:root{
  --bg:#fff; --bg-2:#fafafa; --bg-3:#f4f4f4;
  --ink:#0a0a0a; --mute:#5b5b5b; --line:#ececec;
  --y:#FFD60A; --y-d:#f5c400; --y-l:#fff7c2;
  --shadow-sm:0 4px 16px rgba(0,0,0,.04);
  --shadow:0 12px 40px rgba(0,0,0,.07);
  --r:16px; --ease:cubic-bezier(.22,1,.36,1);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:170px}
body{font-family:"Inter","Noto Sans TC",system-ui,sans-serif;color:var(--ink);background:var(--bg);
  line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none}
.container{max-width:1200px;margin:0 auto;padding:0 24px}
.container-sm{max-width:880px;margin:0 auto;padding:0 24px}

/* ===== NAV ===== */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.85);
  backdrop-filter:saturate(180%) blur(16px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:74px}
.brand{font-weight:800;letter-spacing:-.02em;font-size:1.3rem;display:flex;align-items:center;gap:6px}
.brand .dot{display:inline-block;width:10px;height:10px;background:var(--y);border-radius:50%;box-shadow:0 0 0 4px var(--y-l);animation:pulse 2.4s var(--ease) infinite}
@keyframes pulse{50%{box-shadow:0 0 0 8px rgba(255,214,10,.15)}}
.menu{display:flex;gap:12px;list-style:none;white-space:nowrap}
.menu a{position:relative;font-weight:500;font-size:.78rem;padding:6px 0;color:#222;transition:color .3s}
.nav-inner nav{overflow-x:auto;max-width:calc(100% - 300px);-webkit-overflow-scrolling:touch;scrollbar-width:none}
.nav-inner nav::-webkit-scrollbar{display:none}
.menu a::after{content:"";position:absolute;left:0;bottom:-2px;width:0;height:2px;background:var(--y-d);transition:width .4s var(--ease)}
.menu a:hover::after,.menu a.active::after{width:100%}
.menu a.active{color:#000;font-weight:700}
.nav-cta{display:flex;align-items:center;gap:14px}

.burger{display:none;width:46px;height:46px;border:1px solid var(--line);border-radius:14px;background:#fff;position:relative;
  transition:transform .45s var(--ease),background .3s,border-color .3s}
.burger:hover{background:var(--y);border-color:var(--y-d);transform:rotate(90deg)}
.burger span{position:absolute;left:50%;top:50%;width:20px;height:2px;background:var(--ink);border-radius:2px;transition:transform .5s var(--ease),opacity .3s}
.burger span:nth-child(1){transform:translate(-50%,-7px)}
.burger span:nth-child(2){transform:translate(-50%,-50%)}
.burger span:nth-child(3){transform:translate(-50%,5px)}
.burger.open{transform:rotate(180deg);background:var(--y)}
.burger.open span:nth-child(1){transform:translate(-50%,-50%) rotate(45deg)}
.burger.open span:nth-child(2){opacity:0;transform:translate(-50%,-50%) scale(.2)}
.burger.open span:nth-child(3){transform:translate(-50%,-50%) rotate(-45deg)}

.drawer{position:fixed;inset:74px 0 0 0;background:#fff;transform:translateY(-110%);transition:transform .6s var(--ease);z-index:40;padding:32px 24px;overflow-y:auto}
.drawer.open{transform:translateY(0)}
.drawer ul{list-style:none;display:flex;flex-direction:column;gap:6px}
.drawer a{display:flex;justify-content:space-between;align-items:center;padding:18px 20px;border-radius:14px;font-size:1.2rem;font-weight:600;border:1px solid transparent;transition:all .35s var(--ease)}
.drawer a::after{content:"→";opacity:0;transition:opacity .3s,transform .3s}
.drawer a:hover{background:var(--y);border-color:var(--y-d);transform:translateX(8px)}
.drawer a:hover::after{opacity:1;transform:translateX(4px)}

/* === Buttons === */
.btn{display:inline-flex;align-items:center;gap:10px;padding:13px 24px;border-radius:999px;font-weight:600;font-size:.95rem;border:1px solid var(--ink);
  transition:transform .35s var(--ease),background .3s,color .3s,box-shadow .3s}
.btn:hover{transform:translateY(-3px)}
.btn-primary{background:var(--y);border-color:var(--y);color:#000}
.btn-primary:hover{background:var(--y-d);box-shadow:0 12px 30px rgba(245,196,0,.35)}
.btn-ghost{background:transparent}
.btn-ghost:hover{background:var(--ink);color:#fff}
.btn .arr{display:inline-block;transition:transform .3s var(--ease)}
.btn:hover .arr{transform:translateX(4px)}

/* === Common === */
.eyebrow{display:inline-block;font-size:.78rem;font-weight:700;letter-spacing:.18em;text-transform:uppercase;background:var(--y);padding:7px 14px;border-radius:6px;color:#000}
h1.page{font-size:clamp(2.6rem,7vw,5.4rem);font-weight:800;letter-spacing:-.04em;line-height:1.04}
h1.page em{font-style:italic;font-family:"Playfair Display",serif;font-weight:700}
h1.page mark{background:var(--y);padding:0 .12em;border-radius:10px}
h2{font-size:clamp(1.8rem,3.6vw,2.4rem);font-weight:800;letter-spacing:-.025em;line-height:1.18;margin:0 0 14px}
.lede{font-size:1.05rem;color:var(--mute);max-width:620px}

/* Reveal */
.reveal{opacity:0;transform:translateY(40px);transition:opacity .9s var(--ease),transform .9s var(--ease)}
.reveal.in{opacity:1;transform:none}
.reveal-d2{transition-delay:.12s}
.reveal-d3{transition-delay:.24s}

/* ===== HERO ===== */
.hero{padding:90px 0 50px;position:relative;overflow:hidden;text-align:center}
.hero .blob{position:absolute;width:560px;height:560px;border-radius:50%;
  background:radial-gradient(circle,var(--y-l) 0%,transparent 70%);filter:blur(50px);
  z-index:-1;left:50%;top:-180px;transform:translateX(-50%);animation:blob 14s var(--ease) infinite}
@keyframes blob{50%{transform:translate(calc(-50% + 30px),40px) scale(1.1)}}
.hero p.lede{margin:24px auto 0}

/* ===== Search bar ===== */
.toolbar{position:sticky;top:74px;z-index:30;background:rgba(255,255,255,.92);
  backdrop-filter:blur(14px);border-bottom:1px solid var(--line);padding:18px 0}
.search{position:relative;max-width:680px;margin:0 auto}
.search input{width:100%;padding:18px 56px 18px 56px;border-radius:999px;border:1.5px solid var(--line);
  background:#fff;font-family:inherit;font-size:1rem;color:#000;
  transition:border-color .3s,box-shadow .3s,background .3s}
.search input:focus{outline:none;border-color:var(--y-d);background:#fff;
  box-shadow:0 0 0 4px var(--y-l),0 12px 30px rgba(0,0,0,.06)}
.search .ico{position:absolute;left:22px;top:50%;transform:translateY(-50%);font-size:1.1rem;color:var(--mute);pointer-events:none}
.search .clear{position:absolute;right:14px;top:50%;transform:translateY(-50%);width:34px;height:34px;border-radius:50%;display:none;place-items:center;background:var(--bg-2);transition:background .3s,transform .3s}
.search .clear.show{display:grid}
.search .clear:hover{background:var(--y);transform:translateY(-50%) rotate(90deg)}
.search-meta{display:flex;justify-content:center;gap:8px;margin-top:14px;flex-wrap:wrap}
.chip{padding:7px 14px;border-radius:99px;border:1px solid var(--line);background:#fff;font-size:.82rem;font-weight:600;color:#222;cursor:pointer;transition:all .3s}
.chip:hover{background:var(--bg-2);border-color:#999}
.chip.active{background:#000;color:var(--y);border-color:#000}

/* ===== A-Z index ===== */
.az-bar{padding:24px 0;border-bottom:1px solid var(--line);background:var(--bg-2)}
.az{display:flex;flex-wrap:wrap;justify-content:center;gap:6px}
.az a{width:36px;height:36px;border-radius:10px;display:grid;place-items:center;font-weight:700;font-size:.85rem;
  border:1px solid transparent;color:#222;transition:all .3s var(--ease)}
.az a:hover{background:var(--y);border-color:var(--y-d);transform:translateY(-3px)}
.az a.disabled{color:#bbb;pointer-events:none;opacity:.5}
.az a.active{background:#000;color:var(--y);border-color:#000}

/* ===== Glossary content ===== */
.glossary{padding:60px 0 40px}
.letter-block{margin-bottom:60px}
.letter-block.hidden{display:none}
.letter-head{display:flex;align-items:baseline;gap:18px;margin-bottom:24px;border-bottom:2px solid var(--ink);padding-bottom:14px}
.letter-head .L{font-family:"Playfair Display",serif;font-style:italic;font-weight:700;font-size:4rem;color:var(--y-d);line-height:1;letter-spacing:-.04em}
.letter-head .count{font-size:.85rem;color:var(--mute);font-weight:600;letter-spacing:.1em;text-transform:uppercase}

/* === Term card (flip) === */
.terms{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:20px}
.term{perspective:1200px;height:200px}
.term.hidden{display:none}
.term-inner{position:relative;width:100%;height:100%;transition:transform .8s var(--ease);transform-style:preserve-3d;cursor:pointer}
.term.flipped .term-inner{transform:rotateY(180deg)}
.term-face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;
  border-radius:16px;padding:24px;display:flex;flex-direction:column;justify-content:space-between;
  border:1px solid var(--line);background:#fff}
.term-face.front{background:#fff}
.term-face.back{background:var(--ink);color:#fff;transform:rotateY(180deg);border-color:#000}
.term .top{display:flex;justify-content:space-between;align-items:flex-start}
.term .cat{font-size:.7rem;letter-spacing:.15em;text-transform:uppercase;font-weight:700;color:var(--y-d);background:var(--y-l);padding:5px 10px;border-radius:99px}
.term .flipico{width:30px;height:30px;border-radius:50%;background:var(--bg-2);display:grid;place-items:center;font-size:.8rem;color:#000;transition:transform .4s,background .3s}
.term:hover .flipico{background:var(--y);transform:rotate(180deg)}
.term h4{font-size:1.3rem;font-weight:800;letter-spacing:-.015em;margin-top:12px}
.term .en{font-family:"JetBrains Mono",monospace;font-size:.78rem;color:var(--mute);margin-top:4px;letter-spacing:.02em}
.term-face.back .cat{background:#1a1a1a;color:var(--y)}
.term-face.back p{font-size:.92rem;color:#ddd;line-height:1.6;margin-top:14px}
.term-face.back .hint{font-size:.72rem;color:#888;letter-spacing:.1em;text-transform:uppercase;font-weight:700}
.term-face.back .ex{font-size:.82rem;color:var(--y);margin-top:auto;font-style:italic;border-top:1px solid #2a2a2a;padding-top:10px}

/* No results */
.noresult{padding:80px 20px;text-align:center;color:var(--mute);display:none}
.noresult.show{display:block}
.noresult .big{font-family:"Playfair Display",serif;font-style:italic;font-size:4rem;color:var(--y-d);font-weight:700}
.noresult h3{margin-top:14px;font-size:1.4rem;color:#000;font-weight:700}
.noresult p{margin-top:8px}

/* === Section: highlights === */
.highlights{background:var(--bg-2);padding:70px 0}
.hl-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:0;border:1px solid var(--line);border-radius:18px;overflow:hidden;background:#fff}
.hl{padding:28px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);transition:background .35s,transform .3s}
.hl:hover{background:var(--y-l)}
.hl .num{font-family:"Playfair Display",serif;font-style:italic;font-weight:700;font-size:2.4rem;color:var(--y-d);line-height:1}
.hl h4{margin-top:10px;font-weight:700;font-size:1.05rem}
.hl p{margin-top:6px;font-size:.88rem;color:var(--mute)}

/* CTA */
.cta-band{background:var(--y);border-radius:24px;padding:54px 44px;display:grid;grid-template-columns:1.4fr 1fr;gap:40px;align-items:center;margin:60px 0}
.cta-band h2{margin:0}
.cta-band a.btn{background:#000;color:var(--y);border-color:#000}

/* Footer */
footer{background:var(--ink);color:#eaeaea;padding:72px 0 28px}
.f-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:40px}
footer h5{font-size:.85rem;letter-spacing:.12em;text-transform:uppercase;color:#fff;margin-bottom:18px}
footer ul{list-style:none;display:flex;flex-direction:column;gap:10px}
footer a{color:#bdbdbd;font-size:.92rem;transition:color .3s}
footer a:hover{color:var(--y)}
.f-bottom{margin-top:48px;padding-top:24px;border-top:1px solid #222;display:flex;justify-content:space-between;color:#999;font-size:.85rem;flex-wrap:wrap;gap:12px}

/* Responsive */
@media(max-width:980px){
  .cta-band{grid-template-columns:1fr;padding:40px 28px}
  .f-grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:860px){
  .menu,.nav-cta .btn{display:none}
  .burger{display:block}
  .terms{grid-template-columns:1fr}
  .term{height:180px}
  .az a{width:32px;height:32px;font-size:.78rem}
}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}