html {
  font-size: 14px;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

/* Dark VPN Security Theme */
:root {
    --vpn-dark-bg: #0a0e27;
    --vpn-card-bg: #1a1f3a;
    --vpn-primary: #00d9ff;
    --vpn-secondary: #7c3aed;
    --vpn-accent: #10b981;
    --vpn-danger: #ef4444;
    --vpn-warning: #f59e0b;
    --vpn-text: #e5e7eb;
    --vpn-text-muted: #9ca3af;
    --vpn-border: #2d3748;
}

html {
  position: relative;
  min-height: 100%;
  scroll-behavior: smooth;
}

body {
    margin-bottom: 60px;
    background: linear-gradient(135deg, var(--vpn-dark-bg) 0%, #1a1f3a 50%, #0f172a 100%);
    background-attachment: fixed;
    color: var(--vpn-text);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Cybersecurity grid pattern overlay */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(0, 217, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 217, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: 0;
}

.container, .container-fluid {
    position: relative;
    z-index: 1;
}

/* Navigation Bar */
.navbar-dark {
    background: linear-gradient(90deg, #0a0e27 0%, #1e293b 50%, #0a0e27 100%) !important;
    border-bottom: 2px solid var(--vpn-primary) !important;
    box-shadow: 0 4px 20px rgba(0, 217, 255, 0.3);
}

.navbar-brand {
    color: var(--vpn-primary) !important;
    font-size: 1.5rem;
    text-shadow: 0 0 10px rgba(0, 217, 255, 0.5);
    transition: all 0.3s ease;
}

.navbar-brand:hover {
    text-shadow: 0 0 20px rgba(0, 217, 255, 0.8);
    transform: scale(1.05);
}

.nav-link {
    color: var(--vpn-text) !important;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--vpn-primary);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 80%;
}

.nav-link:hover {
    color: var(--vpn-primary) !important;
}

/* Cards */
.card {
    background: var(--vpn-card-bg);
    border: 1px solid var(--vpn-border);
    border-radius: 12px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    color: var(--vpn-text);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 217, 255, 0.3);
    border-color: var(--vpn-primary);
}

.card-header {
    background: linear-gradient(135deg, var(--vpn-secondary) 0%, var(--vpn-primary) 100%) !important;
    border-bottom: 2px solid var(--vpn-primary);
    color: white !important;
    font-weight: 600;
}

.card-body {
    will-change: auto;
}

/* Buttons */
.btn-primary {
    background: linear-gradient(135deg, var(--vpn-primary) 0%, var(--vpn-secondary) 100%);
    border: none;
    color: white;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 217, 255, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 217, 255, 0.6);
    background: linear-gradient(135deg, var(--vpn-secondary) 0%, var(--vpn-primary) 100%);
}

.btn-success {
    background: var(--vpn-accent);
    border: none;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.btn-success:hover {
    background: #059669;
    box-shadow: 0 6px 25px rgba(16, 185, 129, 0.6);
    transform: translateY(-2px);
}

.btn-outline-primary {
    border-color: var(--vpn-primary);
    color: var(--vpn-primary);
}

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

/* Form Controls */
.form-select, .form-control {
    background-color: #1e293b;
    border: 2px solid var(--vpn-border);
    color: var(--vpn-text);
    transition: all 0.3s ease;
}

.form-select:focus, .form-control:focus {
    background-color: #1e293b;
    border-color: var(--vpn-primary);
    box-shadow: 0 0 0 0.25rem rgba(0, 217, 255, 0.25);
    color: var(--vpn-text);
}

.form-select option {
    background-color: #1e293b;
    color: var(--vpn-text);
}

.form-label {
    color: var(--vpn-text);
    font-weight: 600;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--vpn-text);
}

.display-4, .display-5 {
    font-weight: 700;
    background: linear-gradient(135deg, var(--vpn-primary), var(--vpn-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

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

.text-success {
    color: var(--vpn-accent) !important;
}

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

/* Badges */
.badge {
    padding: 0.5em 0.8em;
    border-radius: 6px;
    font-weight: 600;
}

.bg-primary {
    background: var(--vpn-primary) !important;
    color: var(--vpn-dark-bg) !important;
}

.bg-success {
    background: var(--vpn-accent) !important;
}

.bg-warning {
    background: var(--vpn-warning) !important;
}

.bg-danger {
    background: var(--vpn-danger) !important;
}

.bg-secondary {
    background: var(--vpn-secondary) !important;
}

.bg-info {
    background: var(--vpn-primary) !important;
    color: var(--vpn-dark-bg) !important;
}

/* Comparison sections */
.comparison-section h5 {
    font-weight: 600;
    color: var(--vpn-primary);
}

.comparison-section h5::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 20px;
    background: var(--vpn-primary);
    margin-right: 8px;
    vertical-align: middle;
}

.comparison-section ul li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--vpn-border);
}

.comparison-section ul li:last-child {
    border-bottom: none;
}

/* Footer */
.footer {
    position: absolute;
    bottom: 0;
    width: 100%;
    background: var(--vpn-card-bg);
    border-top: 2px solid var(--vpn-primary);
    color: var(--vpn-text-muted);
}

.footer a {
    color: var(--vpn-primary);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer a:hover {
    color: var(--vpn-secondary);
    text-shadow: 0 0 10px rgba(0, 217, 255, 0.5);
}

/* Special Effects */
.shadow-lg {
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5) !important;
}

/* Loading optimization */
img {
    loading: lazy;
}

/* Glow effect for important elements */
.btn-primary, .card:hover {
    animation: subtle-glow 2s ease-in-out infinite;
}

@keyframes subtle-glow {
    0%, 100% {
        filter: drop-shadow(0 0 5px rgba(0, 217, 255, 0.3));
    }
    50% {
        filter: drop-shadow(0 0 15px rgba(0, 217, 255, 0.5));
    }
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    background: var(--vpn-dark-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--vpn-primary);
    border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--vpn-secondary);
}

/* Validation */
.text-danger {
    color: var(--vpn-danger) !important;
}

.border-bottom {
    border-color: var(--vpn-border) !important;
}

/* Card footer */
.card-footer {
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--vpn-border);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .card {
        margin-bottom: 1.5rem;
    }
}