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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-light: #334155;
    --text: #f1f5f9;
    --text-muted: #94a3b8;
    --border: #334155;
    --success: #10b981;
    --shadow: rgba(0, 0, 0, 0.3);
    --newest-glow: rgba(16, 185, 129, 0.4);
}

html {
    /* Ensure proper sizing on mobile */
    height: 100%;
    height: -webkit-fill-available;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, var(--background) 0%, #1a1f3a 100%);
    color: var(--text);
    min-height: 100vh;
    min-height: 100dvh; /* Dynamic viewport height for mobile */
    min-height: -webkit-fill-available;
    line-height: 1.6;
    /* Smooth scrolling */
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    /* Prevent pull-to-refresh on mobile when not needed */
    overscroll-behavior-y: contain;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    /* Safe area insets for notched devices */
    padding-left: max(2rem, env(safe-area-inset-left));
    padding-right: max(2rem, env(safe-area-inset-right));
    padding-bottom: max(2rem, env(safe-area-inset-bottom));
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
    position: relative;
}

.home-btn {
    position: absolute;
    top: 2rem;
    left: 0;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.home-btn:hover {
    background: var(--surface-light);
    border-color: var(--primary);
    transform: translateY(-2px);
}

.home-btn svg {
    stroke: var(--primary);
}

.logo h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.tagline {
    color: var(--text-muted);
    font-size: 1.1rem;
}

main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.section {
    width: 100%;
    max-width: 1900px;
    margin: 0 auto;
}

/* Publication Selector Styles */
.publication-selector {
    background: var(--surface);
    border-radius: 1rem;
    padding: 2rem;
    margin-bottom: 2rem;
}

.publication-selector h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.publication-selector h2 svg {
    color: var(--primary);
}

.publications-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    max-height: 400px;
    overflow-y: auto;
    padding: 0.5rem;
    scrollbar-width: thin;
    scrollbar-color: rgba(99, 102, 241, 0.5) transparent;
}

.publications-list::-webkit-scrollbar {
    width: 8px;
}

.publications-list::-webkit-scrollbar-track {
    background: transparent;
}

.publications-list::-webkit-scrollbar-thumb {
    background: rgba(99, 102, 241, 0.5);
    border-radius: 4px;
}

.publication-item {
    background: var(--surface-light);
    border: 2px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.25rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.publication-item:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.publication-item.selected {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
}

.publication-item.newest {
    border-color: var(--success);
    box-shadow: 0 0 20px var(--newest-glow);
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        box-shadow: 0 0 20px var(--newest-glow);
    }
    50% {
        box-shadow: 0 0 30px var(--newest-glow), 0 0 40px rgba(16, 185, 129, 0.2);
    }
}

.publication-item.newest::before {
    content: 'NEWEST';
    position: absolute;
    top: -10px;
    right: 10px;
    background: var(--success);
    color: white;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    letter-spacing: 0.05em;
}

.publication-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.publication-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.publication-date {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.publication-size {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.publication-badge {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    color: var(--primary);
    font-weight: 500;
}

.no-publications {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
}

.no-publications svg {
    width: 64px;
    height: 64px;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.no-publications p {
    font-size: 1.1rem;
}

.no-publications.server-notice {
    background: rgba(99, 102, 241, 0.1);
    border: 1px dashed var(--primary);
    border-radius: 0.75rem;
    padding: 2rem;
}

.no-publications.server-notice svg {
    color: var(--primary);
    opacity: 0.8;
}

.no-publications.server-notice code {
    color: var(--text);
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
}

.loading-publications {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
}

.loading-publications .spinner {
    margin-bottom: 1rem;
}

/* Upload Area Styles */
.upload-area {
    background: var(--surface);
    border: 2px dashed var(--border);
    border-radius: 1rem;
    padding: 4rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-area:hover {
    border-color: var(--primary);
    background: var(--surface-light);
    transform: translateY(-2px);
}

.upload-area.dragover {
    border-color: var(--primary);
    background: var(--surface-light);
    transform: scale(1.02);
}

.upload-icon {
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.upload-area h2 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.upload-area p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.btn {
    padding: 0.875rem 2rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: var(--surface-light);
    color: var(--text);
    border: 1px solid var(--border);
}

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

.status-text {
    margin-top: 1rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.processing-container {
    background: var(--surface);
    border-radius: 1rem;
    padding: 4rem 2rem;
    text-align: center;
}

.spinner {
    width: 64px;
    height: 64px;
    border: 4px solid var(--border);
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 2rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.processing-container h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.processing-container p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.progress-bar {
    width: 100%;
    max-width: 400px;
    height: 8px;
    background: var(--surface-light);
    border-radius: 4px;
    overflow: hidden;
    margin: 0 auto 1rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    width: 0%;
    transition: width 0.3s ease;
}

.progress-percentage {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.preview-header {
    text-align: center;
    margin-bottom: 2rem;
}

.preview-header h2 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.preview-header p {
    color: var(--text-muted);
}

.flipbook-container {
    background: var(--surface);
    border-radius: 1rem;
    padding: 2rem;
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
    position: relative;
    overflow: visible;
}

/* When zoomed, enable scrolling */
.flipbook-container.zoomed {
    overflow: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(99, 102, 241, 0.5) transparent;
}

.flipbook-container.zoomed::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.flipbook-container.zoomed::-webkit-scrollbar-track {
    background: transparent;
}

.flipbook-container.zoomed::-webkit-scrollbar-thumb {
    background: rgba(99, 102, 241, 0.5);
    border-radius: 4px;
}

.flipbook-container.zoomed::-webkit-scrollbar-thumb:hover {
    background: rgba(99, 102, 241, 0.7);
}

.flipbook {
    position: relative;
    width: 100%;
    max-width: 1800px;
    height: 75vh;
    margin: 0 auto;
    perspective: 2500px;
    perspective-origin: 50% 50%;
    transform-style: preserve-3d;
    transform-origin: center center;
    transition: transform 0.3s ease;
}

.flipbook-page {
    position: absolute;
    width: 50%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 1s cubic-bezier(0.645, 0.045, 0.355, 1),
                box-shadow 1s cubic-bezier(0.645, 0.045, 0.355, 1);
}

.flipbook-page.left {
    left: 0;
    transform-origin: right center;
}

.flipbook-page.right {
    right: 0;
    transform-origin: left center;
}

.flipbook-page.flipping {
    z-index: 100;
}

/* Front face of the page */
.page-front {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    background: white;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.3);
    overflow: visible;
    transform: rotateY(0deg);
}

.flipbook-page.flipping .page-front {
    box-shadow:
        -5px 0 15px rgba(0, 0, 0, 0.2),
        0 0 30px rgba(0, 0, 0, 0.3),
        10px 0 25px rgba(0, 0, 0, 0.25);
}

/* Back face of the page (blank white) */
.page-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    background: white;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.3);
    transform: rotateY(180deg);
    overflow: visible;
}

.flipbook-page.flipping .page-back {
    box-shadow:
        -5px 0 15px rgba(0, 0, 0, 0.2),
        0 0 30px rgba(0, 0, 0, 0.3),
        10px 0 25px rgba(0, 0, 0, 0.25);
}

/* Shadow gradients on front face during flip */
.page-front::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, rgba(0, 0, 0, 0.1) 0%, transparent 10%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 1s ease;
    z-index: 10;
}

.page-front::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to left, rgba(0, 0, 0, 0.15) 0%, transparent 20%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 1s ease;
    z-index: 10;
}

.flipbook-page.flipping .page-front::before {
    opacity: 1;
}

.flipbook-page.flipping .page-front::after {
    opacity: 1;
}

/* Shadow on back face */
.page-back::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, transparent 80%, rgba(0, 0, 0, 0.1) 100%);
    pointer-events: none;
    z-index: 1;
}

.page-content {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
    position: relative;
    overflow: visible;
}

.page-content img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}

.book-spine {
    position: absolute;
    left: 50%;
    top: 0;
    width: 8px;
    height: 100%;
    background: linear-gradient(to bottom, #d4d4d4, #a3a3a3, #d4d4d4);
    transform: translateX(-50%);
    box-shadow:
        inset 2px 0 3px rgba(0, 0, 0, 0.3),
        inset -2px 0 3px rgba(0, 0, 0, 0.3);
    z-index: 50;
}

.preview-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.nav-controls {
    display: flex;
    gap: 0.5rem;
    background: var(--surface);
    padding: 0.5rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: transparent;
    border: none;
    color: var(--text);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.nav-btn:hover:not(:disabled) {
    background: var(--surface-light);
    transform: translateY(-2px);
}

.nav-btn:active:not(:disabled) {
    transform: translateY(0);
}

.nav-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.nav-btn svg {
    stroke: var(--primary);
    stroke-width: 2;
}

footer {
    text-align: center;
    padding: 2rem 0;
    color: var(--text-muted);
    margin-top: 4rem;
}

/* Flipbook Navigation */
.flipbook-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.9);
    border: none;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.flipbook-nav:hover {
    background: white;
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

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

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

.flipbook-nav svg {
    width: 24px;
    height: 24px;
    stroke: var(--background);
    stroke-width: 2;
}

.page-indicator {
    position: absolute;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.9);
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.9rem;
    color: var(--background);
    font-weight: 600;
}

/* Individual page numbers */
.page-number {
    position: absolute !important;
    bottom: 12px !important;
    background: rgba(0, 0, 0, 0.6);
    color: white;
    padding: 4px 12px;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 600;
    z-index: 100;
    pointer-events: none;
    transform: none !important;
    display: block !important;
    margin: 0 !important;
    text-align: center;
}

.page-number-left {
    left: 12px !important;
    right: auto !important;
    transform: none !important;
}

.page-number-right {
    right: 12px !important;
    left: auto !important;
    transform: none !important;
}

/* Zoom Controls */
.zoom-controls {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.9);
    padding: 0.5rem;
    border-radius: 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    z-index: 150;
}

.zoom-btn {
    width: 36px;
    height: 36px;
    border: none;
    background: transparent;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    color: var(--background);
}

.zoom-btn:hover {
    background: rgba(0, 0, 0, 0.1);
    transform: scale(1.1);
}

.zoom-btn:active {
    transform: scale(0.95);
}

.zoom-btn svg {
    width: 20px;
    height: 20px;
    stroke: var(--background);
    stroke-width: 2;
}

.zoom-level {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--background);
    min-width: 50px;
    text-align: center;
}

.zoom-divider {
    width: 1px;
    height: 24px;
    background: rgba(0, 0, 0, 0.2);
    margin: 0 4px;
}

/* Fullscreen Mode */
.flipbook-container.fullscreen-mode {
    background: #000;
    padding: 1rem;
}

.flipbook-container.fullscreen-mode .flipbook {
    max-width: 100%;
    height: calc(100vh - 100px);
}

.flipbook-container.fullscreen-mode .zoom-controls {
    position: fixed;
    top: 1rem;
    right: 1rem;
}

.flipbook-container.fullscreen-mode .flipbook-nav {
    position: fixed;
}

.flipbook-container.fullscreen-mode .flipbook-nav.prev {
    left: 2rem;
}

.flipbook-container.fullscreen-mode .flipbook-nav.next {
    right: 2rem;
}

.flipbook-container.fullscreen-mode .page-indicator {
    position: fixed;
    bottom: 2rem;
}

/* Divider */
.section-divider {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 2rem 0;
    color: var(--text-muted);
}

.section-divider::before,
.section-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.section-divider span {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* Go To Page Control */
.goto-page-control {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0 0.75rem;
    border-left: 1px solid var(--border);
    border-right: 1px solid var(--border);
    margin: 0 0.25rem;
}

.goto-page-control label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    white-space: nowrap;
}

.goto-page-control input {
    width: 70px;
    padding: 0.5rem 0.75rem;
    background: var(--surface-light);
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    color: var(--text);
    font-size: 0.9rem;
    font-weight: 600;
    text-align: center;
    transition: all 0.2s ease;
    -moz-appearance: textfield;
}

.goto-page-control input::-webkit-outer-spin-button,
.goto-page-control input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.goto-page-control input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

.goto-page-control input::placeholder {
    color: var(--text-muted);
    font-weight: 400;
}

.goto-page-control input.error {
    border-color: #ef4444;
    animation: shake 0.3s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-4px); }
    75% { transform: translateX(4px); }
}

.goto-btn {
    padding: 0.5rem 0.75rem !important;
}

.goto-btn svg {
    stroke: var(--primary);
}

/* Responsive Design */

/* Tablet landscape and smaller desktops */
@media (max-width: 1200px) {
    .flipbook {
        max-width: 100%;
        height: 70vh;
    }
}

/* Tablet portrait */
@media (max-width: 992px) {
    .container {
        padding: 1.5rem;
    }

    .flipbook-container {
        padding: 1.5rem;
        min-height: 70vh;
    }

    .flipbook {
        height: 65vh;
    }

    .flipbook-nav {
        width: 44px;
        height: 44px;
    }

    .flipbook-nav.prev {
        left: 0.5rem;
    }

    .flipbook-nav.next {
        right: 0.5rem;
    }
}

/* Mobile devices */
@media (max-width: 768px) {
    .container {
        padding: 0.75rem;
    }

    header {
        margin-bottom: 1.5rem;
        padding: 1rem 0;
    }

    .home-btn {
        position: static;
        margin-bottom: 1rem;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    .tagline {
        font-size: 0.95rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .flipbook-container {
        padding: 0.5rem;
        min-height: auto;
        border-radius: 0.5rem;
        margin-bottom: 1rem;
    }

    .flipbook {
        /* Use dynamic viewport height for better mobile experience */
        height: 60vh;
        height: 60dvh; /* Dynamic viewport height - accounts for mobile browser UI */
        max-width: 100%;
    }

    .flipbook-page {
        /* Slightly smaller pages for mobile to prevent overflow */
        width: 50%;
    }

    /* Larger touch targets for mobile */
    .flipbook-nav {
        width: 40px;
        height: 40px;
    }

    .flipbook-nav.prev {
        left: 0.25rem;
    }

    .flipbook-nav.next {
        right: 0.25rem;
    }

    .flipbook-nav svg {
        width: 20px;
        height: 20px;
    }

    /* Smaller zoom controls on mobile */
    .zoom-controls {
        top: 0.5rem;
        right: 0.5rem;
        padding: 0.35rem;
        border-radius: 1.5rem;
        gap: 0.25rem;
    }

    .zoom-btn {
        width: 32px;
        height: 32px;
    }

    .zoom-btn svg {
        width: 16px;
        height: 16px;
    }

    .zoom-level {
        font-size: 0.75rem;
        min-width: 40px;
    }

    .zoom-divider {
        height: 20px;
        margin: 0 2px;
    }

    .page-indicator {
        bottom: 0.5rem;
        padding: 0.35rem 0.75rem;
        font-size: 0.8rem;
    }

    .page-number {
        bottom: 8px !important;
        padding: 3px 8px;
        font-size: 0.75rem;
    }

    .page-number-left {
        left: 8px !important;
    }

    .page-number-right {
        right: 8px !important;
    }

    .preview-header {
        margin-bottom: 1rem;
    }

    .preview-header h2 {
        font-size: 1.3rem;
    }

    .preview-header p {
        font-size: 0.85rem;
    }

    .preview-controls {
        flex-direction: column;
        gap: 1rem;
    }

    .btn {
        width: 100%;
        justify-content: center;
        padding: 0.75rem 1.5rem;
    }

    .publications-list {
        grid-template-columns: 1fr;
        max-height: 300px;
    }

    .publication-selector {
        padding: 1rem;
    }

    .publication-selector h2 {
        font-size: 1.2rem;
    }

    .nav-controls {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.35rem;
        padding: 0.35rem;
    }

    .nav-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.85rem;
    }

    .nav-btn span {
        display: none;
    }

    .nav-btn svg {
        width: 20px;
        height: 20px;
    }

    .goto-page-control {
        border-left: none;
        border-right: none;
        border-top: 1px solid var(--border);
        border-bottom: 1px solid var(--border);
        padding: 0.5rem 0;
        margin: 0.25rem 0;
        width: 100%;
        justify-content: center;
    }

    .goto-page-control input {
        width: 60px;
        padding: 0.4rem 0.5rem;
        font-size: 0.85rem;
    }

    footer {
        margin-top: 2rem;
        padding: 1rem 0;
        font-size: 0.85rem;
    }
}

/* Small mobile devices (phones in portrait) */
@media (max-width: 480px) {
    .container {
        padding: 0.5rem;
    }

    header {
        margin-bottom: 1rem;
        padding: 0.75rem 0;
    }

    .logo h1 {
        font-size: 1.25rem;
    }

    .tagline {
        font-size: 0.85rem;
    }

    .flipbook-container {
        padding: 0.25rem;
        border-radius: 0.375rem;
    }

    .flipbook {
        height: 55vh;
        height: 55dvh;
    }

    .flipbook-nav {
        width: 36px;
        height: 36px;
    }

    .flipbook-nav svg {
        width: 18px;
        height: 18px;
    }

    .zoom-controls {
        top: 0.35rem;
        right: 0.35rem;
        padding: 0.25rem;
    }

    .zoom-btn {
        width: 28px;
        height: 28px;
    }

    .zoom-btn svg {
        width: 14px;
        height: 14px;
    }

    .zoom-level {
        font-size: 0.7rem;
        min-width: 35px;
    }

    .page-indicator {
        padding: 0.25rem 0.5rem;
        font-size: 0.75rem;
    }

    .nav-controls {
        padding: 0.25rem;
    }

    .nav-btn {
        padding: 0.4rem 0.6rem;
    }

    .nav-btn svg {
        width: 18px;
        height: 18px;
    }

    .publication-item {
        padding: 1rem;
    }

    .publication-title {
        font-size: 0.9rem;
    }

    .publication-meta {
        font-size: 0.8rem;
    }
}

/* Landscape orientation on mobile */
@media (max-width: 896px) and (orientation: landscape) {
    .container {
        padding: 0.5rem;
    }

    header {
        margin-bottom: 0.5rem;
        padding: 0.5rem 0;
    }

    .home-btn {
        position: absolute;
        top: 0.5rem;
        left: 0.5rem;
        padding: 0.4rem 0.75rem;
        font-size: 0.8rem;
    }

    .logo h1 {
        font-size: 1.25rem;
        margin-bottom: 0.25rem;
    }

    .tagline {
        display: none;
    }

    .flipbook-container {
        min-height: auto;
        padding: 0.5rem;
        margin-bottom: 0.5rem;
    }

    .flipbook {
        height: 70vh;
        height: 70dvh;
    }

    .preview-header {
        margin-bottom: 0.5rem;
    }

    .preview-header h2 {
        font-size: 1.1rem;
        margin-bottom: 0.25rem;
    }

    .preview-header p {
        font-size: 0.75rem;
    }

    .preview-controls {
        flex-direction: row;
        gap: 0.5rem;
    }

    .btn {
        width: auto;
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }

    footer {
        display: none;
    }
}

/* High DPI / Retina displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .flipbook-page img {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    /* Larger touch targets */
    .flipbook-nav {
        min-width: 44px;
        min-height: 44px;
    }

    .zoom-btn {
        min-width: 44px;
        min-height: 44px;
    }

    .nav-btn {
        min-height: 44px;
    }

    /* Remove hover effects on touch devices */
    .flipbook-nav:hover {
        transform: translateY(-50%);
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    }

    .zoom-btn:hover {
        background: transparent;
        transform: none;
    }

    /* Active states for touch feedback */
    .flipbook-nav:active {
        transform: translateY(-50%) scale(0.95);
        background: white;
    }

    .zoom-btn:active {
        background: rgba(0, 0, 0, 0.15);
        transform: scale(0.95);
    }

    .nav-btn:active {
        background: var(--surface-light);
    }

    .publication-item:active {
        transform: scale(0.98);
    }
}

/* Prevent text selection on interactive elements */
.flipbook-nav,
.zoom-btn,
.nav-btn,
.flipbook-page {
    -webkit-user-select: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}