/* Base Styles */
:root {
    --bg-color: #f3f4f6;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --accent-color: #3b82f6;
    --header-bg: rgba(255, 255, 255, 0.85);
    --border-color: rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #111827;
        --text-primary: #f9fafb;
        --text-secondary: #9ca3af;
        --accent-color: #60a5fa;
        --header-bg: rgba(31, 41, 55, 0.85);
        --border-color: rgba(255, 255, 255, 0.05);
    }
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow-x: hidden;
    line-height: 1.5;
}

/* Glassmorphism Header */
.glass-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.title-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.title-container .icon {
    color: var(--accent-color);
}

#document-title {
    font-size: 1.1rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 300px;
}

/* Controls */
.controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s, transform 0.1s;
}

.icon-btn:hover {
    background-color: rgba(156, 163, 175, 0.2);
}

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

.zoom-text {
    font-size: 0.9rem;
    font-weight: 500;
    min-width: 4rem;
    text-align: center;
    font-variant-numeric: tabular-nums;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--accent-color);
    color: #ffffff;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background-color 0.2s, transform 0.1s, box-shadow 0.2s;
    box-shadow: var(--shadow-sm);
    margin-left: 0.5rem;
}

.download-btn:hover {
    background-color: #2563eb;
    box-shadow: var(--shadow-md);
}

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

/* Progress Bar */
.progress-bar-container {
    width: 100%;
    height: 3px;
    background: transparent;
    position: absolute;
    bottom: 0;
    left: 0;
}

.progress-bar {
    height: 100%;
    background-color: var(--accent-color);
    width: 0%;
    transition: width 0.3s ease;
}

/* Main PDF Container */
.pdf-container {
    padding: 2rem 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    min-height: 100vh;
}

.pdf-page-canvas {
    background-color: #ffffff;
    box-shadow: var(--shadow-lg);
    border-radius: 4px;
    width: 100%;
    max-width: 100%;
    height: auto;
    transition: transform 0.2s ease-out;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 60vh;
    gap: 1rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(156, 163, 175, 0.3);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s ease-in-out infinite;
}

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

.loading-screen p {
    color: var(--text-secondary);
    font-weight: 500;
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: .5; }
}

/* Responsive */
@media (max-width: 640px) {
    .header-content {
        padding: 0.5rem 1rem;
    }
    
    #document-title {
        max-width: 150px;
        font-size: 1rem;
    }
    
    .download-btn span {
        display: none; /* Hide text on mobile, keep icon */
    }
    
    .download-btn {
        padding: 0.5rem;
    }
    
    .pdf-container {
        padding: 1rem 0.5rem;
        gap: 1rem;
    }
}