:root {
  --bg: #f6f8fb;
  --panel: #ffffff;
  --panel-border: #e5e7eb;
  --text: #0f172a;
  --muted: #6b7280;
  --primary: #0b7bff;
  --primary-dk: #0969da;
  --danger: #d1242f;
  --accent: #eef6ff;
  --user-bubble: #f3f4f6;
  --assistant-bubble: #eef6ff;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px;
}

header h2, header h3 { margin: 0; }

/* Buttons */
a.button, .btn, button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  background: var(--primary);
  color: #fff !important;
  border-radius: 8px;
  border: none;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 0 1px 2px rgba(0,0,0,0.05);
  transition: background .15s ease, transform .05s ease;
}
a.button:hover, .btn:hover, button:hover { background: var(--primary-dk); }
a.button:active, .btn:active, button:active { transform: translateY(1px); }

.btn-danger, button.btn-danger { background: var(--danger); }
.btn-muted { background: #e5e7eb; color: #111827 !important; }

/* Panels & forms */
.card, form.panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  padding: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
label { display: block; margin: 10px 0 6px; font-weight: 600; }
input[type=text], input[type=password], select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  background: #fff;
  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease;
}
input:focus, select:focus, textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(11,123,255,0.15);
}

/* Tables */
table { width: 100%; border-collapse: collapse; background: var(--panel); border: 1px solid var(--panel-border); border-radius: 10px; overflow: hidden; }
thead th { background: #f3f4f6; text-align: left; font-weight: 700; padding: 10px 12px; border-bottom: 1px solid var(--panel-border); }
td { padding: 10px 12px; border-bottom: 1px solid var(--panel-border); }
tbody tr:hover { background: #fafafa; }

/* Chat */
.chat {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 12px;
  height: 60vh;
  overflow: auto;
  box-shadow: inset 0 1px 0 rgba(0,0,0,0.02);
}
.msg { margin: 12px 0; }
.role { font-weight: 700; margin-bottom: 6px; color: #1f2937; }
.usage { color: var(--muted); font-weight: 400; margin-left: 8px; }
.user, .assistant { padding: 10px 12px; border-radius: 10px; border: 1px solid var(--panel-border); }
.user { background: var(--user-bubble); }
.assistant { background: var(--assistant-bubble); }

.footer { position: sticky; bottom: 0; background: transparent; padding: 10px 0; }
.inputs { display: flex; gap: 10px; flex-wrap: wrap; align-items: flex-start; }
textarea { min-height: 90px; }
.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.small { color: var(--muted); font-size: 12px; }

/* Header */
header {
  display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px;
}
nav a.button { margin-left: 8px; }

/* Utilities */
.pre { white-space: pre-wrap; }

/* Scrollbar */
.chat::-webkit-scrollbar { width: 10px; }
.chat::-webkit-scrollbar-thumb { background: #d1d5db; border-radius: 8px; }
.chat::-webkit-scrollbar-track { background: #f3f4f6; }

/* Responsive */
@media (max-width: 720px) {
  .container { padding: 12px; }
  nav a.button { margin: 6px 4px 0 0; display: inline-flex; }
  textarea { min-height: 70px; }
}