/* 空旻智搭 Hub · Kongmin SmartBuild Hub · 自包含样式（无外网字体 CDN） */
:root {
  --bg: #0b0f14;
  --bg-elev: #121821;
  --bg-card: #161e2a;
  --bg-card-hover: #1c2636;
  --line: #243044;
  --text: #e8eef7;
  --muted: #9aa8bc;
  --faint: #6b7a90;
  --accent: #3d8bfd;
  --accent-soft: rgba(61, 139, 253, 0.14);
  --teal: #2dd4bf;
  --teal-soft: rgba(45, 212, 191, 0.12);
  --warn: #f59e0b;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --max: 1080px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC",
    "Source Han Sans SC", system-ui, -apple-system, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(1200px 600px at 10% -10%, #152033 0%, transparent 55%),
    radial-gradient(900px 500px at 90% 0%, #0f2430 0%, transparent 50%),
    var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
}

.wrap {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(12px);
  background: rgba(11, 15, 20, 0.82);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  color: var(--text);
  text-decoration: none;
}
.brand:hover {
  text-decoration: none;
}
.brand-cn {
  font-weight: 700;
  letter-spacing: 0.04em;
  font-size: 1.05rem;
}
.brand-en {
  font-size: 0.72rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.92rem;
}
.nav-links a {
  color: var(--muted);
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--text);
  text-decoration: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.1rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.btn:hover {
  text-decoration: none;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: #5a9fff;
  color: #fff;
}
.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}
.btn-ghost:hover {
  border-color: var(--muted);
  background: var(--bg-elev);
}
.btn-teal {
  background: var(--teal-soft);
  border-color: rgba(45, 212, 191, 0.35);
  color: var(--teal);
}
.btn-teal:hover {
  background: rgba(45, 212, 191, 0.2);
}

.hero {
  padding: 3.2rem 0 2.2rem;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: #9ec5ff;
  font-size: 0.8rem;
  border: 1px solid rgba(61, 139, 253, 0.25);
  margin-bottom: 1rem;
}
.hero h1 {
  font-size: clamp(1.7rem, 3.2vw, 2.45rem);
  line-height: 1.25;
  margin: 0 0 0.85rem;
  letter-spacing: 0.01em;
}
.hero-lead {
  font-size: 1.08rem;
  color: var(--muted);
  max-width: 42rem;
  margin: 0 0 1.4rem;
}
.hero-points {
  display: grid;
  gap: 0.65rem;
  margin: 0 0 1.6rem;
  padding: 0;
  list-style: none;
}
.hero-points li {
  display: flex;
  gap: 0.65rem;
  align-items: flex-start;
  color: var(--text);
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.75rem 0.95rem;
}
.hero-points .mark {
  color: var(--teal);
  font-weight: 700;
  flex: 0 0 auto;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-bottom: 0.9rem;
}
.hero-note {
  color: var(--faint);
  font-size: 0.86rem;
  margin: 0;
}

.section {
  padding: 1.6rem 0 2.4rem;
}
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.6rem 1rem;
  margin-bottom: 1rem;
}
.section h2 {
  margin: 0;
  font-size: 1.35rem;
}
.section .sub {
  color: var(--muted);
  font-size: 0.92rem;
  margin: 0.35rem 0 0;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.9rem;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.9rem;
}
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.9rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.15rem 1.2rem;
  box-shadow: var(--shadow);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.card:hover {
  background: var(--bg-card-hover);
  border-color: #31445f;
}
.card-kicker {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--teal);
  margin-bottom: 0.45rem;
}
.card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
}
.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}
.card ul {
  margin: 0.6rem 0 0;
  padding-left: 1.1rem;
  color: var(--muted);
  font-size: 0.9rem;
}
.card .tag {
  display: inline-block;
  margin-top: 0.85rem;
  font-size: 0.75rem;
  color: var(--faint);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.18rem 0.55rem;
}
.card.free-tier {
  border-color: rgba(45, 212, 191, 0.35);
}
.card.paid-tier .card-kicker {
  color: #9ec5ff;
}

.teaser-banner {
  margin: 0 0 1.2rem;
  padding: 0.85rem 1rem;
  border-radius: 12px;
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.28);
  color: #f8d48b;
  font-size: 0.9rem;
}

.free-card .hook {
  margin-top: 0.7rem;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--line);
  color: var(--text);
  font-size: 0.95rem;
}
.free-card .meta {
  margin-top: 0.75rem;
  font-size: 0.78rem;
  color: var(--faint);
}

.panel {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem;
}
.panel h2,
.panel h3 {
  margin-top: 0;
}
.muted {
  color: var(--muted);
}
.faint {
  color: var(--faint);
}
.small {
  font-size: 0.88rem;
}

.form {
  display: grid;
  gap: 0.85rem;
  max-width: 32rem;
}
.form label {
  display: grid;
  gap: 0.35rem;
  font-size: 0.9rem;
  color: var(--muted);
}
.form input,
.form textarea,
.form select {
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.7rem 0.85rem;
}
.form input:focus,
.form textarea:focus,
.form select:focus {
  outline: 2px solid rgba(61, 139, 253, 0.45);
  border-color: var(--accent);
}
.form-note {
  font-size: 0.82rem;
  color: var(--faint);
  margin: 0;
}

.divider {
  height: 1px;
  background: var(--line);
  border: 0;
  margin: 0.5rem 0 1.4rem;
}

.site-footer {
  margin-top: 2rem;
  border-top: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.25);
  padding: 1.6rem 0 2rem;
  color: var(--muted);
  font-size: 0.88rem;
}
.footer-grid {
  display: grid;
  gap: 0.35rem;
}
.footer-grid strong {
  color: var(--text);
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.1rem;
  margin-top: 0.85rem;
}
.footer-links a {
  color: var(--muted);
}

.page-title {
  padding: 2.2rem 0 0.6rem;
}
.page-title h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.45rem, 2.6vw, 2rem);
}
.page-title p {
  margin: 0;
  color: var(--muted);
  max-width: 40rem;
}

@media (max-width: 960px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-3 {
    grid-template-columns: 1fr;
  }
}
@media (max-width: 640px) {
  .grid-4,
  .grid-2 {
    grid-template-columns: 1fr;
  }
  .hero {
    padding-top: 2.2rem;
  }
  .nav-links {
    width: 100%;
  }
}