:root {
  --bg: #faf8f5;
  --panel: #f1ede6;
  --text: #2a2622;
  --muted: #776f66;
  --border: #ddd5c9;
  --accent: #3f6b5a;
  --accent-text: #ffffff;
  --user-bubble: #e4ece8;
  --assistant-bubble: #ffffff;
  --danger: #a33b2b;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1d1b19;
    --panel: #262320;
    --text: #ece6de;
    --muted: #a39a8f;
    --border: #3a3631;
    --accent: #7fb39d;
    --accent-text: #102019;
    --user-bubble: #2c3a34;
    --assistant-bubble: #2a2724;
    --danger: #e0806f;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

button, input, select, textarea { font: inherit; color: inherit; }

button {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 12px;
  cursor: pointer;
}
button:hover { border-color: var(--muted); }
button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-text);
}
button.icon { border: none; font-size: 22px; padding: 2px 8px; line-height: 1; }
button:disabled { opacity: .5; cursor: default; }

#app { display: flex; height: 100%; }

/* Sidebar */
#sidebar {
  width: 280px;
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 12px;
  gap: 12px;
}
.side-head { display: flex; align-items: center; justify-content: space-between; }
.side-head h1 { font-size: 20px; margin: 0; }
.new-buttons { display: flex; flex-direction: column; gap: 8px; }
.new-buttons button { white-space: nowrap; }

#conv-list {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-y: auto;
  flex: 1;
}
#conv-list li {
  padding: 8px 10px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
}
#conv-list li:hover { background: var(--bg); }
#conv-list li.active { background: var(--bg); outline: 1px solid var(--border); }
#conv-list .conv-title { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#conv-list .conv-meta { font-size: 12px; color: var(--muted); }

.side-foot { display: flex; flex-direction: column; gap: 8px; }
.sync-row { display: flex; align-items: center; gap: 8px; }
#sync-status { font-size: 12px; color: var(--muted); }
#sync-status.error { color: var(--danger); }

/* Main */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}
#chat-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  min-height: 52px;
}
#chat-title { flex: 1; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#lang-wrap { display: flex; align-items: center; gap: 6px; font-size: 14px; color: var(--muted); }
#lang-wrap select {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px;
}

#messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.msg {
  max-width: 760px;
  width: fit-content;
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  overflow-wrap: anywhere;
}
.msg.user { background: var(--user-bubble); align-self: flex-end; white-space: pre-wrap; }
.msg.assistant { background: var(--assistant-bubble); align-self: flex-start; }
.msg.assistant p:first-child { margin-top: 0; }
.msg.assistant p:last-child { margin-bottom: 0; }
.msg.error { border-color: var(--danger); color: var(--danger); }
.retry { align-self: flex-start; }
.msg.info { align-self: center; font-size: 13px; color: var(--muted); background: transparent; }
.msg-actions { margin-top: 6px; display: flex; gap: 6px; }
.msg-actions button { font-size: 12px; padding: 2px 8px; color: var(--muted); }

.welcome {
  margin: auto;
  max-width: 480px;
  text-align: center;
  color: var(--muted);
}
.welcome .new-buttons { flex-direction: row; justify-content: center; margin-top: 16px; }

#composer {
  border-top: 1px solid var(--border);
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
#input {
  width: 100%;
  resize: vertical;
  min-height: 60px;
  max-height: 50vh;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--assistant-bubble);
}
.composer-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* Settings dialog */
dialog {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg);
  color: var(--text);
  width: min(480px, calc(100vw - 32px));
  padding: 20px;
}
dialog::backdrop { background: rgba(0, 0, 0, .4); }
dialog h2 { margin-top: 0; }
dialog label { display: flex; flex-direction: column; gap: 4px; margin-bottom: 12px; font-size: 14px; }
dialog input {
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--assistant-bubble);
}
dialog fieldset { border: 1px solid var(--border); border-radius: 8px; margin: 0 0 12px; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; }

.only-mobile { display: none; }

@media (max-width: 720px) {
  .only-mobile { display: inline-block; }
  #sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 10;
    transform: translateX(-100%);
    transition: transform .2s;
  }
  #sidebar.open { transform: none; box-shadow: 0 0 24px rgba(0, 0, 0, .25); }
  #chat-head { padding: 8px 12px; gap: 8px; }
  #messages, #composer { padding-left: 12px; padding-right: 12px; }
}