:root {
  color-scheme: dark;
  --hub-bg: #101417;
  --hub-bg-2: #161d24;
  --hub-surface: rgba(19, 27, 34, 0.84);
  --hub-border: rgba(183, 194, 207, 0.12);
  --hub-text: #f0f6fb;
  --hub-muted: #99a7b7;
  --hub-accent: #78d7ff;
  --hub-accent-2: #8fdb8f;
  --hub-accent-3: #ffd36d;
  --hub-shadow: 0 30px 90px rgba(0, 0, 0, 0.36);
}

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

html { scroll-behavior: smooth; }

body.hub-page {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--hub-text);
  min-height: 100vh;
  background:
    radial-gradient(circle at 12% 10%, rgba(120, 215, 255, 0.14), transparent 22%),
    radial-gradient(circle at 82% 12%, rgba(143, 219, 143, 0.12), transparent 24%),
    linear-gradient(180deg, var(--hub-bg), var(--hub-bg-2));
}

a { color: inherit; text-decoration: none; }

.hub-skip {
  position: absolute; left: 1rem; top: -3rem; z-index: 20;
  padding: .75rem 1rem; border-radius: 999px; background: #fff; color: #111; transition: top .2s ease;
}
.hub-skip:focus { top: 1rem; }

.hub-header {
  position: sticky; top: 0; z-index: 15;
  background: rgba(16, 20, 23, 0.72);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(183, 194, 207, 0.1);
}

.hub-shell {
  width: min(1200px, calc(100% - 2rem));
  margin: 0 auto;
  min-height: 4.75rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}

.hub-brand { display: inline-flex; align-items: center; gap: .85rem; }
.hub-mark {
  width: 2.9rem; aspect-ratio: 1; border-radius: 1rem;
  background: linear-gradient(145deg, rgba(120, 215, 255, 0.14), rgba(143, 219, 143, 0.1));
  border: 1px solid rgba(183, 194, 207, 0.14); position: relative;
}
.hub-mark span:first-child {
  position: absolute; left: .6rem; top: .6rem; width: 1rem; height: 1rem; border-radius: 50%; background: var(--hub-accent);
}
.hub-mark span:last-child {
  position: absolute; right: .45rem; bottom: .55rem; width: .95rem; height: .28rem; border-radius: 999px;
  background: linear-gradient(90deg, var(--hub-accent-2), var(--hub-accent-3));
}
.hub-brand strong { display: block; font-size: 1rem; }
.hub-brand small { display: block; color: var(--hub-muted); }

.hub-nav { display: flex; align-items: center; gap: 1.15rem; }
.hub-nav a { color: var(--hub-muted); font-size: .95rem; }

.hub-menu {
  display: none; width: 3rem; height: 3rem; border-radius: 999px; border: 1px solid var(--hub-border);
  background: rgba(255,255,255,.06); align-items: center; justify-content: center; flex-direction: column; gap: .22rem;
}
.hub-menu span { width: 1rem; height: 1.5px; border-radius: 999px; background: #fff; }

.hub-hero, .hub-routes, .hub-resources, .hub-compare, .hub-faq, .hub-footer {
  width: min(1200px, calc(100% - 2rem)); margin: 0 auto;
}

.hub-hero {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, .96fr); gap: 2rem; align-items: center;
  padding: 4rem 0 2rem;
}
.hub-eyebrow, .hub-section-kicker {
  margin: 0 0 .85rem; font-size: .8rem; letter-spacing: .3em; text-transform: uppercase; color: var(--hub-muted);
}
.hub-copy h1 { margin: 0; font-size: clamp(2.8rem, 6vw, 5.2rem); line-height: .96; letter-spacing: -.07em; }
.hub-copy h1 span { display: block; }
.hub-lead { margin: 1.35rem 0 0; max-width: 38rem; color: var(--hub-muted); line-height: 1.88; font-size: 1.03rem; }
.hub-actions { display: flex; flex-wrap: wrap; gap: .9rem; margin-top: 1.6rem; }
.hub-button {
  min-height: 3.25rem; padding: .8rem 1.25rem; border-radius: 999px; display: inline-flex; align-items: center;
  justify-content: center; gap: .5rem; border: 1px solid transparent; font-weight: 700;
}
.hub-button-primary { background: linear-gradient(135deg, #eefbff, #c1edff); color: #0d1720; box-shadow: 0 18px 34px rgba(120,215,255,.12); }
.hub-button-secondary { background: rgba(255,255,255,.04); border-color: var(--hub-border); }
.hub-note { margin-top: 1rem; color: var(--hub-muted); }

.hub-stage {
  position: relative; min-height: 560px; border-radius: 2rem;
  background:
    radial-gradient(circle at 18% 18%, rgba(120, 215, 255, 0.14), transparent 22%),
    radial-gradient(circle at 80% 18%, rgba(143, 219, 143, 0.14), transparent 24%),
    linear-gradient(180deg, rgba(19, 27, 34, 0.94), rgba(13, 18, 24, 0.98));
  border: 1px solid rgba(183, 194, 207, 0.12); box-shadow: var(--hub-shadow); overflow: hidden;
}
.hub-orbit { position: absolute; border-radius: 50%; border: 1px solid rgba(120,215,255,.18); }
.hub-orbit-a { width: 20rem; height: 20rem; right: 1.8rem; top: 1.8rem; }
.hub-orbit-b { width: 13rem; height: 13rem; left: 1.5rem; bottom: 1.5rem; }
.hub-core {
  position: absolute; inset: 50% auto auto 50%; transform: translate(-50%, -50%);
  width: min(74%, 340px); min-height: 250px; border-radius: 1.8rem; padding: 1.5rem; text-align: center;
  background: rgba(255,255,255,.94); color: #10191f; border: 1px solid rgba(183,194,207,.16);
  display: flex; flex-direction: column; justify-content: center; box-shadow: 0 18px 32px rgba(0,0,0,.14);
}
.hub-core span {
  display: inline-flex; width: fit-content; align-self: center; padding: .3rem .65rem; border-radius: 999px;
  background: rgba(120,215,255,.14); color: #2f7d95; font-size: .8rem;
}
.hub-core strong { margin-top: 1rem; font-size: 1.55rem; }
.hub-core p { margin: .75rem 0 0; color: #5d6670; line-height: 1.8; }
.hub-chip {
  position: absolute; padding: .45rem .75rem; border-radius: 999px; background: rgba(255,255,255,.08); color: #fff; letter-spacing: .14em; font-size: .8rem;
}
.hub-chip-top { top: 2rem; left: 2rem; }
.hub-chip-right { right: 2rem; top: 50%; transform: translateY(-50%); }
.hub-chip-bottom { bottom: 2rem; left: 50%; transform: translateX(-50%); }

.hub-routes { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 1rem; padding: 1rem 0 1.2rem; }
.hub-route-card {
  padding: 1.25rem; border-radius: 1.35rem; background: rgba(255,255,255,.05); border: 1px solid var(--hub-border);
  box-shadow: 0 16px 28px rgba(0,0,0,.12);
}
.hub-route-card.is-active { background: linear-gradient(180deg, rgba(120,215,255,.1), rgba(255,255,255,.04)); }
.hub-route-card span { display: inline-flex; padding: .28rem .6rem; border-radius: 999px; background: rgba(120,215,255,.12); color: var(--hub-accent); }
.hub-route-card h2 { margin: .85rem 0 .45rem; }
.hub-route-card p { margin: 0; color: var(--hub-muted); line-height: 1.8; }
.hub-route-card a { display: inline-flex; gap: .45rem; margin-top: .95rem; color: var(--hub-accent); font-weight: 700; }

.hub-resources {
  display: grid; grid-template-columns: minmax(0,1fr) minmax(280px,.96fr); gap: 1rem; padding: 1rem 0 1.2rem;
}
.hub-resource-card {
  border-radius: 1.35rem; background: rgba(255,255,255,.05); border: 1px solid var(--hub-border);
  box-shadow: 0 16px 28px rgba(0,0,0,.12); padding: 1.35rem;
}
.hub-resource-card h2, .hub-compare-head h2, .hub-faq-head h2 { margin: 0; font-size: clamp(1.55rem, 2.2vw, 2.35rem); }
.hub-resource-card p { color: var(--hub-muted); line-height: 1.85; }
.hub-resource-list { display: grid; gap: .75rem; margin-top: 1rem; }
.hub-resource-list a {
  padding: .85rem 1rem; border-radius: 1rem; background: rgba(255,255,255,.04); border: 1px solid var(--hub-border);
}
.hub-resource-card-soft { background: linear-gradient(180deg, rgba(120,215,255,.09), rgba(255,255,255,.04)); }
.hub-resource-card-soft a { display: inline-flex; margin-top: 1rem; color: var(--hub-accent); font-weight: 700; }

.hub-compare { padding: 1rem 0 1.2rem; }
.hub-compare-grid { display: flex; flex-wrap: wrap; gap: .75rem; }
.hub-compare-chip {
  border: 1px solid var(--hub-border); background: rgba(255,255,255,.04); color: var(--hub-text); border-radius: 999px;
  padding: .8rem 1rem; font: inherit; font-weight: 700;
}
.hub-compare-chip.is-active { background: linear-gradient(135deg, rgba(120,215,255,.16), rgba(143,219,143,.14)); }
.hub-compare-detail {
  margin-top: 1rem; padding: 1rem 1.1rem; border-radius: 1.25rem; background: rgba(255,255,255,.04);
  border: 1px solid var(--hub-border); color: var(--hub-muted); line-height: 1.85;
}

.hub-faq { padding: 1rem 0 2rem; }
.hub-faq-head { margin-bottom: 1rem; }
.hub-faq-list { display: grid; gap: .9rem; }
.hub-faq-item {
  border-radius: 1.2rem; overflow: hidden; background: rgba(255,255,255,.04); border: 1px solid var(--hub-border);
}
.hub-faq-item summary { cursor: pointer; list-style: none; padding: 1.05rem 1.1rem; font-weight: 700; }
.hub-faq-item summary::-webkit-details-marker { display: none; }
.hub-faq-item p { margin: 0; padding: 0 1.1rem 1.1rem; color: var(--hub-muted); line-height: 1.85; }

.hub-footer {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1rem 0 2.4rem; color: var(--hub-muted);
}
.hub-footer strong { color: var(--hub-text); }
.hub-footer p { margin: .35rem 0 0; }

@media (max-width: 1100px) {
  .hub-hero, .hub-resources { grid-template-columns: 1fr; }
  .hub-routes { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 860px) {
  .hub-nav { display: none; }
  .hub-menu { display: inline-flex; }
  .hub-nav.is-open {
    display: flex; position: absolute; left: 1rem; right: 1rem; top: 4.7rem; flex-direction: column; padding: 1rem;
    border-radius: 1rem; background: rgba(16,20,23,.98); border: 1px solid var(--hub-border); box-shadow: var(--hub-shadow);
  }
  .hub-routes { grid-template-columns: 1fr; }
  .hub-hero { padding-top: 2.4rem; }
}
@media (max-width: 560px) {
  .hub-shell { width: min(100%, calc(100% - 1rem)); }
  .hub-hero, .hub-routes, .hub-resources, .hub-compare, .hub-faq, .hub-footer {
    width: calc(100% - 1rem);
  }
  .hub-copy h1 { font-size: clamp(2.2rem, 13vw, 3.7rem); }
  .hub-footer { flex-direction: column; align-items: flex-start; }
}