:root {
    --bs-primary-rgb: 13, 110, 253;
    --bs-success-rgb: 25, 135, 84;
    --bs-info-rgb: 13, 202, 240;
    --bs-warning-rgb: 255, 193, 7;
    --bs-danger-rgb: 220, 53, 69;
    
    /* Professional gradients */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --success-gradient: linear-gradient(135deg, #56f39a 0%, #03dac6 100%);
    --info-gradient: linear-gradient(135deg, #74b9ff 0%, #0984e3 100%);
    --warning-gradient: linear-gradient(135deg, #fdcb6e 0%, #e17055 100%);
    
    /* Professional shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.12);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    --shadow-xl: 0 20px 40px rgba(0,0,0,0.2);
    
    /* Professional spacing */
    --border-radius-sm: 0.375rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
}

/* Dark Theme (default) */
[data-theme="dark"] {
    --bg-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-surface: rgba(255, 255, 255, 0.95);
    --bg-card: rgba(255, 255, 255, 0.98);
    --bg-feature: rgba(255, 255, 255, 0.1);
    --bg-nav: rgba(0, 0, 0, 0.9);
    --bg-footer: rgba(0, 0, 0, 0.95);
    --text-primary: #333;
    --text-secondary: #666;
    --text-on-dark: white;
    --text-on-dark-muted: rgba(255, 255, 255, 0.8);
    --border-color: rgba(255, 255, 255, 0.2);
    --shadow-primary: var(--shadow-xl);
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: linear-gradient(135deg, #ffffff 0%, #f8f9ff 100%);
    --bg-surface: rgba(255, 255, 255, 0.98);
    --bg-card: rgba(255, 255, 255, 0.95);
    --bg-feature: rgba(102, 126, 234, 0.08);
    --bg-nav: rgba(255, 255, 255, 0.98);
    --bg-footer: rgba(255, 255, 255, 0.95);
    --text-primary: #2c3e50;
    --text-secondary: #5a6c7d;
    --text-on-dark: #2c3e50;
    --text-on-dark-muted: rgba(44, 62, 80, 0.8);
    --border-color: rgba(102, 126, 234, 0.15);
    --shadow-primary: 0 20px 40px rgba(102,126,234,0.15);
}

/* Grey Theme */
[data-theme="grey"] {
    --bg-primary: linear-gradient(135deg, #adb5bd 0%, #868e96 100%);
    --bg-surface: rgba(255, 255, 255, 0.95);
    --bg-card: rgba(255, 255, 255, 0.98);
    --bg-feature: rgba(173, 181, 189, 0.15);
    --bg-nav: rgba(134, 142, 150, 0.95);
    --bg-footer: rgba(108, 117, 125, 0.95);
    --text-primary: #212529;
    --text-secondary: #495057;
    --text-on-dark: white;
    --text-on-dark-muted: rgba(255, 255, 255, 0.9);
    --border-color: rgba(0, 0, 0, 0.1);
    --shadow-primary: 0 20px 40px rgba(0,0,0,0.12);
}

/* Professional typography */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    font-weight: 400;
    background: var(--bg-primary);
    background-attachment: fixed;
    min-height: 100vh;
    transition: all 0.3s ease;
}

/* Professional hero section */
.hero-section {
    background: var(--bg-surface);
    backdrop-filter: blur(10px);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-primary);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.display-4 {
    font-weight: 700;
    letter-spacing: -0.02em;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Professional card system */
.card {
    border-radius: var(--border-radius-lg);
    border: none;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    background: var(--bg-card);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card-header {
    border-radius: var(--border-radius-lg) var(--border-radius-lg) 0 0 !important;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-surface);
    backdrop-filter: blur(5px);
}

.card-body {
    background: var(--bg-card);
}

/* Professional button system */
.btn {
    border-radius: var(--border-radius-md);
    font-weight: 600;
    letter-spacing: 0.025em;
    text-transform: none;
    position: relative;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-sm);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn:active {
    transform: translateY(0);
}

.btn-lg {
    padding: 0.875rem 2rem;
    font-size: 1.125rem;
    border-radius: var(--border-radius-lg);
}

.btn-primary {
    background: var(--primary-gradient);
    border: none;
}

.btn-success {
    background: var(--success-gradient);
    border: none;
    color: #333;
}

.btn-info {
    background: var(--info-gradient);
    border: none;
}

.btn-warning {
    background: var(--warning-gradient);
    border: none;
    color: #333;
}

/* Platform selection enhancements */
.platform-card {
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.platform-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

.platform-label {
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.platform-label::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.6s;
}

.platform-label:hover::before {
    left: 100%;
}

.btn-check:checked + .platform-label {
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.3);
}

/* Professional form inputs */
.form-control {
    border: 2px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-md);
    transition: all 0.3s ease;
    font-size: 1rem;
    padding: 0.75rem 1rem;
}

.form-control:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
    transform: translateY(-1px);
}

/* Loading states */
.btn-loading {
    position: relative;
    pointer-events: none;
}

.btn-loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    top: 50%;
    left: 50%;
    margin-left: -8px;
    margin-top: -8px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Professional footer */
.professional-footer {
    background: var(--bg-footer);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--border-color);
    margin-top: 5rem;
    transition: all 0.3s ease;
}

/* Theme Switcher */
.theme-switcher {
    position: relative;
    display: inline-flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 25px;
    padding: 4px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.theme-option {
    padding: 8px 12px;
    border-radius: 20px;
    background: transparent;
    border: none;
    color: rgba(255, 255, 255, 0.7);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.85rem;
    font-weight: 500;
}

.theme-option:hover {
    color: rgba(255, 255, 255, 0.9);
    background: rgba(255, 255, 255, 0.1);
}

.theme-option.active {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* Light theme adjustments */
[data-theme="light"] .theme-switcher {
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .theme-option {
    color: rgba(0, 0, 0, 0.6);
}

[data-theme="light"] .theme-option:hover {
    color: rgba(0, 0, 0, 0.8);
    background: rgba(0, 0, 0, 0.05);
}

[data-theme="light"] .theme-option.active {
    background: rgba(0, 0, 0, 0.1);
    color: rgba(0, 0, 0, 0.8);
}

/* Grey theme adjustments */
[data-theme="grey"] .theme-switcher {
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.25);
}

/* Dynamic text colors based on theme */
[data-theme="light"] .text-on-dark,
[data-theme="light"] .text-white {
    color: var(--text-primary) !important;
}

[data-theme="light"] .text-on-dark-muted,
[data-theme="light"] .text-white.opacity-8 {
    color: var(--text-secondary) !important;
}

[data-theme="light"] .professional-footer {
    color: var(--text-primary) !important;
}

/* Enhanced feature cards */
.feature-card {
    background: var(--bg-feature);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.feature-card:hover {
    background: var(--bg-feature);
    transform: translateY(-8px);
    opacity: 0.9;
}

/* Statistics styling */
.hero-stats .stat-item {
    padding: 1rem;
    background: rgba(255, 255, 255, 0.8);
    border-radius: var(--border-radius-md);
    backdrop-filter: blur(5px);
    transition: all 0.3s ease;
}

.hero-stats .stat-item:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
}

/* Responsive improvements */
@media (max-width: 768px) {
    .hero-section {
        margin: 1rem;
        padding: 2rem 1.5rem !important;
    }
    
    .platform-label {
        min-height: 120px !important;
        padding: 1.5rem !important;
    }
    
    .hero-stats {
        gap: 1rem !important;
    }
    
    .hero-stats .stat-item {
        min-width: 80px;
    }
}

/* Progress bar styling */
.progress {
    border-radius: 10px;
    background-color: var(--bs-gray-200);
}

.progress-bar {
    border-radius: 10px;
    background: linear-gradient(45deg, var(--bs-primary), var(--bs-info));
}

/* Package type selection styling */
.btn-check:checked + .btn-outline-success {
    background-color: var(--bs-success);
    border-color: var(--bs-success);
    color: white;
}

.btn-check:checked + .btn-outline-info {
    background-color: var(--bs-info);
    border-color: var(--bs-info);
    color: white;
}

.btn-check:checked + .btn-outline-warning {
    background-color: var(--bs-warning);
    border-color: var(--bs-warning);
    color: var(--bs-dark);
}

.btn-check:checked + .btn-outline-secondary {
    background-color: var(--bs-secondary);
    border-color: var(--bs-secondary);
    color: white;
}

/* Icon styling */
.package-icon {
    opacity: 0.8;
    transition: opacity 0.2s ease-in-out;
}

.package-icon:hover {
    opacity: 1;
}

/* List group styling */
.list-group-item {
    border-radius: 8px !important;
    border: 1px solid var(--bs-border-color);
    margin-bottom: 8px;
    transition: background-color 0.2s ease-in-out;
}

.list-group-item:hover {
    background-color: var(--bs-gray-100);
}

/* Alert styling */
.alert {
    border-radius: 10px;
    border: none;
}

/* Input group styling */
.input-group-text {
    border-radius: 8px 0 0 8px;
}

/* Custom animations */
@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.pulse {
    animation: pulse 2s infinite;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .display-4 {
        font-size: 2rem;
    }
    
    .btn-lg {
        padding: 10px 20px;
        font-size: 1rem;
    }
}

/* Dark theme adjustments */
[data-bs-theme="dark"] .card {
    background-color: var(--bs-dark);
    border-color: var(--bs-gray-700);
    color: var(--bs-light);
}

[data-bs-theme="dark"] .card-body {
    background-color: var(--bs-dark);
    color: var(--bs-light);
}

[data-bs-theme="dark"] .card-body p {
    color: var(--bs-light);
}

[data-bs-theme="dark"] .card-body h5 {
    color: var(--bs-light);
}

[data-bs-theme="dark"] .card-body h6 {
    color: var(--bs-gray-300);
}

[data-bs-theme="dark"] .bg-light {
    background-color: var(--bs-gray-800) !important;
    color: var(--bs-light);
}

[data-bs-theme="dark"] .list-group-item {
    background-color: var(--bs-dark);
    border-color: var(--bs-gray-700);
    color: var(--bs-light);
}

[data-bs-theme="dark"] .list-group-item:hover {
    background-color: var(--bs-gray-800);
}

[data-bs-theme="dark"] .alert-success {
    background-color: rgba(25, 135, 84, 0.1);
    border-color: rgba(25, 135, 84, 0.2);
    color: var(--bs-light);
}

[data-bs-theme="dark"] .text-muted {
    color: var(--bs-gray-400) !important;
}

/* Loading spinner customization */
.fa-spinner {
    animation-duration: 1s;
}

/* Badge styling */
.badge {
    font-weight: 500;
    letter-spacing: 0.02em;
}

/* Footer styling */
footer {
    margin-top: auto;
}

/* Custom utility classes */
.text-gradient {
    background: linear-gradient(45deg, var(--bs-primary), var(--bs-info));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.shadow-custom {
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

/* Form enhancements */
.form-control:focus {
    border-color: var(--bs-primary);
    box-shadow: 0 0 0 0.2rem rgba(var(--bs-primary-rgb), 0.25);
}

/* Navigation enhancements */
.navbar-brand {
    font-weight: 600;
    font-size: 1.5rem;
}

.nav-link {
    font-weight: 500;
    transition: color 0.2s ease-in-out;
}

.nav-link:hover {
    color: var(--bs-light) !important;
}