:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --border-color: #e9ecef;
    --accent-color: #3498db;
    --error-color: #e74c3c;
    --success-color: #2ecc71;
    --warning-color: #f1c40f;
    --card-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --border-color: #404040;
    --accent-color: #3498db;
    --card-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem;
    border-radius: 50%;
    border: none;
    background: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--card-shadow);
}

.nav {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1rem 0;
}

.nav a {
    color: var(--text-primary);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: background-color 0.3s;
}

.nav a:hover {
    background-color: var(--bg-secondary);
}

h1 {
    margin-bottom: 2rem;
    font-weight: 600;
}

.upload-form, .files-list {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--card-shadow);
}

.upload-form form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

input[type="file"], input[type="text"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

button {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    background-color: var(--accent-color);
    color: white;
    cursor: pointer;
    font-weight: 500;
    transition: opacity 0.3s;
}

button:hover {
    opacity: 0.9;
}

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

.progress {
    background-color: var(--bg-primary);
    border-radius: 10px;
    height: 8px;
    overflow: hidden;
}

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

.progress-text {
    margin-top: 0.5rem;
    color: var(--text-secondary);
}

.upload-status {
    margin-top: 1rem;
    color: var(--text-secondary);
}

.error-message {
    color: var(--error-color);
    margin-top: 1rem;
}

.control-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.pause-btn {
    background-color: var(--warning-color);
}

.resume-btn {
    background-color: var(--success-color);
}

.cancel-btn {
    background-color: var(--error-color);
}

.file-item {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.file-item:last-child {
    border-bottom: none;
}

.file-item a {
    color: var(--accent-color);
    text-decoration: none;
    margin-top: 0.5rem;
    display: inline-block;
}

.file-item a:hover {
    text-decoration: underline;
}

.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    display: none;
}

.upload-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--bg-primary);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    z-index: 1000;
    max-width: 500px;
    width: 90%;
}

.popup-content {
    text-align: center;
}

.popup-content h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.popup-details {
    text-align: left;
    background-color: var(--bg-secondary);
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
}

.popup-details p {
    margin: 0.5rem 0;
    color: var(--text-primary);
}

.popup-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.copy-btn {
    background-color: var(--accent-color);
}

.close-btn {
    background-color: var(--text-secondary);
}