:root {
  --board: #1b222b;
  --ink: #f2efe2;
  --muted: #a8b2ba;
  --accent: #f2a37c;
  --accent2: #8fcdea;
  --paper: #f8f3e6;
  --paper-ink: #2c313a;
  --paper-line: #beb49c;
  --ok: #7dcea0;
  --btn: #d85a30;
  --btn-text: #fff;
  --panel: rgba(16, 21, 27, 0.78);
  --card: rgba(255, 255, 255, 0.06);
  --dash: rgba(242, 239, 226, 0.22);
  --border: rgba(255, 255, 255, 0.1);
  --glow: rgba(242, 163, 124, 0.12);
  transition: background-color 0.45s ease, color 0.35s ease;
}

/* Per-slide palettes — inspired by editorial deck systems (OD Guizang-style) */
.deck-shell[data-theme="dawn"] {
  --board: #1a1428;
  --ink: #fff6ef;
  --muted: #c9b8d4;
  --accent: #ff9a6b;
  --accent2: #ffd166;
  --paper: #fff8f2;
  --paper-ink: #3a2540;
  --paper-line: #e8c4b8;
  --ok: #8be0c2;
  --btn: #e85d4c;
  --panel: rgba(58, 28, 72, 0.55);
  --card: rgba(255, 154, 107, 0.12);
  --glow: rgba(255, 154, 107, 0.18);
}

.deck-shell[data-theme="indigo"] {
  --board: #0f1a2e;
  --ink: #eef4ff;
  --muted: #9eb3d4;
  --accent: #7eb6ff;
  --accent2: #b8a0ff;
  --paper: #f0f5ff;
  --paper-ink: #1a2a44;
  --paper-line: #a8bce0;
  --ok: #6ee7c8;
  --btn: #3b6fd9;
  --panel: rgba(20, 40, 80, 0.6);
  --card: rgba(126, 182, 255, 0.1);
  --glow: rgba(126, 182, 255, 0.16);
}

.deck-shell[data-theme="forest"] {
  --board: #0f1f18;
  --ink: #edf8f0;
  --muted: #9bc4ad;
  --accent: #7ddea0;
  --accent2: #f2d98b;
  --paper: #f4faf5;
  --paper-ink: #1f3d2e;
  --paper-line: #a8ccb4;
  --ok: #9cf0b8;
  --btn: #2d8a5e;
  --panel: rgba(24, 56, 42, 0.62);
  --card: rgba(125, 222, 160, 0.12);
  --glow: rgba(125, 222, 160, 0.18);
}

.deck-shell[data-theme="dune"] {
  --board: #2a2218;
  --ink: #faf3e8;
  --muted: #c9b89a;
  --accent: #e8a84a;
  --accent2: #e07a5f;
  --paper: #fff9ef;
  --paper-ink: #4a3728;
  --paper-line: #d4b896;
  --ok: #b8d48a;
  --btn: #c45c26;
  --panel: rgba(74, 55, 40, 0.58);
  --card: rgba(232, 168, 74, 0.14);
  --glow: rgba(232, 168, 74, 0.16);
}

* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; background: var(--board); color: var(--ink); font-family: "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif; font-size: clamp(18px, 1.15vw, 24px); }
button, input { font: inherit; }
button { border: 0; background: var(--btn); color: var(--btn-text); padding: .7rem 1rem; border-radius: 8px; cursor: pointer; font-weight: 700; transition: background 0.25s ease, transform 0.15s ease; }
button:hover { filter: brightness(1.08); }
input { border: 1.5px solid var(--paper-line); background: var(--paper); color: var(--paper-ink); padding: .7rem .85rem; border-radius: 8px; width: 100%; }
code { font-size: .9em; color: var(--accent2); }
.deck-shell {
  width: 100vw; height: 100svh;
  display: grid; grid-template-columns: 220px 1fr; grid-template-rows: minmax(0, 1fr) 58px;
  background: radial-gradient(ellipse 120% 80% at 100% 0%, var(--glow), transparent 55%), var(--board);
}
.toc { padding: 1rem; border-right: 1px solid var(--border); overflow: auto; }
.brand { display: flex; flex-direction: column; gap: .25rem; margin-bottom: 1rem; }
.brand strong { font-size: 1.1rem; }
.builder-badge { font-size: .75rem; color: var(--ok); }
.toc nav button { display: block; width: 100%; text-align: left; background: transparent; color: var(--muted); margin-bottom: .35rem; padding: .4rem .2rem; }
.toc nav button.active { color: var(--ink); font-weight: 700; }
.stage { min-width: 0; min-height: 0; overflow: hidden; }
.slide { display: none; height: calc(100svh - 58px); padding: clamp(1rem, 1.65vw, 2rem); overflow: hidden; gap: clamp(.7rem, 1vw, 1rem); }
.slide.active { display: grid; grid-template-rows: auto minmax(0, 1fr) auto; }
.title-slide.active { grid-template-rows: minmax(0, 1fr) auto; grid-template-columns: minmax(0, 55%) 1fr; align-items: center; }
.title-slide > div { grid-column: 1; grid-row: 1; }
.title-slide .hero-panel { grid-column: 1 / -1; grid-row: 2; display: grid; grid-template-columns: repeat(4, 1fr); gap: .6rem; }
.title-slide .hero-panel span { background: var(--panel); padding: .8rem; border-radius: 8px; text-align: center; border: 1px solid var(--border); }
.slide header { border-bottom: 2px dashed var(--dash); padding-bottom: .6rem; }
.eyebrow { color: var(--accent); margin: 0 0 .25rem; }
h1, h2 { margin: 0 0 .35rem; line-height: 1.15; }
.subtitle, .takeaway { color: var(--muted); margin: 0; }
.soil-frame { background: rgba(255,255,255,.05); padding: .75rem; border-radius: 8px; }
.flow-steps { display: grid; gap: .6rem; height: 100%; align-content: center; }
.flow-steps.four { grid-template-columns: repeat(4, 1fr); }
.flow-steps span { background: var(--card); padding: 1rem; border-radius: 8px; text-align: center; border: 1px solid var(--border); }
.number-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: .8rem; align-content: center; height: 100%; }
.number-grid article { background: var(--card); padding: 1rem; border-radius: 8px; border: 1px solid var(--border); }
.number-grid b { color: var(--accent); display: block; margin-bottom: .35rem; }
.wordcloud-stage { display: flex; flex-direction: column; min-height: 0; height: 100%; }
.inline-form { display: grid; grid-template-columns: 1fr auto; gap: .6rem; max-width: 640px; margin: 0 auto .8rem; width: 100%; }
.word-cloud { flex: 1; min-height: 0; border: 2px dashed var(--dash); border-radius: 12px; padding: 1rem; display: flex; flex-wrap: wrap; align-content: flex-start; gap: .5rem 1rem; overflow: auto; background: var(--card); }
.word-cloud span { color: var(--accent2); line-height: 1.2; }
.controls { grid-column: 1 / -1; display: flex; align-items: center; justify-content: center; gap: 1rem; border-top: 1px solid var(--border); }
.sync-state { font-size: .85rem; color: var(--muted); margin-top: 1rem; }
@media (max-width: 900px) {
  .deck-shell { grid-template-columns: 1fr; }
  .toc { display: none; }
  .title-slide.active { grid-template-columns: 1fr; }
  .flow-steps.four, .number-grid { grid-template-columns: 1fr; }
}