:root {
    /* Apple-style silver/white color scheme */
    --primary-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --secondary-gradient: linear-gradient(135deg, #e0e0e0 0%, #f8f9fa 100%);
    --success-gradient: linear-gradient(135deg, #00c6ff 0%, #0072ff 100%);
    --dark-bg: #fafafa;
    --card-bg: rgba(255, 255, 255, 0.9);
    --card-border: rgba(0, 0, 0, 0.08);
    --text-primary: #1d1d1f;
    --text-secondary: #6e6e73;
    --glass-bg: rgba(255, 255, 255, 0.75);
    --glass-border: rgba(0, 0, 0, 0.1);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    --accent-blue: #0071e3;
    --accent-blue-hover: #0077ed;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background: var(--dark-bg);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background-image:
        linear-gradient(135deg, #f5f7fa 0%, #e8eef5 100%);
}

.container {
    max-width: 600px;
    width: 100%;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 20px;
    border: 1px solid var(--glass-border);
    padding: 40px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 48px 0 rgba(31, 38, 135, 0.5);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, #1d1d1f 0%, #6e6e73 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    text-align: center;
}

.subtitle {
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 30px;
    font-size: 1rem;
}

.upload-area {
    border: 2px dashed var(--glass-border);
    border-radius: 15px;
    padding: 60px 30px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: rgba(102, 126, 234, 0.05);
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.15);
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.7;
}

.upload-text {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.upload-hint {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

input[type="file"] {
    display: none;
}

.btn {
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 14px 32px;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    margin-top: 20px;
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.2);
}

.btn:hover {
    background: var(--accent-blue-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(0, 113, 227, 0.3);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: transparent;
    border: 2px solid var(--accent-blue);
    color: var(--accent-blue);
    box-shadow: none;
}

.btn-secondary:hover {
    background: rgba(0, 113, 227, 0.05);
}

.progress-container {
    margin-top: 30px;
    display: none;
}

.progress-container.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.progress-bar-bg {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    height: 12px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-bar {
    height: 100%;
    background: var(--success-gradient);
    border-radius: 10px;
    transition: width 0.3s ease;
    box-shadow: 0 0 10px rgba(0, 242, 254, 0.5);
}

.progress-stats {
    display: flex;
    justify-content: space-between;
    gap: 15px;
    margin-bottom: 10px;
}

.stat {
    flex: 1;
    background: rgba(255, 255, 255, 0.05);
    padding: 12px 16px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.result-container {
    margin-top: 30px;
    display: none;
}

.result-container.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

.share-code-box {
    background: var(--primary-gradient);
    padding: 20px;
    border-radius: 15px;
    text-align: center;
    margin-bottom: 20px;
}

.share-code-label {
    font-size: 0.9rem;
    margin-bottom: 10px;
    opacity: 0.9;
}

.share-code {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 3px;
    font-family: 'Courier New', monospace;
    cursor: pointer;
    user-select: all;
    transition: all 0.3s ease;
    padding: 10px;
    border-radius: 8px;
}

.share-code:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.05);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.info-item {
    background: rgba(255, 255, 255, 0.05);
    padding: 15px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.info-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
    text-transform: uppercase;
}

.info-value {
    font-size: 1rem;
    font-weight: 600;
}

.copy-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 12px 24px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.95rem;
    font-weight: 500;
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.copy-link-btn {
    background: transparent;
    border: 1px solid var(--accent-blue);
    color: var(--accent-blue);
    padding: 10px 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.85rem;
    font-weight: 500;
    white-space: nowrap;
}

.copy-link-btn:hover {
    background: rgba(0, 113, 227, 0.1);
    transform: translateY(-1px);
}

.error-message {
    background: rgba(245, 87, 108, 0.2);
    border: 1px solid rgba(245, 87, 108, 0.4);
    color: #f5576c;
    padding: 12px 20px;
    border-radius: 8px;
    margin-top: 20px;
    display: none;
    text-align: center;
}

.error-message.active {
    display: block;
}

/* Toast notification for copy feedback */
.toast-notification {
    position: fixed;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-blue);
    color: white;
    padding: 16px 32px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 1rem;
    box-shadow: 0 8px 24px rgba(0, 113, 227, 0.4);
    z-index: 10000;
    transition: top 0.3s ease, opacity 0.3s ease;
    opacity: 0;
    white-space: nowrap;
}

.toast-notification.show {
    top: 30px;
    opacity: 1;
}

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    .card {
        padding: 30px 20px;
    }

    .upload-area {
        padding: 40px 20px;
    }

    .progress-stats {
        flex-direction: column;
    }

    .share-code {
        font-size: 1.5rem;
        letter-spacing: 2px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 15px;
    }

    .card {
        padding: 25px 15px;
    }

    .info-grid {
        grid-template-columns: 1fr;
    }
}