/* ===================== LANDING PAGE STYLES ===================== */
:root {
    --bg-primary: #0f1117;
    --bg-secondary: #1a1b23;
    --bg-card: #22232d;
    --bg-card-hover: #2a2b37;
    --text-primary: #e4e4e7;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --accent: #818cf8;
    --accent-light: #a5b4fc;
    --accent-glow: rgba(129, 140, 248, 0.15);
    --success: #34d399;
    --border: #2e2f3a;
    --radius: 12px;
    --ai-gradient: linear-gradient(135deg, #7c3aed, #06b6d4);
    --dsa-gradient: linear-gradient(135deg, #818cf8, #34d399);
    --na-gradient: linear-gradient(135deg, #06b6d4, #10b981);
    --sad-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
    --cs-gradient: linear-gradient(135deg, #f59e0b, #ef4444);
}

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

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

.landing-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 24px;
    min-height: 100vh;
}

/* Two-column layout */
.landing-layout {
    display: flex;
    gap: 48px;
    max-width: 1200px;
    width: 100%;
    align-items: center;
}

.landing-left {
    flex: 1;
    min-width: 0;
}

.landing-right {
    width: 360px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.video-container {
    width: 100%;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.video-container video {
    width: 100%;
    display: block;
    border-radius: 16px;
}

.landing-verse {
    text-align: center;
    font-size: 16px;
    color: var(--text-secondary);
    font-style: italic;
    line-height: 1.8;
}

.verse-ref {
    font-size: 13px;
    color: var(--text-muted);
    font-style: normal;
    font-weight: 600;
}

/* Header */
.landing-header {
    margin-bottom: 32px;
}

.landing-logo {
    font-size: 36px;
}

.landing-title-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
}

.landing-title {
    font-size: 32px;
    font-weight: 800;
    background: linear-gradient(135deg, #818cf8, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 0;
}

.landing-subtitle {
    color: var(--text-secondary);
    font-size: 16px;
    font-weight: 400;
}

.landing-credit {
    color: var(--text-muted);
    font-size: 13px;
    font-style: italic;
    margin-top: 8px;
}

/* Course Cards List */
.course-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 100%;
}

.course-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px 20px;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    gap: 16px;
}

.course-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 4px;
    border-radius: 12px 0 0 12px;
}

.course-card.dsa::before {
    background: var(--dsa-gradient);
}

.course-card.ai::before {
    background: var(--ai-gradient);
}

.course-card.na::before {
    background: var(--na-gradient);
}

.course-card.sad::before {
    background: var(--sad-gradient);
}

.course-card.cs::before {
    background: var(--cs-gradient);
}

.course-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    transform: translateX(4px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.course-card:active {
    transform: translateX(2px);
}

.course-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.course-info {
    flex: 1;
    min-width: 0;
}

.course-title {
    font-size: 15px;
    font-weight: 700;
    margin-bottom: 2px;
    color: var(--text-primary);
}

.course-desc {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.4;
    margin-bottom: 0;
    display: none;
}

.course-meta {
    display: none;
}

.course-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    background: var(--bg-primary);
    padding: 2px 8px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
}

.course-enter {
    font-size: 13px;
    font-weight: 600;
    color: var(--accent-light);
    flex-shrink: 0;
    transition: color 0.2s;
    margin-left: auto;
}

.course-badge-label {
    font-size: 11px;
    font-weight: 700;
    padding: 3px 10px;
    border-radius: 20px;
    letter-spacing: 0.3px;
    flex-shrink: 0;
}

.course-badge-label.next {
    background: rgba(52, 211, 153, 0.15);
    color: #34d399;
    border: 1px solid rgba(52, 211, 153, 0.3);
}

.course-badge-label.past {
    background: rgba(161, 161, 170, 0.1);
    color: var(--text-muted);
    border: 1px solid rgba(161, 161, 170, 0.2);
}

.course-card:hover .course-enter {
    color: #fff;
}

/* Footer */
.landing-footer {
    text-align: center;
    padding: 24px;
    color: var(--text-muted);
    font-size: 12px;
}

/* Responsive */
@media (max-width: 860px) {
    .landing-layout {
        flex-direction: column-reverse;
        gap: 32px;
        align-items: center;
    }

    .landing-right {
        width: 100%;
        max-width: 400px;
        position: static;
    }

    .landing-left {
        width: 100%;
    }

    .landing-header {
        text-align: center;
    }

    .landing-title-row {
        justify-content: center;
    }

    .landing-title {
        font-size: 24px;
    }

    .landing-logo {
        font-size: 28px;
    }

    .landing-container {
        padding: 32px 16px;
    }

    .course-card {
        padding: 24px 20px;
    }
}