/* roulang page: index */
:root {
  --primary: #00A8C5;
  --primary-dark: #007B90;
  --accent: #FF6B35;
  --accent-dark: #E05A2A;
  --dark-bg: #0B1A2C;
  --light-bg: #F4F9FC;
  --text: #1A1A1A;
  --text-secondary: #555;
  --white: #FFFFFF;
  --border-light: rgba(0,168,197,0.12);
  --shadow-card: 0 4px 20px rgba(0,168,197,0.08);
  --shadow-card-hover: 0 12px 32px rgba(0,168,197,0.18);
  --radius-md: 16px;
  --radius-xl: 30px;
  --radius-sm: 8px;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', Roboto, sans-serif;
  line-height: 1.7;
  color: var(--text);
  font-size: 1rem;
  font-weight: 400;
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.25s ease;
}

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

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

header.scrolled {
  background: rgba(255,255,255,0.98);
  box-shadow: 0 2px 16px rgba(0,0,0,0.08);
  border-bottom-color: rgba(0,168,197,0.1);
}

@media (max-width: 768px) {
  body { 
    font-size: 0.95rem;
  }
  .container {
    padding: 0 20px;
  }
}

header .nav-wrapper {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
}

.primary-btn, 
.secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

.primary-btn {
  background: var(--accent);
  color: var(--white);
  border: 2px solid var(--accent);
  border-radius: var(--radius-xl);
  padding: 12px 36px;
  font-weight: 600;
  letter-spacing: 0.5px;
  font-size: 1.05rem;
}

.primary-btn:hover {
  background: #e8551a;
  border-color: #e8551a;
  box-shadow: 0 6px 24px rgba(255,107,53,0.45);
  transform: translateY(-2px) scale(1.03);
  color: #fff;
}

@media (max-width: 768px) {
  .primary-btn { width: 100%; padding: 14px; }
}