:root {
  --bg: #0f172a;
  --panel: #111827;
  --soft: #1f2937;
  --muted: #94a3b8;
  --text: #f1f5f9;
  --accent: #22c55e;
  --danger: #ef4444;
  --border: #334155;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Inter, Segoe UI, Arial, sans-serif;
  background: radial-gradient(circle at top, #1e293b, #020617 55%);
  color: var(--text);
  min-height: 100vh;
}

.app-shell {
  width: min(1100px, 94vw);
  margin: 24px auto;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
}

h1, h2, h3, p {
  margin: 0;
}

.subtitle {
  color: var(--muted);
  margin-top: 6px;
}

.status-card {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 14px;
  line-height: 1.5;
}

.panel {
  border: 1px solid var(--border);
  background: rgba(2, 6, 23, 0.88);
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.auth-panel {
  width: min(420px, 95vw);
  margin: 40px auto;
  padding: 24px;
  display: grid;
  gap: 14px;
}

.form {
  display: grid;
  gap: 10px;
}

input, button {
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--soft);
  color: var(--text);
  padding: 11px 12px;
  font-size: 15px;
}

button {
  cursor: pointer;
  background: linear-gradient(90deg, #16a34a, #22c55e);
  color: #052e16;
  font-weight: 700;
  border: 0;
}

button:hover {
  filter: brightness(1.05);
}

.form-note {
  color: var(--muted);
  font-size: 13px;
}

.chat-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 14px;
}

.sidebar {
  padding: 16px;
}

.user-box {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: #16a34a;
  color: #052e16;
  display: grid;
  place-items: center;
  font-weight: 800;
}

.user-box p {
  color: var(--muted);
  font-size: 12px;
}

.room-list {
  list-style: none;
  padding: 0;
  margin: 12px 0 18px;
  display: grid;
  gap: 8px;
}

.room-btn {
  width: 100%;
  text-align: left;
  background: #0b1325;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
}

.room-btn span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 12px;
}

.room-btn.active {
  border-color: #22c55e;
  background: #042f1a;
}

.logout-btn {
  width: 100%;
  background: #1e293b;
  color: var(--text);
  border: 1px solid var(--border);
}

.chat-panel {
  padding: 14px;
  display: grid;
  grid-template-rows: auto 1fr auto auto;
  gap: 12px;
  min-height: 620px;
}

.chat-header {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
}

.chat-header h2 {
  color: var(--text);
}

.message-log {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
  overflow-y: auto;
}

.msg {
  background: #0b1325;
  border: 1px solid #223049;
  border-radius: 9px;
  margin-bottom: 8px;
  padding: 9px 10px;
}

.msg .meta {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  margin-bottom: 5px;
  font-size: 12px;
}

.msg p {
  margin: 0;
  line-height: 1.45;
  white-space: pre-wrap;
  word-break: break-word;
}

.message-form {
  display: grid;
  grid-template-columns: 1fr 120px;
  gap: 8px;
}

.error {
  color: var(--danger);
  font-size: 13px;
  min-height: 18px;
}

@media (max-width: 920px) {
  .chat-layout {
    grid-template-columns: 1fr;
  }
  .chat-panel {
    min-height: 520px;
  }
}