:root{
  --bg:#07111f;
  --bg2:#0f1b32;
  --panel:rgba(14,24,45,.78);
  --panel-2:rgba(255,255,255,.05);
  --card:rgba(255,255,255,.06);
  --line:rgba(255,255,255,.10);
  --text:#eef5ff;
  --muted:#a8bbd8;
  --primary:#7c5cff;
  --secondary:#15d1c5;
  --accent:#ffb84d;
  --danger:#ff6b81;
  --success:#22c67a;
  --shadow:0 18px 48px rgba(0,0,0,.35);
  --radius:24px;
  --radius-sm:16px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: "Segoe UI","Noto Sans TC","PingFang TC","Microsoft JhengHei",sans-serif;
}

body.light{
  --bg:#f3f7ff;
  --bg2:#eaf1ff;
  --panel:rgba(255,255,255,.88);
  --panel-2:rgba(40,70,140,.05);
  --card:rgba(21,31,61,.04);
  --line:rgba(17,33,74,.12);
  --text:#10203f;
  --muted:#5d7094;
  --primary:#5a44ff;
  --secondary:#08bfae;
  --accent:#ff9e35;
  --danger:#ef5675;
  --success:#11b96b;
  --shadow:0 18px 42px rgba(33,55,113,.12);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  font-family:var(--sans);
  background:
    radial-gradient(circle at 10% 12%, rgba(124,92,255,.18), transparent 22%),
    radial-gradient(circle at 90% 18%, rgba(21,209,197,.14), transparent 18%),
    radial-gradient(circle at 84% 84%, rgba(255,184,77,.10), transparent 20%),
    linear-gradient(135deg,var(--bg),var(--bg2));
}
a{color:inherit;text-decoration:none}
img{max-width:100%}

.layout{
  display:grid;
  grid-template-columns:280px 1fr;
  min-height:100vh;
}

.sidebar{
  position:sticky;
  top:0;
  height:100vh;
  padding:22px 16px;
  border-right:1px solid var(--line);
  backdrop-filter:blur(18px);
  background:linear-gradient(180deg, rgba(255,255,255,.04), rgba(255,255,255,.02));
}

.brand{
  display:flex;
  gap:14px;
  align-items:center;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:20px;
  padding:14px;
  box-shadow:var(--shadow);
  margin-bottom:18px;
}
.logo{
  width:50px;height:50px;
  border-radius:16px;
  display:grid;place-items:center;
  font-weight:800;color:#fff;font-size:22px;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  box-shadow:0 10px 28px rgba(124,92,255,.35);
}
.brand h1{margin:0;font-size:18px;line-height:1.15}
.brand small{display:block;color:var(--muted);margin-top:4px}

.side-card{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:18px;
  padding:16px;
  margin-bottom:14px;
  box-shadow:var(--shadow);
}
.side-card h3{
  margin:0 0 10px;
  font-size:16px;
}

.nav{
  display:flex;
  flex-direction:column;
  gap:8px;
}
.nav a{
  padding:12px 14px;
  border-radius:14px;
  color:var(--muted);
  transition:.25s ease;
  border:1px solid transparent;
}
.nav a:hover,.nav a.active{
  color:var(--text);
  background:rgba(255,255,255,.05);
  border-color:var(--line);
  transform:translateX(4px);
}

.badge{
  display:inline-block;
  padding:6px 10px;
  font-size:12px;
  border-radius:999px;
  background:rgba(124,92,255,.14);
  border:1px solid rgba(124,92,255,.22);
  color:#ddd6ff;
}
.progress{
  height:10px;
  background:rgba(255,255,255,.08);
  border-radius:999px;
  overflow:hidden;
  margin-top:10px;
}
.progress span{
  display:block;
  height:100%;
  width:0%;
  background:linear-gradient(90deg,var(--primary),var(--secondary));
  transition:.35s ease;
}

.content{
  padding:28px;
}

.topbar{
  display:flex;
  justify-content:space-between;
  gap:12px;
  margin-bottom:22px;
  flex-wrap:wrap;
}
.searchbar{
  flex:1;
  min-width:220px;
  display:flex;
  align-items:center;
  gap:10px;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:18px;
  padding:12px 16px;
  box-shadow:var(--shadow);
}
.searchbar input{
  flex:1;
  border:none;
  outline:none;
  background:transparent;
  color:var(--text);
  font-size:15px;
}

.btn{
  border:none;
  cursor:pointer;
  padding:12px 16px;
  border-radius:14px;
  color:#fff;
  font-weight:700;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
  box-shadow:0 10px 25px rgba(104,97,255,.25);
  transition:.25s ease;
}
.btn:hover{transform:translateY(-2px)}
.btn.ghost{
  background:var(--panel);
  color:var(--text);
  border:1px solid var(--line);
  box-shadow:none;
}
.btn.warn{
  background:linear-gradient(135deg,var(--accent),#ff7b54);
}

.hero{
  border:1px solid var(--line);
  background:
    radial-gradient(circle at top right, rgba(124,92,255,.26), transparent 30%),
    radial-gradient(circle at bottom left, rgba(21,209,197,.15), transparent 28%),
    linear-gradient(145deg, rgba(255,255,255,.08), rgba(255,255,255,.03));
  border-radius:28px;
  padding:32px;
  box-shadow:var(--shadow);
  margin-bottom:24px;
}
.hero-grid{
  display:grid;
  grid-template-columns:1.15fr .85fr;
  gap:20px;
  align-items:center;
}
.kicker{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 12px;
  font-size:12px;
  font-weight:700;
  border-radius:999px;
  background:rgba(124,92,255,.12);
  border:1px solid rgba(124,92,255,.22);
  color:#ddd6ff;
  margin-bottom:12px;
}
.hero h2{
  margin:0 0 14px;
  font-size:clamp(30px,4vw,52px);
  line-height:1.08;
  letter-spacing:-.02em;
}
.hero p{
  margin:0 0 18px;
  line-height:1.8;
  color:var(--muted);
}

.highlight{
  background:linear-gradient(90deg,var(--primary),var(--secondary));
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
}

.stats{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:14px;
}
.stat{
  border:1px solid var(--line);
  background:var(--panel);
  border-radius:20px;
  padding:18px;
  box-shadow:var(--shadow);
}
.stat strong{
  display:block;
  font-size:26px;
  margin-bottom:6px;
}
.stat span{
  color:var(--muted);
  font-size:14px;
}

.panel{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:24px;
  padding:24px;
  box-shadow:var(--shadow);
  margin-bottom:22px;
}
.section-head{
  display:flex;
  justify-content:space-between;
  gap:12px;
  align-items:end;
  margin-bottom:16px;
  flex-wrap:wrap;
}
.section-head h3{
  margin:0;
  font-size:24px;
}
.section-head p{
  margin:6px 0 0;
  color:var(--muted);
}
.mini{font-size:13px;color:var(--muted)}

.grid-2{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:18px;
}
.grid-3{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:18px;
}
.grid-4{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:16px;
}

.card{
  background:linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.02));
  border:1px solid var(--line);
  border-radius:22px;
  padding:20px;
  transition:.25s ease;
}
.card:hover{
  transform:translateY(-4px);
  border-color:rgba(124,92,255,.3);
  box-shadow:0 16px 35px rgba(0,0,0,.15);
}
.card h4{
  margin:0 0 10px;
  font-size:20px;
}
.card p{
  margin:0;
  color:var(--muted);
  line-height:1.75;
}

.codebox{
  margin-top:16px;
  border:1px solid var(--line);
  border-radius:18px;
  overflow:hidden;
  background:#07101e;
}
body.light .codebox{
  background:#0e1a30;
}
.codebar{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:10px 14px;
  border-bottom:1px solid rgba(255,255,255,.08);
  font-size:13px;
  color:#bed1f1;
}
pre{
  margin:0;
  padding:18px;
  overflow:auto;
  color:#dff0ff;
  line-height:1.75;
  font-size:14px;
  font-family:var(--mono);
}

.table-wrap{overflow:auto}
table{
  width:100%;
  border-collapse:collapse;
}
th,td{
  text-align:left;
  padding:12px 14px;
  border-bottom:1px solid var(--line);
  font-size:14px;
}
th{
  background:rgba(255,255,255,.04);
}

.note{
  margin-top:14px;
  padding:14px 16px;
  border-left:4px solid var(--accent);
  background:rgba(255,184,77,.10);
  border-radius:12px;
}
.note.success{
  background:rgba(34,198,122,.12);
  border-left-color:var(--success);
}
.note.danger{
  background:rgba(255,107,129,.12);
  border-left-color:var(--danger);
}

.check{
  display:flex;
  align-items:center;
  gap:8px;
  color:var(--muted);
  font-size:14px;
  margin-top:16px;
}
.check input{
  width:18px;height:18px;
  accent-color:var(--primary);
}

.chips{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
}
.chip{
  padding:10px 12px;
  border-radius:999px;
  background:var(--card);
  border:1px solid var(--line);
  font-size:13px;
}

.playground{
  display:grid;
  grid-template-columns:340px 1fr;
  gap:18px;
}
label{
  display:block;
  margin-bottom:8px;
  color:var(--muted);
  font-size:14px;
}
select,textarea{
  width:100%;
  border:1px solid var(--line);
  outline:none;
  background:rgba(255,255,255,.05);
  color:var(--text);
  border-radius:16px;
  padding:14px;
  font-size:14px;
  font-family:var(--mono);
}
textarea{
  min-height:220px;
  resize:vertical;
}
.input-group{margin-bottom:16px}

.result-panel{
  margin-top:16px;
  border:1px solid var(--line);
  border-radius:18px;
  overflow:hidden;
  background:var(--panel-2);
}

details{
  border:1px solid var(--line);
  background:rgba(255,255,255,.03);
  border-radius:18px;
  overflow:hidden;
}
details + details{margin-top:12px}
summary{
  cursor:pointer;
  padding:16px 18px;
  font-weight:700;
}
.detail-body{
  padding:0 18px 18px;
  color:var(--muted);
  line-height:1.8;
}

.timeline{
  display:grid;
  gap:14px;
}
.step{
  display:grid;
  grid-template-columns:58px 1fr;
  gap:14px;
  align-items:start;
}
.step .num{
  width:46px;height:46px;
  border-radius:16px;
  display:grid;place-items:center;
  font-weight:800;color:#fff;
  background:linear-gradient(135deg,var(--primary),var(--secondary));
}
.step .box{
  padding:18px;
  border-radius:18px;
  border:1px solid var(--line);
  background:var(--card);
}
.step .box h4{margin:0 0 8px}
.step .box p{margin:0;color:var(--muted);line-height:1.75}

.quiz-item{
  padding:16px;
  border:1px solid var(--line);
  border-radius:18px;
  background:var(--card);
}
.quiz-item + .quiz-item{margin-top:12px}
.quiz-item h4{
  margin:0 0 10px;
  font-size:16px;
}
.quiz-item label{
  display:block;
  margin:8px 0;
  background:rgba(255,255,255,.03);
  padding:10px 12px;
  border:1px solid transparent;
  border-radius:12px;
  cursor:pointer;
}
.quiz-item label:hover{
  border-color:var(--line);
}

.footer{
  text-align:center;
  color:var(--muted);
  font-size:13px;
  margin:26px 0 6px;
}

@media (max-width: 1180px){
  .layout{grid-template-columns:1fr}
  .sidebar{position:relative;height:auto}
  .hero-grid,.grid-2,.grid-3,.grid-4,.playground{grid-template-columns:1fr}
}
@media (max-width: 760px){
  .content{padding:16px}
  .hero{padding:24px}
}