* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: #f5f7fb;
    color: #333;
    display: flex;
    justify-content: center;
    padding: 10px;
}

.app-container {
    width: 100%;
    max-width: 480px;
    background-color: #ffffff;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    padding: 20px;
    min-height: 90vh;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

header h1 {
    font-size: 24px;
    color: #1a73e8;
}

header p {
    font-size: 14px;
    color: #666;
}

.tabs {
    display: flex;
    background-color: #f1f3f4;
    padding: 4px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.tab-btn {
    flex: 1;
    border: none;
    padding: 10px;
    background: none;
    font-size: 14px;
    font-weight: 600;
    color: #5f6368;
    border-radius: 6px;
    cursor: pointer;
    transition: 0.2s;
}

.tab-btn.active {
    background-color: #ffffff;
    color: #1a73e8;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.upload-box {
    border: 2px dashed #dadce0;
    border-radius: 12px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    background-color: #f8f9fa;
    margin-bottom: 20px;
}

.prompt-section {
    margin-bottom: 20px;
}

.prompt-section label {
    display: block;
    font-size: 12px;
    margin-bottom: 6px;
    color: #5f6368;
}

.prompt-section input {
    width: 100%;
    padding: 12px;
    border: 1px solid #dadce0;
    border-radius: 8px;
    font-size: 14px;
}

.action-btn {
    width: 100%;
    padding: 14px;
    background-color: #1a73e8;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 20px;
}

.loader {
    text-align: center;
    padding: 20px;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #1a73e8;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 10px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.result-section {
    margin-top: 20px;
    text-align: center;
}

.result-box img {
    max-width: 100%;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 15px;
}

.download-btn {
    display: inline-block;
    padding: 12px 24px;
    background-color: #34a853;
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
}