/* ═══════════════════════════════════════════════════════════
   KnifEnergy Landing Pages — 统一样式
   设计理念：深色科技感 + 渐变强调色 + 清晰信息层级
   ═══════════════════════════════════════════════════════════ */

/* ── 基础重置与变量 ── */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: #1a2235;
  --bg-card-hover: #1f2a40;
  --text-primary: #f0f4f8;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  --accent-red: #ef4444;
  --accent-purple: #8b5cf6;
  --gradient-primary: linear-gradient(135deg, #3b82f6, #06b6d4);
  --gradient-warm: linear-gradient(135deg, #f59e0b, #ef4444);
  --gradient-green: linear-gradient(135deg, #10b981, #06b6d4);
  --border-color: #1e293b;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.4);
  --transition: all 0.3s ease;
}

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

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

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

a { color: var(--accent-cyan); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-blue); }

img { max-width: 100%; height: auto; }

/* ── 导航栏 ── */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(10, 14, 26, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 0 2rem;
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
}
.navbar-brand {
  font-size: 1.25rem; font-weight: 700;
  background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.navbar-links { display: flex; gap: 1.5rem; align-items: center; }
.navbar-links a { color: var(--text-secondary); font-size: 0.9rem; }
.navbar-links a:hover { color: var(--text-primary); }

/* ── Hero 区 ── */
.hero {
  min-height: 100vh;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(ellipse at 30% 50%, rgba(59,130,246,0.08) 0%, transparent 60%),
              radial-gradient(ellipse at 70% 50%, rgba(6,182,212,0.06) 0%, transparent 60%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}
@keyframes heroGlow {
  0% { transform: translate(0, 0); }
  100% { transform: translate(-3%, 2%); }
}
.hero-badge {
  display: inline-block;
  background: rgba(59,130,246,0.15);
  border: 1px solid rgba(59,130,246,0.3);
  color: var(--accent-blue);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.85rem;
  margin-bottom: 1.5rem;
  position: relative;
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  position: relative;
}
.hero h1 .highlight {
  background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero .subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 700px;
  margin-bottom: 2.5rem;
  position: relative;
}

/* ── 按钮 ── */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-sm);
  font-size: 1rem; font-weight: 600;
  cursor: pointer; border: none;
  transition: var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: 0 4px 16px rgba(59,130,246,0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 24px rgba(59,130,246,0.4); color: #fff; }
.btn-outline {
  background: transparent;
  border: 1.5px solid var(--accent-cyan);
  color: var(--accent-cyan);
}
.btn-outline:hover { background: rgba(6,182,212,0.1); color: var(--accent-cyan); }
.btn-group { display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; position: relative; }

/* ── 通用容器 ── */
.container { max-width: 1200px; margin: 0 auto; padding: 0 2rem; }

/* ── 区块 ── */
.section {
  padding: 5rem 0;
  position: relative;
}
.section-title {
  text-align: center;
  margin-bottom: 3rem;
}
.section-title h2 {
  font-size: 2rem; font-weight: 700;
  margin-bottom: 0.75rem;
}
.section-title p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ── 统计数字条 ── */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5rem;
  padding: 2rem 0;
}
.stat-item {
  text-align: center;
  padding: 1.5rem;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}
.stat-number {
  font-size: 2.2rem; font-weight: 800;
  background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  line-height: 1.2;
}
.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.3rem;
}

/* ── 卡片网格 ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 2rem;
  transition: var(--transition);
}
.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(59,130,246,0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}
.card-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}
.card h3 {
  font-size: 1.2rem; font-weight: 700;
  margin-bottom: 0.75rem;
}
.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ── 对比表格 ── */
.compare-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
}
.compare-table th {
  background: rgba(59,130,246,0.1);
  padding: 1rem 1.25rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent-cyan);
  border-bottom: 1px solid var(--border-color);
}
.compare-table td {
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.compare-table tr:last-child td { border-bottom: none; }
.compare-table tr:hover td { background: rgba(59,130,246,0.05); }
.compare-table .highlight-cell { color: var(--accent-green); font-weight: 600; }

/* ── 痛点→方案 ── */
.pain-solution {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}
.pain-list, .solution-list { list-style: none; }
.pain-list li, .solution-list li {
  padding: 0.75rem 0;
  padding-left: 2rem;
  position: relative;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.pain-list li::before {
  content: '✕'; position: absolute; left: 0;
  color: var(--accent-red); font-weight: 700;
}
.solution-list li::before {
  content: '✓'; position: absolute; left: 0;
  color: var(--accent-green); font-weight: 700;
}

/* ── CTA 区 ── */
.cta-section {
  text-align: center;
  padding: 5rem 2rem;
  background: linear-gradient(180deg, var(--bg-primary) 0%, rgba(59,130,246,0.05) 50%, var(--bg-primary) 100%);
}
.cta-section h2 {
  font-size: 2rem; font-weight: 700;
  margin-bottom: 1rem;
}
.cta-section p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 500px;
  margin-left: auto; margin-right: auto;
}

/* ── 联系信息 ── */
.contact-info {
  display: flex;
  gap: 2rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2rem;
}
.contact-item {
  display: flex; align-items: center; gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ── 页脚 ── */
.footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ── 分隔线 ── */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-color), transparent);
  margin: 0;
}

/* ── 标签 ── */
.tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
}
.tag-blue { background: rgba(59,130,246,0.15); color: var(--accent-blue); }
.tag-green { background: rgba(16,185,129,0.15); color: var(--accent-green); }
.tag-orange { background: rgba(245,158,11,0.15); color: var(--accent-orange); }
.tag-purple { background: rgba(139,92,246,0.15); color: var(--accent-purple); }

/* ── 流程步骤 ── */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  counter-reset: step;
}
.step {
  position: relative;
  padding: 2rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  counter-increment: step;
}
.step::before {
  content: counter(step);
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  background: var(--gradient-primary);
  border-radius: 50%;
  font-weight: 700; font-size: 0.9rem;
  margin-bottom: 1rem;
}
.step h4 { font-size: 1.05rem; margin-bottom: 0.5rem; }
.step p { color: var(--text-secondary); font-size: 0.9rem; }

/* ── 响应式 ── */
@media (max-width: 768px) {
  .navbar { padding: 0 1rem; }
  .navbar-links { display: none; }
  .hero { padding: 5rem 1.5rem 3rem; }
  .pain-solution { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .card-grid { grid-template-columns: 1fr; }
  .section { padding: 3rem 0; }
  .container { padding: 0 1.25rem; }
  .compare-table { font-size: 0.8rem; }
  .compare-table th, .compare-table td { padding: 0.6rem 0.75rem; }
}