/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* CSS Variables */
:root {
    /* Colors - Blue & White Theme */
    --primary-blue: #0056D2;
    --primary-blue-dark: #003D99;
    --primary-blue-light: #3B82F6;
    --secondary-blue: #60A5FA;
    --accent-gold: #FDB93A;

    --white: #FFFFFF;
    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-300: #D1D5DB;
    --gray-600: #4B5563;
    --gray-700: #374151;
    --gray-800: #1F2937;
    --gray-900: #111827;

    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* 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: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--gray-50);
    color: var(--gray-800);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--gray-900);
}

/* Navigation Bar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--white);
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
}

.navbar.scrolled {
    box-shadow: var(--shadow-lg);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-blue);
    text-decoration: none;
}

.logo-img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-800);
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: var(--primary-blue);
    transition: var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: translateX(-50%) scaleX(1);
}

.btn-login {
    background: var(--primary-blue);
    color: var(--white) !important;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
}

.btn-login::after {
    display: none;
}

.btn-login:hover {
    background: var(--primary-blue-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    margin-top: 70px;
    background: linear-gradient(135deg, #0056D2 0%, #003D99 50%, #001F4D 100%);
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="40" height="40" patternUnits="userSpaceOnUse"><path d="M 40 0 L 0 0 0 40" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 900px;
    text-align: center;
    color: var(--white);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, #FFFFFF 0%, #60A5FA 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-tagline {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--accent-gold);
}

.hero-description {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.9);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-2xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    border: none;
    cursor: pointer;
    transition: var(--transition-normal);
    text-decoration: none;
    font-family: inherit;
}

.btn-primary {
    background: var(--accent-gold);
    color: var(--gray-900);
    box-shadow: 0 4px 15px rgba(253, 185, 58, 0.3);
}

.btn-primary:hover {
    background: #FDC863;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(253, 185, 58, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-3px);
}

/* Hero Stats */
.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
    max-width: 600px;
    margin: 0 auto;
}

.stat-item {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-gold);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

/* Hero Decoration */
.hero-decoration {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.circle {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(96, 165, 250, 0.15) 0%, transparent 70%);
    animation: float 20s infinite ease-in-out;
}

.circle-1 {
    width: 400px;
    height: 400px;
    top: -200px;
    right: -100px;
    animation-delay: 0s;
}

.circle-2 {
    width: 300px;
    height: 300px;
    bottom: -150px;
    left: -100px;
    animation-delay: 5s;
}

.circle-3 {
    width: 200px;
    height: 200px;
    top: 50%;
    left: 10%;
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
}

/* Section Styles */
section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    color: var(--gray-900);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* About Section */
.about {
    background: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.about-card {
    background: var(--gray-50);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--gray-200);
    transition: var(--transition-normal);
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-blue-light);
}

.about-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-light) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    font-size: 1.5rem;
    color: var(--white);
}

.about-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--gray-900);
}

.about-card p {
    color: var(--gray-600);
    line-height: 1.8;
}

/* Features Section */
.features {
    background: linear-gradient(180deg, var(--gray-50) 0%, var(--white) 100%);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 2px solid var(--gray-200);
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue) 0%, var(--primary-blue-light) 100%);
    transform: scaleX(0);
    transition: var(--transition-normal);
}

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

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

.feature-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-blue-light) 0%, var(--secondary-blue) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    font-size: 1.75rem;
    color: var(--white);
}

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

.feature-card p {
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.feature-badge {
    display: inline-block;
    background: var(--primary-blue);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

/* How It Works Section */
.how-it-works {
    background: var(--white);
}

.steps-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.step-card {
    flex: 1;
    min-width: 250px;
    max-width: 300px;
    background: var(--gray-50);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 2px solid var(--gray-200);
    text-align: center;
    position: relative;
    transition: var(--transition-normal);
}

.step-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-blue);
}

.step-number {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-weight: 800;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
}

.step-icon {
    font-size: 3rem;
    color: var(--primary-blue);
    margin: var(--spacing-md) 0;
}

.step-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--gray-900);
}

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

.step-arrow {
    font-size: 2rem;
    color: var(--primary-blue);
}

/* Leaderboard Section */
.leaderboard {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
    color: var(--white);
}

.leaderboard .section-title,
.leaderboard .section-subtitle {
    color: var(--white);
}

.leaderboard-container {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
}

.leaderboard-table thead {
    background: rgba(0, 0, 0, 0.2);
}

.leaderboard-table th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
}

.leaderboard-table td {
    padding: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.leaderboard-table tbody tr {
    transition: var(--transition-fast);
}

.leaderboard-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.05);
}

.leaderboard-table .no-data {
    text-align: center;
    padding: var(--spacing-2xl);
    color: rgba(255, 255, 255, 0.7);
}

/* FAQ Section */
.faq {
    background: var(--gray-50);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--white);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    border: 1px solid var(--gray-200);
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: none;
    border: none;
    text-align: left;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-900);
    cursor: pointer;
    transition: var(--transition-fast);
    font-family: inherit;
}

.faq-question:hover {
    color: var(--primary-blue);
}

.faq-question i {
    transition: var(--transition-fast);
    color: var(--primary-blue);
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    transition: max-height 0.5s ease-in;
}

.faq-answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--gray-600);
    line-height: 1.8;
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
}

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

.footer-col h4 {
    color: var(--white);
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
}

.footer-col p {
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.footer-col ul li i {
    color: var(--primary-blue-light);
    width: 20px;
}

.footer-col a {
    color: var(--gray-300);
    text-decoration: none;
    transition: var(--transition-fast);
}

.footer-col a:hover {
    color: var(--primary-blue-light);
}

.footer-logo img {
    width: 80px;
    margin-top: var(--spacing-sm);
    opacity: 0.7;
}

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

.social-icon {
    width: 40px;
    height: 40px;
    background: var(--gray-800);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: var(--transition-normal);
}

.social-icon:hover {
    background: var(--primary-blue);
    transform: translateY(-3px);
}

.footer-bottom {
    border-top: 1px solid var(--gray-800);
    padding-top: var(--spacing-md);
    text-align: center;
    font-size: 0.875rem;
}

.developer-credit {
    margin-top: var(--spacing-xs);
    color: var(--gray-400);
}

.developer-credit strong {
    color: var(--primary-blue-light);
}

/* Modal Styles */
.modal {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease-out;
}

.modal-content {
    position: relative;
    background: var(--white);
    border-radius: var(--radius-2xl);
    max-width: 480px;
    width: 100%;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.3s ease-out;
    max-height: 90vh;
    overflow-y: auto;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 40px;
    height: 40px;
    background: var(--gray-100);
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 1.25rem;
    color: var(--gray-600);
}

.modal-close:hover {
    background: var(--gray-200);
    color: var(--gray-900);
}

.modal-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.modal-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
    font-size: 2rem;
    color: var(--white);
}

.modal-header h2 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
}

.modal-header p {
    color: var(--gray-600);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--gray-700);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.form-group label i {
    color: var(--primary-blue);
}

.form-group input {
    padding: 0.875rem var(--spacing-md);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition-fast);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(0, 86, 210, 0.1);
}

.form-hint {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.form-error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.btn-block {
    width: 100%;
    justify-content: center;
    margin-top: var(--spacing-sm);
}

.modal-footer {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--gray-200);
    text-align: center;
}

.modal-footer p {
    font-size: 0.875rem;
    color: var(--gray-600);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-menu {
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--white);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition-normal);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .hero {
        min-height: auto;
        padding: var(--spacing-xl) var(--spacing-md);
    }

    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .step-arrow {
        display: none;
    }

    .steps-container {
        flex-direction: column;
    }

    .about-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }

    .modal-content {
        padding: var(--spacing-md);
    }

    .hero-stats {
        grid-template-columns: 1fr;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.mb-0 { margin-bottom: 0; }
.mt-0 { margin-top: 0; }