/* ==================== CSS CUSTOM PROPERTIES ==================== */
:root {
    /* Colors - Dark Theme with Neon Accents */
    --color-bg-primary: #0a0a0a;
    --color-bg-secondary: #151515;
    --color-bg-tertiary: #1f1f1f;

    /* Neon Gradients */
    --color-accent-pink: #ff006e;
    --color-accent-purple: #8b5cf6;
    --color-accent-blue: #3b82f6;
    --color-accent-cyan: #06b6d4;

    /* IITM Colors */
    --color-iitm-blue: #1e40af;
    --color-iitm-gold: #f59e0b;

    /* Text Colors */
    --color-text-primary: #ffffff;
    --color-text-secondary: #a0a0a0;
    --color-text-muted: #6b7280;

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ==================== RESET & BASE STYLES ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ==================== TYPOGRAPHY ==================== */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.2;
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-accent-pink), var(--color-accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==================== LAYOUT ==================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ==================== HEADER & NAVIGATION ==================== */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(10, 10, 10, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 800;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-normal);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent-pink), var(--color-accent-purple));
    transition: var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 0.4rem;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
    position: relative;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--color-text-primary);
    transition: var(--transition-fast);
}

/* ==================== HERO SECTION ==================== */
.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--spacing-xl) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255, 0, 110, 0.15), transparent);
    border-radius: 50%;
    filter: blur(80px);
    animation: float 8s ease-in-out infinite;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -50%;
    left: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.15), transparent);
    border-radius: 50%;
    filter: blur(80px);
    animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0) scale(1);
    }

    50% {
        transform: translateY(-30px) scale(1.1);
    }
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    animation: fadeInUp 1s ease;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1.2s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

/* ==================== BUTTONS ==================== */
.btn {
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-normal);
    border: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent-pink), var(--color-accent-purple));
    color: white;
    box-shadow: 0 10px 30px rgba(255, 0, 110, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 40px rgba(255, 0, 110, 0.4);
}

.btn-secondary {
    background: var(--glass-bg);
    color: white;
    border: 2px solid var(--glass-border);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    border-color: var(--color-accent-purple);
    transform: translateY(-2px);
}

/* ==================== MILESTONE COUNTERS ==================== */
.milestones {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
    position: relative;
    z-index: 1;
}

.milestone-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;

    text-align: center;
    backdrop-filter: blur(10px);
    transition: var(--transition-normal);
}

.milestone-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-purple);
    box-shadow: 0 10px 30px rgba(139, 92, 246, 0.2);
}

.milestone-number {
    font-size: 1.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-accent-pink), var(--color-accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.milestone-label {
    color: var(--color-text-secondary);
    font-size: 0.75rem;
    margin-top: 0.2rem;
}

/* ==================== SECTIONS ==================== */
.resources-section,
.features-section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    font-size: 1.1rem;
}

.subsection-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    margin: var(--spacing-2xl) 0 var(--spacing-2xl);
    text-align: center;
}

/* ==================== LINKS GRID ==================== */
.links-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.link-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--color-text-primary);
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.link-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-purple);
    box-shadow: 0 10px 30px rgba(139, 92, 246, 0.3);
}

.link-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xs);
}

.link-card h3 {
    font-size: 1rem;
    margin: var(--spacing-xs) 0;
    font-weight: 600;
}

.link-card p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    margin: 0;
}

/* ==================== LEVELS GRID ==================== */
.levels-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
}

.level-card {
    background: var(--glass-bg);
    border: 2px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.level-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--color-accent-pink), var(--color-accent-purple));
    transform: scaleX(0);
    transition: var(--transition-normal);
}

.level-card:hover::before {
    transform: scaleX(1);
}

.level-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-purple);
    box-shadow: 0 15px 40px rgba(139, 92, 246, 0.3);
}

.level-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--color-accent-pink), var(--color-accent-purple));
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.level-card h3 {
    font-size: 1.4rem;
    margin-bottom: var(--spacing-sm);
}

.level-card p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.level-credits {
    color: var(--color-accent-purple);
    font-weight: 600;
    font-size: 1.1rem;
}

/* ==================== FEATURES GRID ==================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-purple);
    box-shadow: 0 10px 30px rgba(139, 92, 246, 0.2);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

/* ==================== FOOTER ==================== */
.footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--glass-border);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
    margin-top: var(--spacing-2xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: var(--color-text-secondary);
}

.footer-links h4,
.footer-social h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.footer-links a,
.social-link {
    display: block;
    color: var(--color-text-secondary);
    text-decoration: none;
    margin-bottom: var(--spacing-xs);
    transition: var(--transition-fast);
}

.footer-links a:hover,
.social-link:hover {
    color: var(--color-accent-purple);
    transform: translateX(5px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--glass-border);
    color: var(--color-text-secondary);
}

/* ==================== MODAL ==================== */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
}

.modal-content {
    background: var(--color-bg-secondary);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    margin: 5% auto;
    padding: var(--spacing-xl);
    max-width: 800px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
}

.close-modal {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    font-size: 1.75rem;
    line-height: 1.2;
    cursor: pointer;
    color: var(--color-text-secondary);
    transition: var(--transition-fast);
}

.close-modal:hover {
    color: var(--color-accent-pink);
}

/* ==================== RESPONSIVE DESIGN ==================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: rgba(10, 10, 10, 0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--spacing-xl);
        transition: var(--transition-normal);
    }

    .nav-menu.active {
        left: 0;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }

    /* Mobile: Links grid - 2 columns */
    .links-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-xs);
    }

    /* Mobile: Levels grid - 1 column for better readability */
    .levels-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }

    /* Mobile: Milestone cards - 3 columns in one row */
    .milestones {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--spacing-xs);
    }

    /* Adjust text sizes for mobile */
    .hero h1 {
        font-size: clamp(1.75rem, 8vw, 2.5rem);
    }

    .section-title,
    .subsection-title {
        font-size: clamp(1.5rem, 6vw, 2rem);
    }

    /* Reduce padding on mobile */
    .resources-section,
    .features-section {
        padding: var(--spacing-lg) 0;
    }

    .link-card,
    .level-card {
        padding: var(--spacing-sm);
    }
}

/* ==================== SCROLLBAR ==================== */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--color-accent-pink), var(--color-accent-purple));
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--color-accent-purple), var(--color-accent-pink));
}