* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0f1115;
  --panel: #181b22;
  --user: #2563eb;
  --assistant: #1f2330;
  --text: #e7e9ee;
  --muted: #8b93a7;
  --border: #2a2f3b;
  --code-bg: #0a0c10;
  --danger: #ef4444;
  --brand: #D97757;
}
html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}
.app {
  display: flex;
  height: 100dvh;
  padding-bottom: env(safe-area-inset-bottom);
}

/* Sidebar */
.sidebar {
  width: 260px; flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow: hidden;
}
.sidebar-head {
  display: flex; gap: 8px; align-items: center;
  padding: 12px;
  border-bottom: 1px solid var(--border);
}
.sidebar-head .ghost { flex: 1; justify-content: flex-start; }
.conv-list {
  flex: 1; overflow-y: auto; padding: 8px;
  display: flex; flex-direction: column; gap: 2px;
}
.conv-item {
  display: flex; align-items: center; gap: 8px;
  padding: 9px 10px; border-radius: 8px;
  font-size: 14px; color: var(--text);
  cursor: pointer; border: 1px solid transparent;
  background: transparent;
  text-align: left;
}
.conv-item:hover { background: var(--assistant); }
.conv-item.active { background: var(--assistant); border-color: var(--border); }
.conv-item .conv-title-text {
  flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.conv-item .del {
  opacity: 0; background: transparent; border: none; color: var(--muted);
  cursor: pointer; padding: 2px 6px; border-radius: 4px;
  font-size: 16px;
}
.conv-item:hover .del { opacity: 1; }
.conv-item .del:hover { background: var(--danger); color: #fff; }

.main {
  flex: 1; display: flex; flex-direction: column;
  min-width: 0; max-width: 820px; margin: 0 auto; width: 100%;
}

header {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
header .title { flex: 1; min-width: 0; }
header .title #conv-title {
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  display: inline-block; max-width: 100%;
}
.title { display: flex; align-items: center; gap: 8px; font-weight: 600; font-size: 15px; }
.logo { display: block; flex-shrink: 0; height: 22px; width: auto; image-rendering: pixelated; }
.logo-lg { display: block; height: 72px; margin: 0 auto 16px; }

button.ghost {
  background: transparent; color: var(--text);
  border: 1px solid var(--border); border-radius: 10px;
  cursor: pointer; font-size: 14px;
  padding: 8px 12px;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
}
button.ghost:hover { background: var(--assistant); }
header button.ghost { width: 36px; height: 36px; padding: 0; font-size: 18px; }

/* Settings panel */
.settings {
  border-bottom: 1px solid var(--border);
  padding: 14px 16px;
  display: flex; flex-direction: column; gap: 12px;
  background: var(--panel);
}
.settings.hidden { display: none; }
.settings label {
  display: flex; flex-direction: column; gap: 6px;
  font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px;
}
.settings select, .settings textarea {
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 8px 10px;
  font: inherit; font-size: 14px; text-transform: none; letter-spacing: 0;
}
.settings textarea { resize: vertical; min-height: 70px; }
.settings .primary {
  align-self: flex-start;
  background: var(--user); color: #fff; border: none;
  padding: 8px 18px; border-radius: 8px; cursor: pointer; font: inherit; font-weight: 500;
}

/* Messages */
.messages {
  flex: 1; overflow-y: auto;
  padding: 16px; display: flex; flex-direction: column; gap: 14px;
  scroll-behavior: smooth;
}
.empty { margin: auto; text-align: center; color: var(--muted); padding: 32px 16px; }
.empty h2 { color: var(--text); font-size: 22px; margin-bottom: 8px; font-weight: 600; }
.empty p { font-size: 14px; }
.msg {
  padding: 12px 16px;
  border-radius: 14px;
  max-width: 88%;
  word-wrap: break-word;
  overflow-wrap: break-word;
}
.msg.user {
  background: var(--user); color: #fff;
  align-self: flex-end; border-bottom-right-radius: 4px;
  white-space: pre-wrap;
}
.msg.assistant {
  background: var(--assistant);
  align-self: flex-start; border-bottom-left-radius: 4px;
}
.msg.assistant.streaming::after {
  content: '▍'; opacity: .6; margin-left: 2px;
  animation: blink 1s steps(2, start) infinite;
}
@keyframes blink { to { visibility: hidden; } }
.msg p { margin: 0 0 8px; }
.msg p:last-child { margin: 0; }
.msg ul, .msg ol { margin: 6px 0 6px 22px; }
.msg pre {
  background: var(--code-bg); padding: 12px; border-radius: 10px;
  overflow-x: auto; margin: 8px 0;
  border: 1px solid var(--border);
  font-size: 13px; line-height: 1.5;
}
.msg code { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; }
.msg :not(pre) > code {
  background: var(--code-bg); padding: 2px 6px; border-radius: 4px; font-size: 90%;
}
.msg.error { background: #3b1d1d; color: #fca5a5; border: 1px solid #7f1d1d; }

/* Input */
.input-row {
  display: flex; gap: 8px; align-items: flex-end;
  padding: 12px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}
textarea {
  flex: 1;
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 14px;
  padding: 12px 14px;
  resize: none; font: inherit;
  max-height: 200px;
  -webkit-appearance: none;
}
textarea:focus { outline: none; border-color: var(--user); }
#send {
  background: var(--user); color: #fff;
  border: none; border-radius: 12px;
  width: 44px; height: 44px;
  font-size: 20px; cursor: pointer;
  flex-shrink: 0;
  transition: background .15s;
}
#send:disabled { opacity: .5; cursor: not-allowed; }
#send.stop { background: var(--danger); }

/* Mobile */
.mobile-only { display: none; }
@media (max-width: 720px) {
  .sidebar {
    position: fixed; left: 0; top: 0; bottom: 0;
    z-index: 50; transform: translateX(-100%);
    transition: transform .2s ease;
    box-shadow: 4px 0 24px rgba(0,0,0,.5);
  }
  .sidebar.open { transform: translateX(0); }
  .mobile-only { display: inline-flex; }
  .main { max-width: 100%; }
}