:root {
    --bg: #fff; --bg2: #f8f9fa; --bg3: #e9ecef;
    --text: #212529; --text2: #6c757d;
    --border: #dee2e6; --accent: #0d6efd; --accent2: #0b5ed7;
    --ok: #198754; --err: #dc3545;
    --radius: 8px; --trans: .2s ease;
}
[data-theme="dark"] {
    --bg: #1a1a1a; --bg2: #242424; --bg3: #2d2d2d;
    --text: #e9ecef; --text2: #adb5bd;
    --border: #404040; --accent: #4dabf7; --accent2: #74c0fc;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; transition: background var(--trans), color var(--trans); }
.container { max-width: 800px; margin: 0 auto; padding: 2rem 1rem; min-height: 100vh; display: flex; flex-direction: column; }
header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2rem; padding-bottom: 1rem; border-bottom: 1px solid var(--border); }
header h1 { font-size: 1.75rem; font-weight: 600; }
#theme-toggle { width: 36px; height: 36px; background: var(--bg2); border: 1px solid var(--border); border-radius: var(--radius); cursor: pointer; position: relative; transition: all var(--trans); }
#theme-toggle::before { content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 18px; height: 18px; border-radius: 50%; background: var(--text); transition: all var(--trans); }
[data-theme="dark"] #theme-toggle::before { background: transparent; box-shadow: inset -6px -2px 0 0 var(--text); width: 14px; height: 14px; }
main { flex: 1; display: flex; flex-direction: column; gap: 0.75rem; }
.tool-section { background: var(--bg2); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.tool-header { display: flex; justify-content: space-between; align-items: center; padding: 0.875rem 1rem; cursor: pointer; transition: background var(--trans); }
.tool-header:hover { background: var(--bg3); }
.tool-header h2 { font-size: 0.95rem; font-weight: 500; }
.toggle-icon { width: 18px; height: 18px; position: relative; }
.toggle-icon::before, .toggle-icon::after { content: ''; position: absolute; background: var(--text2); }
.toggle-icon::before { width: 10px; height: 2px; top: 50%; left: 50%; transform: translate(-50%, -50%); }
.toggle-icon::after { width: 2px; height: 10px; top: 50%; left: 50%; transform: translate(-50%, -50%); transition: all var(--trans); }
.tool-section.expanded .toggle-icon::after { opacity: 0; transform: translate(-50%, -50%) rotate(90deg); }
.tool-content { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.tool-section.expanded .tool-content { max-height: 2000px; }
.tool-body { padding: 0 1rem 1rem; }
textarea, input[type="text"], input[type="number"] { width: 100%; padding: 0.6rem 0.8rem; font: inherit; font-size: 0.9rem; background: var(--bg); color: var(--text); border: 1px solid var(--border); border-radius: var(--radius); transition: border var(--trans); }
textarea:focus, input:focus { outline: none; border-color: var(--accent); }
textarea { min-height: 100px; resize: vertical; font-family: ui-monospace, monospace; font-size: 0.85rem; }
input[type="number"] { width: 80px; }
.form-group { margin-bottom: 0.75rem; }
.form-group label { display: block; margin-bottom: 0.4rem; font-size: 0.85rem; color: var(--text2); }
.input-row { display: flex; gap: 0.5rem; align-items: center; }
.input-row input[type="text"] { flex: 1; }
.options-row { display: flex; gap: 1rem; margin-bottom: 0.75rem; flex-wrap: wrap; }
.options-row label { display: flex; align-items: center; gap: 0.5rem; font-size: 0.9rem; }
.options-row label span { color: var(--text2); }
.options-row input { width: 70px; }
.checkbox-row { display: flex; gap: 1rem; margin: 0.75rem 0; flex-wrap: wrap; }
.checkbox-row label { display: flex; align-items: center; gap: 0.4rem; font-size: 0.875rem; cursor: pointer; }
.checkbox-row input { accent-color: var(--accent); }
.button-group { display: flex; gap: 0.5rem; margin-top: 0.75rem; flex-wrap: wrap; }
button { padding: 0.55rem 1rem; font: inherit; font-size: 0.85rem; font-weight: 500; background: var(--accent); color: #fff; border: none; border-radius: var(--radius); cursor: pointer; transition: all var(--trans); }
button:hover { background: var(--accent2); }
button.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }
button.secondary:hover { background: var(--bg3); }
button:disabled { opacity: 0.6; cursor: not-allowed; }
pre { margin-top: 0.75rem; padding: 0.75rem; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); font-family: ui-monospace, monospace; font-size: 0.8rem; overflow-x: auto; white-space: pre-wrap; word-break: break-all; }
pre:empty { display: none; }
.results-box { margin-top: 0.75rem; padding: 0.75rem; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); font-size: 0.875rem; }
.results-box:empty { display: none; }
.results-box.success { border-color: var(--ok); background: rgba(25,135,84,.1); }
.results-box.error { border-color: var(--err); background: rgba(220,53,69,.1); }
.error-message { margin-top: 0.5rem; padding: 0.6rem; background: rgba(220,53,69,.1); color: var(--err); border-radius: var(--radius); font-size: 0.85rem; }
.error-message:empty { display: none; }
.tree-view { margin-top: 0.75rem; padding: 0.75rem; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); font-family: ui-monospace, monospace; font-size: 0.8rem; overflow-x: auto; }
.tree-view:empty { display: none; }
.tree-node { padding-left: 1.25rem; }
.tree-key { color: var(--accent); cursor: pointer; }
.tree-key:hover { text-decoration: underline; }
.tree-value { color: var(--ok); }
.tree-value.string { color: var(--ok); }
.tree-value.number { color: #e67700; }
.tree-value.boolean { color: #9c36b5; }
.tree-value.null { color: var(--text2); }
.tree-bracket { color: var(--text2); }
.tree-toggle { display: inline-block; width: 1rem; text-align: center; cursor: pointer; color: var(--text2); user-select: none; }
.tree-collapsed > .tree-children { display: none; }
.tree-collapsed > .tree-toggle::before { content: '+'; }
.tree-expanded > .tree-toggle::before { content: '-'; }
.tree-attr { color: #e67700; }
.tree-tag { color: var(--accent); }
.tree-text { color: var(--text); }
.ping-entry { padding: 0.4rem 0; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; }
.ping-entry:last-child { border: none; }
.ping-entry .status { font-weight: 500; }
.ping-entry .status.success { color: var(--ok); }
.ping-entry .status.error { color: var(--err); }
.ping-entry .time { color: var(--text2); font-size: 0.85rem; }
.loading { display: inline-block; width: 14px; height: 14px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin .7s linear infinite; margin-right: 0.4rem; vertical-align: middle; }
@keyframes spin { to { transform: rotate(360deg); } }
footer { margin-top: 1.5rem; padding-top: 0.75rem; border-top: 1px solid var(--border); text-align: center; color: var(--text2); font-size: 0.8rem; }
@media (max-width: 600px) {
    .container { padding: 1rem; }
    .input-row, .button-group { flex-direction: column; }
    .input-row input[type="number"] { width: 100%; }
    button { width: 100%; }
}