:root {
  --bg-0: #071225;
  --bg-1: #0d1d34;
  --panel: rgba(10, 18, 30, 0.9);
  --panel-alt: rgba(17, 28, 44, 0.96);
  --line: rgba(255,255,255,0.08);
  --text: #edf5ff;
  --muted: #a8bfdc;
  --user: linear-gradient(135deg, #2563eb, #1d4ed8);
  --assistant: rgba(255,255,255,0.06);
  --accent-1: #14b8a6;
  --accent-2: #0ea5e9;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  font-family: Tahoma, Arial, sans-serif;
  background: radial-gradient(circle at top, #0d1d34 0%, #071225 42%, #030811 100%);
  color: var(--text);
}

body.chat-page-body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 26px 12px;
}

.chat-page-shell {
  width: min(980px, 100%);
  min-height: min(84vh, 760px);
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: rgba(7, 13, 24, 0.88);
  box-shadow: 0 24px 60px rgba(0,0,0,0.38);
  overflow: hidden;
  backdrop-filter: blur(10px);
}

.chat-page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
  background: rgba(16, 24, 38, 0.9);
}

.chat-page-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.chat-page-badge {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-size: 20px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
}

.chat-page-brand strong {
  display: block;
  font-size: 17px;
}

.chat-page-brand span {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-top: 2px;
}

.chat-page-header a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 14px;
  border-radius: 12px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  color: var(--text);
  text-decoration: none;
  font-size: 13px;
}

.chat-page-panel {
  display: flex;
  flex: 1;
  flex-direction: column;
  min-height: 0;
}

.chat-page-messages {
  flex: 1;
  overflow-y: auto;
  padding: 18px 18px 10px;
  background: linear-gradient(180deg, rgba(9, 13, 22, 0.96), rgba(7, 13, 24, 0.96));
}

.chat-message {
  display: flex;
  margin-bottom: 14px;
}

.chat-message.user { justify-content: flex-end; }
.chat-message.assistant { justify-content: flex-start; }

.chat-bubble-wrap {
  max-width: min(80%, 620px);
}

.chat-bubble {
  padding: 12px 14px;
  border-radius: 16px;
  line-height: 1.8;
  font-size: 14px;
  white-space: pre-wrap;
  word-break: break-word;
}

.chat-message.user .chat-bubble {
  background: var(--user);
  color: #fff;
  border-bottom-left-radius: 4px;
}

.chat-message.assistant .chat-bubble {
  border: 1px solid var(--line);
  background: var(--assistant);
  color: var(--text);
  border-bottom-right-radius: 4px;
}

.chat-message-meta {
  margin-top: 6px;
  font-size: 11px;
  line-height: 1.6;
  color: rgba(232, 239, 255, 0.7);
  text-align: left;
  padding: 0 4px;
}

.chat-message.user .chat-message-meta {
  text-align: right;
}

.chat-page-compose {
  display: flex;
  gap: 10px;
  padding: 16px 18px 18px;
  border-top: 1px solid var(--line);
  background: rgba(12, 18, 30, 0.96);
}

.chat-page-compose textarea {
  flex: 1;
  min-height: 54px;
  max-height: 150px;
  resize: vertical;
  border-radius: 14px;
  border: 1px solid var(--line);
  padding: 12px 14px;
  background: rgba(255,255,255,0.04);
  color: var(--text);
  font-size: 14px;
  font-family: Tahoma, Arial, sans-serif;
}

.chat-page-compose textarea::placeholder {
  color: rgba(232,239,255,0.58);
}

.chat-page-compose button {
  min-width: 120px;
  border: 0;
  border-radius: 14px;
  font-size: 14px;
  font-weight: 700;
  color: white;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  cursor: pointer;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.chat-page-compose button:hover { transform: translateY(-1px); }
.chat-page-compose button:disabled { opacity: 0.7; cursor: wait; }

/* حالت مستقل صفحه چت: منوی اصلی سایت و فوتر نمایش داده نمی‌شوند. */
body.chat-page-body {
  min-height: 100vh;
  padding: 18px;
}

body.chat-page-body > .topbar,
body.chat-page-body > footer {
  display: none !important;
}

body.chat-page-body > main {
  width: 100%;
  max-width: none;
  margin: 0;
  min-height: calc(100vh - 36px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.chat-home-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 14px;
  border-radius: 12px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  color: var(--text);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: .2s ease;
}

.chat-home-link:hover {
  background: rgba(255,255,255,0.08);
  transform: translateY(-1px);
}

@media (max-width: 600px) {
  body.chat-page-body { padding: 10px; }
  body.chat-page-body > main { min-height: calc(100vh - 20px); }
  .chat-page-header { padding: 12px 14px; }
  .chat-page-brand strong { font-size: 15px; }
  .chat-page-header a { padding: 8px 11px; font-size: 12px; }
  .chat-page-compose { flex-direction: column; }
  .chat-page-compose button { min-width: 100%; height: 46px; }
  .chat-bubble { max-width: 90%; }
}