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

/* Dark theme (default) */
:root {
    --bg-color: #050505;
    --surface-color: #1E1F23;
    --surface-hover: #2A2C31;
    --text-primary: #F5F5F7;
    --text-secondary: #8A8D94;
    --border-color: #3C3F45;
    --accent-color: #6366F1;
    --accent-hover: #818CF8;
    --progress-color: #6366F1;
    --font-size-base: 1.15rem;
    --header-bg: rgba(5, 5, 5, 0.5);
}

/* Light theme */
body.theme-light {
    --bg-color: #FAFAFA;
    --surface-color: #FFFFFF;
    --surface-hover: #F0F0F0;
    --text-primary: #1A1A1A;
    --text-secondary: #666666;
    --border-color: #E0E0E0;
    --accent-color: #4F46E5;
    --accent-hover: #6366F1;
    --header-bg: rgba(250, 250, 250, 0.5);
}

/* Sepia theme */
body.theme-sepia {
    --bg-color: #F4ECD8;
    --surface-color: #FAF6EB;
    --surface-hover: #EDE5D0;
    --text-primary: #433422;
    --text-secondary: #7D6B54;
    --border-color: #D4C9B5;
    --accent-color: #8B6914;
    --accent-hover: #A67C00;
    --header-bg: rgba(244, 236, 216, 0.5);
}

/* Font sizes - use !important to override media queries */
body.font-size-1 #chapter-text { font-size: 0.85rem !important; line-height: 1.7 !important; }
body.font-size-2 #chapter-text { font-size: 0.95rem !important; line-height: 1.75 !important; }
body.font-size-3 #chapter-text { font-size: 1.05rem !important; line-height: 1.8 !important; }
body.font-size-4 #chapter-text { font-size: 1.15rem !important; line-height: 1.85 !important; }
body.font-size-5 #chapter-text { font-size: 1.3rem !important; line-height: 1.9 !important; }
body.font-size-6 #chapter-text { font-size: 1.45rem !important; line-height: 1.95 !important; }
body.font-size-7 #chapter-text { font-size: 1.65rem !important; line-height: 2 !important; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 100%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    background-color: var(--header-bg);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    padding: 1rem 2rem;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
    -webkit-transition: transform 0.3s ease, background-color 0.3s ease;
    -moz-transition: transform 0.3s ease, background-color 0.3s ease;
    transition: transform 0.3s ease, background-color 0.3s ease;
    -webkit-transform: translateY(0);
    -moz-transform: translateY(0);
    transform: translateY(0);
}

header.header-hidden {
    -webkit-transform: translateY(-100%);
    -moz-transform: translateY(-100%);
    transform: translateY(-100%);
}

/* Spacer for fixed header */
.header-spacer {
    height: 30px;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    color: var(--text-primary);
    text-transform: uppercase;
    text-shadow: 0 0 10px var(--bg-color);
}

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

.language-selector {
    display: flex;
    gap: 0.5rem;
}

/* Settings controls */
.settings-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.font-size-control {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.font-btn {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    width: 32px;
    height: 32px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.font-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.theme-control {
    display: flex;
    gap: 0.25rem;
}

.theme-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    width: 28px;
    height: 28px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
}

.theme-btn:hover {
    transform: scale(1.1);
}

.theme-btn.active {
    border-width: 2px;
    border-color: var(--accent-color);
}

.theme-btn.dark {
    background: #1A1A1A;
}

.theme-btn.light {
    background: #FAFAFA;
}

.theme-btn.sepia {
    background: #F4ECD8;
}

.scroll-to-comments-btn {
    background: transparent;
    border: none;
    font-size: 1.1rem;
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: all 0.2s ease;
    opacity: 0.7;
}

.scroll-to-comments-btn:hover {
    opacity: 1;
    transform: scale(1.1);
}

.comments-link {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    text-decoration: none;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: all 0.2s ease;
    margin-left: 0.5rem;
}

.comments-link:hover {
    background: var(--bg-secondary);
    transform: scale(1.1);
}

.back-to-reading-btn {
    display: none;
    width: 100%;
    margin-top: 1.5rem;
    padding: 0.75rem 1rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.back-to-reading-btn:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
    border-color: var(--accent-color);
}

.lang-btn {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.2s ease;
    font-weight: 500;
    letter-spacing: 0.05em;
}

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

.lang-btn.active {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

/* Chapter Navigation - Top */
.chapter-nav {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0.3rem 2rem;
    gap: 1rem;
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
}

/* Chapter selector in header */
.header-controls .chapter-selector {
    flex: 0 1 280px;
}

.header-controls .chapter-selector #chapter-select {
    padding: 0.5rem 2rem 0.5rem 0.75rem;
    font-size: 0.85rem;
}

.chapter-selector {
    flex: 0 1 400px;
}

#chapter-select {
    width: 100%;
    padding: 0.6rem 2.5rem 0.6rem 1rem;
    background-color: var(--bg-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
    font-family: inherit;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238A8D94' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
}

#chapter-select:focus {
    outline: none;
    border-color: var(--accent-color);
}

#chapter-select option {
    background-color: var(--surface-color);
    color: var(--text-primary);
}

/* Main Content */
main {
    flex: 1;
    padding: 4rem 2rem;
    position: relative;
}

#chapter-content {
    max-width: 700px;
    margin: 0 auto;
}

#chapter-title {
    margin-top: 2rem;
    margin-bottom: 2rem;
    font-size: 1.8rem;
    font-weight: 500;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-primary);
}

#chapter-text {
    font-family: 'Literata', 'Source Serif 4', 'Georgia', serif;
    font-size: 1.15rem;
    line-height: 1.9;
    color: var(--text-primary);
    font-optical-sizing: auto;
    letter-spacing: 0.01em;
    font-weight: 400;
}

/* H1 title styling */
#chapter-text h1:first-child {
    margin-top: 2rem;
    margin-bottom: 2rem;
    font-size: 1.8rem;
    font-weight: 500;
    text-align: center;
}

#chapter-text p {
    margin-bottom: 1.5em;
    text-align: left;
    text-indent: 0;
    -webkit-hyphens: auto;
    hyphens: auto;
}

#chapter-text em {
    font-style: italic;
    color: var(--text-secondary);
}

#chapter-text strong {
    font-weight: 600;
    color: var(--text-primary);
}

#chapter-text hr {
    margin: 3rem auto;
    border: none;
    height: 1px;
    background: linear-gradient(to right, transparent, var(--border-color), transparent);
    width: 30%;
}

/* Chapter end marker */
#chapter-text .chapter-end {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    color: var(--text-secondary);
}

/* Side Navigation Arrows - Kindle Style */
.side-nav {
    position: fixed;
    top: 50%;
    transform: translateY(-50%);
    z-index: 50;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.side-nav.visible {
    opacity: 1;
    pointer-events: auto;
}

.side-nav.prev {
    left: 1rem;
}

.side-nav.next {
    right: 1rem;
}

.side-nav-btn {
    width: 60px;
    height: 120px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    color: var(--text-secondary);
}

.side-nav-btn:hover {
    background-color: var(--surface-hover);
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: scale(1.05);
}

.side-nav-btn:disabled {
    opacity: 0.2;
    cursor: not-allowed;
    pointer-events: none;
}

.side-nav-btn svg {
    width: 32px;
    height: 32px;
    fill: currentColor;
}

/* Bottom Chapter Navigation */
.chapter-nav-bottom {
    max-width: 700px;
    margin: 4rem auto 0;
    padding-top: 3rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    gap: 1.5rem;
}

.chapter-link {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.25s ease;
    cursor: pointer;
}

.chapter-link:hover {
    background-color: var(--surface-hover);
    border-color: var(--accent-color);
    transform: translateY(-3px);
}

.chapter-link.disabled {
    opacity: 0.3;
    pointer-events: none;
}

.chapter-link.prev {
    text-align: left;
}

.chapter-link.next {
    text-align: right;
}

.chapter-link-label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.chapter-link-title {
    font-family: 'Literata', 'Source Serif 4', 'Georgia', serif;
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1.4;
    color: var(--text-primary);
}

.chapter-link-arrow {
    font-size: 1.5rem;
    margin-top: 0.75rem;
    color: var(--text-secondary);
}

/* Progress Indicator */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-hover));
    z-index: 1000;
    transition: width 0.1s ease;
}

/* Footer */
footer {
    padding: 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    border-top: 1px solid var(--border-color);
    background-color: var(--surface-color);
}

/* Comments Section */
.comments-section {
    max-width: 700px;
    margin: 3rem auto 0;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.comments-title {
    font-family: 'Literata', 'Source Serif 4', 'Georgia', serif;
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.comments-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.comments-form textarea {
    width: 100%;
    padding: 1rem;
    background-color: var(--surface-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: vertical;
    min-height: 100px;
}

.comments-form textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

.comments-form textarea::placeholder {
    color: var(--text-secondary);
}

.comments-form-footer {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.comments-form-footer input {
    flex: 1;
    padding: 0.75rem 1rem;
    background-color: var(--surface-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.9rem;
}

.comments-form-footer input:focus {
    outline: none;
    border-color: var(--accent-color);
}

.comments-form-footer input::placeholder {
    color: var(--text-secondary);
}

.comment-btn {
    padding: 0.75rem 1.5rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

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

.comment-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.comments-list {
    margin-top: 2rem;
}

.comment-item {
    padding: 1rem;
    background-color: var(--surface-color);
    border-radius: 8px;
    margin-bottom: 1rem;
}

.comment-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.comment-author {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.comment-date {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.comment-body {
    color: var(--text-primary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.comments-status {
    margin-top: 1rem;
    padding: 0.75rem;
    border-radius: 6px;
    font-size: 0.9rem;
    display: none;
}

.comments-status.success {
    display: block;
    background-color: rgba(34, 197, 94, 0.1);
    color: #22c55e;
    border: 1px solid rgba(34, 197, 94, 0.3);
}

.comments-status.error {
    display: block;
    background-color: rgba(239, 68, 68, 0.1);
    color: #ef4444;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

/* Loading State */
.loading {
    text-align: center;
    padding: 4rem;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .side-nav.prev {
        left: 0.5rem;
    }
    .side-nav.next {
        right: 0.5rem;
    }
    .side-nav-btn {
        width: 50px;
        height: 100px;
    }
    .side-nav-btn svg {
        width: 28px;
        height: 28px;
    }
}

@media (max-width: 900px) {
    .side-nav {
        display: none;
    }
}

@media (max-width: 768px) {
    .header-spacer {
        height: 100px;
    }

    header {
        padding: 0.5rem 0.75rem;
    }

    .header-content {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.5rem;
        justify-content: space-between;
    }

    h1 {
        font-size: 0.9rem;
        flex: 0 0 auto;
    }

    .header-controls {
        flex: 1;
        justify-content: flex-end;
        gap: 0.5rem;
        flex-wrap: nowrap;
    }

    .language-selector {
        gap: 0.2rem;
    }

    .lang-btn {
        padding: 0.25rem 0.4rem;
        font-size: 0.65rem;
    }

    .settings-controls {
        gap: 0.3rem;
    }

    .font-btn {
        width: 24px;
        height: 24px;
        font-size: 0.75rem;
    }

    .theme-btn {
        width: 20px;
        height: 20px;
    }

    .chapter-nav {
        padding: 0.75rem 1rem;
    }

    .chapter-selector {
        flex: 1;
        width: 100%;
        max-width: 100%;
    }

    main {
        padding: 2.5rem 1.25rem;
    }

    #chapter-title {
        font-size: 1.5rem;
        margin-bottom: 2rem;
        padding-top: 1rem;
    }

    #chapter-text {
        font-size: 1.05rem;
        line-height: 1.8;
    }

    .chapter-nav-bottom {
        flex-direction: column;
        gap: 1rem;
        margin-top: 3rem;
        padding-top: 2rem;
    }

    .chapter-link {
        padding: 1.25rem;
    }

    .chapter-link.prev,
    .chapter-link.next {
        text-align: left;
    }
}

/* Extra small screens */
@media (max-width: 400px) {
    .header-content {
        flex-direction: column;
        align-items: center;
    }

    h1 {
        text-align: center;
        margin-bottom: 0.25rem;
    }

    .header-controls {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .header-controls .chapter-selector {
        flex: 1 1 100%;
        order: -1;
    }

    .header-controls .chapter-selector #chapter-select {
        font-size: 0.8rem;
    }
}

/* Smooth scroll behavior */
html {
    scroll-behavior: smooth;
}

/* Selection styling */
::selection {
    background: var(--accent-color);
    color: white;
}

/* Focus styles for accessibility */
:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

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