:root {
  --bg: #0b1220;
  --bg-elev: #121a2b;
  --bg-soft: #182238;
  --line: rgba(148, 163, 184, 0.18);
  --text: #e8eefc;
  --muted: #9aa8c3;
  --accent: #f7931a;
  --accent-2: #3b82f6;
  --up: #22c55e;
  --down: #ef4444;
  --card-shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  --radius: 18px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(247, 147, 26, 0.16), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(59, 130, 246, 0.14), transparent 50%),
    var(--bg);
  line-height: 1.65;
  min-height: 100vh;
}

a { color: #93c5fd; text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(11, 18, 32, 0.78);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.brand-badge {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, #f7931a, #fbbf24);
  color: #111;
  font-weight: 800;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  font-size: 0.95rem;
}

.nav-links a { color: var(--muted); }
.nav-links a:hover { color: var(--text); }

.hero {
  padding: 2.2rem 0 1rem;
}

.hero h1 {
  margin: 0 0 0.6rem;
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  letter-spacing: 0.02em;
}

.hero-lead {
  margin: 0;
  color: var(--muted);
  max-width: 46rem;
}

.grid {
  display: grid;
  gap: 1rem;
  margin: 1.2rem 0 2rem;
}

.price-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.03), transparent 40%), var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 1.15rem 1.25rem;
}

.card h2, .card h3 {
  margin: 0 0 0.8rem;
  font-size: 1.1rem;
}

.price-label {
  color: var(--muted);
  font-size: 0.92rem;
}

.price-value {
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  font-weight: 750;
  margin: 0.25rem 0;
  font-variant-numeric: tabular-nums;
}

.price-sub {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-soft);
}

.up { color: var(--up); }
.down { color: var(--down); }
.flat { color: var(--muted); }

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  align-items: center;
  margin: 0.8rem 0 1.4rem;
}

.btn {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--bg-soft);
  color: var(--text);
  border-radius: 12px;
  padding: 0.55rem 0.95rem;
  cursor: pointer;
  font: inherit;
}

.btn:hover { border-color: rgba(247, 147, 26, 0.55); }
.btn-primary {
  background: linear-gradient(135deg, #f7931a, #f59e0b);
  color: #111;
  border: none;
  font-weight: 700;
}

.btn.active {
  outline: 2px solid rgba(59, 130, 246, 0.55);
}

.meta-line {
  color: var(--muted);
  font-size: 0.9rem;
}

.countdown {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.16);
  border: 1px solid rgba(59, 130, 246, 0.35);
  color: #dbeafe;
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}

.countdown strong {
  color: #fff;
  font-size: 1.05rem;
  min-width: 1.5ch;
  text-align: center;
}

.alert {
  border: 1px solid rgba(239, 68, 68, 0.35);
  background: rgba(239, 68, 68, 0.1);
  color: #fecaca;
  border-radius: 12px;
  padding: 0.75rem 1rem;
  margin: 0.8rem 0;
  display: none;
}

.alert.show { display: block; }

.chart-wrap {
  position: relative;
  height: 320px;
}

.converter-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
}

label {
  display: block;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

input, select {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #0d1526;
  color: var(--text);
  padding: 0.7rem 0.8rem;
  font: inherit;
}

.faq details {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0.85rem 1rem;
  background: var(--bg-elev);
  margin-bottom: 0.7rem;
}

.faq summary {
  cursor: pointer;
  font-weight: 650;
}

.faq p {
  margin: 0.7rem 0 0;
  color: var(--muted);
}

.section {
  margin: 2rem 0;
}

.section > h2 {
  margin: 0 0 0.9rem;
  font-size: 1.35rem;
}

.tips {
  color: var(--muted);
  font-size: 0.95rem;
}

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 2.5rem;
  padding: 1.5rem 0 2.2rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.disclaimer {
  margin-top: 0.6rem;
}

@media (max-width: 800px) {
  .price-grid,
  .converter-grid {
    grid-template-columns: 1fr;
  }
  .nav-links { display: none; }
  .chart-wrap { height: 260px; }
}