family: var(--font-mono);
  font-size: 10.5px;
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 1px 6px;
  color: var(--text-secondary);
}

/* ── Welcome screen ───────────────────────── */
.welcome-canvas {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 60px 32px 80px;
}
.welcome-card {
  max-width: 580px;
  width: 100%;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 44px 48px;
  box-shadow: var(--shadow-elev);
}
.welcome-card .eyebrow {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-tertiary);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.welcome-card h1 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 38px;
  letter-spacing: -0.025em;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: 22px;
}
.welcome-card h1 em {
  font-style: italic;
  color: var(--accent);
  font-weight: 400;
}
.welcome-card p {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 14px;
}
.welcome-card p strong { color: var(--text-primary); font-weight: 500; }
.welcome-card ul {
  list-style: none;
  padding: 0;
  margin: 0 0 20px;
}
.welcome-card ul li {
  padding: 12px 16px;
  background: var(--bg-sunken);
  border-radius: 10px;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-primary);
  line-height: 1.5;
  margin-bottom: 8px;
}
.welcome-card ul li strong {
  color: var(--accent-ink);
  font-weight: 600;
  margin-right: 4px;
}
.welcome-card ul.welcome-tips {
  margin: 4px 0 24px;
}
.welcome-card ul.welcome-tips li {
  background: transparent !important;
  padding: 2px 0 2px 16px !important;
  position: relative;
  font-size: 12.5px;
  color: var(--text-secondary);
  margin-bottom: 4px;
  line-height: 1.55;
  border-radius: 0;
}
.welcome-card ul.welcome-tips li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--text-tertiary);
  font-weight: 700;
}
.welcome-card label {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-tertiary);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: 24px;
  margin-bottom: 8px;
}
.welcome-card input {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font-family: var(--font-sans);
  font-size: 16px;
  color: var(--text-primary);
  background: var(--bg-surface);
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
.welcome-card input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-tint);
}
.welcome-card .welcome-start {
  margin-top: 22px;
  width: 100%;
  padding: 14px;
  font-size: 15px;
}

@media (max-width: 860px) {
  .topbar-inner {
    padding: 8px 14px;
    flex-wrap: wrap;
    gap: 8px 10px;
    row-gap: 6px;
  }
  .brand {
    font-size: 17px;
    gap: 8px;
    flex: 1 1 auto;
    min-width: 0;
  }
  .brand .sub { display: none; }
  .participant-chip {
    font-size: 10.5px;
    padding: 2px 4px 2px 8px;
  }
  .topbar-controls {
    width: 100%;
    justify-content: flex-start;
    gap: 8px;
  }
  .nav {
    flex: 1;
    min-width: 0;
    overflow-x: auto;
    font-size: 12px;
  }
  .nav button { padding: 5px 11px; }
  .topbar-controls .lang-seg {
    margin-left: auto;
    flex-shrink: 0;
  }
  .canvas {
    padding: 28px 16px 60px;
  }
  .canvas-compact {
    padding: 12px 14px 14px;
  }
  .welcome-canvas {
    padding: 36px 16px 48px;
  }
  .welcome-card {
    padding: 28px 24px;
  }
  .welcome-card h1 {
    font-size: 32px;
  }
  .welcome-lang {
    align-items: flex-start;
    flex-direction: column;
  }
}

/* ── Scrollbar (webkit) ───────────────────── */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 999px; border: 2px solid var(--bg-base); }
::-webkit-scrollbar-thumb:hover { background: var(--border-strong); }