/* ========================================
   BACK TO HOME BUTTON
   ======================================== */
.back-home {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: all var(--transition-base);
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.back-home:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 255, 0, 0.4);
}

.back-home svg {
    width: 18px;
    height: 18px;
}

.back-home span {
    display: inline-block;
}

@media (max-width: 480px) {
    .back-home span {
        display: none;
    }
    
    .back-home {
        padding: var(--spacing-sm);
        width: 40px;
        height: 40px;
        justify-content: center;
    }
}/* ========================================
   CSS VARIABLES - BLACK & GREEN THEME
   ======================================== */
:root {
    /* Black and Green Theme */
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #141414;
    --text-primary: #00ff00;
    --text-secondary: #00cc00;
    --text-muted: #008800;
    --accent-primary: #00ff00;
    --accent-secondary: #00cc00;
    --border-color: #00ff00;
    --glass-bg: rgba(0, 0, 0, 0.9);
    --glass-border: rgba(0, 255, 0, 0.3);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;

    /* Z-index */
    --z-sidebar: 1000;
}

/* ========================================
   GLOBAL STYLES
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
}

/* ========================================
   SIDEBAR
   ======================================== */
.sidebar {
    position: fixed;
    top: 0;
    left: -320px;
    width: 320px;
    height: 100vh;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-right: 1px solid var(--glass-border);
    transition: left var(--transition-base);
    z-index: var(--z-sidebar);
    overflow-y: auto;
}

.sidebar.active {
    left: 0;
}

.sidebar-content {
    padding: var(--spacing-lg);
}

.sidebar-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.sidebar-section {
    margin-bottom: var(--spacing-xl);
}

.section-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.section-icon {
    width: 20px;
    height: 20px;
}

.video-container {
    width: 100%;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.video-player {
    width: 100%;
    display: block;
}

.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
    z-index: calc(var(--z-sidebar) - 1);
}

.sidebar-overlay.active {
    opacity: 1;
    pointer-events: all;
}

/* ========================================
   MAIN CONTENT
   ======================================== */
.main-content {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.viewer-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.page-viewer {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: grab;
    position: relative;
}

.page-viewer.grabbing {
    cursor: grabbing;
}

.page-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
    transition: transform 600ms cubic-bezier(0.4, 0, 0.2, 1);
}

.page-content.flip-out {
    transform: rotateY(90deg);
}

.page-content.flip-in {
    transform: rotateY(-90deg);
}

.page-image {
    max-width: 100%;
    max-height: 85vh;
    object-fit: contain;
    user-select: none;
    -webkit-user-drag: none;
    transition: transform var(--transition-base);
    transform-origin: center;
}

.page-loading,
.page-error {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    color: var(--text-secondary);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.page-error svg {
    width: 64px;
    height: 64px;
    color: var(--text-muted);
}

/* ========================================
   CONTROLS
   ======================================== */
.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-top: 1px solid var(--glass-border);
}

.zoom-controls,
.navigation-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.control-btn,
.nav-btn {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.control-btn:hover,
.nav-btn:hover:not(:disabled) {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 255, 0, 0.5);
}

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

.control-btn svg,
.nav-btn svg {
    width: 24px;
    height: 24px;
}

.zoom-level {
    min-width: 60px;
    text-align: center;
    font-weight: 600;
    color: var(--text-primary);
}

.page-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.page-select {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    min-width: 120px;
}

.page-select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.page-total {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 768px) {
    .controls {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .zoom-controls,
    .navigation-controls {
        width: 100%;
        justify-content: center;
    }
}

/* Support Button */
.support-btn {
    width: 100%;
    padding: 1rem;
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.support-btn:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 255, 0, 0.5);
}

/* QR Modal */
.qr-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.qr-modal.active {
    display: flex;
}

.qr-content {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-color);
    max-width: 400px;
    width: 90%;
    text-align: center;
}

.qr-content h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.qr-image {
    width: 100%;
    max-width: 300px;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
}

.close-qr {
    padding: 0.75rem 1.5rem;
    background: var(--accent-primary);
    color: var(--bg-primary);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
}

.close-qr:hover {
    background: var(--accent-secondary);
    transform: scale(1.05);
}