/* teaching.css — AI 跨領域應用 期中報告 成果展 */
:root {
  --bg: #fafaf7;
  --bg-2: #f4f3ee;
  --card: #ffffff;
  --fg: #1a1814;
  --fg-1: #2c2925;
  --fg-2: #6b6864;
  --fg-3: #a3a09a;
  --rule: rgba(26, 24, 20, 0.08);
  --rule-strong: rgba(26, 24, 20, 0.16);
  --accent: oklch(0.45 0.12 260);
  --accent-soft: oklch(0.94 0.04 260);
  --max: 1200px;
  --pad: clamp(20px, 4vw, 56px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0d0a;
    --bg-2: #16140f;
    --card: #1a1814;
    --fg: #f4f2ea;
    --fg-1: #d4cfc1;
    --fg-2: #8b8678;
    --fg-3: #4f4c46;
    --rule: rgba(244, 242, 234, 0.08);
    --rule-strong: rgba(244, 242, 234, 0.18);
    --accent: oklch(0.7 0.1 260);
    --accent-soft: oklch(0.18 0.03 260);
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html, body { overflow-x: hidden; max-width: 100%; }
body {
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.55 "Inter", "Noto Sans TC", system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  word-wrap: break-word;
  overflow-wrap: anywhere;
}
a { color: inherit; text-decoration: none; }
.muted { color: var(--fg-2); }

/* ── Header ──────────────────────────────────────────────────────────── */
.page-head {
  padding: 32px var(--pad) clamp(64px, 8vw, 96px);
  border-bottom: 1px solid var(--rule);
  position: relative;
  overflow: hidden;
}
.page-head::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 0% 0%, var(--accent-soft) 0, transparent 35%),
    radial-gradient(circle at 100% 100%, var(--accent-soft) 0, transparent 40%);
  opacity: .6;
  z-index: 0;
}
.page-head > * { position: relative; z-index: 1; }

.head-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: clamp(48px, 7vw, 80px);
}
.head-brand { display: flex; align-items: center; gap: 14px; }
.brand-mark {
  width: 42px; height: 42px;
  display: grid; place-items: center;
  position: relative;
}
.brand-mark img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.brand-mark-dot {
  position: absolute;
  right: -2px; bottom: -2px;
  width: 10px; height: 10px;
  background: var(--accent);
  border: 2px solid var(--bg);
  border-radius: 50%;
}
.brand-name { font-weight: 600; line-height: 1.2; letter-spacing: -0.005em; font-size: 14px; }
.brand-sub { font-size: 12px; color: var(--fg-2); margin-top: 2px; }

.lang-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font: inherit;
  font-size: 12px;
  border: 1px solid var(--rule-strong);
  border-radius: 999px;
  background: transparent;
  color: var(--fg-2);
  cursor: pointer;
}
.lang-pill:hover { border-color: var(--accent); color: var(--fg); }
.lp-opt.is-on { color: var(--fg); font-weight: 600; }
.lp-sep { color: var(--fg-3); }

/* Hero */
.hero-block { max-width: var(--max); }
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--fg-2);
  margin-bottom: 24px;
}
.eb-dot { width: 6px; height: 6px; background: var(--accent); border-radius: 50%; }
.eb-sep { color: var(--fg-3); }

.hero-title {
  font-size: clamp(36px, 5.6vw, 72px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  font-weight: 600;
  margin: 0 0 24px;
  text-wrap: balance;
}
.ht-line { display: block; }
.ht-line.muted {
  color: var(--fg-2);
  font-weight: 300;
  font-style: italic;
  font-family: ui-serif, "Source Serif 4", Georgia, serif;
}
.hero-sub {
  font-size: clamp(15px, 1.3vw, 18px);
  color: var(--fg-1);
  line-height: 1.7;
  max-width: 60ch;
  text-wrap: pretty;
  margin: 0;
}

/* ── Tools / filters ─────────────────────────────────────────────────── */
.page-main {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(40px, 6vw, 72px) var(--pad);
}

.tools {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-bottom: 24px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--rule);
}
.tools-count { font-size: 12px; color: var(--fg-2); letter-spacing: 0.04em; }

.filters { display: flex; flex-wrap: wrap; gap: 4px; }
.filter {
  appearance: none;
  border: 1px solid var(--rule);
  background: transparent;
  padding: 6px 12px;
  font: inherit;
  font-size: 12px;
  color: var(--fg-2);
  border-radius: 999px;
  cursor: pointer;
  transition: color .15s, border-color .15s, background .15s;
}
.filter:hover { color: var(--fg); border-color: var(--rule-strong); }
.filter.is-active { background: var(--fg); color: var(--bg); border-color: var(--fg); }

/* ── Grid ────────────────────────────────────────────────────────────── */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 1px solid var(--rule);
}
@media (max-width: 900px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }

.card {
  background: var(--card);
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  min-height: 240px;
  position: relative;
  transition: background .2s, transform .2s;
  cursor: pointer;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  min-width: 0;
  overflow: hidden;
}
@media (max-width: 560px) {
  .card { padding: 20px 18px 18px; min-height: 200px; }
}
/* 桌機 3 欄：第 3、6、9… 張卡（右側邊緣）不畫右邊框 */
@media (min-width: 901px) {
  .card:nth-child(3n) { border-right: 0; }
}
/* 平板 2 欄：第 2、4、6… 張卡不畫右邊框 */
@media (max-width: 900px) and (min-width: 561px) {
  .card:nth-child(2n) { border-right: 0; }
}
/* 手機 1 欄：全部不畫右邊框 */
@media (max-width: 560px) {
  .card { border-right: 0; }
}
.card:hover { background: var(--bg-2); }
.card:hover .card-cta { color: var(--accent); gap: 8px; }
.card:hover .card-title { color: var(--accent); }

.card-num {
  font: 11px ui-monospace, Menlo, monospace;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 4px;
}
.card-theme {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-2);
  margin-bottom: 12px;
}
.card-title {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.005em;
  line-height: 1.3;
  margin: 0 0 16px;
  text-wrap: pretty;
  transition: color .18s;
}
.card-student {
  display: flex; align-items: baseline; gap: 8px;
  margin-bottom: auto;
  padding-bottom: 20px;
}
.cs-label {
  font: 10px ui-monospace, Menlo, monospace;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-3);
}
.cs-name { font-size: 15px; font-weight: 500; color: var(--fg); }

.card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
}
.card-url {
  font: 11px ui-monospace, Menlo, monospace;
  color: var(--fg-3);
  letter-spacing: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
}
.card-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--fg-2);
  white-space: nowrap;
  transition: color .18s, gap .18s;
}

/* ── Footer ──────────────────────────────────────────────────────────── */
.page-foot {
  border-top: 1px solid var(--rule);
  padding: 32px var(--pad);
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--fg-1);
}
.foot-l > div:first-child { font-weight: 500; margin-bottom: 4px; }