:root {
    --primary-blue: #3b82f6;
    --primary-purple: #8b5cf6;
    --primary-pink: #ec4899;
    --primary-cyan: #06b6d4;
    --primary-emerald: #10b981;
    --primary-orange: #f59e0b;
    --primary-red: #ef4444;
    
    --bg-primary: #fefefe;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-glass: rgba(255, 255, 255, 0.9);
    
    --text-primary: #010611;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --text-white: #ffffff;
    
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    
    --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.15);
    --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 8px 40px rgba(0, 0, 0, 0.12);
    
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-success: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --gradient-warm: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    --gradient-cool: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
    --gradient-neon: linear-gradient(135deg, #d299c2 0%, #fef9d7 100%);
    
    --border-radius: 16px;
    --border-radius-lg: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease-out;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #fafafa 0%, #f4f6f8 100%);
    line-height: 1.6;
    color: var(--text-primary);
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Floating particles animation */
.floating-particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: linear-gradient(45deg, #3b82f6, #8b5cf6);
    border-radius: 50%;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); opacity: 0.4; }
    50% { transform: translateY(-20px) rotate(180deg); opacity: 0.8; }
}

/* Main Content */
.main {
    padding: 2rem 0;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 3rem;
    padding: 3rem 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(9, 39, 89, 0.05) 0%, transparent 70%);
    transform: translate(-50%, -50%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: translate(-50%, -50%) scale(1); }
    50% { transform: translate(-50%, -50%) scale(1.1); }
}

.hero-title {
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    z-index: 2;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 2rem;
    line-height: 1.6;
    position: relative;
    z-index: 2;
}

.hero-badges {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
    position: relative;
    z-index: 2;
}

.badge {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-light);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition);
    box-shadow: var(--shadow-card);
    position: relative;
    overflow: hidden;
}

.badge::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    transition: left 0.5s;
}

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

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

.badge a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 600;
}

/* Study Materials Sections */
.materials-section {
    margin-bottom: 3rem;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    position: relative;
    overflow: hidden;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-card);
}

.materials-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
}

.materials-section.paper-2::before {
    background: var(--gradient-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-title {
    font-size: clamp(1.75rem, 3vw, 2.25rem);
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    letter-spacing: -0.01em;
}

.section-description {
    color: var(--text-secondary);
    font-size: 1rem;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
}

.material-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-decoration: none;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
    box-shadow: var(--shadow-card);
    min-height: 180px;
}

.material-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-primary);
    opacity: 0;
    transition: var(--transition);
}

.paper-2 .material-card:nth-child(1)::before { background: var(--gradient-secondary); }
.paper-2 .material-card:nth-child(2)::before { background: var(--gradient-accent); }
.paper-2 .material-card:nth-child(3)::before { background: var(--gradient-success); }
.paper-2 .material-card:nth-child(4)::before { background: var(--gradient-warm); }

.material-card:nth-child(1)::before { background: var(--gradient-primary); }
.material-card:nth-child(2)::before { background: var(--gradient-cool); }
.material-card:nth-child(3)::before { background: var(--gradient-neon); }
.material-card:nth-child(4)::before { background: var(--gradient-warm); }

.material-card:hover::before {
    opacity: 1;
}

.material-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-hover);
    border-color: transparent;
}

.material-card-content {
    position: relative;
    z-index: 2;
    transition: var(--transition);
    width: 100%;
}

.material-card:hover .material-card-content {
    color: var(--text-white);
}

.material-icon {
    width: 3rem;
    height: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.2), rgba(255, 255, 255, 0.1));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition);
}

.material-card:hover .material-icon {
    background: rgba(255, 255, 255, 0.25);
    transform: scale(1.1);
}

.material-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    transition: var(--transition);
}

.material-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
    transition: var(--transition);
    flex-grow: 1;
}

.material-card:hover .material-title,
.material-card:hover .material-description {
    color: var(--text-white);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 2rem 0;
        margin-bottom: 2rem;
    }

    .materials-section {
        padding: 1.5rem;
        margin-bottom: 2rem;
    }

    .materials-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .material-card {
        min-height: 160px;
        padding: 1.25rem;
    }

    .hero-badges {
        gap: 0.5rem;
    }

    .badge {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
}

@media (max-width: 480px) {
    .materials-section {
        padding: 1rem;
    }

    .material-card {
        padding: 1rem;
        min-height: 140px;
    }

    .material-icon {
        width: 2.5rem;
        height: 2.5rem;
        font-size: 1.25rem;
    }

    .material-title {
        font-size: 1.1rem;
    }

    .material-description {
        font-size: 0.85rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus states */
.material-card:focus {
    outline: 3px solid var(--primary-blue);
    outline-offset: 2px;
}

/* Loading animation */
@keyframes shimmer {
    0% { background-position: -200px 0; }
    100% { background-position: calc(200px + 100%) 0; }
}

/* Entrance animations */
.materials-section {
    animation: slideInUp 0.6s ease-out forwards;
    opacity: 0;
    transform: translateY(30px);
}

.materials-section:nth-child(2) { animation-delay: 0.1s; }
.materials-section:nth-child(3) { animation-delay: 0.2s; }

@keyframes slideInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Glowing border effect */
.material-card {
    position: relative;
}

.material-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: var(--border-radius);
    padding: 1px;
    background: linear-gradient(45deg, transparent, rgba(59, 130, 246, 0.3), transparent);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    opacity: 0;
    transition: var(--transition);
}

.material-card:hover::after {
    opacity: 1;
}

.site-footer {
    background: linear-gradient(to right, #eef1f7, #e5ebf5);
    color: #00050a;
    padding: 2.5rem 1rem;
    text-align: center;
    border-top: 4px solid #041b3b;
    margin-top: 3rem;
    border-radius: 8px 8px 0 0;
}

.site-footer .site-title {
    font-size: 1.8rem;
    font-weight: 700;
    margin: 0;
    line-height: 1.3;
    margin-bottom: 0.5rem;
}

.site-footer .site-title span {
    font-weight: 400;
    color: #011024;
}

.site-footer .site-tagline {
    font-size: 1rem;
    margin-top: 0.5rem;
    margin-bottom: 2rem;
    color: #020e1d;
    font-style: italic;
}

.contact-section {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid #d1d9e6;
}

.contact-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: #041b3b;
    margin-bottom: 1.5rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    align-items: center;
}

.contact-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: #00050a;
    padding: 1rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.3);
    border: 1px solid rgba(4, 27, 59, 0.1);
    transition: all 0.3s ease;
    min-width: 120px;
}

.contact-item:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.5);
    border-color: #041b3b;
    box-shadow: 0 4px 12px rgba(4, 27, 59, 0.15);
}

.contact-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: #041b3b;
}

.contact-label {
    font-weight: 600;
    font-size: 0.9rem;
    color: #041b3b;
    margin-bottom: 0.2rem;
}

.contact-desc {
    font-size: 0.8rem;
    color: #020e1d;
    text-align: center;
    line-height: 1.3;
}

.footer-bottom {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid #d1d9e6;
    font-size: 0.85rem;
    color: #020e1d;
}

@media (max-width: 768px) {
    .site-footer .site-title {
        font-size: 1.4rem;
    }

    .site-footer .site-tagline {
        font-size: 0.9rem;
    }

    .contact-links {
        gap: 1rem;
    }

    .contact-item {
        min-width: 100px;
        padding: 0.8rem;
    }

    .contact-title {
        font-size: 1.1rem;
    }
}

@media (max-width: 500px) {
    .contact-links {
        flex-direction: column;
        gap: 1rem;
    }

    .contact-item {
        width: 100%;
        max-width: 250px;
    }
}

/* Custom Logo of Abhi Physics */
.logo-icon {
    background: transparent !important; /* Remove any background color */
}

.logo-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 4px;
}