/* =========================================================
   AI 應用入門實戰 — main.css (Warm Paper)
   紙底 / 襯線標題 / 磚紅點綴 / 細線
   ========================================================= */

:root {
  color-scheme: light;

  --paper-50:  #FAF7F2;
  --paper-100: #F4EFE6;
  --paper-200: #E9E1D2;
  --paper-300: #D6CAB3;

  --ink-900: #1A1714;
  --ink-700: #44403A;
  --ink-500: #78716C;
  --ink-300: #A8A29E;

  --brick-600: #B14B3D;
  --brick-500: #C8604F;
  --brick-100: #F2D9D2;
  --brick-50:  #FAEDE8;

  --r-sm: 2px;
  --r-md: 4px;
  --r-lg: 6px;

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --t-base: 200ms;
}

html { scroll-behavior: smooth; }

body {
  font-family: "Noto Sans TC", system-ui, sans-serif;
  background-color: var(--paper-50);
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.10 0 0 0 0 0.09 0 0 0 0 0.08 0 0 0 0.04 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  background-attachment: fixed;
  color: var(--ink-900);
  font-feature-settings: "palt" 1;
  -webkit-font-smoothing: antialiased;
}

.page-shell { min-height: 100vh; display: flex; flex-direction: column; }

/* Type */
.font-serif-tc { font-family: "Noto Serif TC", "Source Han Serif TC", serif; }
.font-mono     { font-family: "JetBrains Mono", ui-monospace, monospace; }

.type-display {
  font-family: "Noto Serif TC", "Source Han Serif TC", serif;
  font-weight: 900;
  font-size: clamp(2.4rem, 5vw, 4rem);
  line-height: 1.18;
  letter-spacing: -0.01em;
}
.type-h1 {
  font-family: "Noto Serif TC", "Source Han Serif TC", serif;
  font-weight: 900;
  font-size: clamp(1.9rem, 3.5vw, 2.6rem);
  line-height: 1.25;
}
.type-h2 {
  font-family: "Noto Serif TC", "Source Han Serif TC", serif;
  font-weight: 900;
  font-size: clamp(1.5rem, 2.4vw, 1.95rem);
  line-height: 1.3;
}
.type-h3 {
  font-family: "Noto Serif TC", "Source Han Serif TC", serif;
  font-weight: 700;
  font-size: 1.2rem;
  line-height: 1.45;
}
.type-lead { font-size: 1.125rem; line-height: 1.85; color: var(--ink-700); }
.type-body { font-size: 1rem; line-height: 1.85; color: var(--ink-700); }
.type-small { font-size: 0.875rem; line-height: 1.7; color: var(--ink-500); }
.type-meta {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.72rem; font-weight: 700; line-height: 1.4;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--brick-600);
}

/* Lines */
.rule         { height: 1px; background: var(--paper-200); }
.rule-strong  { height: 1px; background: var(--ink-900); }
.rule-dotted  { height: 1px; background-image: linear-gradient(to right, var(--paper-300) 50%, transparent 50%); background-size: 8px 1px; background-repeat: repeat-x; background-color: transparent; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.85rem 1.6rem;
  font-weight: 700;
  font-size: 0.95rem;
  transition: all var(--t-base) var(--ease);
  cursor: pointer; white-space: nowrap;
  border-radius: 9999px;
}
.btn-primary { background: var(--ink-900); color: var(--paper-50); border: 1px solid var(--ink-900); }
.btn-primary:hover { background: var(--brick-600); border-color: var(--brick-600); }
.btn-secondary { background: transparent; color: var(--ink-900); border: 1px solid var(--ink-900); }
.btn-secondary:hover { background: var(--ink-900); color: var(--paper-50); }
.btn .arrow { transition: transform var(--t-base) var(--ease); }
.btn:hover .arrow, a:hover .arrow { transform: translateX(3px); }

/* Tag */
.tag {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.25rem 0.6rem;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--ink-900);
  background: transparent;
  border: 1px solid var(--ink-900);
  border-radius: 0;
}
.tag-brick { color: var(--brick-600); border-color: var(--brick-600); }
.tag-ghost { color: var(--ink-500); border-color: var(--paper-300); }

/* Module Card */
.module-card {
  display: flex; flex-direction: column;
  height: 100%;
  padding: 1.75rem;
  background: var(--paper-50);
  border: 1px solid var(--paper-200);
  border-radius: var(--r-md);
  transition: all var(--t-base) var(--ease);
  position: relative;
}
.module-card:hover { border-color: var(--ink-900); background: #fff; }
.module-card .num {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.72rem; font-weight: 800; letter-spacing: 0.2em;
  color: var(--brick-600);
  text-transform: uppercase;
}
.module-card h3 {
  margin-top: 0.85rem;
  font-family: "Noto Serif TC", "Source Han Serif TC", serif;
  font-weight: 900; font-size: 1.3rem; line-height: 1.4;
  color: var(--ink-900);
}
.module-card .desc { margin-top: 0.85rem; font-size: 0.9rem; line-height: 1.75; color: var(--ink-700); }
.module-card .meta-row {
  margin-top: auto; padding-top: 1.2rem;
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.8rem; color: var(--ink-500);
  border-top: 1px solid var(--paper-200);
}
.module-card .enter {
  display: inline-flex; align-items: center; gap: 0.35rem;
  font-weight: 700; color: var(--ink-900);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  letter-spacing: 0.08em; font-size: 0.78rem;
  text-transform: uppercase;
}
.module-card:hover .enter { color: var(--brick-600); }

/* Stage Roadmap */
.roadmap { position: relative; }
.roadmap-line {
  position: absolute; left: 0; right: 0; top: 2.5rem;
  height: 1px;
  background-image: linear-gradient(to right, var(--paper-300) 50%, transparent 50%);
  background-size: 10px 1px; background-repeat: repeat-x;
  z-index: 0;
}
@media (max-width: 767px) { .roadmap-line { display: none; } }
.stage-pill {
  position: relative; z-index: 1;
  display: flex; flex-direction: column; align-items: center; text-align: center;
  padding: 0 0.5rem;
}
.stage-num {
  width: 5rem; height: 5rem;
  background: var(--paper-50);
  border: 1px solid var(--ink-900);
  display: flex; align-items: center; justify-content: center;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 1.4rem; font-weight: 800;
  color: var(--ink-900);
  transition: all var(--t-base) var(--ease);
  border-radius: 9999px;
}
.stage-pill:hover .stage-num { background: var(--brick-600); border-color: var(--brick-600); color: var(--paper-50); }
.stage-label { margin-top: 1rem; font-family: "Noto Serif TC", serif; font-size: 1.25rem; font-weight: 900; color: var(--ink-900); }
.stage-modules {
  margin-top: 0.35rem;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.7rem; letter-spacing: 0.14em;
  color: var(--brick-600); text-transform: uppercase;
}

/* Tool Workspace */
.tool-workspace {
  background: #fff; border: 1px solid var(--ink-900);
  border-radius: var(--r-sm); position: relative; overflow: hidden;
}
.tool-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid var(--ink-900);
  background: var(--paper-100);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.75rem; letter-spacing: 0.14em; text-transform: uppercase;
}
.tool-body { padding: 1.5rem; }

/* Code / Prompt block */
.code-block {
  position: relative;
  background: var(--ink-900); color: var(--paper-100);
  border-radius: var(--r-sm);
  padding: 2.4rem 1.25rem 1.25rem 1.25rem;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.8125rem; line-height: 1.85;
  overflow-x: auto;
  border: 1px solid var(--ink-900);
}
.code-block::before {
  content: attr(data-label);
  position: absolute; top: 0.6rem; left: 1rem;
  font-size: 0.65rem; font-weight: 700; letter-spacing: 0.22em;
  color: var(--brick-500); text-transform: uppercase;
}
.code-block::after {
  content: "";
  position: absolute; top: 0.85rem; right: 1rem;
  width: 1.5rem; height: 1px; background: var(--brick-500);
}

/* Practice block */
.practice-step {
  position: relative;
  background: var(--brick-50);
  border: 1px solid var(--brick-100);
  border-left: 3px solid var(--brick-600);
  border-radius: var(--r-sm);
  padding: 1.25rem 1.25rem 1.25rem 1.5rem;
}
.practice-step .step-num {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.7rem; font-weight: 800; letter-spacing: 0.16em;
  color: var(--brick-600); text-transform: uppercase;
}

/* Floating buttons (右下浮動鈕：Warm Paper 風格 — 細邊、無陰影、印刷感) */
.floating-btn {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.16em; text-transform: uppercase;
  padding: 0.7rem 1rem;
  background: var(--paper-50);
  color: var(--ink-900);
  border: 1px solid var(--ink-900);
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: all var(--t-base) var(--ease);
}
.floating-btn:hover { background: var(--ink-900); color: var(--paper-50); }
.floating-btn.is-primary { background: var(--ink-900); color: var(--paper-50); }
.floating-btn.is-primary:hover { background: var(--brick-600); border-color: var(--brick-600); }

/* AI Assistant widget — Warm Paper 化 */
.assistant-shell {
  background: var(--paper-50);
  border: 1px solid var(--ink-900);
  border-radius: var(--r-sm);
}
.assistant-shell header {
  background: var(--paper-100);
  border-bottom: 1px solid var(--ink-900);
  font-family: "JetBrains Mono", ui-monospace, monospace;
}
.assistant-open { transform: translateY(0) scale(1); opacity: 1; pointer-events: auto; }
.assistant-closed { transform: translateY(1rem) scale(0.98); opacity: 0; pointer-events: none; }

/* Glossary modal — Warm Paper 化 */
.glossary-card {
  background: var(--paper-50);
  border: 1px solid var(--paper-300);
  border-radius: var(--r-sm);
  padding: 1rem 1.1rem;
}
.glossary-card .term {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.7rem; font-weight: 800;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--brick-600);
}
.glossary-card .name {
  font-family: "Noto Serif TC", serif;
  font-weight: 900; font-size: 1.1rem;
  color: var(--ink-900);
  margin-top: 0.25rem;
}

/* A11y */
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--brick-600);
  outline-offset: 3px;
}

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

@media print {
  body { background: #fff; background-image: none; }
  [data-floating], #floating-glossary-button, #floating-ai-button, #glossary-modal, #ai-assistant-root { display: none !important; }
}