/* ============================================================
   社團 AI 行政效率教學 — styles.css
   白藍風 · 白底 + 乾淨電光藍 · 俐落亮色介面
   行動優先
   ============================================================ */

:root {
  /* ── 亮色中性 ── */
  --bg:        #FBFCFE;
  --bg-2:      #F2F6FC;
  --surface:   #FFFFFF;
  --surface-2: #F7FAFE;
  --elevated:  #0E1726;
  --fg:        #0E1726;
  --body:      #46505F;
  --muted:     #6B7686;
  --border:        #E5EAF1;
  --border-strong: #CFD9E5;

  /* ── 藍色強調 ── */
  --accent:      #2E7BF6;
  --accent-2:    #4F9CF9;
  --accent-ink:  #1B5FCC;
  --accent-soft: #E8F0FE;

  /* ── 語意色 ── */
  --success:      #1F9D57;
  --success-soft: #E3F4EB;

  /* ── 漸層 ── */
  --gradient-hero:   linear-gradient(180deg, #FFFFFF 0%, #EAF1FE 100%);
  --gradient-accent: linear-gradient(180deg, #4F9CF9 0%, #2E7BF6 100%);

  /* ── 字體 ── */
  --font-display: 'Inter', 'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei', sans-serif;
  --font-body:    'Inter', 'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei', sans-serif;

  /* ── 動態 ── */
  --ease-out: cubic-bezier(0.25, 0.46, 0.45, 0.94);

  /* ── 形狀 ── */
  --radius:    12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(14,23,38,0.06);
  --shadow-md: 0 14px 36px rgba(28,68,140,0.10);
  --shadow-lg: 0 24px 60px rgba(14,23,38,0.16);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-body);
  color: var(--body);
  background: var(--bg);
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4 { font-family: var(--font-display); color: var(--fg); font-weight: 600; line-height: 1.18; letter-spacing: -0.02em; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
code, pre { font-family: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, monospace; }

.container { width: 100%; max-width: 1140px; margin: 0 auto; padding: 0 22px; }

/* ── 共用元件 ── */
.eyebrow {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-ink);
  background: var(--accent-soft);
  border: 1px solid rgba(46,123,246,0.2);
  padding: 0.32rem 0.8rem;
  border-radius: 6px;
  margin-bottom: 1rem;
}
.section { padding: clamp(3.5rem, 8vw, 6.5rem) 0; }
.section-head { max-width: 660px; margin-bottom: 2.6rem; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-title { font-size: clamp(1.8rem, 4.5vw, 2.7rem); letter-spacing: -0.03em; }
.section-sub { margin-top: 0.9rem; font-size: 1.02rem; color: var(--muted); }

.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-body); font-weight: 600; font-size: 0.96rem;
  padding: 0.78rem 1.5rem; border-radius: 9px;
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.18s var(--ease-out), box-shadow 0.25s var(--ease-out), background 0.2s var(--ease-out), border-color 0.2s var(--ease-out);
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--gradient-accent); color: #fff; box-shadow: 0 8px 22px rgba(46,123,246,0.32); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(46,123,246,0.42); }
.btn-ghost { background: var(--surface); color: var(--fg); border-color: var(--border-strong); }
.btn-ghost:hover { background: var(--surface-2); border-color: var(--accent); color: var(--accent-ink); }

/* ============================================================
   Navbar
   ============================================================ */
.navbar {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  padding: 1.05rem 0; background: transparent;
  transition: all 0.4s var(--ease-out);
}
.navbar.scrolled {
  background: rgba(255,255,255,0.78);
  backdrop-filter: blur(18px) saturate(160%); -webkit-backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--border);
  padding: 0.65rem 0;
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; }
.nav-brand {
  display: flex; align-items: center; gap: 0.55rem;
  font-family: var(--font-display); font-weight: 600; font-size: 1.06rem; color: var(--fg);
  letter-spacing: -0.01em;
  padding: 0.38rem 0; transition: all 0.3s var(--ease-out);
}
.nav-brand .mark { display: inline-flex; color: var(--accent); }
.nav-links { display: none; gap: 1.9rem; align-items: center; }
.nav-links a {
  font-family: var(--font-body); font-size: 0.92rem; font-weight: 500; color: var(--body);
  position: relative; transition: color 0.22s;
}
.nav-links a:hover { color: var(--accent-ink); }
.nav-links a::after {
  content: ''; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
  background: var(--accent); transition: width 0.3s var(--ease-out);
}
.nav-links a:hover::after { width: 100%; }

.nav-toggle { display: inline-flex; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--fg); border-radius: 2px; transition: all 0.3s var(--ease-out); }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-menu {
  position: fixed; inset: 0 0 0 auto; width: min(78%, 320px); z-index: 999;
  background: var(--surface); border-left: 1px solid var(--border); box-shadow: var(--shadow-lg);
  transform: translateX(100%); transition: transform 0.4s var(--ease-out);
  display: flex; flex-direction: column; padding: 5.5rem 2rem 2rem;
}
.mobile-menu.open { transform: translateX(0); }
.mobile-menu a { font-family: var(--font-display); padding: 1rem 0; font-size: 1.1rem; font-weight: 600; color: var(--fg); border-bottom: 1px solid var(--border); }
.menu-backdrop { position: fixed; inset: 0; background: rgba(14,23,38,0.4); z-index: 998; opacity: 0; visibility: hidden; transition: all 0.3s; }
.menu-backdrop.open { opacity: 1; visibility: visible; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  background: var(--gradient-hero); overflow: hidden; color: var(--fg);
  padding: 7rem 0 4rem;
  border-bottom: 1px solid var(--border);
}
.hero::before {
  content: ''; position: absolute; inset: 0; pointer-events: none; opacity: 0.7;
  background-image: linear-gradient(rgba(46,123,246,0.06) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(46,123,246,0.06) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 78%);
          mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 78%);
}
#particles { position: absolute; inset: 0; overflow: hidden; pointer-events: none; }
.particle { position: absolute; border-radius: 50%; background: rgba(46,123,246,0.4); animation: float linear infinite; }
@keyframes float {
  0%   { transform: translateY(0)     rotate(0deg);   opacity: 0.2;  }
  50%  { transform: translateY(-32px) rotate(180deg); opacity: 0.55; }
  100% { transform: translateY(0)     rotate(360deg); opacity: 0.2;  }
}
.hero-glow { position: absolute; width: 560px; height: 560px; border-radius: 50%; filter: blur(120px); opacity: 0.5; pointer-events: none; }
.hero-glow.one { background: rgba(79,156,249,0.4);  top: -200px; right: -80px; }
.hero-glow.two { background: rgba(46,123,246,0.22); bottom: -220px; left: -140px; }

.hero-inner { position: relative; z-index: 2; max-width: 780px; }
.hero-chip {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font-body); font-size: 0.82rem; font-weight: 500; letter-spacing: 0.01em; color: var(--accent-ink);
  background: var(--accent-soft); border: 1px solid rgba(46,123,246,0.24);
  padding: 0.4rem 0.9rem; border-radius: 999px; margin-bottom: 1.6rem;
}
.hero-chip .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(46,123,246,0.18); }
.hero h1 {
  font-size: clamp(2.2rem, 7vw, 4.2rem); line-height: 1.08;
  letter-spacing: -0.035em; margin-bottom: 1.3rem; font-weight: 600; color: var(--fg);
}
.hero h1 .hl { color: var(--accent); }
.hero-lead { font-family: var(--font-body); font-size: clamp(1.02rem, 2.4vw, 1.2rem); color: var(--body); max-width: 560px; margin-bottom: 2.2rem; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 0.9rem; }

.hero-stats { display: flex; flex-wrap: wrap; gap: 2.6rem; margin-top: 3.4rem; }
.hero-stats .stat .num { font-family: var(--font-display); font-size: 2.2rem; font-weight: 600; color: var(--fg); letter-spacing: -0.03em; }
.hero-stats .stat .num .suffix { color: var(--accent); }
.hero-stats .stat .label { font-family: var(--font-body); font-size: 0.86rem; color: var(--muted); margin-top: 0.2rem; }

.scroll-hint { position: absolute; bottom: 1.6rem; left: 50%; transform: translateX(-50%); z-index: 2; color: rgba(46,123,246,0.5); animation: bob 2s var(--ease-out) infinite; }
@keyframes bob { 0%,100%{ transform: translate(-50%,0);} 50%{ transform: translate(-50%,8px);} }

/* ============================================================
   Why / value cards
   ============================================================ */
.why { background: var(--bg); }
.value-grid { display: grid; grid-template-columns: 1fr; gap: 1.2rem; }
.value-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.8rem; box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease-out), border-color 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}
.value-card:hover { transform: translateY(-4px); border-color: var(--border-strong); box-shadow: var(--shadow-md); }
.value-card .ic {
  display: inline-flex; align-items: center; justify-content: center;
  width: 50px; height: 50px; border-radius: 12px; margin-bottom: 1.1rem;
  background: var(--accent-soft); color: var(--accent); border: 1px solid rgba(46,123,246,0.2);
}
.value-card h3 { font-size: 1.22rem; margin-bottom: 0.55rem; }
.value-card p { font-size: 0.97rem; color: var(--body); }

/* ============================================================
   Steps (SOP)
   ============================================================ */
.steps { background: var(--bg-2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.flow { display: grid; grid-template-columns: 1fr; gap: 1.1rem; counter-reset: step; margin-top: 0.5rem; }
.step {
  position: relative; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.6rem 1.6rem 1.6rem 4.6rem;
  box-shadow: var(--shadow-sm); transition: transform 0.3s var(--ease-out), border-color 0.3s var(--ease-out);
}
.step:hover { transform: translateX(4px); border-color: var(--border-strong); }
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; left: 1.4rem; top: 1.5rem;
  width: 2.3rem; height: 2.3rem; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display); font-weight: 600; font-size: 1.05rem;
  background: var(--gradient-accent); color: #fff; box-shadow: 0 4px 12px rgba(46,123,246,0.3);
}
.step h3 { font-size: 1.18rem; margin-bottom: 0.4rem; }
.step p { font-size: 0.96rem; color: var(--body); }
.step .hint { font-size: 0.88rem; color: var(--muted); margin-top: 0.5rem; }
.step ul.bullets { margin-top: 0.6rem; display: grid; gap: 0.35rem; }
.step ul.bullets li { position: relative; padding-left: 1.1rem; font-size: 0.93rem; color: var(--body); }
.step ul.bullets li::before { content: ''; position: absolute; left: 0; top: 0.62em; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

.callout {
  margin-top: 1.4rem; background: var(--accent-soft); border: 1px solid rgba(46,123,246,0.24);
  border-radius: var(--radius); padding: 1.3rem 1.4rem; display: flex; gap: 0.85rem; align-items: flex-start;
}
.callout .ic { color: var(--accent); flex-shrink: 0; margin-top: 2px; }
.callout p { font-size: 0.95rem; color: #234B86; }
.callout strong { color: var(--accent-ink); }

/* ============================================================
   Copy block (code / prompt) — 保留深色，對比更俐落
   ============================================================ */
.copy-block { background: #0C1320; border: 1px solid #1B2940; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-md); }
.copy-bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.7rem 0.9rem 0.7rem 1.1rem; background: rgba(255,255,255,0.03);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.copy-bar .title { font-family: var(--font-body); font-size: 0.84rem; font-weight: 600; color: #8FC0FF; display: flex; align-items: center; gap: 0.5rem; letter-spacing: 0.01em; }
.copy-block pre {
  margin: 0; padding: 1.2rem; overflow-x: auto;
  font-size: 0.86rem; line-height: 1.7; color: #CDD7E5; white-space: pre-wrap; word-break: break-word;
  max-height: 360px; overflow-y: auto;
}
.copy-block pre .edit { color: #6FB0FF; font-weight: 600; }

.copy-btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--font-body); font-size: 0.84rem; font-weight: 600;
  color: #fff; background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.18);
  padding: 0.45rem 0.85rem; border-radius: 8px; cursor: pointer;
  transition: all 0.2s var(--ease-out); white-space: nowrap;
}
.copy-btn:hover { background: rgba(255,255,255,0.16); border-color: rgba(255,255,255,0.3); }
.copy-btn:active { transform: scale(0.96); }
.copy-btn.copied { background: var(--success); border-color: var(--success); color: #fff; }
.copy-btn .ic-check { display: none; }
.copy-btn.copied .ic-copy { display: none; }
.copy-btn.copied .ic-check { display: inline-flex; }

/* ============================================================
   NotebookLM tips
   ============================================================ */
.notebook { background: var(--bg); }
.nb-grid { display: grid; grid-template-columns: 1fr; gap: 2rem; align-items: start; }
.nb-tips { display: grid; gap: 0.9rem; }
.nb-tip { display: flex; gap: 0.85rem; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.1rem 1.2rem; box-shadow: var(--shadow-sm); transition: border-color 0.3s var(--ease-out); }
.nb-tip:hover { border-color: var(--border-strong); }
.nb-tip .ic { color: var(--accent); flex-shrink: 0; margin-top: 2px; }
.nb-tip h4 { font-size: 1.04rem; margin-bottom: 0.2rem; }
.nb-tip p { font-size: 0.92rem; color: var(--body); }
.nb-sources { background: linear-gradient(165deg,#123163,#0C1320); border: 1px solid #1B2940; border-radius: var(--radius-lg); padding: 1.7rem; color: #fff; box-shadow: var(--shadow-md); }
.nb-sources h3 { color: #fff; font-size: 1.2rem; margin-bottom: 1rem; display: flex; align-items: center; gap: 0.55rem; }
.nb-sources h3 svg { color: #8FC0FF; }
.nb-sources ul { display: grid; gap: 0.65rem; }
.nb-sources li { display: flex; gap: 0.6rem; align-items: flex-start; font-family: var(--font-body); font-size: 0.94rem; color: rgba(255,255,255,0.86); }
.nb-sources li .ic { color: #8FC0FF; flex-shrink: 0; margin-top: 3px; }

/* ============================================================
   Prompt library
   ============================================================ */
.library { background: var(--bg-2); border-top: 1px solid var(--border); }
.filter-bar {
  display: flex; gap: 0.5rem; overflow-x: auto; padding: 0.3rem 0 1.6rem;
  -webkit-overflow-scrolling: touch; scrollbar-width: none;
}
.filter-bar::-webkit-scrollbar { display: none; }
.filter-chip {
  flex-shrink: 0; font-family: var(--font-body); font-size: 0.9rem; font-weight: 600; color: var(--body);
  background: var(--surface); border: 1px solid var(--border);
  padding: 0.55rem 1.1rem; border-radius: 8px; cursor: pointer;
  transition: all 0.2s var(--ease-out);
}
.filter-chip:hover { border-color: var(--border-strong); color: var(--accent-ink); }
.filter-chip.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.prompt-grid { display: grid; grid-template-columns: 1fr; gap: 1.3rem; }
.prompt-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.5rem; box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease-out), border-color 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}
.prompt-card:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow-md); }
.prompt-card .pc-head { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 0.5rem; }
.prompt-card .pc-tag {
  font-family: var(--font-body); font-size: 0.74rem; font-weight: 600; color: var(--accent-ink);
  background: var(--accent-soft); padding: 0.22rem 0.7rem; border-radius: 6px; letter-spacing: 0.02em;
}
.prompt-card h3 { font-size: 1.16rem; }
.prompt-card .pc-desc { font-family: var(--font-body); font-size: 0.92rem; color: var(--muted); margin-bottom: 1rem; }

/* ============================================================
   Footer
   ============================================================ */
.footer { background: #0C1320; border-top: 1px solid #1B2940; color: rgba(255,255,255,0.66); padding: 3rem 0 2rem; }
.footer-top { display: flex; flex-direction: column; gap: 1.4rem; padding-bottom: 1.8rem; border-bottom: 1px solid rgba(255,255,255,0.1); }
.footer-brand { font-family: var(--font-display); font-weight: 600; font-size: 1.3rem; color: #fff; }
.footer p { font-family: var(--font-body); font-size: 0.9rem; max-width: 460px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 1.2rem 1.8rem; }
.footer-links a { font-family: var(--font-body); font-size: 0.9rem; color: rgba(255,255,255,0.8); }
.footer-links a:hover { color: #8FC0FF; }
.footer-bottom { font-family: var(--font-body); padding-top: 1.5rem; font-size: 0.82rem; color: rgba(255,255,255,0.45); }

/* ── Toast ── */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translate(-50%, 120%);
  background: #0E1726; color: #fff; border: 1px solid rgba(255,255,255,0.14);
  padding: 0.8rem 1.4rem; border-radius: 10px;
  font-family: var(--font-body); font-size: 0.92rem; font-weight: 600; box-shadow: var(--shadow-lg); z-index: 2000;
  display: flex; align-items: center; gap: 0.5rem; transition: transform 0.35s var(--ease-out);
}
.toast.show { transform: translate(-50%, 0); }
.toast .ic { color: #5BE08C; }

/* ============================================================
   Scroll reveal
   ============================================================ */
.js-ready .reveal { opacity: 0; transform: translateY(40px); transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out); }
.reveal.visible, .js-ready .reveal.visible { opacity: 1; transform: translateY(0); }
.stagger-children .reveal:nth-child(1){transition-delay:0s}
.stagger-children .reveal:nth-child(2){transition-delay:.08s}
.stagger-children .reveal:nth-child(3){transition-delay:.16s}
.stagger-children .reveal:nth-child(4){transition-delay:.24s}
.stagger-children .reveal:nth-child(5){transition-delay:.32s}
.stagger-children .reveal:nth-child(6){transition-delay:.40s}

@media (prefers-reduced-motion: reduce) {
  .js-ready .reveal { opacity: 1; transform: none; transition: none; }
  .particle, .scroll-hint { animation: none; }
  html { scroll-behavior: auto; }
}

/* ============================================================
   Responsive
   ============================================================ */
@media (min-width: 640px) {
  .value-grid { grid-template-columns: repeat(2, 1fr); }
  .prompt-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 768px) {
  .nav-links { display: flex; }
  .nav-toggle { display: none; }
  .value-grid { grid-template-columns: repeat(3, 1fr); }
  .nb-grid { grid-template-columns: 1.4fr 1fr; }
  .footer-top { flex-direction: row; justify-content: space-between; align-items: flex-start; }
}
@media (min-width: 1024px) {
  .prompt-grid { grid-template-columns: repeat(2, 1fr); }
}