:root {
    --bg: #0f1115;
    --bg-2: #161922;
    --bg-3: #1d212c;
    --bg-4: #232836;
    --border: #262a36;
    --text: #ececf1;
    --text-dim: #a0a3b1;
    --accent: #10a37f;
    --accent-hover: #0e8c6c;
    --blue: #4f46e5;
    --danger: #ef4444;
    --json-key: #7dd3fc;
    --json-string: #a7f3d0;
    --json-number: #fbbf24;
    --json-bool: #f472b6;
    --json-null: #94a3b8;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 14px;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Topbar */
.topbar {
    display: flex;
    align-items: center;
    gap: 24px;
    padding: 12px 24px;
    border-bottom: 1px solid var(--border);
    background: var(--bg);
}
.brand { display: flex; align-items: center; gap: 10px; }
.logo {
    width: 28px; height: 28px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--blue) 100%);
    color: white; display: grid; place-items: center;
    font-weight: 700; font-size: 15px;
}
.title { font-weight: 600; font-size: 15px; }
.title .sub { color: var(--text-dim); font-weight: 400; margin-left: 4px; }
.topbar nav { display: flex; gap: 4px; margin-left: 12px; }
.topbar nav a {
    color: var(--text-dim);
    text-decoration: none;
    padding: 6px 10px;
    border-radius: 6px;
    font-size: 13px;
}
.topbar nav a:hover { background: var(--bg-2); color: var(--text); }
.topbar nav a.active { background: var(--bg-3); color: var(--text); }
.endpoint { margin-left: auto; display: flex; align-items: center; gap: 8px; font-size: 13px; }
.endpoint .method {
    background: var(--accent);
    color: white;
    border-radius: 5px;
    padding: 2px 8px;
    font-weight: 600;
    font-size: 11px;
    letter-spacing: 0.5px;
}
.endpoint code {
    background: var(--bg-2);
    border: 1px solid var(--border);
    padding: 3px 8px;
    border-radius: 5px;
    font-family: "SF Mono", Menlo, Consolas, monospace;
    color: var(--text);
}
.badge {
    font-size: 11px;
    padding: 3px 8px;
    border-radius: 999px;
    background: var(--bg-2);
    border: 1px solid var(--border);
    color: var(--text-dim);
}
.badge.ready { background: rgba(16, 163, 127, 0.15); border-color: rgba(16, 163, 127, 0.4); color: #6ee7b7; }
.badge.loading { background: rgba(245, 158, 11, 0.15); border-color: rgba(245, 158, 11, 0.4); color: #fbbf24; }
.badge.error { background: rgba(239, 68, 68, 0.15); border-color: rgba(239, 68, 68, 0.4); color: #fca5a5; }

/* Layout */
.playground {
    flex: 1;
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 1px;
    background: var(--border);
    overflow: hidden;
}

.form-panel, .json-panel { background: var(--bg); padding: 24px; overflow-y: auto; }
.form-panel h2 { margin: 0 0 6px; font-size: 17px; font-weight: 600; }
.form-panel .hint { color: var(--text-dim); margin: 0 0 20px; font-size: 13px; }

.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
.field .label { font-size: 12px; color: var(--text-dim); font-weight: 600; letter-spacing: 0.3px; text-transform: uppercase; }
.field .value { font-weight: 400; color: var(--text); text-transform: none; letter-spacing: 0; margin-left: 6px; }
.field input[type="text"], .field input[type="number"], .field textarea {
    background: var(--bg-2);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 8px;
    padding: 10px 12px;
    font-family: inherit;
    font-size: 14px;
    resize: vertical;
    transition: border-color 0.15s;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--accent); }
.field input[type="range"] { accent-color: var(--accent); }
.field.checkbox { flex-direction: row; align-items: center; gap: 8px; }
.field.checkbox .label { text-transform: none; letter-spacing: 0; font-weight: 400; color: var(--text); font-size: 14px; }

.messages-builder { margin-bottom: 18px; }
.row-header { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.row-header .label { font-size: 12px; color: var(--text-dim); font-weight: 600; letter-spacing: 0.3px; text-transform: uppercase; flex: 1; }
.add-btn {
    background: var(--bg-2);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 6px;
    padding: 4px 10px;
    font-size: 12px;
    cursor: pointer;
}
.add-btn:hover { background: var(--bg-3); }
.message-list { display: flex; flex-direction: column; gap: 8px; }
.msg-row {
    background: var(--bg-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px;
    display: grid;
    grid-template-columns: 100px 1fr auto;
    gap: 8px;
    align-items: start;
}
.msg-row select {
    background: var(--bg-3);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 6px;
    padding: 6px 8px;
    font-family: inherit;
    font-size: 13px;
}
.msg-row textarea {
    background: var(--bg-3);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 6px;
    padding: 8px 10px;
    font-family: inherit;
    font-size: 13px;
    resize: vertical;
    min-height: 60px;
}
.msg-row .remove {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-dim);
    border-radius: 6px;
    padding: 4px 8px;
    cursor: pointer;
    font-size: 12px;
    height: 30px;
}
.msg-row .remove:hover { color: var(--danger); border-color: var(--danger); }

.param-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-bottom: 20px;
}

.actions { display: flex; gap: 8px; }
.send {
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 10px 18px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.15s;
}
.send:hover { background: var(--accent-hover); }
.send:disabled { background: var(--bg-3); color: var(--text-dim); cursor: not-allowed; }
.ghost, .ghost-sm {
    background: transparent;
    color: var(--text-dim);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 13px;
    cursor: pointer;
}
.ghost-sm { padding: 4px 10px; font-size: 12px; }
.ghost:hover, .ghost-sm:hover { color: var(--text); background: var(--bg-2); }

/* JSON panels */
.json-panel { display: flex; flex-direction: column; gap: 16px; background: var(--bg-2); }
.panel {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
}
.panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-2);
    gap: 8px;
}
.panel-head h3 { margin: 0; font-size: 13px; font-weight: 600; color: var(--text); }
.panel-head .meta { font-size: 11px; color: var(--text-dim); flex: 1; text-align: right; }
.json {
    margin: 0;
    padding: 14px;
    overflow: auto;
    font-family: "SF Mono", Menlo, Consolas, monospace;
    font-size: 12.5px;
    line-height: 1.55;
    white-space: pre-wrap;
    word-break: break-word;
    flex: 1;
    min-height: 200px;
}
.json.placeholder { color: var(--text-dim); font-style: italic; }
.json .k { color: var(--json-key); }
.json .s { color: var(--json-string); }
.json .n { color: var(--json-number); }
.json .b { color: var(--json-bool); }
.json .nu { color: var(--json-null); }
.json .err { color: var(--danger); }

@media (max-width: 980px) {
    .playground { grid-template-columns: 1fr; }
    .param-grid { grid-template-columns: 1fr; }
    .topbar { flex-wrap: wrap; gap: 12px; }
    .endpoint { margin-left: 0; }
}

/* Scrollbar */
.form-panel::-webkit-scrollbar, .json-panel::-webkit-scrollbar, .json::-webkit-scrollbar { width: 8px; height: 8px; }
.form-panel::-webkit-scrollbar-thumb, .json-panel::-webkit-scrollbar-thumb, .json::-webkit-scrollbar-thumb { background: #2b3140; border-radius: 4px; }
.form-panel::-webkit-scrollbar-thumb:hover, .json-panel::-webkit-scrollbar-thumb:hover, .json::-webkit-scrollbar-thumb:hover { background: #3a4054; }