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

:root {
    --color-white: #ffffff;
    --color-black: #000000;
    --color-gray-light: #f5f5f5;
    --color-gray-medium: #cccccc;
    --color-gray-dark: #333333;
    --color-dark-bg: #1a1a1a;
    --color-dark-surface: #2a2a2a;
    --color-dark-text: #ffffff;
}

body {
    font-family: Verdana, Arial, sans-serif;
    background-color: var(--color-white);
    color: var(--color-black);
    transition: all 0.3s ease;
    overflow-x: hidden;
}

body.dark-mode {
    background-color: var(--color-dark-bg);
    color: var(--color-dark-text);
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background-color: var(--color-gray-light);
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--color-gray-medium);
    transition: all 0.3s ease;
}

.dark-mode .header {
    background-color: var(--color-dark-surface);
    border-bottom-color: var(--color-gray-dark);
}

.app-title {
    font-family: Verdana, sans-serif;
    font-size: 24px;
    font-weight: bold;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 20px;
    padding: 5px;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    background-color: var(--color-gray-medium);
}

.dark-mode .theme-toggle:hover {
    background-color: var(--color-gray-dark);
}

/* Upload Section */
.upload-section {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 50px 20px;
}

.upload-area {
    text-align: center;
    padding: 40px;
    border: 2px dashed var(--color-gray-medium);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    max-width: 400px;
    width: 100%;
}

.upload-area:hover {
    border-color: var(--color-gray-dark);
    background-color: rgba(0, 0, 0, 0.02);
}

.dark-mode .upload-area {
    border-color: var(--color-gray-dark);
}

.dark-mode .upload-area:hover {
    border-color: var(--color-gray-medium);
    background-color: rgba(255, 255, 255, 0.05);
}

.file-input {
    display: none;
}

.upload-label {
    cursor: pointer;
    display: block;
    width: 100%;
}

.upload-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.upload-text {
    font-family: Verdana, sans-serif;
    font-size: 18px;
    margin-bottom: 8px;
    font-weight: bold;
}

.upload-subtext {
    font-family: Verdana, sans-serif;
    font-size: 14px;
    color: var(--color-gray-dark);
    opacity: 0.7;
}

/* PDF Viewer Section */
.pdf-viewer-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pdf-viewer-section.hidden {
    display: none;
}

.pdf-controls {
    background-color: var(--color-gray-light);
    padding: 10px 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    border-bottom: 1px solid var(--color-gray-medium);
    transition: all 0.3s ease;
}

.dark-mode .pdf-controls {
    background-color: var(--color-dark-surface);
    border-bottom-color: var(--color-gray-dark);
}

.pdf-controls.hidden {
    opacity: 0;
    pointer-events: none;
}

.nav-button, .scroll-toggle, .close-button {
    background: none;
    border: 1px solid var(--color-gray-medium);
    padding: 8px 12px;
    cursor: pointer;
    border-radius: 3px;
    font-size: 16px;
    color: inherit;
    transition: all 0.2s ease;
}

.nav-button:hover, .scroll-toggle:hover, .close-button:hover {
    background-color: var(--color-gray-medium);
}

.dark-mode .nav-button, .dark-mode .scroll-toggle, .dark-mode .close-button {
    border-color: var(--color-gray-dark);
}

.dark-mode .nav-button:hover, .dark-mode .scroll-toggle:hover, .dark-mode .close-button:hover {
    background-color: var(--color-gray-dark);
}

.page-info {
    display: flex;
    align-items: center;
    position: relative;
}

.page-display {
    font-family: Verdana, sans-serif;
    font-size: 14px;
    cursor: pointer;
    padding: 5px 10px;
    border-radius: 3px;
    transition: all 0.2s ease;
}

.page-display:hover {
    background-color: var(--color-gray-medium);
}

.dark-mode .page-display:hover {
    background-color: var(--color-gray-dark);
}

.page-input {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 1px solid var(--color-gray-medium);
    background-color: var(--color-white);
    color: var(--color-black);
    text-align: center;
    font-family: Verdana, sans-serif;
    font-size: 14px;
    border-radius: 3px;
}

.dark-mode .page-input {
    background-color: var(--color-dark-surface);
    color: var(--color-dark-text);
    border-color: var(--color-gray-dark);
}

.page-input.hidden {
    display: none;
}

/* PDF Container */
.pdf-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: auto;
    padding: 20px;
    padding-bottom: 60px; /* Extra bottom padding to prevent cutoff */
}

.pdf-container canvas {
    max-width: 100%;
    max-height: 100%;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    cursor: grab;
}

.pdf-container canvas:active {
    cursor: grabbing;
}

.pdf-scroll-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    padding-bottom: 100px; /* Extra bottom padding for scroll mode */
}

.pdf-scroll-container.hidden {
    display: none;
}

.pdf-scroll-page {
    margin-bottom: 20px;
    display: flex;
    justify-content: center;
    min-height: 400px; /* Placeholder height */
}

.pdf-scroll-page canvas {
    max-width: 100%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.pdf-scroll-page.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-gray-light);
    border-radius: 4px;
}

.dark-mode .pdf-scroll-page.loading {
    background-color: var(--color-gray-dark);
}

/* PWA Install Prompt */
.install-prompt {
    position: fixed;
    bottom: 20px;
    left: 20px;
    right: 20px;
    background-color: var(--color-white);
    border: 1px solid var(--color-gray-medium);
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    animation: slideUp 0.3s ease;
}

.dark-mode .install-prompt {
    background-color: var(--color-dark-surface);
    border-color: var(--color-gray-dark);
}

.install-prompt.hidden {
    display: none;
}

@keyframes slideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.install-prompt-content {
    display: flex;
    align-items: center;
    gap: 15px;
}

.install-icon {
    font-size: 24px;
}

.install-text {
    font-family: Verdana, sans-serif;
    font-weight: bold;
    font-size: 16px;
    margin-bottom: 2px;
}

.install-subtext {
    font-family: Verdana, sans-serif;
    font-size: 12px;
    opacity: 0.7;
}

.install-buttons {
    margin-left: auto;
    display: flex;
    gap: 10px;
    align-items: center;
}

.install-button {
    background-color: var(--color-black);
    color: var(--color-white);
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    font-family: Verdana, sans-serif;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.install-button:hover {
    background-color: var(--color-gray-dark);
}

.dark-mode .install-button {
    background-color: var(--color-white);
    color: var(--color-black);
}

.dark-mode .install-button:hover {
    background-color: var(--color-gray-medium);
}

.install-close {
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    color: inherit;
    padding: 4px;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.install-close:hover {
    background-color: var(--color-gray-medium);
}

.dark-mode .install-close:hover {
    background-color: var(--color-gray-dark);
}

/* Hide scrollbars */
.pdf-container::-webkit-scrollbar,
.pdf-scroll-container::-webkit-scrollbar {
    display: none;
}

.pdf-container,
.pdf-scroll-container {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .header {
        padding: 10px 15px;
    }

    .app-title {
        font-size: 20px;
    }

    .pdf-controls {
        padding: 8px 15px;
        gap: 10px;
    }

    .nav-button, .scroll-toggle, .close-button {
        padding: 6px 10px;
        font-size: 14px;
    }

    .upload-area {
        padding: 30px 20px;
    }

    .upload-text {
        font-size: 16px;
    }

    .install-prompt {
        bottom: 10px;
        left: 10px;
        right: 10px;
        padding: 15px;
    }

    .install-prompt-content {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }

    .install-buttons {
        margin-left: 0;
        justify-content: center;
        width: 100%;
    }
}

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

/* PWA specific optimizations */
@media (display-mode: standalone) {
    .header {
        padding-top: 20px; /* Account for status bar */
    }
}