:root {
    --bg-color: #141815;
    --card-bg: #1f2521;
    --card-border: #2e3630;
    --accent-color: #43a047;
    --accent-hover: #388e3c;
    --text-color: #e2e8e3;
    --text-muted: #9ea8a0;
    --header-bg: #0b0e0c;
    --table-header: #181d19;
    --table-hover: #28302b;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: var(--header-bg);
    padding: 1.2rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--accent-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.6rem;
    font-weight: bold;
    color: var(--accent-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

nav {
    display: flex;
    gap: 0.5rem;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: background-color 0.2s, color 0.2s;
}

nav a:hover, nav a.active {
    background-color: var(--accent-color);
    color: #ffffff;
}

main {
    max-width: 1100px;
    margin: 2rem auto;
    padding: 0 1.5rem;
    flex: 1;
    width: 100%;
}

h1 {
    font-size: 2.2rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.8rem;
    margin-top: 1.5rem;
}

.card {
    background-color: var(--card-bg);
    border-radius: 10px;
    padding: 1.25rem;
    border: 1px solid var(--card-border);
    display: flex;
    flex-direction: column;
    transition: transform 0.2s, border-color 0.2s;
}

.card:hover {
    transform: translateY(-3px);
    border-color: var(--accent-color);
}

.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1rem;
    background-color: #121513;
}

.card h3 {
    font-size: 1.3rem;
    color: var(--text-color);
    margin-bottom: 0.4rem;
}

.card .tag {
    display: inline-block;
    background-color: #121613;
    color: var(--accent-color);
    border: 1px solid var(--card-border);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    align-self: flex-start;
}

.table-container {
    overflow-x: auto;
    margin-top: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--card-border);
}

.geo-table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--card-bg);
    font-size: 0.92rem;
}

.geo-table th, .geo-table td {
    padding: 0.85rem 1rem;
    border: 1px solid var(--card-border);
    text-align: left;
    vertical-align: top;
}

.geo-table th {
    background-color: var(--table-header);
    color: var(--accent-color);
    font-weight: 700;
    text-transform: uppercase;
    font-size: 0.85rem;
}

.geo-table tr:hover {
    background-color: var(--table-hover);
}

.eon-col {
    font-weight: bold;
    color: #81c784;
}

.era-col {
    font-weight: 600;
}

.quiz-card {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    border: 1px solid var(--card-border);
    max-width: 700px;
    margin: 2rem auto;
}

.quiz-progress {
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 1rem;
}

.quiz-question {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.quiz-btn {
    background-color: #151a17;
    color: var(--text-color);
    border: 1px solid var(--card-border);
    padding: 1rem 1.2rem;
    border-radius: 6px;
    text-align: left;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
}

.quiz-btn:hover {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
    color: #ffffff;
}

.action-btn {
    background-color: var(--accent-color);
    color: #ffffff;
    border: none;
    padding: 0.8rem 1.8rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    margin-top: 1.5rem;
    transition: background-color 0.2s;
}

.action-btn:hover {
    background-color: var(--accent-hover);
}

footer {
    background-color: var(--header-bg);
    border-top: 1px solid var(--card-border);
    text-align: center;
    padding: 1.5rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 3rem;
}