/* 
  Chinese KY Kaiyuan Group Official Website
  Theme: Light Black & Gold (淡黑金)
  Style: Luxurious, Professional, Modern
*/

:root {
  --color-gold: #d4af37;
  --color-gold-light: #f1e5ac;
  --color-gold-dark: #b8860b;
  --color-black-pure: #0f0f0f;
  --color-black-bg: #1a1a1a;
  --color-black-soft: #2d2d2d;
  --color-white: #ffffff;
  --color-gray-light: #f5f5f5;
  --color-text-main: #e0e0e0;
  --font-serif: 'Playfair Display', serif;
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600&family=Playfair+Display:ital,wght@0,700;1,700&display=swap');

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-black-bg);
  color: var(--color-text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

li {
  list-style: none;
}

/* Layout Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section-padding {
  padding: 100px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 60px;
  position: relative;
}

.section-title h2 {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  color: var(--color-gold);
  margin-bottom: 15px;
}

.section-title span {
  display: block;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--color-gold-dark);
}

/* Navigation */
header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(15, 15, 15, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(212, 175, 55, 0.2);
  transition: var(--transition);
}

nav {
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--color-gold);
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-links a:hover {
  color: var(--color-gold);
}

.nav-links a.active {
  color: var(--color-gold);
}

/* Hero Section */
.hero {
  height: 100vh;
  position: relative;
  display: flex;
  align-items: center;
  background: linear-gradient(rgba(0,0,0,0.6), rgba(0,0,0,0.6)), url('https://tse-mm.bing.com/th?q=Corporate+Headquarters+Luxury');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}

.hero-content {
  max-width: 800px;
  animation: fadeInUp 1s ease;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: 3.5rem;
  color: var(--color-gold);
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero p {
  font-size: 1.25rem;
  margin-bottom: 30px;
  color: var(--color-white);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 35px;
  border: 1px solid var(--color-gold);
  border-radius: 0;
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  background: transparent;
  color: var(--color-gold);
}

.btn-primary {
  background: var(--color-gold);
  color: var(--color-black-pure);
}

.btn-primary:hover {
  background: transparent;
  color: var(--color-gold);
}

/* Cards */
.card {
  background: var(--color-black-soft);
  border: 1px solid rgba(212, 175, 55, 0.1);
  padding: 30px;
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-10px);
  border-color: var(--color-gold);
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

/* Animation Keyframes */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Footer Control */
footer {
  background: var(--color-black-pure);
  padding: 60px 0;
  border-top: 1px solid rgba(212, 175, 55, 0.1);
}

.footer-top {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

/* Responsive Customization */
@media (max-width: 768px) {
  .hero h1 { font-size: 2.5rem; }
  .nav-links { display: none; }
}

/* Online Service Button */
.online-cs {
  position: fixed;
  right: 30px;
  bottom: 30px;
  width: 60px;
  height: 60px;
  background: var(--color-gold);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  cursor: pointer;
  z-index: 999;
}

.online-cs i {
  color: var(--color-black-pure);
  font-size: 24px;
}