:root {
  --bg: #f5f3ee;
  --panel: #ffffff;
  --ink: #1a1a1a;
  --ink-muted: #6b6b6b;
  --accent: #2e5b8a;
  --accent-ink: #ffffff;
  --bubble-user: #2e5b8a;
  --bubble-user-ink: #ffffff;
  --bubble-assistant: #ececec;
  --bubble-assistant-ink: #1a1a1a;
  --border: #e2ddd2;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

.chat {
  display: flex;
  flex-direction: column;
  max-width: 720px;
  margin: 0 auto;
  height: 100vh;
  background: var(--panel);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}

.chat__header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.chat__header h1 {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.chat__subtitle {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--ink-muted);
}

.chat__messages {
  flex: 1;
  overflow-y: auto;
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.message {
  max-width: 78%;
  padding: 10px 14px;
  border-radius: 16px;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-size: 15px;
}

.message--user {
  align-self: flex-end;
  background: var(--bubble-user);
  color: var(--bubble-user-ink);
  border-bottom-right-radius: 4px;
}

.message--assistant {
  align-self: flex-start;
  background: var(--bubble-assistant);
  color: var(--bubble-assistant-ink);
  border-bottom-left-radius: 4px;
}

.message--typing {
  display: inline-flex;
  gap: 4px;
  align-items: center;
}

.message--typing span {
  width: 6px;
  height: 6px;
  background: var(--ink-muted);
  border-radius: 50%;
  opacity: 0.4;
  animation: typing 1.2s infinite ease-in-out;
}

.message--typing span:nth-child(2) { animation-delay: 0.15s; }
.message--typing span:nth-child(3) { animation-delay: 0.3s; }

@keyframes typing {
  0%, 80%, 100% { opacity: 0.3; transform: translateY(0); }
  40% { opacity: 1; transform: translateY(-2px); }
}

.chat__composer {
  display: flex;
  gap: 10px;
  padding: 14px 16px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}

.chat__input {
  flex: 1;
  padding: 11px 14px;
  font-size: 15px;
  border: 1px solid var(--border);
  border-radius: 22px;
  outline: none;
  background: var(--panel);
  color: var(--ink);
}

.chat__input:focus {
  border-color: var(--accent);
}

.chat__send {
  padding: 11px 22px;
  font-size: 15px;
  font-weight: 600;
  color: var(--accent-ink);
  background: var(--accent);
  border: none;
  border-radius: 22px;
  cursor: pointer;
}

.chat__send:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

@media (max-width: 720px) {
  .chat {
    border: none;
  }
  .message {
    max-width: 88%;
  }
}