:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #0f172a;
    --accent: #f43f5e;
    --bg-main: #ffffff;
    --bg-soft: #f8fafc;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --white: #ffffff;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-md: 12px;
    --radius-lg: 20px;
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

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

body {
    font-family: 'Inter', -apple-system, sans-serif;
    color: var(--text-main);
    background-color: var(--bg-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Base Components */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Premium Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s ease;
}

.navbar .container {
    height: 72px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.125rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #475569;
    font-weight: 500;
    font-size: 0.875rem;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary);
}

/* Premium Hero */
.hero {
    position: relative;
    padding: 10rem 0 6rem;
    background: 
        radial-gradient(circle at 100% 0%, rgba(37, 99, 235, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 0% 100%, rgba(37, 99, 235, 0.05) 0%, transparent 40%),
        var(--bg-soft);
    text-align: center;
    overflow: hidden;
}

.hero .college-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 3rem;
    margin-bottom: 3.5rem;
}

.hero .college-logos img {
    height: 64px;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.05));
    transition: transform 0.3s ease;
}

.hero .college-logos img:hover {
    transform: translateY(-4px);
}

.hero .org-tag {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--primary);
    margin-bottom: 1.5rem;
    display: block;
}

.hero h1 {
    font-size: clamp(2.25rem, 5vw, 3.75rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1.1;
    color: var(--secondary);
    margin: 0 auto 2rem;
    max-width: 900px;
}

.hero .hero-data {
    display: inline-flex;
    align-items: center;
    gap: 1rem;
    background: white;
    padding: 0.5rem 1.25rem;
    border-radius: 100px;
    box-shadow: var(--shadow-md);
    font-weight: 600;
    font-size: 0.9375rem;
    margin-bottom: 2.5rem;
}

.hero .hero-data span {
    color: var(--primary);
}

/* Section Styling */
section {
    padding: 7rem 0;
}

.section-head {
    text-align: center;
    margin-bottom: 4.5rem;
}

.section-head span {
    color: var(--primary);
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: block;
    margin-bottom: 0.75rem;
}

.section-head h2 {
    font-size: 2.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--secondary);
}

/* Premium Cards */
.card-premium {
    background: white;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    padding: 2.5rem;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.card-premium:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37, 99, 235, 0.2);
}

/* Committee Section */
.committee-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.committee-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.committee-card h3::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.committee-card ul {
    list-style: none;
}

.committee-card li {
    padding: 0.75rem 0;
    color: #475569;
    font-size: 0.9375rem;
    border-bottom: 1px solid var(--bg-soft);
}

.committee-card li:last-child {
    border-bottom: none;
}

/* Themes Section */
.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
}

.theme-card {
    background: var(--bg-soft);
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    font-weight: 500;
    color: var(--secondary);
    border: 1px solid transparent;
    transition: all 0.2s ease;
}

.theme-card:hover {
    background: white;
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: var(--shadow-md);
}

/* Important Dates */
.dates-table {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    overflow: hidden;
}

.date-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border);
}

.date-row:last-child {
    border-bottom: none;
}

.date-label {
    font-weight: 600;
    color: var(--secondary);
}

.date-value {
    color: var(--primary);
    font-weight: 700;
    background: rgba(37, 99, 235, 0.05);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
}

/* Registration */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.price-card {
    text-align: center;
    padding: 3.5rem 2rem;
    position: relative;
    overflow: hidden;
}

.price-card.featured {
    border: 2px solid var(--primary);
    scale: 1.05;
}

.price-card.featured::before {
    content: 'RECOMMENDED';
    position: absolute;
    top: 1rem;
    right: -1.5rem;
    background: var(--primary);
    color: white;
    font-size: 0.625rem;
    font-weight: 800;
    padding: 0.25rem 2rem;
    transform: rotate(45deg);
}

.price-card .price {
    font-size: 3rem;
    font-weight: 800;
    color: var(--secondary);
    margin-bottom: 1rem;
}

.price-card .price span {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 400;
}

/* Buttons */
.btn-premium {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2.5rem;
    background: var(--primary);
    color: white !important;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9375rem;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
}

.btn-premium:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px -6px rgba(37, 99, 235, 0.5);
}

/* Mobile Nav Toggle */
.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--secondary);
    cursor: pointer;
    padding: 0.5rem;
}

/* Responsive Overrides */
@media (max-width: 992px) {
    .nav-links {
        display: none;
    }
    
    .nav-links.active {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        padding: 2rem;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
        text-align: center;
        gap: 1.5rem;
    }

    .mobile-toggle {
        display: block;
    }

    .hero {
        padding-top: 8rem;
    }

    .hero .college-logos {
        gap: 1.5rem;
        flex-wrap: wrap;
    }

    .hero .college-logos img {
        height: 48px;
    }

    .price-card.featured {
        scale: 1;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .date-row {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
        padding: 1.25rem;
    }
}