:root {
    --primary-color: #0052cc;
    --primary-hover: #0041a3;
    --accent-red: #de350b;
    --accent-green: #006400; /* For success */
    --text-dark: #172b4d;
    --text-light: #5e6c84;
    --background-color: #f4f5f7;
    --container-bg: #ffffff;
    --border-color: #dfe1e6;
    --light-blue-bg: #f0f6ff;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-family-mono: 'Roboto Mono', monospace;
}

body {
    font-family: var(--font-family);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    background-color: var(--background-color);
    color: var(--text-dark);
}

.container {
    background-color: var(--container-bg);
    padding: 50px;
    border-radius: 12px;
    box-shadow: 0 8px 24px -4px rgba(9, 30, 66, 0.15), 0 0 1px rgba(9, 30, 66, 0.2);
    text-align: center;
    max-width: 650px;
    width: 100%;
}

.main-header {
    margin-bottom: 40px;
}

h1 {
    font-size: 2.8em;
    font-weight: 700;
    margin: 0 0 2px 0;
}

.logo-accent {
    color: var(--accent-red);
}

.logo-tagline {
    font-family: var(--font-family-mono);
    margin: 0 auto 18px auto;
    font-size: 0.8em;
    font-weight: 500;
    color: var(--text-light); /* Sets color for brackets */
}

.logo-tagline .tag-dark {
    color: var(--text-light);
}
.logo-tagline .tag-blue {
    color: var(--primary-color);
}
.logo-tagline .tag-red {
    color: var(--accent-red);
}

.subtitle {
    font-size: 1.1em;
    color: var(--text-light);
    max-width: 480px;
    margin: 0 auto;
    line-height: 1.6;
}

.steps {
    display: flex;
    justify-content: space-between;
    gap: 25px;
    margin-bottom: 40px;
    text-align: center;
}

.step {
    flex: 1;
}

.step-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--light-blue-bg);
    color: var(--primary-color);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
    transition: transform 0.2s ease-out;
}

.step:hover .step-icon {
    transform: scale(1.1);
}

.step h3 {
    font-size: 1em;
    font-weight: 600;
    margin: 0 0 5px 0;
}

.step p {
    font-size: 0.9em;
    color: var(--text-light);
    margin: 0;
    line-height: 1.5;
}

.file-input-hidden {
    display: none;
}

.upload-area-wrapper {
    margin-bottom: 25px;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 10px;
    padding: 30px 20px;
    background-color: #fafbfc;
    transition: all 0.25s ease-in-out;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 180px;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: #f7f9fd;
    transform: translateY(-2px);
}

.upload-icon {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.file-input-label {
    font-size: 1.1em;
    color: var(--text-light);
}

.file-input-label strong {
    color: var(--primary-color);
    font-weight: 600;
}

#file-name {
    display: block;
    margin-top: 5px;
    font-weight: 600;
    font-size: 1.2em;
    color: var(--text-dark);
}

.upload-constraints {
    font-size: 0.85em;
    color: var(--text-light);
    margin-top: 15px;
}

#upload-button, #download-link {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 8px;
    font-size: 1.05em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    width: 100%;
    box-sizing: border-box;
    text-decoration: none;
    display: inline-block;
    position: relative;
}

#upload-button:hover, #download-link:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 12px rgba(0, 82, 204, 0.25);
    transform: translateY(-2px);
}

#upload-button:focus-visible, #download-link:focus-visible {
    outline: 3px solid var(--primary-hover);
    outline-offset: 2px;
}

#status-message {
    margin-top: 20px;
    font-size: 0.9em;
    min-height: 20px;
    font-weight: 500;
    color: var(--text-light);
}

.status-info {
    color: var(--primary-color);
}
.status-success {
    color: var(--accent-green);
}
.status-error {
    color: var(--accent-red);
}


#result-area {
    margin-top: 30px;
    border-top: 1px solid var(--border-color);
    padding-top: 30px;
}

#result-area h3 {
    margin: 0 0 20px 0;
    font-weight: 600;
}

.refresh-notice {
    margin-top: 20px;
    font-size: 0.9em;
    color: var(--text-light);
}

.beta-notice {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    font-size: 0.9em;
    color: var(--text-light);
}

.copyright {
    margin-top: 30px;
    font-size: 0.8em;
    color: var(--text-light);
}


/* --- Responsive Styles --- */
@media (max-width: 768px) {
    body {
        padding: 15px;
    }

    .container {
        padding: 25px;
    }

    h1 {
        font-size: 2.2em;
    }
    
    .logo-tagline {
        font-size: 0.75em;
    }

    .subtitle {
        font-size: 1em;
    }

    .steps {
        flex-direction: column;
        gap: 30px;
    }

    .upload-area {
        min-height: 160px;
    }
}


.upload-area.drag-over {
    border-color: var(--primary-color);
    background-color: #f7f9fd;
    box-shadow: 0 0 15px rgba(0, 82, 204, 0.3);
    transform: scale(1.02);
}

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

#upload-button.loading {
    color: transparent;
    cursor: not-allowed;
}

#upload-button.loading::after {
    content: '';
    display: block;
    position: absolute;
    left: 50%;
    top: 50%;
    margin-left: -12px; /* Half of width */
    margin-top: -12px; /* Half of height */
    
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: #ffffff;
    animation: spin 0.8s linear infinite;
}