:root {
    --bg: #f5f5f5;
    --bg-card: #ffffff;
    --bg-input: #f0f0f0;
    --bg-hover: #e8e8e8;
    --bg-active: #e0e6f0;
    --text: #1e1e1e;
    --text-secondary: #444;
    --text-muted: #666;
    --border: #ddd;
    --border-light: #ccc;
    --accent: #2270b8;
    --accent-hover: #1a5c9e;
    --accent-on: #fff;
    --tag-bg: #e0e6f0;
    --tag-color: #444;
    --btn-bg: #e0e0e0;
    --btn-border: #bbb;
    --btn-hover: #d0d0d0;
}
[data-theme="dark"] {
    --bg: #1e1e1e;
    --bg-card: #252526;
    --bg-input: #2d2d2d;
    --bg-hover: #333;
    --bg-active: #37373d;
    --text: #e0e0e0;
    --text-secondary: #ccc;
    --text-muted: #888;
    --border: #333;
    --border-light: #444;
    --accent: #569cd6;
    --accent-hover: #4a8bc2;
    --accent-on: #1e1e1e;
    --tag-bg: #333;
    --tag-color: #ccc;
    --btn-bg: #333;
    --btn-border: #555;
    --btn-hover: #444;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}
.container { max-width: 960px; margin: 0 auto; padding: 0 1rem; }
nav {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 0.6rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}
nav .container {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}
.logo {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--accent);
    text-decoration: none;
}
.nav-dropdown { position: relative; flex: 1; }
.nav-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.25rem 0;
    transition: color 0.15s;
}
.nav-toggle:hover { color: var(--text); }
.nav-toggle .nav-current { color: var(--accent); font-weight: 600; }
.nav-toggle svg {
    width: 12px; height: 12px; flex-shrink: 0;
    transition: transform 0.2s;
}
.nav-toggle.open svg { transform: rotate(180deg); }
.nav-menu {
    display: none;
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.3rem 0;
    min-width: 190px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.08);
    z-index: 200;
    list-style: none;
}
[data-theme="dark"] .nav-menu { box-shadow: 0 6px 20px rgba(0,0,0,0.35); }
.nav-menu.open { display: block; }
.nav-menu a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.88rem;
    padding: 0.45rem 1rem;
    transition: background 0.12s, color 0.12s;
}
.nav-menu a:hover { background: var(--bg-hover); color: var(--text); }
.nav-menu a.active {
    color: var(--accent);
    font-weight: 600;
    background: var(--bg-active);
}
/* Footer */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 1.2rem 0;
    margin-top: 2rem;
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
}
.site-footer a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.15s;
}
.site-footer a:hover { color: var(--accent); }
.site-footer .footer-links {
    display: flex;
    justify-content: center;
    gap: 1.2rem;
    flex-wrap: wrap;
}
.theme-toggle {
    background: var(--btn-bg);
    border: 1px solid var(--btn-border);
    border-radius: 4px;
    padding: 0.35rem 0.6rem;
    cursor: pointer;
    color: var(--text);
    font-size: 1rem;
    line-height: 1;
    flex-shrink: 0;
}
.theme-toggle:hover { background: var(--btn-hover); }
main { padding: 1.5rem 0; }
.input-row {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}
.input-row input {
    flex: 1;
    background: var(--bg-input);
    border: 1px solid var(--border-light);
    border-radius: 4px;
    padding: 0.5rem 0.75rem;
    color: var(--text);
    font-size: 0.95rem;
}
.input-row input:focus { outline: none; border-color: var(--accent); }
.btn-primary {
    background: var(--accent);
    color: var(--accent-on);
    border: none;
    border-radius: 4px;
    padding: 0.5rem 1.2rem;
    font-weight: 600;
    cursor: pointer;
    font-size: 0.95rem;
    white-space: nowrap;
    transition: background 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}
.btn-primary:hover { background: var(--accent-hover); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; }
.btn-secondary {
    background: var(--btn-bg);
    color: var(--text);
    border: 1px solid var(--btn-border);
    border-radius: 4px;
    padding: 0.4rem 0.8rem;
    cursor: pointer;
    font-size: 0.85rem;
    transition: background 0.15s;
}
.btn-secondary:hover { background: var(--btn-hover); }
textarea {
    width: 100%;
    min-height: 200px;
    background: var(--bg-input);
    border: 1px solid var(--border-light);
    border-radius: 4px;
    padding: 0.75rem;
    color: var(--text);
    font-family: 'SF Mono', Monaco, Consolas, monospace;
    font-size: 0.85rem;
    resize: vertical;
    line-height: 1.5;
}
textarea:focus { outline: none; border-color: var(--accent); }
.error-msg {
    color: #d44;
    font-size: 0.9rem;
    margin-top: 0.5rem;
}
.hidden { display: none; }
@keyframes spin {
    to { transform: rotate(360deg); }
}
.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-light);
    border-top-color: var(--accent-on);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    vertical-align: middle;
}
@media (max-width: 768px) {
    nav .container { gap: 0.8rem; }
    .logo { font-size: 1rem; }
    main { padding: 1rem 0; }
    textarea { min-height: 150px; font-size: 0.8rem; }
}
@media (max-width: 480px) {
    nav .container { gap: 0.5rem; }
    .logo { font-size: 0.95rem; }
    .input-row { flex-direction: column; }
    .input-row input { width: 100%; }
    .btn-primary { width: 100%; justify-content: center; }
    textarea { min-height: 120px; }
}