/* ============================================
   未科新能官网 - 增强视觉样式 v2.0
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;600;700;900&display=swap');

/* === Reset & Base === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --primary: #1a56db;
  --primary-dark: #1240a8;
  --primary-light: #e8f0fe;
  --primary-lighter: #f0f5ff;
  --accent: #f97316;
  --accent-dark: #ea580c;
  --text: #1a1a2e;
  --text-light: #4a5568;
  --text-lighter: #9ca3af;
  --bg: #ffffff;
  --bg-gray: #f7f8fc;
  --bg-dark: #0f172a;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 40px -10px rgba(0,0,0,0.1);
  --radius: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --max-width: 1200px;
  --header-height: 72px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: 0.01em;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; display: block; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 28px; }

/* === Header === */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  height: var(--header-height);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid rgba(226,232,240,0.6);
  transition: all var(--transition);
}
.site-header.scrolled { box-shadow: 0 4px 20px rgba(0,0,0,0.06); }

.header-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 28px;
  display: flex; align-items: center; justify-content: space-between;
  height: 100%;
}

.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo img { height: 38px; width: auto; }
.logo-text { font-size: 19px; font-weight: 800; color: var(--text); letter-spacing: -0.02em; }
.logo-text span { color: var(--primary); }

.main-nav { display: flex; align-items: center; gap: 2px; }
.main-nav > li { list-style: none; position: relative; }
.main-nav > li > a {
  display: block; padding: 8px 14px;
  font-size: 14.5px; font-weight: 500; color: var(--text);
  border-radius: var(--radius);
  transition: all var(--transition);
  position: relative;
}
.main-nav > li > a:hover, .main-nav > li > a.active {
  color: var(--primary); background: var(--primary-light);
}
.main-nav > li > a.active::after {
  content: ''; position: absolute; bottom: 0; left: 50%; transform: translateX(-50%);
  width: 20px; height: 3px; background: var(--primary); border-radius: 2px;
}

/* Dropdown */
.dropdown-menu {
  position: absolute; top: calc(100% + 8px); left: -10px; min-width: 260px;
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 8px;
  box-shadow: 0 12px 36px rgba(0,0,0,0.1);
  opacity: 0; visibility: hidden; transform: translateY(6px);
  transition: all 0.25s ease;
}
.main-nav > li:hover .dropdown-menu { opacity: 1; visibility: visible; transform: translateY(0); }
.dropdown-menu a {
  display: block; padding: 11px 16px; color: var(--text);
  border-radius: var(--radius); font-size: 14px; font-weight: 500;
  transition: all 0.2s;
}
.dropdown-menu a:hover { background: var(--primary-lighter); color: var(--primary); transform: translateX(4px); }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span {
  display: block; width: 22px; height: 2px; background: var(--text);
  margin: 5px 0; transition: all var(--transition); border-radius: 2px;
}

/* === Hero === */
.hero {
  padding: 140px 0 100px;
  background: linear-gradient(135deg, #0f2350 0%, #1a56db 50%, #3b82f6 100%);
  color: #fff; text-align: center; position: relative; overflow: hidden;
  min-height: 560px; display: flex; align-items: center;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 20% 80%, rgba(59,130,246,0.3) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, rgba(99,102,241,0.2) 0%, transparent 50%);
}
.hero::after {
  content: ''; position: absolute; bottom: -2px; left: 0; right: 0; height: 60px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 60'%3E%3Cpath fill='%23ffffff' d='M0,30 C360,60 1080,0 1440,30 L1440,60 L0,60 Z'/%3E%3C/svg%3E") no-repeat bottom;
  background-size: cover;
}
.hero-content { position: relative; z-index: 1; width: 100%; }
.hero h1 {
  font-size: 44px; font-weight: 900; margin-bottom: 20px;
  line-height: 1.25; letter-spacing: -0.01em;
  text-shadow: 0 2px 20px rgba(0,0,0,0.15);
}
.hero p { font-size: 18px; opacity: 0.9; max-width: 680px; margin: 0 auto 36px; line-height: 1.8; }

.hero-page {
  padding: 150px 0 90px;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1a365d 100%);
  color: #fff; position: relative; overflow: hidden;
  min-height: 400px;
}
.hero-page::after {
  content: ''; position: absolute; bottom: -2px; left: 0; right: 0; height: 50px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 50'%3E%3Cpath fill='%23ffffff' d='M0,25 C360,50 1080,0 1440,25 L1440,50 L0,50 Z'/%3E%3C/svg%3E") no-repeat bottom;
  background-size: cover;
}
.hero-page h1 { font-size: 40px; font-weight: 900; margin-bottom: 16px; letter-spacing: -0.01em; }
.hero-page p { font-size: 17px; opacity: 0.85; max-width: 700px; line-height: 1.8; }

/* === Buttons === */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 30px; border-radius: var(--radius);
  font-size: 15px; font-weight: 600; cursor: pointer;
  border: none; transition: all var(--transition);
  text-decoration: none; letter-spacing: 0.01em;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, #fb923c 100%);
  color: #fff; box-shadow: 0 4px 16px rgba(249,115,22,0.35);
}
.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-dark) 0%, var(--accent) 100%);
  transform: translateY(-2px); box-shadow: 0 6px 24px rgba(249,115,22,0.45); color: #fff;
}
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,0.4); }
.btn-outline:hover { border-color: #fff; background: rgba(255,255,255,0.1); color: #fff; }
.btn-white { background: #fff; color: var(--primary); box-shadow: var(--shadow); }
.btn-white:hover { background: #f8f9fa; color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow-lg); }

/* === Sections === */
.section { padding: 96px 0; }
.section-gray { background: var(--bg-gray); }
.section-dark { background: var(--bg-dark); color: #fff; }

.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 {
  font-size: 34px; font-weight: 900; margin-bottom: 14px;
  color: var(--text); letter-spacing: -0.02em; line-height: 1.3;
}
.section-title p { color: var(--text-light); font-size: 16px; max-width: 580px; margin: 0 auto; line-height: 1.7; }

/* === Cards === */
.card {
  background: #fff; border-radius: var(--radius-lg);
  border: 1px solid var(--border); padding: 36px;
  transition: all var(--transition); position: relative; overflow: hidden;
}
.card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0;
  height: 4px; background: linear-gradient(90deg, var(--primary), #3b82f6);
  transform: scaleX(0); transform-origin: left; transition: transform 0.4s ease;
}
.card:hover { box-shadow: var(--shadow-xl); border-color: transparent; transform: translateY(-6px); }
.card:hover::before { transform: scaleX(1); }

.card-icon {
  width: 64px; height: 64px; border-radius: 16px;
  background: linear-gradient(135deg, var(--primary-light) 0%, #dbeafe 100%);
  display: flex; align-items: center; justify-content: center;
  font-size: 30px; margin-bottom: 24px;
}
.card h3 { font-size: 20px; font-weight: 700; margin-bottom: 14px; color: var(--text); }
.card p { color: var(--text-light); font-size: 15px; line-height: 1.8; }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* === Stats === */
.stats-bar { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; padding: 48px 0; }
.stat-item { text-align: center; }
.stat-number {
  font-size: 48px; font-weight: 900; color: var(--primary);
  line-height: 1; letter-spacing: -0.03em;
}
.stat-label {
  font-size: 14px; color: var(--text-light); margin-top: 10px;
  font-weight: 500; letter-spacing: 0.02em;
}

/* === Timeline === */
.timeline { position: relative; padding-left: 44px; }
.timeline::before {
  content: ''; position: absolute; left: 16px; top: 0; bottom: 0;
  width: 2px; background: linear-gradient(to bottom, var(--primary), #93c5fd);
}
.timeline-item { position: relative; padding-bottom: 40px; }
.timeline-item::before {
  content: ''; position: absolute; left: -36px; top: 5px;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--primary); border: 3px solid var(--primary-light);
  box-shadow: 0 0 0 4px rgba(26,86,219,0.1);
}
.timeline-item h4 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.timeline-item p { color: var(--text-light); font-size: 15px; line-height: 1.7; }

/* === Partners === */
.partner-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 16px;
}
.partner-item {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 20px 16px; display: flex; align-items: center; justify-content: center;
  min-height: 90px; transition: all var(--transition);
  filter: grayscale(60%); opacity: 0.85;
}
.partner-item:hover {
  box-shadow: var(--shadow-lg); border-color: var(--primary);
  filter: grayscale(0%); opacity: 1; transform: translateY(-3px);
}
.partner-item img { max-height: 44px; max-width: 110px; object-fit: contain; }
.partner-item strong { font-size: 14px; color: var(--text); font-weight: 600; }

/* === Footer === */
.site-footer { background: var(--bg-dark); color: #fff; padding: 64px 0 30px; position: relative; }
.site-footer::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent), var(--primary));
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px;
  padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand p { color: rgba(255,255,255,0.55); font-size: 14px; line-height: 1.9; margin-top: 16px; }
.footer-col h4 { font-size: 15px; font-weight: 700; margin-bottom: 20px; letter-spacing: 0.02em; }
.footer-col a {
  display: block; color: rgba(255,255,255,0.55); font-size: 14px; padding: 5px 0;
  transition: all 0.2s;
}
.footer-col a:hover { color: #fff; transform: translateX(4px); }
.footer-bottom { padding-top: 24px; text-align: center; color: rgba(255,255,255,0.35); font-size: 13px; }

/* === Breadcrumb === */
.breadcrumb { padding: 16px 0; font-size: 14px; color: rgba(255,255,255,0.6); }
.breadcrumb a { color: rgba(255,255,255,0.6); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { margin: 0 8px; }

/* === Feature List === */
.feature-list { list-style: none; }
.feature-list li {
  padding: 14px 0; padding-left: 36px; position: relative;
  border-bottom: 1px solid var(--border);
  font-size: 15px; color: var(--text-light); line-height: 1.7;
}
.feature-list li::before {
  content: '✓'; position: absolute; left: 4px; color: var(--primary);
  font-weight: 700; font-size: 16px;
}

/* === Placeholder === */
.img-placeholder {
  background: linear-gradient(135deg, var(--primary-light) 0%, #dbeafe 100%);
  border-radius: var(--radius-lg);
  display: flex; align-items: center; justify-content: center;
  flex-direction: column; color: var(--primary); font-size: 14px; font-weight: 500;
  min-height: 200px;
}

/* === Tabs === */
.tabs { display: flex; gap: 4px; margin-bottom: 36px; border-bottom: 2px solid var(--border); }
.tab-btn {
  padding: 12px 24px; background: none; border: none; cursor: pointer;
  font-size: 15px; font-weight: 600; color: var(--text-light);
  border-bottom: 3px solid transparent; margin-bottom: -2px;
  transition: all var(--transition);
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* === Table === */
.data-table {
  width: 100%; border-collapse: collapse; background: #fff;
  border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-sm);
}
.data-table th {
  background: linear-gradient(135deg, var(--primary) 0%, #2563eb 100%);
  color: #fff; padding: 15px 20px; text-align: left; font-size: 14px; font-weight: 600;
}
.data-table td { padding: 14px 20px; border-bottom: 1px solid var(--border); font-size: 14px; }
.data-table tr:hover td { background: var(--bg-gray); }

/* === CTA === */
.cta-section {
  background: linear-gradient(135deg, #0f2350 0%, var(--primary) 50%, #3b82f6 100%);
  padding: 72px 0; text-align: center; color: #fff; position: relative; overflow: hidden;
}
.cta-section::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.05) 0%, transparent 60%);
}
.cta-section h2 { font-size: 32px; font-weight: 900; margin-bottom: 16px; position: relative; }
.cta-section p { font-size: 17px; opacity: 0.9; margin-bottom: 36px; position: relative; }

/* === Process Steps === */
.process-steps { display: flex; gap: 12px; align-items: flex-start; }
.process-step { flex: 1; text-align: center; position: relative; padding: 24px 12px; }
.process-step::after {
  content: '→'; position: absolute; right: -14px; top: 46px;
  font-size: 22px; color: var(--primary); font-weight: 700;
}
.process-step:last-child::after { display: none; }
.step-number {
  width: 56px; height: 56px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, #3b82f6 100%);
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 22px; font-weight: 800; margin: 0 auto 16px;
  box-shadow: 0 4px 14px rgba(26,86,219,0.3);
}

/* === Badge === */
.badge {
  display: inline-block; padding: 5px 14px;
  background: var(--primary-light); color: var(--primary);
  border-radius: 20px; font-size: 13px; font-weight: 600;
}
.badge-accent { background: #fff7ed; color: var(--accent); }

/* === Animations === */
.fade-in {
  opacity: 0; transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-in.visible { opacity: 1; transform: translateY(0); }

@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes pulse { 0%,100% { opacity: 0.4; } 50% { opacity: 1; } }

/* === Responsive === */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --header-height: 64px; }
  .hero { padding: 110px 0 80px; min-height: auto; }
  .hero h1 { font-size: 28px; }
  .hero p { font-size: 16px; }
  .hero-page { padding: 110px 0 60px; }
  .hero-page h1 { font-size: 28px; }
  .section { padding: 56px 0; }
  .section-title h2 { font-size: 26px; }
  .section-title { margin-bottom: 40px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: 1fr 1fr; gap: 24px; }
  .stat-number { font-size: 36px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .nav-toggle { display: block; }
  .main-nav {
    position: fixed; top: var(--header-height); left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 16px;
    border-bottom: 1px solid var(--border); box-shadow: var(--shadow-lg);
    transform: translateY(-100%); opacity: 0; visibility: hidden;
    transition: all var(--transition);
  }
  .main-nav.open { transform: translateY(0); opacity: 1; visibility: visible; }
  .main-nav > li > a { padding: 12px 16px; }
  .dropdown-menu {
    position: static; opacity: 1; visibility: visible;
    transform: none; box-shadow: none; border: none; padding: 0 0 0 16px;
  }
  .process-steps { flex-direction: column; }
  .process-step::after { content: '↓'; right: auto; left: 50%; top: auto; bottom: -12px; transform: translateX(-50%); }
}