:root {
    /* Light theme */
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #818cf8;
    --secondary-color: #10b981;
    --background-color: #ffffff;
    --surface-color: #f3f4f6;
    --border-color: #e5e7eb;
    --text-color: #111827;
    --text-secondary: #6b7280;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --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);
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #818cf8;
        --primary-dark: #6366f1;
        --primary-light: #a5b4fc;
        --secondary-color: #34d399;
        --background-color: #111827;
        --surface-color: #1f2937;
        --border-color: #374151;
        --text-color: #f9fafb;
        --text-secondary: #9ca3af;
        --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
        --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.4), 0 1px 2px -1px rgb(0 0 0 / 0.4);
        --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4), 0 2px 4px -2px rgb(0 0 0 / 0.4);
        --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4), 0 4px 6px -4px rgb(0 0 0 / 0.4);
    }
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.25;
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-dark);
}

/* Layout */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.main-nav {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-color);
    font-weight: 500;
    padding: 0.5rem;
    border-radius: 0.375rem;
    transition: all 0.2s;
}

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 0.375rem;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s;
    gap: 0.5rem;
}

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

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

.btn-secondary {
    background-color: var(--surface-color);
    color: var(--text-color);
    border-color: var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--border-color);
}

.btn-success {
    background-color: var(--success-color);
    color: white;
}

.btn-error {
    background-color: var(--error-color);
    color: white;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.form-input {
    width: 100%;
    padding: 0.625rem;
    font-size: 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    background-color: var(--background-color);
    color: var(--text-color);
    transition: all 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.form-input.error {
    border-color: var(--error-color);
}

.form-error {
    color: var(--error-color);
    font-size: 0.75rem;
    margin-top: 0.25rem;
}

/* Cards */
.card {
    background-color: var(--surface-color);
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.card-body {
    padding: 1rem;
}

.card-footer {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 0.375rem;
    margin-bottom: 1rem;
}

.alert-success {
    background-color: #dcfce7;
    color: #166534;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
}

.alert-warning {
    background-color: #fef3c7;
    color: #92400e;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 9999px;
}

.badge-primary {
    background-color: var(--primary-light);
    color: var(--primary-dark);
}

.badge-success {
    background-color: #dcfce7;
    color: #166534;
}

.badge-warning {
    background-color: #fef3c7;
    color: #92400e;
}

.badge-error {
    background-color: #fee2e2;
    color: #991b1b;
}

/* Loading states */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    inset: 0;
    background-color: var(--background-color);
    opacity: 0.7;
}

.spinner {
    width: 1.5rem;
    height: 1.5rem;
    border: 2px solid var(--primary-light);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--surface-color);
        padding: 1rem;
        flex-direction: column;
        gap: 0.5rem;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu {
        display: block;
    }
}

/* Grid system */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
    .grid-cols-4 { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
    .grid-cols-3, .grid-cols-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
    .grid-cols-2, .grid-cols-3, .grid-cols-4 { grid-template-columns: 1fr; }
}

/* User menu */
.user-menu {
    position: relative;
}

.user-menu-btn {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.5rem 0;
    min-width: 150px;
    display: none;
    z-index: 1000;
}

.user-menu:hover .dropdown-menu {
    display: block;
}

.dropdown-menu a {
    display: block;
    padding: 0.5rem 1rem;
    color: var(--text-color);
}

.dropdown-menu a:hover {
    background-color: var(--primary-color);
    color: white;
}

/* Mobile menu */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 5px 0;
    transition: 0.3s;
}

/* Game grid */
.game-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    padding: 1.5rem;
}

.game-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.3s;
}

.game-card:hover {
    transform: translateY(-5px);
}

.game-card img {
    width: 100%;
    height: 150px;
    object-fit: cover;
}

.game-card-content {
    padding: 1rem;
}

.game-card-title {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.game-card-author {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Leaderboard */
.leaderboard {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.leaderboard th,
.leaderboard td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.leaderboard th {
    background-color: var(--surface-color);
}

/* Game interface */
.game-container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.game-header {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.game-controls {
    display: flex;
    gap: 0.5rem;
}

.game-frame {
    width: 100%;
    min-height: 500px;
    border: none;
}

/* Footer */
footer {
    background-color: var(--surface-color);
    padding: 3rem 0 1.5rem;
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Mobile menu */
.mobile-menu {
    display: none;
}