body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.converter-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px 25px;
    width: 100%;
    max-width: 600px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.converter-card:hover {
    transform: translateY(-5px);
}

h1 {
    font-size: clamp(24px, 5vw, 32px);
    color: #333;
    margin-bottom: 10px;
    text-align: center;
    font-weight: 600;
}

.subtitle {
    text-align: center;
    color: #666;
    margin-bottom: 30px;
    font-size: clamp(14px, 3vw, 16px);
    line-height: 1.5;
}

.upload-area {
    border: 2px dashed #cbd5e0;
    border-radius: 15px;
    padding: 30px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 25px;
    background: #f8fafc;
}

.upload-area:hover, .upload-area.dragover {
    border-color: #667eea;
    background: #e3e8ff;
}

.upload-icon {
    font-size: 48px;
    margin-bottom: 10px;
    color: #667eea;
}

.upload-text {
    color: #4a5568;
    font-size: clamp(14px, 3vw, 16px);
    margin-bottom: 5px;
}

.upload-hint {
    color: #718096;
    font-size: clamp(12px, 2.5vw, 14px);
}

.file-info {
    background: #f0f4f8;
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 25px;
    display: none;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.file-info.show {
    display: block;
}

.file-name {
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 5px;
    word-break: break-all;
    font-size: clamp(14px, 3vw, 16px);
}

.file-size {
    color: #718096;
    font-size: clamp(12px, 2.5vw, 14px);
}

.conversion-options {
    margin-bottom: 25px;
}

.option-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 15px;
    flex-wrap: wrap;
    gap: 10px;
}

.option-label {
    font-weight: 500;
    color: #4a5568;
    font-size: clamp(14px, 3vw, 16px);
    min-width: 120px;
}

select {
    flex: 1;
    min-width: 200px;
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: clamp(14px, 3vw, 16px);
    background: white;
    cursor: pointer;
    transition: border-color 0.3s ease;
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 15px center;
    background-size: 15px;
}

select:focus {
    outline: none;
    border-color: #667eea;
}

.convert-btn {
    width: 100%;
    padding: 16px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: clamp(16px, 4vw, 18px);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    margin-bottom: 20px;
}

.convert-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.convert-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    background: linear-gradient(135deg, #a0aec0 0%, #718096 100%);
    box-shadow: none;
}

.status-message {
    text-align: center;
    padding: 15px;
    border-radius: 10px;
    font-size: clamp(14px, 3vw, 16px);
    display: none;
    margin-bottom: 20px;
}

.status-message.show {
    display: block;
    animation: slideIn 0.3s ease;
}

.status-message.success {
    background: #c6f6d5;
    color: #22543d;
}

.status-message.error {
    background: #fed7d7;
    color: #742a2a;
}

.status-message.info {
    background: #bee3f8;
    color: #2c5282;
}

.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
    margin-right: 10px;
}

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

.supported-formats {
    text-align: center;
    color: #718096;
    font-size: clamp(12px, 2.5vw, 14px);
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #e2e8f0;
}

.format-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-top: 10px;
}

.format-badge {
    background: #e2e8f0;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: clamp(11px, 2vw, 13px);
    color: #4a5568;
}

@media (max-width: 480px) {
    .converter-card {
        padding: 20px 15px;
    }

    .option-row {
        flex-direction: column;
        align-items: stretch;
    }

    .option-label {
        margin-bottom: 5px;
    }

    select {
        width: 100%;
    }
}