/* guanwei-website/styles.css */

:root {
  /* Color Palette */
  --bg-color: #f4f7fa;
  --text-dark: #172033;
  --text-light: #647184;
  --primary-navy: #071222;
  --primary-blue: #1e4e79;
  --primary-hover: #153b5f;
  --accent-orange: #c86528;
  --line-color: #dfe7ef;
  --nav-bg: rgba(255, 255, 255, 0.95);
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.5);
  
  /* Tyopgraphy */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  /* Spacing & Sizes */
  --header-height: 78px;
  --section-padding: 6rem 2rem;
  --border-radius: 8px;
  --container-width: 1200px;
  
  /* Transitions */
  --ease: 0.3s ease-in-out;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--ease);
}

ul {
  list-style: none;
}

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

/* Utilities */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  width: 100%;
}

.text-center { text-align: center; }
.section-title {
  font-size: 2.5rem;
  color: var(--primary-navy);
  margin-bottom: 3rem;
  font-weight: 700;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 50px;
  height: 4px;
  background-color: var(--primary-blue);
  border-radius: 2px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 56px;
  padding: 0.85rem 1.35rem;
  background-color: var(--primary-blue);
  color: #fff;
  font-weight: 800;
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: all var(--ease);
  box-shadow: 0 12px 24px rgba(30, 78, 121, 0.22);
}

.btn:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 16px 28px rgba(30, 78, 121, 0.24);
}

.btn-light {
  background: #fff;
  color: var(--primary-navy);
  box-shadow: 0 12px 24px rgba(0,0,0,0.12);
}

.btn-light:hover {
  background: #e9eef4;
  color: var(--primary-navy);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary-navy);
  border: 2px solid var(--primary-navy);
  box-shadow: none;
}

.btn-secondary:hover {
  background-color: var(--primary-navy);
  color: #fff;
}

/* Header */
header {
  position: fixed;
  top: 0;
  width: 100%;
  height: var(--header-height);
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(223, 231, 239, 0.88);
  box-shadow: none;
  z-index: 1000;
  display: flex;
  align-items: center;
  transition: background var(--ease);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

.logo {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  width: auto;
  min-height: 64px;
  color: var(--primary-navy);
}

.brand-logo {
  display: block;
  width: auto;
  height: 64px;
  max-width: 220px;
  object-fit: contain;
}

.brand-logo-footer {
  width: min(210px, 100%);
  height: auto;
}

.nav-links {
  display: flex;
  gap: 1.8rem;
}

.nav-links a {
  font-size: 0.92rem;
  font-weight: 800;
  color: var(--text-dark);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: var(--primary-blue);
  transition: width var(--ease);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.mobile-menu-btn {
  display: none;
  width: 42px;
  height: 42px;
  font-size: 1.35rem;
  cursor: pointer;
  background: #fff;
  border: 1px solid var(--line-color);
  border-radius: 4px;
  color: var(--primary-navy);
}

/* Footer */
footer {
  background-color: var(--primary-navy);
  color: #fff;
  padding: 4rem 2rem 2rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  max-width: var(--container-width);
  margin: 0 auto;
}

.footer-col h3 {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.footer-col h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: var(--primary-blue);
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  width: 210px;
  max-width: 100%;
  margin-bottom: 1.25rem;
  border: none;
  padding: 0;
}

.footer-col p, .footer-col li {
  margin-bottom: 0.75rem;
  color: #cbd5e1;
}

.footer-col a {
  color: #cbd5e1;
}

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

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  margin-top: 3rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: #94a3b8;
  font-size: 0.875rem;
}

/* Animations */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s ease-out;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: -100%;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background: var(--nav-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: left var(--ease);
    backdrop-filter: blur(10px);
    padding: 2rem;
  }
  
  .nav-links.active {
    left: 0;
  }
  
  .mobile-menu-btn {
    display: block;
  }

  .logo {
    min-height: 56px;
  }

  .brand-logo {
    height: 56px;
    max-width: 184px;
  }

  .section-title {
    font-size: 2rem;
  }

  :root {
    --section-padding: 4rem 1.25rem;
  }
}

.footer-col .footer-logo::after { display: none; }