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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: #333;
}

.container {
    width: 100%;
    max-width: 580px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 24px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 40px;
    backdrop-filter: blur(10px);
    animation: fadeInUp 0.6s ease;
}

header {
    text-align: center;
    margin-bottom: 32px;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: #4a00e0;
    background: linear-gradient(to right, #8e2de2, #4a00e0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 8px;
}

.subtitle {
    color: #666;
    font-size: 0.95rem;
}

.warning-box {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 24px;
    color: #856404;
    font-size: 0.9rem;
    line-height: 1.5;
}

.upload-card {
    border: 2px dashed #d1d5db;
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s ease;
}

.upload-area {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.upload-icon {
    color: #8e2de2;
    margin-bottom: 20px;
    opacity: 0.8;
}

.upload-text {
    font-size: 1.1rem;
    margin-bottom: 6px;
    color: #374151;
}

.upload-hint {
    font-size: 0.85rem;
    color: #9ca3af;
    margin-bottom: 20px;
}

.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.25s;
}

.btn-primary {
    background: linear-gradient(135deg, #8e2de2, #4a00e0);
    color: white;
    box-shadow: 0 4px 15px rgba(142, 45, 226, 0.4);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(142, 45, 226, 0.6);
}

.file-info {
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.file-name {
    font-weight: 600;
    font-size: 1.1rem;
    word-break: break-all;
}

.file-size {
    color: #6b7280;
    font-size: 0.9rem;
}

.btn-convert {
    background: #10b981;
    color: white;
    box-shadow: 0 4px 10px rgba(16, 185, 129, 0.3);
}
.btn-convert:hover {
    background: #059669;
    transform: translateY(-2px);
}

.btn-cancel {
    background: #ef4444;
    color: white;
}
.btn-cancel:hover {
    background: #dc2626;
}

.btn-outline {
    background: transparent;
    border: 2px solid #8e2de2;
    color: #8e2de2;
}
.btn-outline:hover {
    background: #8e2de2;
    color: white;
}

.progress-container {
    margin-top: 20px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e5e7eb;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 10px;
}

.progress-fill {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, #8e2de2, #4a00e0);
    transition: width 0.4s ease;
}

.progress-text {
    color: #6b7280;
    font-size: 0.9rem;
}

.result-card {
    text-align: center;
    margin-top: 24px;
}

.result-status {
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.result-status.success {
    color: #059669;
    font-weight: 600;
}

.result-status.error {
    color: #dc2626;
}

.download-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.download-btn {
    background: #f3f4f6;
    color: #374151;
    padding: 10px 24px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
}
.download-btn:hover {
    background: #e5e7eb;
    transform: scale(1.03);
}

footer {
    margin-top: 32px;
    text-align: center;
    color: #9ca3af;
    font-size: 0.8rem;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式 */
@media (max-width: 480px) {
    .container {
        padding: 24px;
    }
    header h1 {
        font-size: 1.6rem;
    }
}