/* ===== CSS Variables ===== */
:root {
    /* Colors - Elegant dark palette */
    --bg-primary: #0f0d15;
    --bg-secondary: #1a1625;
    --bg-card: rgba(30, 25, 45, 0.7);
    --bg-card-hover: rgba(45, 38, 65, 0.8);
    --text-primary: #f5f3f7;
    --text-secondary: #a8a3b3;
    --text-muted: #6b6578;
    --accent-gold: #d4af37;
    --accent-gold-light: #f0d77a;
    --accent-purple: #9b7fd4;
    --accent-rose: #c9a0a0;
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(212, 175, 55, 0.3);

    /* Typography */
    --font-serif: 'Cormorant Garamond', Georgia, serif;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;

    /* Effects */
    --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(212, 175, 55, 0.15);
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    background-image:
        radial-gradient(ellipse at 20% 0%, rgba(155, 127, 212, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 100%, rgba(212, 175, 55, 0.08) 0%, transparent 50%);
}

/* ===== App Container ===== */
.app {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--space-md);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===== Header ===== */
.header {
    text-align: center;
    padding: var(--space-xl) 0 var(--space-lg);
    animation: fadeInDown 0.6s ease-out;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--accent-gold);
    margin-bottom: var(--space-sm);
    letter-spacing: 0.05em;
}

.logo-icon {
    font-size: 1.4rem;
}

.title {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 500;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    margin-bottom: var(--space-xs);
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-gold-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* ===== Section Titles ===== */
.section-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: var(--space-md);
}

/* ===== Mode Selection ===== */
.mode-selection {
    animation: fadeInUp 0.4s ease-out;
}

.mode-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-md);
}

.mode-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-smooth);
    backdrop-filter: blur(10px);
    font-family: inherit;
    color: inherit;
}

.mode-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-glow);
    box-shadow: var(--shadow-glow);
    transform: translateY(-4px);
}

.mode-card:focus {
    outline: 2px solid var(--accent-gold);
    outline-offset: 2px;
}

.mode-icon {
    font-size: 3rem;
    margin-bottom: var(--space-sm);
    display: block;
}

.mode-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--accent-gold-light);
}

.mode-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* ===== Author Selection ===== */
.author-selection {
    animation: fadeInUp 0.4s ease-out;
}

.author-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.author-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    cursor: pointer;
    transition: all var(--transition-smooth);
    text-align: center;
    font-family: inherit;
    color: inherit;
}

.author-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent-purple);
    transform: translateY(-2px);
}

.author-card:focus {
    outline: 2px solid var(--accent-gold);
    outline-offset: 2px;
}

.author-card-name {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.author-card-count {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.back-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    background: transparent;
    border: 1px solid var(--border-subtle);
    color: var(--text-secondary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.back-btn:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

/* ===== Loading State ===== */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
    animation: fadeIn 0.3s ease-out;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border-subtle);
    border-top-color: var(--accent-gold);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--space-sm);
}

.loading p {
    color: var(--text-secondary);
    font-style: italic;
}

.loading-hint {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
    opacity: 0;
    animation: fadeIn 0.5s ease-out forwards;
}

.reading-hint {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
    margin-bottom: var(--space-md);
    font-style: italic;
}

.reading-hint[data-state="ready"] {
    color: var(--accent-gold);
}

.reading-hint[data-state="error"] {
    color: var(--accent-rose);
}

/* ===== Reading Display ===== */
.reading-display {
    flex: 1;
    animation: fadeInUp 0.5s ease-out;
}

.reading-header {
    text-align: center;
    padding: var(--space-md) 0;
    border-bottom: 1px solid var(--border-subtle);
    margin-bottom: var(--space-md);
}

.author-name {
    font-size: 0.95rem;
    color: var(--accent-purple);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    display: block;
    margin-bottom: var(--space-xs);
}

.book-title {
    font-family: var(--font-serif);
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 500;
    color: var(--accent-gold-light);
    font-style: italic;
    margin-bottom: var(--space-xs);
}

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

.chapter-content {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-md);
    max-height: 60vh;
    overflow-y: auto;
    scrollbar-gutter: stable;
}

.chapter-content p {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    line-height: 1.9;
    color: var(--text-primary);
    margin-bottom: 1.25em;
    text-align: justify;
    hyphens: auto;
}

.chapter-content p:last-child {
    margin-bottom: 0;
}

.chapter-content .chapter-message {
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
}

.chapter-content .chapter-message.error {
    color: var(--accent-rose);
}

.chapter-content:focus-visible {
    outline: 2px solid var(--accent-gold);
    outline-offset: 3px;
}

/* Custom Scrollbar */
.chapter-content::-webkit-scrollbar {
    width: 8px;
}

.chapter-content::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 4px;
}

.chapter-content::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: 4px;
}

.chapter-content::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* ===== Action Buttons ===== */
.reading-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
}

.action-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
}

.action-btn:focus-visible,
.back-btn:focus-visible {
    outline: 2px solid var(--accent-gold);
    outline-offset: 3px;
}

.action-btn.primary {
    background: linear-gradient(135deg, var(--accent-gold) 0%, var(--accent-gold-light) 100%);
    color: var(--bg-primary);
}

.action-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(212, 175, 55, 0.4);
}

.action-btn.secondary {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    color: var(--text-primary);
}

.action-btn.secondary:hover {
    background: var(--bg-card-hover);
    border-color: var(--text-muted);
}

.action-btn:disabled,
.action-btn:disabled:hover {
    cursor: default;
    opacity: 0.5;
    transform: none;
    box-shadow: none;
}

/* ===== Footer ===== */
.footer {
    text-align: center;
    padding: var(--space-lg) 0 var(--space-md);
    margin-top: auto;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.footer a {
    color: var(--accent-gold);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer a:hover {
    color: var(--accent-gold-light);
}

/* ===== Utility Classes ===== */
.hidden {
    display: none !important;
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
    .app {
        padding: var(--space-sm);
    }

    .header {
        padding: var(--space-lg) 0 var(--space-md);
    }

    .mode-cards {
        grid-template-columns: 1fr;
    }

    .mode-card {
        padding: var(--space-md);
    }

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

    .chapter-content {
        padding: var(--space-md);
        max-height: 50vh;
    }

    .chapter-content p {
        font-size: 1.05rem;
        text-align: left;
    }

    .reading-actions {
        flex-direction: column;
    }

    .action-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}