:root {
    --bg-color: #f4f4f9;
    --text-color: #333;
    --header-bg: #fff;
    --card-bg: #fff;
    --border-color: #ddd;
    --accent-color: #007bff;
    --accent-hover: #0056b3;
    --error-color: #d32f2f;
    --success-color: #2e7d32;
    --font-mono: 'Consolas', 'Monaco', 'Courier New', monospace;
}

body.dark-mode {
    --bg-color: #1e1e1e;
    --text-color: #e0e0e0;
    --header-bg: #252526;
    --card-bg: #2d2d2d;
    --border-color: #444;
    --accent-color: #4daafc;
    --accent-hover: #2b89e0;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

header {
    background-color: var(--header-bg);
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}

.site-logo {
    font-weight: bold;
    font-size: 1.5rem;
    color: var(--text-color);
    text-decoration: none;
}

.site-logo:hover {
    text-decoration: none;
}

.title-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 600;
}

.privacy-notice {
    font-size: 0.85rem;
    color: var(--success-color);
    font-weight: bold;
    margin-left: 1rem;
    display: inline-block;
}

.controls-top {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.controls-top a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
}

.controls-top a:hover {
    text-decoration: underline;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

body.dark-mode .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.help-text {
    padding: 0.5rem 2rem;
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
    text-align: center;
    flex-shrink: 0;
}

main {
    flex: 1;
    display: flex;
    padding: 1rem 2rem;
    gap: 1rem;
    overflow: hidden;
}

.pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    overflow: hidden;
}

.pane-header {
    padding: 0.5rem 1rem;
    background-color: rgba(0, 0, 0, 0.03);
    border-bottom: 1px solid var(--border-color);
    font-weight: bold;
    font-size: 0.9rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

textarea {
    flex: 1;
    width: 100%;
    border: none;
    padding: 1rem;
    resize: none;
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.5;
    background-color: var(--card-bg);
    color: var(--text-color);
    outline: none;
}

textarea:focus {
    background-color: rgba(0, 0, 0, 0.02);
}

body.dark-mode textarea:focus {
    background-color: rgba(255, 255, 255, 0.02);
}

.actions {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 1rem;
    padding: 0 0.5rem;
}

.btn {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1rem;
    transition: opacity 0.2s;
    white-space: nowrap;
}

.btn:hover {
    opacity: 0.9;
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-copy {
    background-color: var(--success-color);
    color: white;
    font-size: 0.8rem;
    padding: 0.3rem 0.8rem;
}

.options {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    justify-content: center;
}

.error-message {
    color: var(--error-color);
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    background-color: rgba(211, 47, 47, 0.1);
    font-size: 0.9rem;
    display: none;
    max-height: 150px;
    overflow-y: auto;
    white-space: pre-wrap;
}

/* Mobile Layout */
@media (max-width: 768px) {
    main {
        flex-direction: column;
        padding: 1rem;
        overflow-y: auto;
    }

    .pane {
        min-height: 200px;
    }

    .actions {
        flex-direction: row;
        padding: 0.5rem 0;
        flex-wrap: wrap;
    }

    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        padding: 1rem;
    }

    .controls-top {
        width: 100%;
        justify-content: space-between;
    }

    .privacy-notice {
        margin-left: 0;
        display: block;
    }
}