/* ==========================================================================
   SBR MOBILITY × DONGFENG — GLOBAL PREMIUM LIGHT AUTOMOTIVE DESIGN SYSTEM
   Visual System: Clean Minimalist Luxury (Porsche / Tesla / Polestar Inspired)
   Background: #F4F6F8 | Surface: #FFFFFF | Primary: #0F172A | Secondary: #64748B
   Borders: #E2E8F0 | Hover: #F1F5F9 | Typography: Inter / Plus Jakarta Sans
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Space+Grotesk:wght@500;600;700&display=swap');

:root {
  /* Core Light Automotive Color Tokens */
  --background: #F4F6F8;
  --surface: #FFFFFF;
  --surface-elevated: #FFFFFF;
  --surface-glass: rgba(255, 255, 255, 0.85);
  --surface-glass-floating: rgba(255, 255, 255, 0.72);
  --surface-glass-solid: rgba(255, 255, 255, 0.94);
  
  --muted-background: #F8FAFC;
  --hover-background: #F1F5F9;
  
  /* Primary & Slate Typography */
  --primary: #0F172A;
  --primary-dark: #000000;
  --secondary: #64748B;
  --text-muted: #94A3B8;
  --border: #E2E8F0;
  --border-subtle: #F1F5F9;
  --border-focus: #0F172A;
  
  /* Brand Accent Tokens (Restrained & Minimal) */
  --brand-navy: #0F172A;
  --brand-blue: #0284C7;
  --brand-slate: #334155;
  
  /* Semantic Status Tokens */
  --success: #16A34A;
  --warning: #CA8A04;
  --error: #DC2626;

  /* Typography Families */
  --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Inter', 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Space Grotesk', monospace;

  /* Luxury Soft Shadows */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
  --shadow-sm: 0 4px 12px 0 rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 30px 0 rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 20px 40px -15px rgba(15, 23, 42, 0.08);
  --shadow-floating-nav: 0 10px 30px -5px rgba(15, 23, 42, 0.08), 0 0 0 1px rgba(255, 255, 255, 0.8) inset;
  --shadow-hover-card: 0 20px 40px -10px rgba(15, 23, 42, 0.1);

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.5s cubic-bezier(0.16, 1, 0.3, 1);

  /* Global Layout Dimensions */
  --container-max: 1280px;
  --nav-height: 72px;
}

/* ==========================================================================
   01. Base Resets & Global Styles
   ========================================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  color-scheme: light;
  background-color: var(--background);
}

body {
  font-family: var(--font-body);
  color: var(--primary);
  background-color: var(--background);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

img, picture, video, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

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

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  outline: none;
}

/* ==========================================================================
   02. Typography System
   ========================================================================== */

.font-display { font-family: var(--font-display); }
.font-body { font-family: var(--font-body); }
.font-mono { font-family: var(--font-mono); }

/* Headlines */
h1, h2, h3, h4, h5, h6,
.display-hero, .display-1, .display-2, .heading-1, .heading-2, .heading-3, .heading-4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--primary);
}

.display-hero {
  font-size: clamp(2.75rem, 6.5vw, 4.75rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  color: var(--primary);
  text-transform: uppercase;
}

.display-1 {
  font-size: clamp(2.25rem, 4.5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--primary);
  text-transform: uppercase;
}

.display-2 {
  font-size: clamp(1.85rem, 3.5vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.15;
  color: var(--primary);
}

.heading-1 { font-size: 2.25rem; font-weight: 700; }
.heading-2 { font-size: 1.75rem; font-weight: 700; }
.heading-3 { font-size: 1.35rem; font-weight: 600; }
.heading-4 { font-size: 1.125rem; font-weight: 600; }

.text-lead {
  font-size: clamp(1.05rem, 1.35vw, 1.25rem);
  font-weight: 400;
  color: var(--secondary);
  line-height: 1.6;
  max-width: 680px;
}

.text-body {
  font-size: 1rem;
  color: var(--secondary);
  line-height: 1.65;
}

.text-secondary {
  color: var(--secondary);
}

.text-muted {
  color: var(--text-muted);
}

.text-primary {
  color: var(--primary);
}

.text-pure {
  color: var(--primary);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--secondary);
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--primary);
}

/* ==========================================================================
   03. Global Layout & Spacing
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1.25rem, 4vw, 3rem);
  padding-right: clamp(1.25rem, 4vw, 3rem);
}

.section {
  padding-top: clamp(5rem, 8vw, 7rem);
  padding-bottom: clamp(5rem, 8vw, 7rem);
  position: relative;
}

.section-hero {
  padding-top: clamp(7.5rem, 12vw, 10rem);
  padding-bottom: clamp(4rem, 6vw, 6rem);
  min-height: 85vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

.section-header {
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}

.section-header-center {
  text-align: center;
  max-width: 780px;
  margin-left: auto;
  margin-right: auto;
}

/* Responsive Grids */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(1.5rem, 2.5vw, 2.5rem);
}

.col-12 { grid-column: span 12; }
.col-8  { grid-column: span 8; }
.col-7  { grid-column: span 7; }
.col-6  { grid-column: span 6; }
.col-5  { grid-column: span 5; }
.col-4  { grid-column: span 4; }
.col-3  { grid-column: span 3; }

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: clamp(1.5rem, 2.5vw, 2.5rem);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.5rem, 2vw, 2rem);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(1rem, 2vw, 1.75rem);
}

@media (max-width: 1024px) {
  .col-8, .col-7, .col-6, .col-5, .col-4 {
    grid-column: span 12;
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  .order-2-mobile {
    order: 2;
  }
}

/* ==========================================================================
   04. Premium Button System (Soft, Minimal, Confident, Rounded-Full)
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.85rem 1.85rem;
  border-radius: 9999px;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn svg {
  width: 16px;
  height: 16px;
  transition: transform var(--transition-fast);
}

.btn:hover svg {
  transform: translateX(3px);
}

/* Primary Button: Solid Slate #0F172A */
.btn-primary {
  background-color: var(--primary);
  color: #FFFFFF;
  border: 1px solid var(--primary);
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.16);
}

.btn-primary:hover {
  background-color: #000000;
  border-color: #000000;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.25);
  transform: translateY(-2px);
  color: #FFFFFF;
}

/* Secondary Button: Clean White with Subtle Slate Border */
.btn-secondary, .btn-glass {
  background-color: #FFFFFF;
  color: var(--primary);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow-xs);
}

.btn-secondary:hover, .btn-glass:hover {
  background-color: var(--hover-background);
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 0.95rem;
}

.btn-sm {
  padding: 0.6rem 1.25rem;
  font-size: 0.8rem;
}

.w-100 {
  width: 100%;
}

/* ==========================================================================
   05. Premium Light Cards
   ========================================================================== */

.card-glass, .card-surface {
  background-color: var(--surface);
  border-radius: 1.75rem;
  border: 1px solid rgba(226, 232, 240, 0.8);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  overflow: hidden;
  position: relative;
}

.card-glass:hover, .card-surface:hover {
  box-shadow: var(--shadow-hover-card);
  transform: translateY(-3px);
  border-color: rgba(203, 213, 225, 0.9);
}

/* Badges */
.badge-clean {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  background: rgba(15, 23, 42, 0.05);
  color: var(--primary);
  border: 1px solid rgba(15, 23, 42, 0.08);
}

.badge-electric {
  background: rgba(2, 132, 199, 0.08);
  color: #0284C7;
  border: 1px solid rgba(2, 132, 199, 0.2);
}

.badge-hybrid {
  background: rgba(22, 163, 74, 0.08);
  color: #16A34A;
  border: 1px solid rgba(22, 163, 74, 0.2);
}

.badge-utility {
  background: rgba(15, 23, 42, 0.08);
  color: #0F172A;
  border: 1px solid rgba(15, 23, 42, 0.15);
}

/* ==========================================================================
   06. Form Controls & Inputs
   ========================================================================== */

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

.form-control {
  width: 100%;
  padding: 0.95rem 1.25rem;
  font-size: 0.95rem;
  color: var(--primary);
  background-color: var(--muted-background);
  border: 1.5px solid var(--border);
  border-radius: 1rem;
  transition: all var(--transition-fast);
}

.form-control::placeholder {
  color: var(--text-muted);
}

.form-control:focus {
  background-color: #FFFFFF;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(15, 23, 42, 0.08);
}

textarea.form-control {
  min-height: 120px;
  resize: vertical;
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1.25rem center;
  background-size: 16px;
  padding-right: 2.75rem;
}

/* Utility Helpers */
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-xs { gap: 0.5rem; }
.gap-sm { gap: 1rem; }
.gap-md { gap: 1.5rem; }
.gap-lg { gap: 2.5rem; }
.p-2 { padding: 0.75rem; }
.p-3 { padding: 1.25rem; }
.p-4 { padding: 1.75rem; }
.p-5 { padding: 2.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-6 { margin-bottom: 3.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }
.text-center { text-align: center; }
.text-xs { font-size: 0.75rem; }
.text-sm { font-size: 0.875rem; }
.text-lg { font-size: 1.125rem; }
.font-bold { font-weight: 700; }
.uppercase { text-transform: uppercase; }
.letter-spacing { letter-spacing: 0.15em; }
.hidden { display: none !important; }
.img-cover { width: 100%; height: 100%; object-fit: cover; }