/* ==========================================================================
   Thang Máy Việt Hưng — Design Tokens & Base Accessibility Reset
   Colors follow uxui.md (60-30-10 rule): #FFFFFF/#F8FAFC, #1E293B/#0F172A, #C8102E/#D4AF37
   ========================================================================== */

:root {
  /* Brand Colors */
  --primary-red: #C8102E;
  --primary-red-hover: #A50D25;
  --accent-bright: #DC2626;
  --premium-gold: #D4AF37;
  --premium-gold-hover: #B5952F;

  /* Neutrals */
  --text-main: #1E293B;
  --text-muted: #64748B;
  --bg-light: #F8FAFC;
  --bg-dark: #0F172A;
  --white: #FFFFFF;
  --border-color: #E2E8F0;

  /* Typography */
  --font-family: 'Be Vietnam Pro', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  /* Elevation & Motion */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --transition: all 0.25s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--text-main);
  background-color: var(--bg-light);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

button, input, select, textarea {
  font-family: inherit;
}

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

ul, ol {
  list-style: none;
}

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

address {
  font-style: normal;
}

:focus-visible {
  outline: 2px solid var(--primary-red);
  outline-offset: 2px;
}

/* Accessibility utilities */
.sr-only,
.screen-reader-text {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 9999;
  padding: 12px 20px;
  background: var(--bg-dark);
  color: var(--white);
  font-weight: 700;
  border-radius: 0 0 8px 0;
}

.skip-link:focus {
  left: 12px;
  top: 12px;
}

/* Containers & Sections */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

.site-main {
  flex: 1 0 auto;
}

.section {
  padding: 96px 0;
}

.section-light {
  background-color: var(--bg-light);
}

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

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 16px;
  line-height: 1.3;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.125rem;
  max-width: 720px;
  margin: 0 auto;
  line-height: 1.7;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  gap: 8px;
  font-family: inherit;
  line-height: 1.2;
}

.btn-lg {
  min-height: 54px;
  padding: 12px 28px;
  font-size: 1.05rem;
}

.btn-md {
  min-height: 44px;
  padding: 10px 22px;
  font-size: 0.95rem;
}

.btn-sm {
  min-height: 36px;
  padding: 6px 14px;
  font-size: 0.875rem;
}

.btn-primary {
  background-color: var(--primary-red);
  color: var(--white);
  box-shadow: 0 4px 14px 0 rgba(200, 16, 46, 0.35);
}

.btn-primary:hover {
  background-color: var(--primary-red-hover);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(200, 16, 46, 0.25);
}

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

.btn-outline:hover {
  background-color: var(--bg-light);
  border-color: var(--text-main);
}

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

.btn-gold:hover {
  background-color: var(--premium-gold);
  color: var(--bg-dark);
}

@media (max-width: 768px) {
  .section {
    padding: 64px 0;
  }
  .section-header {
    margin-bottom: 40px;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .container {
    padding: 0 16px;
  }
}