/* Reset & Base Styles */
html {
    scroll-behavior: smooth;
}

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

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f9f9fb;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --accent: #ff5a00; /* Custom premium orange accent representing high-end sound tech */
    --accent-light: #ffefe5;
    --border-color: #e5e7eb;
    --max-width: 1100px;
    --font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header Styles */
.header {
    background-color: var(--bg-primary);
    padding: 4rem 0 2rem 0;
    border-bottom: 1px solid var(--border-color);
    position: relative;
}

.header::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.logo-text {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    color: var(--text-primary);
    text-transform: uppercase;
    line-height: 1.1;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--text-primary) 60%, var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: var(--transition);
}

.logo-text:hover {
    transform: translateY(-2px);
}

.subtitle {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

/* Navigation Tab Bar */
.tab-navigation {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.tab-link {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.6rem 1.2rem;
    border-radius: 99px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.tab-link:hover {
    color: var(--accent);
    border-color: var(--accent);
    background-color: var(--accent-light);
}

/* Main Content Styles */
.main-content {
    flex: 1;
    padding: 3rem 0;
}

.page-section {
    margin-bottom: 5rem;
    scroll-margin-top: 2rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    margin-bottom: 3.5rem;
    position: relative;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    text-transform: uppercase;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 60px;
    height: 2px;
    background-color: var(--accent);
}

/* Chapters List */
.chapters-list {
    display: flex;
    flex-direction: column;
    gap: 6rem;
}

.chapter-card {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 5rem;
    align-items: center;
    background-color: var(--bg-primary);
    transition: var(--transition);
    padding: 2.5rem;
    border-radius: 32px;
    border: 1px solid transparent;
}

.chapter-card:hover {
    border-color: var(--border-color);
    background-color: var(--bg-secondary);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.015);
}

.chapter-card:nth-child(even) {
    direction: rtl;
}

.chapter-card:nth-child(even) .chapter-content {
    direction: ltr;
}

.chapter-image-container {
    position: relative;
    border-radius: 24px;
    overflow: hidden;
    aspect-ratio: 4 / 5;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
    transition: var(--transition);
}

.chapter-card:hover .chapter-image-container {
    transform: translateY(-4px) scale(1.01);
    box-shadow: 0 20px 45px rgba(0, 0, 0, 0.08);
    border-color: var(--accent);
}

.chapter-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.chapter-card:hover .chapter-image {
    transform: scale(1.03);
}

.chapter-content {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 0.5rem 0;
}

.chapter-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.chapter-number {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.15em;
}

.chapter-date {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 400;
}

.chapter-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.25rem;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

.chapter-text {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 400;
    line-height: 1.7;
}

.chapter-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 700;
    font-size: 1.05rem;
    transition: var(--transition);
    align-self: flex-start;
    border-bottom: 2px solid var(--accent);
    padding-bottom: 0.25rem;
}

.chapter-link:hover {
    color: var(--accent);
    border-color: var(--text-primary);
}

/* Empty State / Welcome Area */
.empty-state {
    text-align: center;
    padding: 6rem 2rem;
    background-color: var(--bg-secondary);
    border-radius: 24px;
    border: 1px dashed var(--border-color);
    transition: var(--transition);
}

.empty-state:hover {
    border-color: var(--accent);
    background-color: var(--accent-light);
}

.empty-state p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* Footer Styles */
.footer {
    background-color: var(--bg-secondary);
    padding: 3rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-top: 6rem;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .header {
        padding: 3rem 0 1.5rem 0;
    }
    
    .logo-text {
        font-size: 2.5rem;
    }
    
    .subtitle {
        font-size: 1.1rem;
    }
    
    .container {
        padding: 0 1.5rem;
    }
    
    .main-content {
        padding: 3rem 0;
    }
    
    .chapters-list {
        gap: 3rem;
    }
    
    .chapter-card {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.5rem;
        background-color: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: 24px;
    }
    
    .chapter-card:nth-child(even) {
        direction: ltr;
    }
    
    .chapter-image-container {
        aspect-ratio: 4 / 5;
        max-width: 280px;
        width: 100%;
        margin: 0 auto;
    }
    
    .chapter-title {
        font-size: 1.75rem;
        margin-bottom: 1rem;
    }
    
    .chapter-text {
        font-size: 1.05rem;
        margin-bottom: 1.5rem;
    }
}