:root {
  --bg: #101418;
  --panel: #1a2028;
  --panel-2: #232b36;
  --border: #2e3946;
  --text: #e6edf3;
  --text-dim: #9aa7b4;
  --accent: #4f8cff;
  --danger: #e5534b;
  --focus: #ffd166;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #000;
  padding: 8px 12px;
  z-index: 100;
}
.skip-link:focus { left: 8px; top: 8px; }

button, input, textarea, select {
  font: inherit;
  color: inherit;
}
button {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 14px;
  cursor: pointer;
}
button:hover { border-color: var(--accent); }
button.danger { background: var(--danger); border-color: var(--danger); color: #fff; }
.link-btn {
  background: none; border: none; color: var(--accent);
  padding: 2px; text-decoration: underline;
}
input, textarea, select {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 9px 12px;
  width: 100%;
}
textarea { resize: vertical; min-height: 44px; }

/* auth */
.auth {
  max-width: 380px;
  margin: 12vh auto 0;
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.form { display: flex; flex-direction: column; gap: 8px; }
.form label { font-size: 0.9rem; color: var(--text-dim); }
.form button[type="submit"] { background: var(--accent); border-color: var(--accent); color: #000; font-weight: 600; margin-top: 6px; }
.auth-alt { font-size: 0.9rem; color: var(--text-dim); }
.auth-alt button { background: none; border: none; color: var(--accent); padding: 0; text-decoration: underline; }
.error { color: var(--danger); }

/* app layout */
.topbar {
  display: flex; align-items: center; gap: 16px;
  padding: 10px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}
.topbar h1 { font-size: 1.1rem; margin: 0; flex: 0 0 auto; }
.provider-picker { display: flex; align-items: center; gap: 14px; flex: 1; flex-wrap: wrap; }
.provider-picker .picker-field { display: flex; align-items: center; gap: 6px; }
.provider-picker label { color: var(--text-dim); font-size: 0.9rem; white-space: nowrap; }
.provider-picker select { width: auto; min-width: 180px; }
.topbar-actions { display: flex; gap: 8px; align-items: center; }
.balance { color: var(--text-dim); font-size: 0.85rem; white-space: nowrap; }
.balance #balance-value { color: var(--text); font-variant-numeric: tabular-nums; }

.layout { display: flex; height: calc(100vh - 57px); }

#sidebar {
  width: 240px;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 12px;
  overflow-y: auto;
}
#sidebar button { width: 100%; margin-bottom: 10px; }
#chat-list { list-style: none; margin: 0; padding: 0; }
#chat-list li { margin-bottom: 2px; }
#chat-list .chat-item {
  display: flex; align-items: center; gap: 6px;
  width: 100%; text-align: left;
  background: none; border: none;
  padding: 8px 10px; border-radius: 6px;
  color: var(--text);
}
#chat-list .chat-item:hover, #chat-list .chat-item[aria-current="true"] {
  background: var(--panel-2);
}
#chat-list .chat-title { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#chat-list .chat-del {
  background: none; border: none; color: var(--text-dim);
  padding: 2px 6px; font-size: 0.9rem;
}
#chat-list .chat-del:hover { color: var(--danger); }

#main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

#message-log {
  flex: 1; overflow-y: auto;
  padding: 20px 24px;
  display: flex; flex-direction: column; gap: 18px;
}
#message-log:focus { outline: none; }

.msg { max-width: 78%; display: flex; flex-direction: column; }
.msg.user { align-self: flex-end; }
.msg.assistant { align-self: flex-start; }
.msg .bubble {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 16px;
  overflow-wrap: anywhere;
}
.msg.user .bubble { background: var(--accent); color: #000; }
.msg .msg-role { font-size: 0.75rem; color: var(--text-dim); margin-bottom: 2px; }
.msg .msg-heading {
  margin: 0 0 6px;
  font-size: 1.05em;
  font-weight: 700;
  line-height: 1.3;
}
.msg.user .msg-heading { color: #000; }
.msg .copy-btn {
  align-self: flex-start;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 0.78rem;
  padding: 2px 4px;
  margin-top: 4px;
  cursor: pointer;
  text-decoration: underline;
}
.msg.user .copy-btn { align-self: flex-end; }
.msg .copy-btn:hover { color: var(--accent); }

.msg-content > :first-child { margin-top: 0; }
.msg-content > :last-child { margin-bottom: 0; }
.msg-content p { margin: 0 0 8px; white-space: pre-wrap; }
.msg-content h1, .msg-content h2, .msg-content h3, .msg-content h4 {
  margin: 14px 0 6px; font-size: 1.05em; font-weight: 700; line-height: 1.3;
}
.msg-content h1 { font-size: 1.2em; }
.msg-content ul, .msg-content ol { margin: 0 0 8px; padding-left: 20px; }
.msg-content li { margin: 2px 0; white-space: pre-wrap; }
.msg-content code {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
}
.msg-content pre {
  background: #0d1117;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  overflow-x: auto;
  margin: 0 0 8px;
}
.msg-content pre code { background: none; border: none; padding: 0; }
.msg-content blockquote {
  margin: 0 0 8px;
  padding: 2px 12px;
  border-left: 3px solid var(--accent);
  color: var(--text-dim);
}
.msg-content a { color: var(--accent); }
.msg.user .msg-content a { color: #00205c; }
.msg.user .msg-content code { background: rgba(0,0,0,0.12); border-color: rgba(0,0,0,0.2); }

.reasoning {
  margin-bottom: 10px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  background: var(--panel-2);
}
.reasoning summary {
  padding: 8px 12px;
  cursor: pointer;
  color: var(--text-dim);
  font-size: 0.85rem;
}
.reasoning .reasoning-body {
  padding: 8px 12px;
  white-space: pre-wrap;
  color: var(--text-dim);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

.composer-wrap { padding: 12px 16px 16px; border-top: 1px solid var(--border); background: var(--panel); }
#composer-form { display: flex; gap: 8px; align-items: flex-end; }
.composer-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 6px; }
.composer-meta-left { display: flex; align-items: center; gap: 12px; }
.hint { margin: 0; font-size: 0.78rem; color: var(--text-dim); }
.attach-wrap { display: inline-flex; }
.attach-btn {
  display: inline-block;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  color: var(--text-dim);
  font-size: 0.85rem;
  cursor: pointer;
}
.attach-btn:hover { border-color: var(--accent); color: var(--text); }
.attach-wrap:focus-within .attach-btn { outline: 3px solid var(--focus); outline-offset: 2px; }

/* dialogs */
.dialog-backdrop {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex; align-items: center; justify-content: center;
  z-index: 50;
}
.dialog {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  width: 100%;
  max-width: 440px;
}
.dialog h2 { margin: 0 0 10px; font-size: 1.05rem; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 16px; }

/* image generation */
.image-controls { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 8px; }
.img-ctrl { display: flex; align-items: center; gap: 6px; }
.img-ctrl label { color: var(--text-dim); font-size: 0.9rem; white-space: nowrap; }
.img-ctrl select { width: auto; min-width: 130px; }
.img-wrap { margin: 4px 0 8px; }
.img-wrap img {
  max-width: 100%; display: block;
  border: 1px solid var(--border); border-radius: 8px;
}
.img-download {
  display: inline-block; margin-top: 6px;
  color: var(--accent); text-decoration: underline; font-size: 0.9rem;
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}