:root {
    color-scheme: light;
    font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --bg: #ffffff;
    --panel: #ffffff;
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --border: #d0d7e6;
    --text: #0f172a;
    --muted: #475569;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
}

.page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
}

.hero {
    background: transparent;
    border-radius: 0;
    padding: 0;
    margin: 0;
}

.hero h1 {
    margin: 0 0 12px;
    font-size: 34px;
}

.hero p {
    margin: 0;
    color: var(--muted);
}

.eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 12px;
    color: var(--primary-dark);
    margin-bottom: 12px;
}

.alert {
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 24px;
    font-size: 15px;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
}

.alert-error ul {
    margin: 8px 0 0;
    padding-left: 18px;
}

.page-grid {
    display: grid;
    grid-template-columns: minmax(280px, 1fr) minmax(360px, 1fr);
    gap: 28px;
    align-items: start;
}

.panel {
    background: var(--panel);
    border-radius: 0;
    padding: 0;
    box-shadow: none;
}

.panel h2 {
    margin-top: 0;
    margin-bottom: 16px;
}

.form .field {
    margin-bottom: 18px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
}

textarea,
select,
input[type="text"] {
    width: 100%;
    font: inherit;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 12px 14px;
    background: #f8fafc;
    transition: border-color 0.2s ease;
}

textarea:focus,
select:focus,
input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

textarea {
    min-height: 160px;
    resize: vertical;
}

button {
    font: inherit;
    background: #4f883d;
    border: none;
    border-radius: 5px;
    color: #fff;
    font-weight: 600;
    padding: 14px 24px;
    width: 100%;
    cursor: pointer;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

button:hover:not(:disabled) {
    opacity: 0.95;
    transform: translateY(-1px);
    background: #3b692f;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.thumbnail-section {
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
    background: #f8fafc;
}

.thumbnail-label {
    margin: 0 0 10px;
    color: var(--muted);
    font-size: 14px;
}

.thumbnail-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.thumbnail-row img {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: #fff;
    padding: 6px;
}

.preview {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.preview-header h2 {
    margin: 0 0 6px;
}

.preview-actions {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 200px;
}

.preview-refresh,
.preview-download {
    width: 100%;
    padding-inline: 22px;
}

#previewFrame {
    width: 100%;
    min-height: 520px;
    border: 1px solid var(--border);
    border-radius: 16px;
    background: #fff;
}

.preview-status {
    font-size: 14px;
    color: var(--muted);
}

.preview-status.success {
    color: #166534;
}

.preview-status.error {
    color: #b91c1c;
}

.preview-status.loading {
    color: #0f172a;
}

.info-card {
    margin-top: 32px;
    background: #e0f2fe;
    border-radius: 20px;
    padding: 24px;
}

.info-card h3 {
    margin-top: 0;
}

.info-card ol {
    padding-left: 20px;
}

@media (max-width: 849px) {
    .page-grid {
        grid-template-columns: 1fr;
    }
}

/* Preview iframe content */
.preview-page {
    font-family: "Inter", sans-serif;
    padding: 24px;
    color: #0f172a;
}

.preview-page h1 {
    margin-bottom: 4px;
}

.preview-meta {
    color: #475569;
    font-size: 13px;
}

.preview-page .legend-list {
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 12px 16px;
}

.preview-page .legend-entry {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 6px 0;
    border-bottom: 1px solid #f1f5f9;
}

.preview-page .legend-entry:last-child {
    border-bottom: none;
}

.preview-page .legend-entry-letter {
    font-weight: 700;
    font-size: 18px;
}

.preview-page .legend-entry-icon img {
    height: 28px;
}

.preview-cipher {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.preview-cipher .cipher-block {
    width: 44px;
    height: 44px;
    border-radius: 8px;
}