/* ===============================================
   UNIVERSAL BACKGROUND & THEME SYSTEM
   Perfect vibe for all pages with dynamic backgrounds
   =============================================== */

:root {
    /* Background Images */
    --bg-primary-image: url('background.jpg');
    --bg-overlay-light: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    --bg-overlay-dark: linear-gradient(135deg, rgba(15, 23, 42, 0.85) 0%, rgba(30, 41, 59, 0.9) 100%);
    --bg-pattern: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    
    /* Enhanced Color System */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;
    
    --purple-400: #a78bfa;
    --purple-500: #8b5cf6;
    --purple-600: #7c3aed;
    
    /* Glass Effects */
    --glass-light: rgba(255, 255, 255, 0.15);
    --glass-dark: rgba(30, 41, 59, 0.3);
    --glass-border-light: rgba(255, 255, 255, 0.2);
    --glass-border-dark: rgba(255, 255, 255, 0.1);
    
    /* Enhanced Shadows */
    --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.3);
    --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-elevated: 0 20px 60px rgba(0, 0, 0, 0.15);
    
    /* Animation Variables */
    --transition-smooth: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: all 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* Universal Background System */
body {
    position: relative;
    min-height: 100vh;
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary, #ffffff);
    color: var(--text-primary, #1e293b);
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: var(--bg-primary-image), var(--bg-pattern);
    background-size: cover, 60px 60px;
    background-position: center, 0 0;
    background-repeat: no-repeat, repeat;
    background-attachment: fixed;
    z-index: -2;
}

body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-overlay-light);
    -webkit-backdrop-filter: blur(1px);
    backdrop-filter: blur(1px);
    z-index: -1;
    transition: var(--transition-smooth);
}

/* Dark Mode Background */
[data-theme="dark"] body::after {
    background: var(--bg-overlay-dark);
    -webkit-backdrop-filter: blur(2px);
    backdrop-filter: blur(2px);
}

/* Animated Background Elements */
.floating-shapes {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.floating-shape {
    position: absolute;
    border-radius: 50%;
    background: linear-gradient(45deg, var(--primary-400), var(--purple-500));
    opacity: 0.1;
    animation: float 20s infinite linear;
}

.floating-shape:nth-child(1) {
    width: 80px;
    height: 80px;
    left: 10%;
    animation-delay: 0s;
}

.floating-shape:nth-child(2) {
    width: 120px;
    height: 120px;
    left: 80%;
    animation-delay: 5s;
}

.floating-shape:nth-child(3) {
    width: 60px;
    height: 60px;
    left: 60%;
    animation-delay: 10s;
}

.floating-shape:nth-child(4) {
    width: 100px;
    height: 100px;
    left: 30%;
    animation-delay: 15s;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.1;
    }
    90% {
        opacity: 0.1;
    }
    100% {
        transform: translateY(-100px) rotate(360deg);
        opacity: 0;
    }
}

/* Glass Morphism Cards */
.glass-card {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border-light);
    border-radius: 20px;
    box-shadow: var(--shadow-glass);
    transition: var(--transition-smooth);
}

[data-theme="dark"] .glass-card {
    background: var(--glass-dark);
    border-color: var(--glass-border-dark);
}

.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-elevated);
}

/* Enhanced Navigation */
.navbar {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border-light);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition-smooth);
}

[data-theme="dark"] .navbar {
    background: var(--glass-dark);
    border-bottom-color: var(--glass-border-dark);
}

/* Hero Sections */
.hero,
.landing-hero,
.roommate-hero {
    position: relative;
    background: transparent;
    color: white;
    text-align: center;
    padding: 6rem 0;
    overflow: hidden;
}

.hero::before,
.landing-hero::before,
.roommate-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.8) 0%, rgba(139, 92, 246, 0.8) 100%);
    z-index: -1;
}

[data-theme="dark"] .hero::before,
[data-theme="dark"] .landing-hero::before,
[data-theme="dark"] .roommate-hero::before {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.6) 0%, rgba(139, 92, 246, 0.6) 100%);
}

/* Section Backgrounds */
.section {
    position: relative;
    padding: 4rem 0;
}

.section-light {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}

[data-theme="dark"] .section-light {
    background: var(--glass-dark);
}

/* Enhanced Cards */
.card,
.hostel-card,
.roommate-card,
.access-card,
.campus-card {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border-light);
    border-radius: 16px;
    padding: 1.5rem;
    transition: var(--transition-bounce);
    box-shadow: var(--shadow-glass);
}

[data-theme="dark"] .card,
[data-theme="dark"] .hostel-card,
[data-theme="dark"] .roommate-card,
[data-theme="dark"] .access-card,
[data-theme="dark"] .campus-card {
    background: var(--glass-dark);
    border-color: var(--glass-border-dark);
}

.card:hover,
.hostel-card:hover,
.roommate-card:hover,
.access-card:hover,
.campus-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-elevated), var(--shadow-glow);
}

/* Buttons Enhancement */
.btn,
.cta-button {
    background: linear-gradient(135deg, var(--primary-500), var(--purple-500));
    color: white;
    border: none;
    border-radius: 12px;
    padding: 0.875rem 2rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition-bounce);
    box-shadow: var(--shadow-glass);
    position: relative;
    overflow: hidden;
}

.btn::before,
.cta-button::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 ease;
}

.btn:hover::before,
.cta-button:hover::before {
    left: 100%;
}

.btn:hover,
.cta-button:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: var(--shadow-elevated), var(--shadow-glow);
}

.btn-secondary,
.cta-button.secondary {
    background: var(--glass-light);
    color: var(--primary-600);
    border: 2px solid var(--primary-500);
}

[data-theme="dark"] .btn-secondary,
[data-theme="dark"] .cta-button.secondary {
    background: var(--glass-dark);
    color: var(--primary-300);
}

/* Modal Enhancement */
.modal {
    background: rgba(0, 0, 0, 0.6);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}

.modal-content {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(30px);
    backdrop-filter: blur(30px);
    border: 1px solid var(--glass-border-light);
    border-radius: 24px;
    box-shadow: var(--shadow-elevated);
}

[data-theme="dark"] .modal-content {
    background: var(--glass-dark);
    border-color: var(--glass-border-dark);
}

/* Form Enhancement */
.form-group input,
.form-group select,
.form-group textarea {
    background: var(--glass-light);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border-light);
    border-radius: 12px;
    transition: var(--transition-smooth);
}

[data-theme="dark"] .form-group input,
[data-theme="dark"] .form-group select,
[data-theme="dark"] .form-group textarea {
    background: var(--glass-dark);
    border-color: var(--glass-border-dark);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1), var(--shadow-glow);
}

/* Footer Enhancement */
.footer {
    background: var(--glass-dark);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-top: 1px solid var(--glass-border-dark);
    color: white;
}

/* Loading Animation */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--glass-dark);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-smooth);
}

.loading-overlay.active {
    opacity: 1;
    visibility: visible;
}

.loading-spinner {
    width: 60px;
    height: 60px;
    border: 3px solid var(--glass-border-light);
    border-top: 3px solid var(--primary-500);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Scroll Enhancement */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--glass-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--primary-500), var(--purple-500));
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, var(--primary-600), var(--purple-600));
}

/* Text Enhancement */
.text-gradient {
    background: linear-gradient(135deg, var(--primary-500), var(--purple-500));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Responsive Enhancements */
@media (max-width: 768px) {
    body::before {
        background-attachment: scroll;
    }
    
    .floating-shapes {
        display: none;
    }
    
    .hero,
    .landing-hero,
    .roommate-hero {
        padding: 4rem 0;
    }
}

/* Accessibility Enhancements */
@media (prefers-reduced-motion: reduce) {
    .floating-shape,
    .loading-spinner {
        animation: none;
    }
    
    .btn,
    .cta-button,
    .card {
        transition: none;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    .glass-card,
    .modal-content {
        background: var(--bg-primary);
        border: 2px solid var(--text-primary);
    }
}