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

:root {
    /* Dark Theme Colors - Warm Sepia */
    --bg-primary: #1a1612;
    --bg-secondary: #252119;
    --bg-tertiary: #332d23;
    --text-primary: #e8e3d8;
    --text-secondary: #aca595;
    --accent-primary: #c17d5a;
    --accent-secondary: #a66b4f;
    --border-color: #3d3728;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --transition: all 0.3s ease;

    /* Rank badge colors - Dark theme */
    --rank-1-bg: linear-gradient(135deg, #d4a373, #c8956e);
    --rank-1-text: #1a1612;
    --rank-2-bg: linear-gradient(135deg, #b39b87, #a68f7d);
    --rank-2-text: #1a1612;
    --rank-3-bg: linear-gradient(135deg, #a07860, #8d6b55);
    --rank-3-text: #faf8f3;
}

[data-theme="light"] {
    /* Light Theme Colors - Warm Cream */
    --bg-primary: #faf8f3;
    --bg-secondary: #f3f0e8;
    --bg-tertiary: #e8e4d9;
    --text-primary: #2d2a23;
    --text-secondary: #6b655a;
    --border-color: #d9d4c8;
    --accent-primary: #a66b4f;
    --accent-secondary: #8d5d45;

    /* Rank badge colors - Light theme */
    --rank-1-bg: linear-gradient(135deg, #c8956e, #b88a64);
    --rank-1-text: #2d2a23;
    --rank-2-bg: linear-gradient(135deg, #a68f7d, #998371);
    --rank-2-text: #2d2a23;
    --rank-3-bg: linear-gradient(135deg, #8d6b55, #7d604b);
    --rank-3-text: #faf8f3;
}

body {
    font-family: 'JetBrains Mono', 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Mono', 'Droid Sans Mono', 'Source Code Pro', monospace;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.navbar {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: var(--transition);
}

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

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem;
    border-radius: 0.375rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--bg-tertiary);
}

.theme-icon {
    display: none;
    width: 20px;
    height: 20px;
}

.theme-icon-sun {
    display: block;
}

[data-theme="light"] .theme-icon-sun {
    display: none;
}

[data-theme="light"] .theme-icon-moon {
    display: block;
}

.hero {
    padding: 4rem 0 3.5rem;
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    letter-spacing: -0.03em;
}

.title-main {
    color: var(--text-primary);
    display: inline-block;
}

.title-accent {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
    position: relative;
}

.title-accent::after {
    content: '';
    position: absolute;
    bottom: 0.2em;
    left: 0;
    right: 0;
    height: 0.15em;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0.3;
    border-radius: 0.1em;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    white-space: nowrap;
}

.hero-description {
    max-width: 650px;
    margin: 0 auto 2rem;
}

.hero-description p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.btn-wrapper {
    position: relative;
    display: inline-flex;
    align-items: stretch;
}

.tooltip {
    position: absolute;
    bottom: -2.5rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 0.5rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    pointer-events: none;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.tooltip::before {
    content: '';
    position: absolute;
    top: -0.25rem;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 0.5rem;
    height: 0.5rem;
    background-color: var(--bg-tertiary);
    border-left: 1px solid var(--border-color);
    border-top: 1px solid var(--border-color);
}

.btn-wrapper:hover .tooltip,
.btn-wrapper .btn:focus + .tooltip {
    opacity: 1;
    visibility: visible;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    font-family: inherit;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-weight: 500;
    text-decoration: none;
}

.btn-icon {
    width: 14px;
    height: 14px;
}

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

.btn-primary:hover {
    background-color: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

/* Section Styles */
section {
    padding: 4rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-align: center;
}

.section-description {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1rem;
    max-width: 800px;
    margin: 0 auto 2rem;
    line-height: 1.8;
}

/* Leaderboard */
.leaderboard {
    background-color: var(--bg-secondary);
}

.leaderboard-chart {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 2rem;
    margin-bottom: 2rem;
    overflow-x: auto;
}

.leaderboard-chart-wrapper {
    width: 100%;
}

.chart-footnote {
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
}

.leaderboard-table {
    overflow-x: auto;
    border-radius: 0.5rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    min-width: 800px;
}

thead {
    background-color: var(--bg-tertiary);
}

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

th {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    white-space: nowrap;
}

td {
    font-size: 0.875rem;
}

tbody tr {
    transition: var(--transition);
}

tbody tr:hover {
    background-color: var(--bg-secondary);
}

tbody tr:last-child td {
    border-bottom: none;
}

/* Tasks Grid */
.task-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.task-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1.5rem;
    transition: var(--transition);
    cursor: pointer;
}

.task-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
    box-shadow: 0 10px 30px rgba(59, 130, 246, 0.1);
}

.task-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.task-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.difficulty-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.difficulty-easy {
    background-color: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.difficulty-medium {
    background-color: rgba(245, 158, 11, 0.2);
    color: var(--warning);
}

.difficulty-hard {
    background-color: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

.task-description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.task-meta {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.task-tag {
    background-color: var(--bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* About Section */
.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-content > p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
    text-align: center;
}

.setup-info {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 2rem;
    margin-bottom: 3rem;
}

.setup-info h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.setup-info ul {
    list-style: none;
    padding: 0;
}

.setup-info li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.setup-info strong {
    color: var(--accent-primary);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.stat-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 2rem;
    text-align: center;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Team Section */
.team {
    padding: 2.5rem 0;
    background-color: var(--bg-primary);
}

.team-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    max-width: 800px;
    margin: 0 auto;
}

.team-member-link {
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    cursor: pointer;
    border-bottom: 1px solid transparent;
}

.team-member-link:hover {
    color: var(--accent-secondary);
    border-bottom: 1px solid var(--accent-secondary);
}

.team-separator {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Citation Section */
.citation {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.citation-box {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 2rem;
    position: relative;
}

.citation-text {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    color: var(--text-primary);
    margin: 0;
    overflow-x: auto;
    white-space: pre;
    line-height: 1.6;
}

.copy-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    border: none;
    border-radius: 0.375rem;
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

.copy-btn:active {
    transform: translateY(0);
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Rank Badge */
.rank-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    font-weight: 700;
    font-size: 0.875rem;
}

.rank-1 {
    background: var(--rank-1-bg);
    color: var(--rank-1-text);
}

.rank-2 {
    background: var(--rank-2-bg);
    color: var(--rank-2-text);
}

.rank-3 {
    background: var(--rank-3-bg);
    color: var(--rank-3-text);
}

.rank-other {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Responsive Design */
@media (max-width: 968px) {
    .container {
        padding: 0 1.5rem;
    }

    .hero-title {
        font-size: 3rem;
    }

    .hero-subtitle {
        font-size: 1.15rem;
    }

    .nav-links a {
        font-size: 0.8rem;
    }

    table {
        font-size: 0.8rem;
    }

    th, td {
        padding: 0.75rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 2.5rem 0 2rem;
    }

    .hero-title {
        font-size: 2.25rem;
    }

    .hero-subtitle {
        font-size: 1rem;
        white-space: normal;
    }

    .hero-description p {
        font-size: 0.9rem;
    }

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

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

    .nav-links {
        gap: 0.75rem;
    }

    .nav-links a {
        font-size: 0.75rem;
    }

    .logo {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .section-description {
        font-size: 0.9rem;
    }

    .leaderboard-chart {
        padding: 1rem;
    }

    .task-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

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

    table {
        font-size: 0.75rem;
        min-width: 600px;
    }

    th, td {
        padding: 0.5rem;
    }

    th {
        font-size: 0.65rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.75rem;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .hero-description p {
        font-size: 0.85rem;
    }

    .nav-links a {
        font-size: 0.7rem;
    }

    .logo {
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    table {
        font-size: 0.7rem;
        min-width: 500px;
    }

    th, td {
        padding: 0.4rem;
    }
}