:root {
    --bg: #f5f7fa;
    --surface: #ffffff;
    --surface-2: #eef2f7;
    --text: #0f172a;
    --text-muted: #475569;
    --border: #d8dee9;
    --primary: #0ea5e9;
    --primary-hover: #0284c7;
    --danger: #dc2626;
    --success: #16a34a;
    --warning: #d97706;
    --shadow: 0 1px 2px rgba(15, 23, 42, 0.06), 0 4px 12px rgba(15, 23, 42, 0.05);
    --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

[data-theme="dark"] {
    --bg: #0b1220;
    --surface: #111a2e;
    --surface-2: #16213a;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --border: #1f2a44;
    --primary: #38bdf8;
    --primary-hover: #0ea5e9;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 6px 18px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 14px;
    line-height: 1.45;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand h1 {
    margin: 0;
    font-size: 18px;
    font-weight: 600;
    letter-spacing: 0.2px;
}

.logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--primary);
    color: #fff;
    border-radius: 8px;
    font-family: var(--mono);
    font-weight: 700;
    font-size: 14px;
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.badge {
    background: var(--surface-2);
    color: var(--text-muted);
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 4px 10px;
    font-size: 12px;
}

.icon-btn {
    background: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--text);
    width: 32px;
    height: 32px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.icon-btn:hover { background: var(--border); }

.container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding: 16px 20px;
    max-width: 1600px;
    width: 100%;
    margin: 0 auto;
}

.toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
    justify-content: space-between;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 10px 12px;
    box-shadow: var(--shadow);
}

.toolbar-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
}

.btn {
    cursor: pointer;
    background: var(--surface-2);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 7px 14px;
    font-size: 13px;
    font-weight: 500;
    transition: background 120ms ease, transform 80ms ease, box-shadow 120ms ease;
}
.btn:hover { background: var(--border); }
.btn:active { transform: translateY(1px); }

.btn.primary {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}
.btn.primary:hover { background: var(--primary-hover); border-color: var(--primary-hover); }

.btn.ghost { background: transparent; }
.btn.ghost:hover { background: var(--surface-2); }

.btn.danger { color: var(--danger); }
.btn.danger:hover { background: rgba(220, 38, 38, 0.1); }

.inline-field {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-muted);
}
.inline-field.checkbox { gap: 4px; }

select {
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 5px 8px;
    font-size: 13px;
}

.panes {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    min-height: 60vh;
}

@media (max-width: 880px) {
    .panes { grid-template-columns: 1fr; }
}

.pane {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow);
    min-height: 320px;
}

.pane-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    background: var(--surface-2);
}

.pane-header h2 {
    margin: 0;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.6px;
}

.pane-actions { display: flex; gap: 8px; }

.link-btn {
    background: none;
    border: none;
    color: var(--primary);
    cursor: pointer;
    font-size: 13px;
    padding: 2px 4px;
    border-radius: 4px;
}
.link-btn:hover { background: rgba(14, 165, 233, 0.12); }

textarea {
    flex: 1;
    width: 100%;
    border: none;
    outline: none;
    resize: none;
    padding: 4px 14px;
    background: var(--surface);
    color: var(--text);
    font-family: var(--mono);
    font-size: 13px;
    line-height: 1.55;
    tab-size: 4;
}
textarea::placeholder { color: var(--text-muted); opacity: 0.7; }

/* Input editor with line-number gutter */
.editor {
    flex: 1 1 auto;
    display: flex;
    min-height: 0;
    background: var(--surface);
    overflow: hidden;
}
.editor textarea {
    flex: 1 1 auto;
    overflow: auto;
}
.gutter {
    flex: 0 0 auto;
    min-width: 3.5em;
    padding: 4px 8px 4px 6px;
    text-align: right;
    color: var(--text-muted);
    background: var(--surface-2);
    border-right: 1px solid var(--border);
    font-family: var(--mono);
    font-size: 13px;
    line-height: 1.55;
    user-select: none;
    overflow: hidden;
    white-space: pre;
}

.output {
    flex: 1 1 auto;
    width: 100%;
    margin: 0;
    overflow: auto;
    background: var(--surface);
    color: var(--text);
    font-family: var(--mono);
    font-size: 13px;
    line-height: 1.55;
    padding: 0;
    user-select: text;
    cursor: text;
}
.output:empty::before {
    content: attr(data-placeholder);
    color: var(--text-muted);
    opacity: 0.7;
    padding: 8px 14px;
    display: inline-block;
}

/* Line rows */
.line {
    display: flex;
    align-items: flex-start;
    min-height: 1.55em;
}
.line:hover { background: rgba(127, 127, 127, 0.06); }
.line.path-active { background: rgba(14, 165, 233, 0.08); }

.ln {
    flex: 0 0 auto;
    min-width: 3.5em;
    padding: 0 8px 0 6px;
    text-align: right;
    color: var(--text-muted);
    user-select: none;
    border-right: 1px solid var(--border);
    background: var(--surface-2);
}

.fold-toggle {
    flex: 0 0 auto;
    width: 1.4em;
    text-align: center;
    cursor: pointer;
    user-select: none;
    color: var(--text-muted);
    background: transparent;
    border: none;
    padding: 0;
    font: inherit;
    line-height: inherit;
}
.fold-toggle:hover { color: var(--primary); }
.fold-toggle.empty { cursor: default; visibility: hidden; }
.fold-toggle::before { content: "\2212"; } /* − */
.block.collapsed > .line:first-child .fold-toggle::before { content: "+"; }

.code {
    flex: 1 1 auto;
    min-width: 0;
    padding-left: 4px;
    padding-right: 12px;
    white-space: pre;
}
.indent { white-space: pre; }

/* Folding */
.block.collapsed > .block-body { display: none; }
.block.collapsed > .line:last-child { display: none; }
.fold-summary { display: none; color: var(--text-muted); font-style: italic; }
.block.collapsed > .line:first-child .fold-summary { display: inline; }
.fold-count { color: var(--text-muted); margin-left: 8px; font-style: normal; }

/* Bracket matching */
.bracket.matched {
    background: rgba(14, 165, 233, 0.22);
    outline: 1px solid var(--primary);
    border-radius: 2px;
}

/* JSON syntax highlighting */
.tok-key    { color: #b91c1c; }
.tok-string { color: #047857; }
.tok-number { color: #1d4ed8; }
.tok-bool   { color: #7c3aed; font-weight: 600; }
.tok-null   { color: #6b7280; font-style: italic; }
.tok-punct  { color: var(--text-muted); }

[data-theme="dark"] .tok-key    { color: #f87171; }
[data-theme="dark"] .tok-string { color: #34d399; }
[data-theme="dark"] .tok-number { color: #60a5fa; }
[data-theme="dark"] .tok-bool   { color: #c084fc; }
[data-theme="dark"] .tok-null   { color: #94a3b8; }

/* Path display in output header */
.path {
    flex: 1 1 auto;
    min-width: 0;
    margin: 0 12px;
    color: var(--text-muted);
    font-family: var(--mono);
    font-size: 12px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    cursor: pointer;
    padding: 2px 6px;
    border-radius: 4px;
}
.path:empty { cursor: default; }
.path:not(:empty):hover { color: var(--text); background: var(--surface); }
.path.copied { color: var(--success); }

.status {
    min-height: 22px;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 13px;
    font-family: var(--mono);
    border: 1px solid transparent;
    background: transparent;
    color: var(--text-muted);
    white-space: pre-wrap;
    word-break: break-word;
}
.status.success {
    color: var(--success);
    background: rgba(22, 163, 74, 0.08);
    border-color: rgba(22, 163, 74, 0.3);
}
.status.error {
    color: var(--danger);
    background: rgba(220, 38, 38, 0.08);
    border-color: rgba(220, 38, 38, 0.3);
}
.status.info {
    color: var(--text);
    background: var(--surface-2);
    border-color: var(--border);
}
.status[hidden] { display: none; }
.status-dock {
    position: fixed;
    left: 20px;
    right: 20px;
    bottom: 12px;
    z-index: 20;
    max-width: 1560px;
    margin: 0 auto;
    box-shadow: var(--shadow);
}

.footer {
    text-align: center;
    padding: 12px;
    font-size: 12px;
    color: var(--text-muted);
    border-top: 1px solid var(--border);
    background: var(--surface);
}
.footer a {
    color: var(--primary);
    text-decoration: none;
}
.footer a:hover { text-decoration: underline; }