/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #60a5fa;
    --secondary: #14b8a6;
    --secondary-dark: #0f766e;
    --accent: #f97316;
    --accent-dark: #ea580c;
    
    --success: #16a34a;
    --warning: #d97706;
    --error: #dc2626;
    --info: #0ea5e9;
    
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    --white: #ffffff;
    --black: #000000;
    
    /* Typography */
    --font-primary: 'Inter', 'Segoe UI', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --spacing-xs: 0.25rem;   /* 4px */
    --spacing-sm: 0.5rem;    /* 8px */
    --spacing-md: 1rem;      /* 16px */
    --spacing-lg: 1.5rem;    /* 24px */
    --spacing-xl: 2rem;      /* 32px */
    --spacing-2xl: 3rem;     /* 48px */
    --spacing-3xl: 4rem;     /* 64px */
    
    /* Border Radius */
    --radius-sm: 0.375rem;   /* 6px */
    --radius-md: 0.5rem;     /* 8px */
    --radius-lg: 0.75rem;    /* 12px */
    --radius-xl: 1rem;       /* 16px */
    --radius-full: 9999px;
    
    /* Shadows */
    --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);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
    
    /* Z-Index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal: 1040;
    --z-tooltip: 1060;
}

body {
    font-family: var(--font-primary);
    font-weight: var(--font-weight-normal);
    line-height: 1.5;
    color: var(--gray-900);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Utility Classes */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: var(--font-weight-bold);
    text-align: center;
    margin-bottom: var(--spacing-md);
    color: var(--gray-900);
}

.section-subtitle {
    font-size: 1.25rem;
    text-align: center;
    margin-bottom: var(--spacing-3xl);
    color: var(--gray-600);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bg-gray {
    background-color: var(--gray-50);
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: var(--font-weight-medium);
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--white);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
}

.btn-small {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.75rem;
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    transition: all var(--transition-fast);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    max-width: 1280px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--primary);
    text-decoration: none;
}

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

.nav-link {
    color: var(--gray-700);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav-link:hover::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: var(--radius-full);
}

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

.nav-user-menu {
    position: relative;
}

.user-dropdown {
    position: relative;
}

.user-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--gray-100);
    border: none;
    border-radius: var(--radius-lg);
    color: var(--gray-700);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.user-btn:hover {
    background: var(--gray-200);
}

.dropdown-content {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: var(--spacing-sm);
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    min-width: 200px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: var(--z-dropdown);
}

.user-dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    color: var(--gray-700);
    text-decoration: none;
    transition: background var(--transition-fast);
}

.dropdown-content a:hover {
    background: var(--gray-50);
}

.dropdown-content hr {
    border: none;
    border-top: 1px solid var(--gray-200);
    margin: var(--spacing-sm) 0;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--gray-700);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);
    padding: calc(var(--spacing-3xl) + 60px) 0 var(--spacing-3xl);
    overflow: hidden;
    position: relative;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.hero-content {
    z-index: 2;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: var(--font-weight-bold);
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
    color: var(--gray-900);
}

.hero-description {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: var(--spacing-xl);
    line-height: 1.6;
}

.hero-stats {
    display: flex;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: var(--font-weight-bold);
    color: var(--primary);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-600);
    margin-top: var(--spacing-xs);
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.code-window {
    background: var(--gray-900);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 500px;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

.window-header {
    background: var(--gray-800);
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.window-controls {
    display: flex;
    gap: var(--spacing-sm);
}

.control {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.control.red { background: #ff5f56; }
.control.yellow { background: #ffbd2e; }
.control.green { background: #27ca3f; }

.window-title {
    color: var(--gray-400);
    font-size: 0.875rem;
    font-family: var(--font-mono);
}

.code-content {
    padding: var(--spacing-lg);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.6;
}

.code-line {
    margin-bottom: var(--spacing-sm);
}

.keyword { color: #ff79c6; }
.function { color: #50fa7b; }
.param { color: #f1fa8c; }
.variable { color: #8be9fd; }
.string { color: #f1fa8c; }
.comment { color: #6272a4; }

/* Hackathons Grid */
.hackathons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.hackathon-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: all var(--transition-normal);
    cursor: pointer;
}

.hackathon-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.hackathon-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-100);
}

.hackathon-status {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: var(--font-weight-medium);
    text-transform: uppercase;
    margin-bottom: var(--spacing-md);
}

.status-active {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.status-registration {
    background: rgba(249, 115, 22, 0.1);
    color: var(--accent);
}

.status-upcoming {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

.hackathon-title {
    font-size: 1.25rem;
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: var(--spacing-sm);
}

.hackathon-description {
    color: var(--gray-600);
    line-height: 1.5;
}

.hackathon-body {
    padding: var(--spacing-lg);
}

.hackathon-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.meta-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--gray-600);
    font-size: 0.875rem;
}

.meta-item i {
    color: var(--primary);
}

.hackathon-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.prize-pool {
    font-size: 1.25rem;
    font-weight: var(--font-weight-bold);
    color: var(--success);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all var(--transition-normal);
    border: 1px solid var(--gray-200);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
    font-size: 1.5rem;
    color: var(--white);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-md);
    color: var(--gray-900);
}

.feature-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

/* Leaderboard */
.leaderboard-container {
    background: var(--white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.leaderboard-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.leaderboard-filters {
    display: flex;
    gap: var(--spacing-sm);
}

.filter-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--gray-300);
    background: var(--white);
    color: var(--gray-700);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.875rem;
    font-weight: var(--font-weight-medium);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary);
    color: var(--white);
    border-color: var(--primary);
}

.leaderboard-table {
    overflow-x: auto;
}

.leaderboard-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-100);
    transition: background var(--transition-fast);
}

.leaderboard-item:hover {
    background: var(--gray-50);
}

.leaderboard-item:last-child {
    border-bottom: none;
}

.rank {
    font-size: 1.25rem;
    font-weight: var(--font-weight-bold);
    color: var(--primary);
    width: 60px;
    text-align: center;
}

.rank.top-3 {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.user-info {
    flex: 1;
    margin-left: var(--spacing-md);
}

.user-name {
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: var(--spacing-xs);
}

.user-stats {
    display: flex;
    gap: var(--spacing-lg);
    font-size: 0.875rem;
    color: var(--gray-600);
}

.score {
    font-size: 1.125rem;
    font-weight: var(--font-weight-bold);
    color: var(--success);
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand {
    max-width: 400px;
}

.footer-brand .brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.footer-brand p {
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--gray-800);
    color: var(--gray-400);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-2px);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.link-group h4 {
    color: var(--white);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-lg);
}

.link-group a {
    display: block;
    color: var(--gray-400);
    text-decoration: none;
    margin-bottom: var(--spacing-sm);
    transition: color var(--transition-fast);
}

.link-group a:hover {
    color: var(--primary);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--gray-800);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: var(--spacing-lg);
        border-top: 1px solid var(--gray-200);
        transform: translateY(-100%);
        transition: transform var(--transition-normal);
    }
    
    .nav-menu.active {
        transform: translateY(0);
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .hackathons-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-container {
        padding: 0 var(--spacing-sm);
    }
    
    .btn-large {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.875rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
}

/* Loading States */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-300);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

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

/* Focus styles */
*:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

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

::-webkit-scrollbar-track {
    background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--gray-400);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-500);
}