/**
 * 智竞界官网 — 浅色干净风
 * Logo 仅出现在导航 / 页脚，避免重复堆叠
 */
:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fc;
  --text: #111827;
  --muted: #6b7280;
  --line: #e8ecf2;
  --blue: #2563eb;
  --blue-deep: #1d4ed8;
  --cyan: #38bdf8;
  --radius: 16px;
  --font: "Noto Sans SC", "Inter", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img {
  display: block;
  max-width: 100%;
}

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

.container {
  width: min(1040px, calc(100% - 40px));
  margin-inline: auto;
}

/* Nav */
.site-nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.site-nav.is-solid {
  border-bottom-color: var(--line);
  box-shadow: 0 8px 24px rgba(17, 24, 39, 0.04);
}

.site-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 20px;
}

.brand-lockup img {
  height: 32px;
  width: auto;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
}

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

.nav-cta {
  height: 36px;
  padding: 0 16px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  background: var(--blue);
}

.nav-cta:hover {
  background: var(--blue-deep);
}

/* Hero — light, brand once */
.hero {
  position: relative;
  padding: 132px 0 88px;
  overflow: hidden;
  background:
    radial-gradient(ellipse 70% 55% at 85% 0%, rgba(56, 189, 248, 0.14), transparent 55%),
    radial-gradient(ellipse 50% 45% at 0% 30%, rgba(37, 99, 235, 0.08), transparent 50%),
    linear-gradient(180deg, #fbfcfe 0%, #ffffff 55%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(17, 24, 39, 0.045) 1px, transparent 1px);
  background-size: 22px 22px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 85%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: 720px;
}

.hero h1 {
  font-size: clamp(44px, 7vw, 68px);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 14px;
  background: linear-gradient(120deg, #1d4ed8 0%, #2563eb 45%, #0ea5e9 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: rise 0.7s ease both;
}

.hero-tagline {
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 16px;
  animation: rise 0.7s ease 0.05s both;
}

.hero-lead {
  font-size: 16px;
  color: var(--muted);
  max-width: 34em;
  margin-bottom: 32px;
  animation: rise 0.7s ease 0.1s both;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  animation: rise 0.7s ease 0.16s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 0;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.15s ease, border-color 0.15s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 12px 28px rgba(37, 99, 235, 0.22);
}

.btn-primary:hover {
  background: var(--blue-deep);
}

.btn-secondary {
  color: var(--text);
  background: #fff;
  border: 1px solid var(--line);
}

.btn-secondary:hover {
  border-color: #c9d3e3;
}

.download-hint {
  display: none;
  margin-top: 14px;
  font-size: 13px;
  color: var(--muted);
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* Sections */
.section {
  padding: 88px 0;
}

.section.alt {
  background: var(--bg-soft);
}

.section-kicker {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 10px;
}

.section-title {
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.section-desc {
  color: var(--muted);
  font-size: 16px;
  max-width: 36em;
  margin-bottom: 36px;
}

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

.feature-item {
  padding: 24px 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
  opacity: 0;
  transform: translateY(12px);
}

.feature-item.is-in {
  opacity: 1;
  transform: none;
}

.feature-item:hover {
  border-color: #d4ddea;
  box-shadow: 0 14px 36px rgba(17, 24, 39, 0.06);
}

.feature-num {
  font-size: 12px;
  font-weight: 650;
  letter-spacing: 0.08em;
  color: var(--blue);
  margin-bottom: 12px;
}

.feature-item h3 {
  font-size: 17px;
  font-weight: 650;
  margin-bottom: 8px;
}

.feature-item p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}

.about-copy {
  max-width: 640px;
}

.about-copy p + p {
  margin-top: 14px;
}

.contact-list {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.contact-row {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
}

.contact-row dt {
  color: var(--muted);
  font-weight: 500;
}

.contact-row dd {
  font-weight: 500;
  word-break: break-word;
}

.contact-row a:hover {
  color: var(--blue);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 40px 0 28px;
  background: #fff;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 28px;
  padding-bottom: 28px;
}

.footer-brand strong {
  display: block;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text);
}

.footer-brand p {
  margin-top: 10px;
  font-size: 14px;
  color: var(--muted);
  max-width: 26em;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 28px 40px;
}

.footer-col h5 {
  font-size: 13px;
  font-weight: 650;
  margin-bottom: 12px;
}

.footer-col ul {
  list-style: none;
  display: grid;
  gap: 8px;
}

.footer-col a {
  font-size: 13px;
  color: var(--muted);
}

.footer-col a:hover {
  color: var(--blue);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  justify-content: space-between;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: #9ca3af;
}

.footer-bottom a:hover {
  color: var(--text);
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 112px 0 64px;
  }

  .contact-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}