/* ============================================
   阿越云验证 - 统一设计系统
   白色简约 | 现代化 | 高品质
   ============================================ */

:root {
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --primary-50: #eef2ff;
  --primary-100: #e0e7ff;
  --success: #10b981;
  --success-light: #d1fae5;
  --danger: #ef4444;
  --danger-light: #fee2e2;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --info: #3b82f6;
  --info-light: #dbeafe;

  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  --white: #ffffff;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);

  --radius-sm: 6px;
  --radius: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --transition: all 0.2s ease;
  --transition-slow: all 0.3s ease;
}

/* ---- Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--font-sans);
  color: var(--gray-800);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
}

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

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

/* ---- Typography ---- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--gray-900);
}

/* ---- Layout ---- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 480px; margin: 0 auto; padding: 0 24px; }

/* ---- Navbar ---- */
.navbar {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(255,255,255,0.9);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.navbar-brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--gray-900);
  display: flex;
  align-items: center;
  gap: 10px;
}

.navbar-brand .logo {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 14px;
}

.navbar-toggle {
  display: none;
  background: none;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 6px 10px;
  cursor: pointer;
  color: var(--gray-600);
  font-size: 20px;
  line-height: 1;
  transition: var(--transition);
}

.navbar-toggle:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-50);
}

.navbar-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.navbar-nav a {
  padding: 8px 16px;
  color: var(--gray-600);
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius);
  transition: var(--transition);
  white-space: nowrap;
}

.navbar-nav a:hover,
.navbar-nav a.active {
  color: var(--primary);
  background: var(--primary-50);
}

.navbar-nav .btn-nav {
  background: var(--primary);
  color: white !important;
  padding: 8px 20px;
  border-radius: var(--radius-full);
  font-weight: 600;
}

.navbar-nav .btn-nav:hover {
  background: var(--primary-dark);
  color: white !important;
}

.navbar-mobile {
  display: none;
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
}

.navbar-mobile.show {
  display: block;
}

.navbar-mobile a {
  display: block;
  padding: 12px 24px;
  color: var(--gray-600);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: var(--transition);
}

.navbar-mobile a:hover,
.navbar-mobile a.active {
  color: var(--primary);
  background: var(--primary-50);
}

.navbar-mobile .btn-mobile {
  display: block;
  margin: 8px 24px;
  padding: 12px;
  background: var(--primary);
  color: white;
  text-align: center;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 15px;
}

.navbar-mobile .btn-mobile:hover {
  background: var(--primary-dark);
  color: white;
}

/* ---- Hero ---- */
.hero {
  padding: 100px 0 80px;
  text-align: center;
  background: linear-gradient(180deg, var(--white) 0%, var(--gray-50) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -200px;
  right: -200px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--primary-50) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -200px;
  left: -200px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, var(--primary-100) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  opacity: 0.5;
}

.hero h1 {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--gray-900) 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 20px;
  color: var(--gray-500);
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero .btn-group {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
  text-decoration: none;
  line-height: 1;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--gray-700);
  border: 1.5px solid var(--gray-200);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-50);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
}

.btn-ghost:hover {
  background: var(--gray-100);
  color: var(--gray-900);
}

.btn-lg { padding: 16px 36px; font-size: 16px; border-radius: var(--radius-md); }
.btn-sm { padding: 8px 16px; font-size: 13px; }
.btn-block { width: 100%; }

.btn-success { background: var(--success); color: white; }
.btn-success:hover { background: #059669; color: white; }
.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { background: #dc2626; color: white; }
.btn-warning { background: var(--warning); color: white; }

/* ---- Cards ---- */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-body { padding: 24px; }
.card-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  font-weight: 600;
  color: var(--gray-800);
}

/* ---- Feature Grid ---- */
.features {
  padding: 80px 0;
}

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

.feature-card {
  text-align: center;
  padding: 40px 24px;
  border-radius: var(--radius-md);
  background: var(--white);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-100);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 24px;
}

.feature-icon.blue { background: var(--primary-50); color: var(--primary); }
.feature-icon.green { background: var(--success-light); color: var(--success); }
.feature-icon.orange { background: var(--warning-light); color: var(--warning); }
.feature-icon.red { background: var(--danger-light); color: var(--danger); }

.feature-card h5 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--gray-800);
}

.feature-card p {
  font-size: 14px;
  color: var(--gray-500);
  line-height: 1.6;
}

/* ---- FAQ ---- */
.faq { padding: 80px 0; }

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  background: var(--white);
}

.faq-question {
  padding: 18px 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 500;
  color: var(--gray-700);
  transition: var(--transition);
}

.faq-question:hover { color: var(--primary); }

.faq-question::after {
  content: '+';
  font-size: 20px;
  color: var(--gray-400);
  transition: var(--transition);
}

.faq-item.active .faq-question::after { content: '-'; }

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  color: var(--gray-500);
  font-size: 14px;
  line-height: 1.8;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 24px 18px;
}

/* ---- Footer ---- */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 40px;
}

.footer h6 {
  color: var(--white);
  font-size: 16px;
  margin-bottom: 16px;
}

.footer p {
  font-size: 14px;
  line-height: 1.8;
}

.footer ul { list-style: none; }

.footer ul li {
  margin-bottom: 10px;
}

.footer ul a {
  color: var(--gray-400);
  font-size: 14px;
}

.footer ul a:hover { color: var(--white); }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 20px 0;
  text-align: center;
  font-size: 13px;
}

/* ---- Section Headers ---- */
.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-header p {
  font-size: 16px;
  color: var(--gray-500);
  max-width: 500px;
  margin: 0 auto;
}

/* ---- Login / Auth Pages ---- */
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  padding: 40px 24px;
  position: relative;
}

.auth-page::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--primary-50) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  padding: 48px 40px;
  position: relative;
  z-index: 1;
}

.auth-logo {
  text-align: center;
  margin-bottom: 32px;
}

.auth-logo .icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius-md);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 20px;
  margin-bottom: 16px;
}

.auth-logo h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 4px;
}

.auth-logo p {
  font-size: 14px;
  color: var(--gray-400);
}

.auth-form .form-group {
  margin-bottom: 20px;
}

.auth-form label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 6px;
}

.auth-form input[type="text"],
.auth-form input[type="password"],
.auth-form input[type="email"] {
  width: 100%;
  height: 48px;
  padding: 0 16px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--gray-800);
  background: var(--white);
  transition: var(--transition);
  font-family: var(--font-sans);
  outline: none;
}

.auth-form input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-50);
}

.auth-form input::placeholder {
  color: var(--gray-400);
}

.auth-form .input-icon {
  position: relative;
}

.auth-form .input-icon i {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-400);
  font-size: 16px;
}

.auth-form .input-icon input {
  padding-left: 42px;
}

.auth-form .form-check {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--gray-500);
  margin-bottom: 20px;
}

.auth-form .form-check input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--primary);
}

.auth-form .form-links {
  display: flex;
  justify-content: space-between;
  margin-top: 16px;
  font-size: 14px;
}

.auth-form .form-links a {
  color: var(--gray-500);
}

.auth-form .form-links a:hover {
  color: var(--primary);
}

.auth-form .code-row {
  display: flex;
  gap: 12px;
}

.auth-form .code-row input {
  flex: 1;
}

.auth-form .code-row .btn {
  flex-shrink: 0;
}

.auth-footer {
  text-align: center;
  margin-top: 24px;
  font-size: 13px;
  color: var(--gray-400);
}

.auth-footer a { color: var(--gray-500); }

/* ---- Dashboard Layout ---- */
.dashboard {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 260px;
  background: var(--gray-900);
  color: var(--gray-300);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 50;
  transition: transform 0.3s ease;
  overflow-y: auto;
}

.sidebar-header {
  padding: 20px 24px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-header .logo {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 14px;
  flex-shrink: 0;
}

.sidebar-header .brand {
  font-size: 16px;
  font-weight: 700;
  color: var(--white);
}

.sidebar-nav {
  flex: 1;
  padding: 16px 12px;
  overflow-y: auto;
}

.sidebar-section {
  margin-bottom: 24px;
}

.sidebar-section-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-500);
  padding: 0 12px;
  margin-bottom: 8px;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  color: var(--gray-400);
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius);
  transition: var(--transition);
  text-decoration: none;
}

.sidebar-nav a:hover {
  color: var(--white);
  background: rgba(255,255,255,0.08);
}

.sidebar-nav a.active {
  color: var(--white);
  background: var(--primary);
}

.sidebar-nav a i {
  width: 20px;
  text-align: center;
  font-size: 16px;
}

.sidebar-footer {
  padding: 16px 24px;
  border-top: 1px solid rgba(255,255,255,0.08);
  font-size: 13px;
}

.sidebar-footer a {
  color: var(--gray-400);
  display: flex;
  align-items: center;
  gap: 8px;
}

.sidebar-footer a:hover { color: var(--white); }

/* ---- Main Content ---- */
.main-content {
  flex: 1;
  margin-left: 260px;
  display: flex;
  flex-direction: column;
}

.topbar {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 40;
}

.topbar-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--gray-800);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.topbar-user {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--gray-600);
}

.topbar-user .avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--primary-50);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-weight: 600;
  font-size: 14px;
}

.content {
  flex: 1;
  padding: 32px;
}

/* ---- Stats Grid ---- */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.stat-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: var(--transition);
}

.stat-card:hover {
  box-shadow: var(--shadow-md);
}

.stat-card .stat-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--gray-500);
  margin-bottom: 8px;
}

.stat-card .stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--gray-900);
  line-height: 1;
}

.stat-card .stat-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  margin-bottom: 16px;
}

/* ---- Tables ---- */
.table-container {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.table-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.table-header h3 {
  font-size: 16px;
  font-weight: 600;
}

table {
  width: 100%;
  border-collapse: collapse;
}

table th {
  padding: 12px 24px;
  text-align: left;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-500);
  background: var(--gray-50);
  border-bottom: 1px solid var(--border);
}

table td {
  padding: 14px 24px;
  font-size: 14px;
  color: var(--gray-600);
  border-bottom: 1px solid var(--gray-100);
}

table tr:hover td {
  background: var(--gray-50);
}

table tr:last-child td {
  border-bottom: none;
}

/* ---- Badges ---- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-full);
}

.badge-success { background: var(--success-light); color: var(--success); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-warning { background: var(--warning-light); color: var(--warning); }
.badge-info { background: var(--info-light); color: var(--info); }
.badge-gray { background: var(--gray-100); color: var(--gray-500); }

/* ---- Alerts ---- */
.alert {
  padding: 14px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.alert-success { background: var(--success-light); color: #065f46; border: 1px solid #a7f3d0; }
.alert-danger { background: var(--danger-light); color: #991b1b; border: 1px solid #fecaca; }
.alert-warning { background: var(--warning-light); color: #92400e; border: 1px solid #fde68a; }
.alert-info { background: var(--info-light); color: #1e40af; border: 1px solid #bfdbfe; }

/* ---- Forms ---- */
.form-group { margin-bottom: 20px; }

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  height: 44px;
  padding: 0 14px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--gray-800);
  background: var(--white);
  transition: var(--transition);
  font-family: var(--font-sans);
  outline: none;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-50);
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%236b7280' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
}

textarea.form-control {
  height: auto;
  min-height: 100px;
  padding: 12px 14px;
  resize: vertical;
}

/* ---- Pagination ---- */
.pagination {
  display: flex;
  gap: 4px;
  justify-content: center;
  margin-top: 24px;
}

.pagination a,
.pagination span {
  padding: 8px 14px;
  font-size: 14px;
  border-radius: var(--radius);
  color: var(--gray-600);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.pagination a:hover {
  background: var(--gray-50);
  color: var(--primary);
}

.pagination .active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .sidebar { transform: translateX(-100%); transition: transform 0.3s ease; }
  .sidebar.open { transform: translateX(0); box-shadow: 4px 0 20px rgba(0,0,0,0.15); }
  .main-content { margin-left: 0; }
  .sidebar-overlay { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.3); z-index: 45; }
  .sidebar.open ~ .sidebar-overlay { display: block; }
}

@media (max-width: 768px) {
  .navbar-toggle { display: block; }
  .navbar-nav { display: none; }
  .hero { padding: 60px 0 50px; }
  .hero h1 { font-size: 32px; }
  .hero .subtitle { font-size: 15px; }
  .features-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .faq { padding: 40px 0; }
}

@media (max-width: 640px) {
  .hero h1 { font-size: 28px; }
  .hero .subtitle { font-size: 14px; }
  .hero .btn-group { flex-direction: column; align-items: center; }
  .hero .btn-group .btn { width: 100%; max-width: 280px; }
  .features-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .auth-card { padding: 32px 24px; }
  .topbar { padding: 0 16px; }
  .content { padding: 20px 16px; }
  .section-header h2 { font-size: 24px; }
}

/* ---- Utilities ---- */
.text-center { text-align: center; }
.text-primary { color: var(--primary) !important; }
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-muted { color: var(--gray-400) !important; }
.mt-4 { margin-top: 16px; }
.mb-4 { margin-bottom: 16px; }
.gap-3 { gap: 12px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }