*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }
.cursor { animation: blink 1s step-start infinite; }

:root {
  --bg: #f5f0e8;
  --surface: #ede6d9;
  --border: #d6cbbe;
  --text: #3b2f24;
  --text-muted: #9e8e7e;
  --accent: #8b6347;
  --user-bubble: #e2d5c3;
  --bot-bubble: #faf6f0;
  --radius: 16px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

html, body { height: 100%; background: var(--bg); color: var(--text); font-family: var(--font); }

.layout {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  max-width: 720px;
  margin: 0 auto;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.logo {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--accent);
}

.reset-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 12px;
  padding: 5px 12px;
  border-radius: 20px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
}
.reset-btn:hover { color: var(--text); border-color: #444; }

.messages {
  flex: 1;
  overflow-y: auto;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message { display: flex; }
.message.user { justify-content: flex-end; }
.message.bot  { justify-content: flex-start; }

.bubble {
  max-width: 80%;
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 15px;
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
}

.message.user .bubble {
  background: var(--user-bubble);
  border: 1px solid #c9b99e;
  border-bottom-right-radius: 4px;
}

.message.bot .bubble {
  background: var(--bot-bubble);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
  color: var(--text);
}

.input-bar {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  padding: 14px 20px;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

textarea {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 14px;
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.5;
  resize: none;
  outline: none;
  transition: border-color 0.2s;
  min-height: 42px;
  max-height: 160px;
}
textarea:focus { border-color: var(--accent); }
textarea::placeholder { color: var(--text-muted); }

button[type="submit"] {
  background: var(--accent);
  border: none;
  color: white;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  font-size: 18px;
  cursor: pointer;
  flex-shrink: 0;
  transition: opacity 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}
button[type="submit"]:hover { opacity: 0.85; }

/* Scrollbar */
.messages::-webkit-scrollbar { width: 4px; }
.messages::-webkit-scrollbar-track { background: transparent; }
.messages::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

@media (max-width: 480px) {
  .bubble { max-width: 92%; font-size: 14px; }
  header, .messages, .input-bar { padding-left: 14px; padding-right: 14px; }
}