:root {
    --bg-color: #0b0f12;
    --card-bg: #11171d;
    --border-color: #212c35;
    --text-primary: #c9d1d9;
    --text-muted: #8b949e;
    --accent-color: #58a6ff;
    --accent-hover: #79c0ff;
    --font-mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-mono);
    line-height: 1.6;
    padding: 2rem 1rem;
}

.terminal-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

/* Header */
.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
    margin-bottom: 2rem;
}

.logo-area {
    font-size: 1.1rem;
    font-weight: bold;
    letter-spacing: 0.05em;
}

.prompt {
    color: var(--accent-color);
}

.site-title {
    color: #ffffff;
}

.cursor {
    animation: blink 1s infinite;
    color: var(--accent-color);
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lang-switch {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.lang-switch a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.lang-switch a:hover {
    color: var(--accent-hover);
}

.active-lang {
    color: var(--accent-color);
    font-weight: bold;
}

.version-tag {
    font-size: 0.8rem;
    color: var(--text-muted);
    background: #161b22;
    padding: 0.2rem 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 3px;
}

/* Intro Block */
.intro-block {
    margin-bottom: 2.5rem;
    padding: 1rem;
    background-color: #161b22;
    border-left: 3px solid var(--accent-color);
    font-size: 0.95rem;
}

/* Module Grid */
.module-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.module-card {
    background-color: #161b22;
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 4px;
    transition: border-color 0.2s ease;
}

.module-card:hover {
    border-color: var(--accent-color);
}

.module-id {
    font-size: 0.75rem;
    color: var(--accent-color);
    letter-spacing: 0.1em;
    margin-bottom: 0.5rem;
}

.module-card h2 {
    font-size: 1.2rem;
    color: #ffffff;
    margin-bottom: 0.75rem;
}

.module-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

/* Article Lists */
.article-list {
    list-style: none;
}

.article-list li {
    margin-bottom: 0.5rem;
}

.article-list a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

.article-list a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
}

@media (min-width: 768px) {
    .module-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}