/* ============================================================
   SOVEREIGN REAL ESTATE & LAND REORGANIZATION GROUP
   主權級營建古典主義與當代鋼骨幾何美學
   Design System & Global Styles
   ============================================================ */

:root {
  /* Core Color Palette */
  --color-obsidian-deep: #070D19;        /* 曜石深邃藍 - Primary Background */
  --color-steel-gold: #E0A93B;           /* 都市鋼骨金 - Primary Accent */
  --color-credit-blue: #00A3FF;          /* 信貸流動藍 - Dynamic Pulse */
  --color-risk-red: #FF3B30;             /* 風控預警紅 - Alert */
  --color-white: #FFFFFF;
  --color-light-gray: #F5F5F5;
  --color-dark-gray: #1A1A1A;
  --color-medium-gray: #333333;
  
  /* Typography */
  --font-display: 'Georgia', 'Garamond', serif;
  --font-body: 'Segoe UI', 'Helvetica Neue', sans-serif;
  --font-mono: 'Courier New', monospace;
  
  /* Spacing Scale */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 5rem;
  --spacing-5xl: 6rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.15);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.2);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);
  
  /* Border Radius */
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.23, 1, 0.32, 1);
  --transition-normal: 300ms cubic-bezier(0.23, 1, 0.32, 1);
  --transition-slow: 500ms cubic-bezier(0.23, 1, 0.32, 1);
}

/* ============================================================
   RESET & BASE STYLES
   ============================================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-obsidian-deep);
  color: var(--color-white);
  line-height: 1.6;
  font-size: 16px;
}

/* ============================================================
   TYPOGRAPHY
   ============================================================ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-lg);
  letter-spacing: -0.5px;
}

h1 {
  font-size: 3.5rem;
  color: var(--color-white);
}

h2 {
  font-size: 2.5rem;
  color: var(--color-white);
}

h3 {
  font-size: 1.875rem;
  color: var(--color-white);
}

h4 {
  font-size: 1.5rem;
  color: var(--color-white);
}

h5 {
  font-size: 1.25rem;
  color: var(--color-white);
}

h6 {
  font-size: 1rem;
  color: var(--color-white);
}

p {
  margin-bottom: var(--spacing-md);
  line-height: 1.8;
  font-size: 1rem;
}

a {
  color: var(--color-steel-gold);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-credit-blue);
  text-decoration: underline;
}

/* ============================================================
   LAYOUT & GRID
   ============================================================ */

.container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
}

.container-fluid {
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
}

.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-col {
  display: flex;
  flex-direction: column;
}

/* ============================================================
   NAVIGATION
   ============================================================ */

.navbar {
  background-color: var(--color-obsidian-deep);
  border-bottom: 1px solid rgba(224, 169, 59, 0.2);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-md);
}

.navbar-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-brand {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-steel-gold);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.navbar-brand span {
  font-size: 0.875rem;
  color: var(--color-credit-blue);
  font-weight: 400;
  letter-spacing: 1px;
}

.navbar-nav {
  display: flex;
  list-style: none;
  gap: var(--spacing-2xl);
  align-items: center;
}

.nav-link {
  color: var(--color-white);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
  padding-bottom: var(--spacing-sm);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-steel-gold);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-steel-gold);
  transition: width var(--transition-fast);
}

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

/* ============================================================
   BUTTONS
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  gap: var(--spacing-sm);
}

.btn-primary {
  background-color: var(--color-steel-gold);
  color: var(--color-obsidian-deep);
}

.btn-primary:hover {
  background-color: #F0B85C;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background-color: var(--color-credit-blue);
  color: var(--color-white);
}

.btn-secondary:hover {
  background-color: #00B8FF;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--color-steel-gold);
  color: var(--color-steel-gold);
}

.btn-outline:hover {
  background-color: var(--color-steel-gold);
  color: var(--color-obsidian-deep);
}

.btn-danger {
  background-color: var(--color-risk-red);
  color: var(--color-white);
}

.btn-danger:hover {
  background-color: #FF5147;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-lg {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: 1.1rem;
}

.btn-sm {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.875rem;
}

/* ============================================================
   HERO SECTION
   ============================================================ */

.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--color-obsidian-deep) 0%, #0F1B2E 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: var(--spacing-5xl) var(--spacing-xl);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 50%, rgba(0, 163, 255, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(224, 169, 59, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
}

.hero h1 {
  font-size: 4rem;
  margin-bottom: var(--spacing-xl);
  background: linear-gradient(135deg, var(--color-white) 0%, var(--color-steel-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: fadeInUp 0.8s ease-out;
}

.hero p {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--spacing-2xl);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

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

/* ============================================================
   CARDS
   ============================================================ */

.card {
  background-color: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(224, 169, 59, 0.2);
  border-radius: var(--radius-lg);
  padding: var(--spacing-2xl);
  transition: all var(--transition-normal);
  backdrop-filter: blur(10px);
}

.card:hover {
  background-color: rgba(255, 255, 255, 0.08);
  border-color: var(--color-steel-gold);
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(224, 169, 59, 0.15);
}

.card-title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-steel-gold);
}

.card-text {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.8;
}

/* ============================================================
   SECTIONS
   ============================================================ */

section {
  padding: var(--spacing-5xl) var(--spacing-xl);
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.section-title h2 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
}

.section-title p {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.7);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================================
   FOOTER
   ============================================================ */

footer {
  background-color: #050A13;
  border-top: 1px solid rgba(224, 169, 59, 0.2);
  padding: var(--spacing-3xl) var(--spacing-xl);
  margin-top: var(--spacing-5xl);
}

.footer-content {
  max-width: 1440px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-3xl);
  margin-bottom: var(--spacing-3xl);
}

.footer-section h4 {
  color: var(--color-steel-gold);
  margin-bottom: var(--spacing-lg);
  font-size: 1.1rem;
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  margin-bottom: var(--spacing-md);
}

.footer-section a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
}

.footer-section a:hover {
  color: var(--color-steel-gold);
}

.footer-bottom {
  border-top: 1px solid rgba(224, 169, 59, 0.2);
  padding-top: var(--spacing-2xl);
  text-align: center;
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.9rem;
}

/* ============================================================
   RESPONSIVE DESIGN
   ============================================================ */

@media (max-width: 768px) {
  .container,
  .container-fluid {
    padding: 0 var(--spacing-lg);
  }
  
  h1 {
    font-size: 2.5rem;
  }
  
  h2 {
    font-size: 1.875rem;
  }
  
  .hero h1 {
    font-size: 2.5rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .navbar-nav {
    gap: var(--spacing-lg);
  }
  
  .nav-link {
    font-size: 0.85rem;
  }
  
  section {
    padding: var(--spacing-3xl) var(--spacing-lg);
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container,
  .container-fluid {
    padding: 0 var(--spacing-md);
  }
  
  h1 {
    font-size: 1.875rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .hero {
    min-height: auto;
    padding: var(--spacing-3xl) var(--spacing-md);
  }
  
  .hero h1 {
    font-size: 1.875rem;
  }
  
  .hero p {
    font-size: 0.95rem;
  }
  
  .navbar-nav {
    gap: var(--spacing-md);
    flex-wrap: wrap;
  }
  
  .btn {
    width: 100%;
  }
  
  .hero-cta {
    flex-direction: column;
  }
}

/* ============================================================
   UTILITY CLASSES
   ============================================================ */

.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.mt-1 { margin-top: var(--spacing-md); }
.mt-2 { margin-top: var(--spacing-lg); }
.mt-3 { margin-top: var(--spacing-2xl); }
.mt-4 { margin-top: var(--spacing-3xl); }

.mb-1 { margin-bottom: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-lg); }
.mb-3 { margin-bottom: var(--spacing-2xl); }
.mb-4 { margin-bottom: var(--spacing-3xl); }

.pt-1 { padding-top: var(--spacing-md); }
.pt-2 { padding-top: var(--spacing-lg); }
.pt-3 { padding-top: var(--spacing-2xl); }
.pt-4 { padding-top: var(--spacing-3xl); }

.pb-1 { padding-bottom: var(--spacing-md); }
.pb-2 { padding-bottom: var(--spacing-lg); }
.pb-3 { padding-bottom: var(--spacing-2xl); }
.pb-4 { padding-bottom: var(--spacing-3xl); }

.opacity-50 {
  opacity: 0.5;
}

.opacity-75 {
  opacity: 0.75;
}

.hidden {
  display: none;
}

.visible {
  display: block;
}