:root {
  --bg: #0f1412;
  --bg-elevated: #171e1b;
  --panel: #1c2622;
  --ink: #e8f0ec;
  --muted: #9aada3;
  --line: #2a3832;
  --accent: #3d9b74;
  --accent-ink: #04150e;
  --danger: #c45b4a;
  --ok: #3d9b74;
  --font-display: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-body: "Segoe UI", "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(61, 155, 116, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(40, 70, 90, 0.25), transparent 50%),
    var(--bg);
}

.brand {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: 0.02em;
}

.auth-body { display: grid; place-items: center; min-height: 100vh; padding: 1.5rem; }
.auth-shell { width: min(420px, 100%); }
.auth-panel {
  background: linear-gradient(180deg, rgba(28, 38, 34, 0.96), rgba(18, 24, 21, 0.98));
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 2rem;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}
.auth-panel h1 {
  margin: 0.75rem 0 0.35rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.8rem;
}
.lede { margin: 0 0 1.25rem; color: var(--muted); line-height: 1.45; }
.auth-form { display: grid; gap: 0.9rem; }
label { display: grid; gap: 0.35rem; font-size: 0.9rem; color: var(--muted); }
input, textarea, button {
  font: inherit;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--bg-elevated);
  color: var(--ink);
}
input, textarea { padding: 0.75rem 0.85rem; width: 100%; }
button {
  cursor: pointer;
  padding: 0.8rem 1rem;
  background: var(--accent);
  color: var(--accent-ink);
  border: none;
  font-weight: 600;
}
button.ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.alert {
  margin-bottom: 1rem;
  padding: 0.75rem 0.9rem;
  border-radius: 10px;
  background: rgba(196, 91, 74, 0.15);
  border: 1px solid rgba(196, 91, 74, 0.4);
  color: #f0c2ba;
}

.app-body {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
}
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 1.25rem;
  border-right: 1px solid var(--line);
  background: rgba(12, 16, 14, 0.72);
  backdrop-filter: blur(10px);
}
.sidebar-top, .sidebar-bottom { display: grid; gap: 0.75rem; }
.session-list {
  display: grid;
  gap: 0.4rem;
  align-content: start;
  overflow: auto;
  flex: 1;
}
.session-item {
  text-align: left;
  background: transparent;
  color: var(--muted);
  border: 1px solid transparent;
  padding: 0.65rem 0.75rem;
}
.session-item:hover, .session-item.active {
  color: var(--ink);
  border-color: var(--line);
  background: var(--panel);
}
.user { margin: 0; color: var(--muted); font-size: 0.9rem; }
.status {
  font-size: 0.85rem;
  padding: 0.4rem 0.6rem;
  border-radius: 999px;
  width: fit-content;
  border: 1px solid var(--line);
}
.status.ok { color: var(--ok); }
.status.bad { color: var(--danger); }

.chat {
  display: grid;
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
}
.chat-header {
  padding: 1.5rem 1.75rem 0.75rem;
  border-bottom: 1px solid transparent;
}
.chat-header h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
}
.chat-header p { margin: 0.35rem 0 0; color: var(--muted); }
.messages {
  padding: 1rem 1.75rem 1.5rem;
  overflow: auto;
  display: grid;
  gap: 0.9rem;
  align-content: start;
}
.bubble {
  max-width: min(760px, 100%);
  padding: 0.9rem 1rem;
  border-radius: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
}
.bubble.user {
  justify-self: end;
  background: #24352e;
  border: 1px solid #355246;
}
.bubble.assistant {
  justify-self: start;
  background: var(--panel);
  border: 1px solid var(--line);
}
.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.75rem;
  padding: 1rem 1.75rem 1.5rem;
  border-top: 1px solid var(--line);
  background: rgba(12, 16, 14, 0.65);
}
.composer textarea { resize: vertical; min-height: 56px; }

@media (max-width: 860px) {
  .app-body { grid-template-columns: 1fr; }
  .sidebar { border-right: none; border-bottom: 1px solid var(--line); max-height: 40vh; }
}