/* ==========================================================================
   Supersonic Intakes Book Website - Main Styles
   ========================================================================== */

:root {
    --ink: #0a0f1a;
    --paper: #f8f7f4;
    --accent: #c73e1d;
    --steel: #2d3a4a;
    --silver: #8a9bae;
    --highlight: #e8f4fd;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'IBM Plex Sans', sans-serif;
    background: var(--paper);
    color: var(--ink);
    line-height: 1.7;
    font-weight: 400;
}

/* Noise texture overlay */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.03;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    z-index: 9999;
}

/* ==========================================================================
   Header
   ========================================================================== */

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 1.5rem 4rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
    background: rgba(248, 247, 244, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--steel);
    text-decoration: none;
    transition: color 0.3s;
}

.logo:hover {
    color: var(--accent);
}

nav {
    display: flex;
    align-items: center;
}

nav a {
    font-size: 0.85rem;
    color: var(--steel);
    text-decoration: none;
    margin-left: 2.5rem;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--accent);
}

.header-dropdown {
    margin-left: 2.5rem;
}

.btn-header-order {
    background: var(--accent);
    color: var(--paper);
    padding: 0.5rem 1.25rem;
    font-size: 0.85rem;
    border: none;
    cursor: pointer;
    font-weight: 500;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.btn-header-order:hover {
    background: #d94a2a;
    transform: translateY(-2px);
}

.btn-header-order::after {
    content: '▼';
    font-size: 0.6rem;
    margin-left: 0.5rem;
    transition: transform 0.3s;
}

.dropdown:hover .btn-header-order::after {
    transform: rotate(180deg);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--steel);
    transition: all 0.3s;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    padding: 8rem 4rem 4rem;
    position: relative;
    overflow: visible;
    z-index: 1;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 200%;
    background: linear-gradient(135deg, transparent 0%, rgba(199, 62, 29, 0.03) 50%, transparent 100%);
    transform: rotate(-15deg);
    pointer-events: none;
}

.hero-content {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-right: 4rem;
    animation: fadeSlideUp 1s ease-out;
    position: relative;
    z-index: 2;
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tag {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.tag::before {
    content: '';
    width: 2rem;
    height: 1px;
    background: var(--accent);
}

h1 {
    font-family: 'DM Serif Display', serif;
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    line-height: 1.15;
    color: var(--ink);
    margin-bottom: 1.5rem;
}

.subtitle {
    font-size: 1.15rem;
    color: var(--steel);
    max-width: 500px;
    margin-bottom: 2.5rem;
    font-weight: 300;
}

.authors-line {
    font-size: 0.95rem;
    color: var(--silver);
    margin-bottom: 3rem;
}

.authors-line strong {
    color: var(--steel);
    font-weight: 500;
}

.cta-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: 2px;
    transition: all 0.3s ease;
    font-family: 'IBM Plex Sans', sans-serif;
}

.btn-primary {
    background: var(--ink);
    color: var(--paper);
}

.btn-primary:hover {
    background: var(--accent);
    transform: translateY(-2px);
}

.btn-secondary {
    border: 1px solid var(--steel);
    color: var(--steel);
    background: transparent;
}

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-accent {
    background: var(--accent);
    color: var(--paper);
    padding: 1.2rem 3rem;
    font-size: 1rem;
}

.btn-accent:hover {
    background: #d94a2a;
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(199, 62, 29, 0.3);
}

.btn-github {
    background: #24292e;
    color: #fff;
    border: none;
}

.btn-github:hover {
    background: #000;
    transform: translateY(-2px);
}

.btn-page {
    background: rgba(255,255,255,0.1);
    color: var(--paper);
    border: 1px solid rgba(255,255,255,0.2);
}

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

/* Dropdown Button */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown::before {
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 0.5rem;
    background: transparent;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: white;
    min-width: 220px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
    border-radius: 4px;
    z-index: 10000;
    margin-top: 0.5rem;
    overflow: hidden;
}

.dropdown-content a {
    color: var(--ink);
    padding: 0.875rem 1.25rem;
    text-decoration: none;
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.dropdown-content a:last-child {
    border-bottom: none;
}

.dropdown-content a:hover {
    background-color: var(--highlight);
    color: var(--accent);
}


.dropdown:hover .dropdown-content {
    display: block;
    animation: dropdownSlide 0.3s ease-out;
}

@keyframes dropdownSlide {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.dropdown .btn::after {
    content: '▼';
    font-size: 0.7rem;
    margin-left: 0.5rem;
    transition: transform 0.3s;
}

.dropdown:hover .btn::after {
    transform: rotate(180deg);
}

/* ==========================================================================
   Book Visual
   ========================================================================== */

.hero-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    animation: fadeSlideUp 1s ease-out 0.3s backwards;
}

.book-container {
    position: relative;
    perspective: 1500px;
}

.book-cover-image {
    width: 340px;
    height: auto;
    border-radius: 4px;
    box-shadow:
        20px 20px 60px rgba(0,0,0,0.25),
        -5px -5px 20px rgba(255,255,255,0.1);
    transition: transform 0.4s ease;
    transform-origin: left center;
}

.book-cover-image:hover {
    transform: translateY(-10px) rotateY(-10deg);
}

.book-3d {
    position: relative;
    transform-style: preserve-3d;
    transform: rotateY(-25deg) rotateX(5deg);
    transition: transform 0.5s ease;
}

.book-3d:hover {
    transform: rotateY(-15deg) rotateX(3deg);
}

.book-cover {
    width: 320px;
    height: 440px;
    background: linear-gradient(145deg, #1a2530 0%, #0f1419 100%);
    border-radius: 0 6px 6px 0;
    box-shadow: 
        -2px 0 0 rgba(255,255,255,0.1) inset,
        20px 20px 60px rgba(0,0,0,0.3),
        -5px -5px 20px rgba(255,255,255,0.05);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    padding: 2.5rem 2rem;
}

.book-spine {
    position: absolute;
    left: -30px;
    top: 0;
    width: 30px;
    height: 100%;
    background: linear-gradient(90deg, #0a0f14 0%, #1a2530 100%);
    transform: rotateY(90deg);
    transform-origin: right center;
    border-radius: 3px 0 0 3px;
}

.book-cover::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(45deg, transparent 40%, rgba(199, 62, 29, 0.15) 45%, rgba(199, 62, 29, 0.08) 55%, transparent 60%),
        repeating-linear-gradient(0deg, transparent 0px, transparent 2px, rgba(255,255,255,0.02) 2px, rgba(255,255,255,0.02) 3px);
    pointer-events: none;
}

.shock-pattern {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 120px;
    transform: translateY(-50%);
    overflow: hidden;
    opacity: 0.6;
}

.shock-line {
    position: absolute;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    animation: shockPulse 3s ease-in-out infinite;
}

.shock-line:nth-child(1) { top: 20%; width: 60%; left: 10%; animation-delay: 0s; }
.shock-line:nth-child(2) { top: 35%; width: 80%; left: 5%; animation-delay: 0.5s; }
.shock-line:nth-child(3) { top: 50%; width: 70%; left: 15%; animation-delay: 1s; }
.shock-line:nth-child(4) { top: 65%; width: 75%; left: 8%; animation-delay: 1.5s; }
.shock-line:nth-child(5) { top: 80%; width: 55%; left: 20%; animation-delay: 2s; }

@keyframes shockPulse {
    0%, 100% { opacity: 0.3; transform: scaleX(0.8); }
    50% { opacity: 1; transform: scaleX(1); }
}

.book-publisher {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.6rem;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: rgba(255,255,255,0.4);
    margin-bottom: auto;
}

.book-title-text {
    font-family: 'DM Serif Display', serif;
    font-size: 1.4rem;
    color: #fff;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.book-subtitle {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.6);
    line-height: 1.5;
}

.book-authors-text {
    margin-top: auto;
    font-size: 0.75rem;
    color: rgba(255,255,255,0.5);
    line-height: 1.6;
}

.mach-badge {
    position: absolute;
    bottom: -30px;
    right: -30px;
    width: 100px;
    height: 100px;
    background: var(--paper);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    animation: float 4s ease-in-out infinite;
    text-decoration: none;
    transition: transform 0.3s, box-shadow 0.3s;
}

.mach-badge:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 50px rgba(0,0,0,0.2);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.mach-badge .label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.65rem;
    letter-spacing: 0.05em;
    color: var(--silver);
    text-transform: uppercase;
    line-height: 1.3;
}

.mach-badge .value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: var(--accent);
    line-height: 1.3;
    text-transform: uppercase;
    font-weight: 500;
}

/* ==========================================================================
   Gallery Section
   ========================================================================== */

.gallery {
    padding: 6rem 4rem;
    background: linear-gradient(180deg, var(--paper) 0%, #f0eeeb 100%);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    max-width: 1200px;
    margin: 3rem auto 0;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: 4px;
    background: var(--ink);
}

.gallery-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.4s ease, opacity 0.4s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
    opacity: 0.8;
}

.gallery-item figcaption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 1rem;
    background: linear-gradient(transparent, rgba(0,0,0,0.8));
    color: var(--paper);
    font-size: 0.8rem;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.gallery-item:hover figcaption {
    transform: translateY(0);
}

/* ==========================================================================
   Section Headers
   ========================================================================== */

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 1rem;
    display: block;
}

.section-title {
    font-family: 'DM Serif Display', serif;
    font-size: 2.5rem;
    color: var(--paper);
    font-weight: 400;
}

.section-title.dark,
.section-tag.dark {
    color: var(--ink);
}

.section-tag.dark {
    color: var(--accent);
}

/* ==========================================================================
   Features Section
   ========================================================================== */

.features {
    padding: 8rem 4rem;
    background: var(--ink);
    position: relative;
    z-index: 0;
}

.features::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    padding: 2.5rem;
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 4px;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 0;
    background: var(--accent);
    transition: height 0.4s ease;
}

.feature-card:hover {
    border-color: rgba(199, 62, 29, 0.3);
    transform: translateY(-5px);
}

.feature-card:hover::before {
    height: 100%;
}

.feature-icon {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    color: var(--accent);
    margin-bottom: 1.5rem;
    letter-spacing: 0.1em;
}

.feature-title {
    font-family: 'DM Serif Display', serif;
    font-size: 1.3rem;
    color: var(--paper);
    margin-bottom: 1rem;
    font-weight: 400;
}

.feature-desc {
    font-size: 0.9rem;
    color: var(--silver);
    line-height: 1.7;
}

/* ==========================================================================
   Contents Section
   ========================================================================== */

.contents {
    padding: 8rem 4rem;
    background: var(--paper);
}

.contents-wrapper {
    max-width: 900px;
    margin: 0 auto;
}

.contents-intro {
    text-align: center;
    color: var(--silver);
    margin-bottom: 3rem;
    font-size: 0.95rem;
}

.chapters-container {
    margin-top: 2rem;
}

.chapter-item {
    border-bottom: 1px solid rgba(0,0,0,0.08);
    overflow: hidden;
}

.chapter-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.25rem 0;
    cursor: pointer;
    transition: all 0.3s ease;
    user-select: none;
}

.chapter-header:hover {
    padding-left: 1rem;
    background: rgba(199, 62, 29, 0.02);
}

.chapter-num {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent);
    min-width: 4rem;
}

.chapter-title {
    font-size: 1.05rem;
    color: var(--steel);
    flex: 1;
    font-weight: 400;
}

.chapter-toggle {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--silver);
    transition: all 0.3s ease;
    border-radius: 50%;
    background: rgba(0,0,0,0.03);
}

.chapter-item.active .chapter-toggle {
    transform: rotate(180deg);
    color: var(--accent);
    background: rgba(199, 62, 29, 0.1);
}

.chapter-abstract {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0 0 0 5.5rem;
}

.chapter-item.active .chapter-abstract {
    max-height: 500px;
    padding: 0 0 1.5rem 5.5rem;
}

.chapter-abstract p {
    font-size: 0.95rem;
    color: var(--silver);
    line-height: 1.8;
    border-left: 2px solid rgba(199, 62, 29, 0.3);
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

.chapter-link {
    display: inline-block;
    font-size: 0.85rem;
    color: var(--accent);
    text-decoration: none;
    margin-left: 1.5rem;
    padding-left: 1.5rem;
    font-weight: 500;
    transition: all 0.3s;
}

.chapter-link:hover {
    color: var(--ink);
    text-decoration: underline;
}

/* ==========================================================================
   Authors Section
   ========================================================================== */

.authors-section {
    padding: 8rem 4rem;
    background: linear-gradient(180deg, #f0eeeb 0%, var(--paper) 100%);
}

.authors-group-photo {
    max-width: 400px;
    margin: 0 auto 4rem;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
}

.authors-group-photo img {
    width: 100%;
    height: auto;
    display: block;
}

.authors-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
    max-width: 1100px;
    margin: 0 auto;
}

.author-card {
    text-align: center;
    padding: 2rem;
}

.author-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    margin: 0 auto 1.5rem;
    overflow: hidden;
    position: relative;
}

.author-photo::after {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    border: 1px solid var(--accent);
    opacity: 0.3;
    pointer-events: none;
}

.author-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.author-avatar {
    width: 100%;
    height: 100%;
    background: var(--ink);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'DM Serif Display', serif;
    font-size: 2.5rem;
    color: var(--paper);
}

.author-name {
    font-family: 'DM Serif Display', serif;
    font-size: 1.3rem;
    color: var(--ink);
    margin-bottom: 0.5rem;
}

.author-title {
    font-size: 0.85rem;
    color: var(--accent);
    margin-bottom: 1rem;
    font-weight: 500;
}

.author-affiliation {
    font-size: 0.85rem;
    color: var(--steel);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.author-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.author-links a {
    color: var(--silver);
    transition: color 0.3s;
}

.author-links a:hover {
    color: var(--accent);
}

/* ==========================================================================
   Resources Section
   ========================================================================== */

.resources {
    padding: 8rem 4rem;
    background: var(--ink);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    max-width: 1100px;
    margin: 3rem auto 0;
}

.resource-card {
    padding: 2.5rem;
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 4px;
    text-align: center;
    transition: all 0.3s ease;
}

.resource-card:hover {
    border-color: rgba(199, 62, 29, 0.4);
    transform: translateY(-5px);
}

.resource-icon {
    color: var(--accent);
    margin-bottom: 1.5rem;
}

.resource-title {
    font-family: 'DM Serif Display', serif;
    font-size: 1.2rem;
    color: var(--paper);
    margin-bottom: 0.75rem;
}

.resource-desc {
    font-size: 0.9rem;
    color: var(--silver);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* ==========================================================================
   Footer
   ========================================================================== */

footer {
    padding: 4rem 4rem 2rem;
    background: var(--ink);
    border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
    padding-bottom: 2rem;
}

.footer-section {
    display: flex;
    flex-direction: column;
}

.footer-copyright {
    font-size: 0.85rem;
    color: var(--paper);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.footer-publisher {
    font-size: 0.8rem;
    color: var(--silver);
}

.footer-heading {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.85rem;
    color: var(--paper);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 1rem;
    font-weight: 600;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    font-size: 0.85rem;
    color: var(--silver);
    text-decoration: none;
    transition: color 0.3s;
    line-height: 1.6;
}

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

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 1024px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 10rem 2rem 4rem;
    }

    .hero-content {
        padding-right: 0;
        align-items: center;
    }

    .tag::before {
        display: none;
    }

    .hero-visual {
        margin-top: 4rem;
    }

    .features-grid,
    .authors-grid,
    .resources-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
    }

    .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    header {
        padding: 1rem 2rem;
    }

    nav {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .chapter-abstract {
        padding-left: 4rem !important;
    }

    .chapter-item.active .chapter-abstract {
        padding-left: 4rem !important;
    }
}

@media (max-width: 640px) {
    .book-cover-image {
        width: 260px;
    }

    .book-cover {
        width: 260px;
        height: 360px;
    }

    h1 {
        font-size: 2rem;
    }

    .cta-group {
        flex-direction: column;
        align-items: center;
    }

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

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .chapter-header {
        gap: 1rem;
    }

    .chapter-num {
        min-width: 3rem;
    }

    .chapter-abstract,
    .chapter-item.active .chapter-abstract {
        padding-left: 0 !important;
    }
}