/* NexusCore 官网样式 - 深色科技风 */
:root {
  --bg: #0a0e1a;
  --bg-alt: #0d1322;
  --card: #131a2c;
  --card-hover: #182136;
  --border: #233048;
  --text: #e6ebf5;
  --muted: #8b97ad;
  --primary: #3b82f6;
  --cyan: #22d3ee;
  --gradient: linear-gradient(120deg, #3b82f6, #22d3ee);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.accent { color: var(--cyan); }
.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ===== 导航 ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 18px 0;
  transition: all .3s ease;
}
.navbar.scrolled {
  background: rgba(10,14,26,.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-icon { width: 34px; height: 34px; }
.logo-text { font-size: 22px; font-weight: 700; color: var(--text); letter-spacing: .5px; }
.nav-menu { display: flex; align-items: center; gap: 30px; list-style: none; }
.nav-menu a { color: var(--muted); text-decoration: none; font-size: 15px; transition: color .2s; }
.nav-menu a:hover { color: var(--text); }
.btn-nav {
  background: var(--gradient) !important;
  color: #fff !important;
  padding: 9px 20px; border-radius: 8px; font-weight: 600;
}
.btn-nav:hover { opacity: .9; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; padding: 6px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: all .3s; }

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex; align-items: center;
  padding: 140px 0 80px;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.orb { position: absolute; border-radius: 50%; filter: blur(90px); opacity: .35; }
.orb-1 { width: 480px; height: 480px; background: #2563eb; top: -120px; right: -80px; animation: float 9s ease-in-out infinite; }
.orb-2 { width: 380px; height: 380px; background: #0891b2; bottom: -100px; left: -100px; animation: float 11s ease-in-out infinite reverse; }
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-30px); } }
.grid-overlay {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 40%, transparent 100%);
}
.hero-content { position: relative; text-align: center; max-width: 900px; }
.hero-tag {
  display: inline-block;
  font-size: 13px; letter-spacing: 3px;
  color: var(--cyan);
  border: 1px solid rgba(34,211,238,.3);
  background: rgba(34,211,238,.08);
  padding: 7px 18px; border-radius: 100px;
  margin-bottom: 26px;
}
.hero h1 { font-size: clamp(34px, 5.4vw, 62px); font-weight: 800; line-height: 1.25; letter-spacing: 1px; }
.hero-sub { font-size: 17px; color: var(--muted); max-width: 680px; margin: 24px auto 0; }
.hero-cta { display: flex; gap: 16px; justify-content: center; margin-top: 40px; flex-wrap: wrap; }
.btn {
  display: inline-block; text-decoration: none;
  padding: 14px 32px; border-radius: 10px;
  font-size: 16px; font-weight: 600;
  transition: all .25s ease;
}
.btn-primary { background: var(--gradient); color: #fff; box-shadow: 0 8px 30px rgba(37,99,235,.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 40px rgba(37,99,235,.5); }
.btn-ghost { color: var(--text); border: 1px solid var(--border); background: rgba(255,255,255,.03); }
.btn-ghost:hover { border-color: var(--primary); background: rgba(59,130,246,.08); }
.btn-lg { padding: 17px 44px; font-size: 17px; }

.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 20px; margin-top: 76px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}
.stat-num { font-size: 40px; font-weight: 800; background: var(--gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.stat-plus { font-size: 26px; font-weight: 800; color: var(--cyan); }
.stat p { color: var(--muted); font-size: 14px; margin-top: 2px; }

.scroll-hint { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); }
.scroll-hint span {
  display: block; width: 24px; height: 38px;
  border: 2px solid var(--muted); border-radius: 14px;
  position: relative;
}
.scroll-hint span::after {
  content: ''; position: absolute; top: 7px; left: 50%; transform: translateX(-50%);
  width: 4px; height: 8px; border-radius: 2px;
  background: var(--cyan);
  animation: scrollDot 1.8s ease infinite;
}
@keyframes scrollDot { 0% { opacity: 1; top: 7px; } 100% { opacity: 0; top: 20px; } }

/* ===== Section ===== */
.section { padding: 100px 0; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-tag { font-size: 13px; letter-spacing: 3px; color: var(--cyan); font-weight: 600; margin-bottom: 12px; }
.section-title { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; letter-spacing: 1px; }
.section-desc { color: var(--muted); font-size: 16px; margin-top: 14px; max-width: 640px; }

.grid { display: grid; gap: 22px; margin-top: 52px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px 28px;
  transition: all .3s ease;
}
.card:hover {
  background: var(--card-hover);
  border-color: rgba(59,130,246,.5);
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(0,0,0,.35);
}
.card h3 { font-size: 19px; margin: 0 0 10px; font-weight: 700; }
.card p { color: var(--muted); font-size: 14.5px; }
.card-icon {
  width: 54px; height: 54px; border-radius: 13px;
  background: linear-gradient(135deg, rgba(59,130,246,.18), rgba(34,211,238,.18));
  border: 1px solid rgba(59,130,246,.3);
  display: flex; align-items: center; justify-content: center;
  color: var(--cyan);
  margin-bottom: 20px;
}
.card-icon svg { width: 27px; height: 27px; }

.card-line h3 { display: flex; align-items: baseline; gap: 12px; font-size: 17.5px; }
.card-line .num {
  font-size: 14px; font-weight: 800;
  background: var(--gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}

/* ===== 流程 ===== */
.process { display: flex; align-items: flex-start; gap: 8px; margin-top: 56px; }
.step { flex: 1; text-align: center; padding: 0 6px; }
.step-dot {
  width: 52px; height: 52px; border-radius: 50%;
  background: var(--card); border: 2px solid var(--primary);
  color: var(--cyan); font-size: 20px; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 18px;
  box-shadow: 0 0 0 6px rgba(59,130,246,.12);
}
.step h3 { font-size: 16.5px; margin-bottom: 8px; }
.step p { font-size: 13.5px; color: var(--muted); }
.step-arrow {
  flex: 0 0 34px; height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--cyan));
  margin-top: 26px; border-radius: 2px; opacity: .5;
}

/* ===== 技术栈 ===== */
.tech-groups { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; margin-top: 48px; }
.tech-group {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 16px; padding: 26px 28px;
}
.tech-group h4 { font-size: 15px; color: var(--cyan); margin-bottom: 16px; letter-spacing: 1px; }
.tags { display: flex; flex-wrap: wrap; gap: 10px; }
.tags span {
  font-size: 13.5px; color: var(--text);
  background: rgba(59,130,246,.1);
  border: 1px solid rgba(59,130,246,.25);
  padding: 7px 16px; border-radius: 100px;
}

/* ===== 关于 ===== */
.about-wrap { display: grid; grid-template-columns: 1.5fr 1fr; gap: 60px; align-items: start; }
.about-text p { color: var(--muted); margin-top: 18px; font-size: 15.5px; }
.about-text strong { color: var(--text); }
.about-points { display: flex; gap: 40px; margin-top: 34px; }
.point strong { display: block; font-size: 30px; font-weight: 800; background: var(--gradient); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.point span { font-size: 13.5px; color: var(--muted); }

.about-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 18px; padding: 34px 32px;
}
.about-card h3 { font-size: 18px; margin-bottom: 22px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
.about-card ul { list-style: none; }
.about-card li { display: flex; justify-content: space-between; gap: 16px; padding: 11px 0; font-size: 14.5px; }
.about-card li span { color: var(--muted); flex-shrink: 0; }
.about-card li em { font-style: normal; text-align: right; color: var(--text); }

/* ===== 联系 ===== */
.contact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-top: 52px; }
.contact-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 16px; padding: 34px 28px; text-align: center;
  transition: all .3s ease;
}
.contact-card:hover { border-color: rgba(34,211,238,.5); transform: translateY(-6px); }
.contact-card .card-icon { margin: 0 auto 18px; }
.contact-card h3 { font-size: 17.5px; margin-bottom: 8px; }
.contact-card p { color: var(--muted); font-size: 13.5px; }
.contact-value { display: block; margin-top: 10px; color: var(--cyan) !important; font-size: 15px; font-weight: 600; text-decoration: none; word-break: break-all; }
a.contact-value:hover { text-decoration: underline; }
.contact-cta { text-align: center; margin-top: 46px; }

/* ===== Footer ===== */
.footer { background: #070b14; border-top: 1px solid var(--border); padding: 64px 0 0; }
.footer-wrap { display: grid; grid-template-columns: 1.4fr 1fr 1.3fr; gap: 44px; padding-bottom: 46px; }
.footer-brand p { color: var(--muted); font-size: 14px; margin-top: 16px; }
.footer-links { display: flex; flex-direction: column; gap: 11px; }
.footer-links h4 { font-size: 15px; margin-bottom: 6px; }
.footer-links a, .footer-links span { color: var(--muted); font-size: 14px; text-decoration: none; }
.footer-links a:hover { color: var(--cyan); }
.footer-bottom { border-top: 1px solid var(--border); padding: 20px 0; }
.footer-bottom .container { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.footer-bottom p { color: #6b7690; font-size: 13px; }
.footer-bottom a { color: #6b7690; text-decoration: none; }
.footer-bottom a:hover { color: var(--cyan); }

/* ===== 动效 ===== */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 960px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .tech-groups { grid-template-columns: 1fr; }
  .about-wrap { grid-template-columns: 1fr; gap: 40px; }
  .footer-wrap { grid-template-columns: 1fr 1fr; }
  .process { flex-direction: column; align-items: stretch; gap: 0; }
  .step-arrow { display: none; }
  .step { display: flex; text-align: left; gap: 18px; padding: 14px 0; align-items: flex-start; }
  .step-dot { margin: 0; flex-shrink: 0; }
  .contact-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 28px; }
}

@media (max-width: 640px) {
  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed; top: 64px; right: -100%;
    flex-direction: column; align-items: flex-start;
    background: rgba(13,19,34,.97);
    width: min(78vw, 320px); height: 100vh;
    padding: 34px 28px; gap: 22px;
    border-left: 1px solid var(--border);
    transition: right .3s ease;
  }
  .nav-menu.open { right: 0; }
  .grid-3 { grid-template-columns: 1fr; }
  .footer-wrap { grid-template-columns: 1fr; }
  .footer-bottom .container { flex-direction: column; text-align: center; }
  .about-points { gap: 26px; flex-wrap: wrap; }
  .hero { padding-top: 120px; }
}