/* ===== CSS Variables ===== */
:root {
  --color-primary: #E85D3F;
  --color-primary-hover: #FF6B4F;
  --color-secondary: #F2C94C;
  --color-bg-dark: #0A0A0A;
  --color-bg-section: #111111;
  --color-bg-card: #1A1A1A;
  --color-bg-card-hover: #222222;
  --color-border: #2A2A2A;
  --color-text: #FFFFFF;
  --color-text-secondary: #BBBBBB;
  --color-text-muted: #888888;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-card: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-glow: 0 0 40px rgba(232,93,63,0.15);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1200px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  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-sans);
  background-color: var(--color-bg-dark);
  color: var(--color-text-secondary);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
}

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

a:hover {
  color: var(--color-primary-hover);
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--color-text);
  font-weight: 700;
  line-height: 1.3;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(1.8rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

p {
  margin-bottom: 1em;
}

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

section {
  padding: 100px 0;
}

/* ===== Gradient Utilities ===== */
.gradient-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-border {
  position: relative;
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
}

.gradient-border::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  z-index: -1;
  opacity: 0;
  transition: opacity 0.3s;
}

.gradient-border:hover::before {
  opacity: 1;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 15px;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-family: var(--font-sans);
}

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

.btn-primary:hover {
  background: var(--color-primary-hover);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(232,93,63,0.3);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 10px 24px;
  font-size: 14px;
}

/* ===== Section Header ===== */
.section-label {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-primary);
  margin-bottom: 16px;
}

.section-title {
  margin-bottom: 16px;
}

.section-desc {
  font-size: 18px;
  color: var(--color-text-muted);
  max-width: 600px;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-header .section-desc {
  margin: 0 auto;
}

/* ===== Cards ===== */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
}

.card:hover {
  border-color: rgba(232,93,63,0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

/* ===== Grid ===== */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

/* ===== Fade-in Animation ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Divider ===== */
.divider {
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border: none;
  margin: 16px auto;
  border-radius: 2px;
}