:root {
  /* Тёплая бумага + лесной акцент: спокойно читать длинные вопросы,
     без «фиолетового AI» и без холодного серого SaaS. */
  --bg: #f3efe6;
  --ink: #1c2420;
  --muted: #5c675f;
  --card: #fffdf8;
  --line: #d7d0c3;
  --accent: #2f5d50;
  --accent-ink: #f7fff9;
  --assist: #e7f0eb;
  --user: #fff7e8;
  --error: #8b2e2e;
  --info: #265c48;
  --shadow: 0 10px 40px rgba(28, 36, 32, 0.08);
  --col: min(640px, calc(100% - 32px));
  font-family: "Segoe UI", "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(47,93,80,.12), transparent 40%),
    linear-gradient(180deg, #f7f2e8, var(--bg));
  min-height: 100vh;
}

.auth {
  display: grid;
  place-items: center;
  padding: 24px;
}

.card {
  width: min(440px, 100%);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 28px;
  box-shadow: var(--shadow);
}

h1, h2 { margin: 0 0 8px; letter-spacing: -0.02em; }
.lead, .muted { color: var(--muted); }
.stack { display: grid; gap: 14px; margin-top: 18px; }
label { display: grid; gap: 6px; font-size: 14px; }
input[type="email"], input[type="text"] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  font: inherit;
  background: #fff;
}
button, .ghost {
  border: 0;
  border-radius: 12px;
  padding: 12px 16px;
  font: inherit;
  cursor: pointer;
  background: var(--accent);
  color: var(--accent-ink);
  text-decoration: none;
}
.ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.error { color: var(--error); }
.info { color: var(--info); }

.app {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: 100vh;
}

.top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  background: rgba(255,253,248,.9);
  backdrop-filter: blur(8px);
}
.top-actions { display: flex; gap: 8px; align-items: center; }

.chat {
  overflow: auto;
  padding: 28px 16px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
}
.chat.busy {
  opacity: 0.72;
  transition: opacity 0.15s ease;
}

.bubble {
  width: var(--col);
  max-width: var(--col);
  padding: 18px 22px;
  border-radius: 18px;
  border: 1px solid var(--line);
  white-space: pre-wrap;
  line-height: 1.55;
  text-align: center;
  box-shadow: var(--shadow);
}
.bubble.assist,
.bubble.step {
  background: var(--assist);
  font-size: 1.05rem;
}
.bubble.user,
.bubble.answer {
  background: var(--user);
  font-size: 0.98rem;
  color: var(--ink);
}
.bubble.answer::before {
  content: 'Твой ответ';
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 8px;
}

.composer {
  border-top: 1px solid var(--line);
  background: rgba(255,253,248,.95);
  padding: 14px 16px 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.composer-inner {
  width: var(--col);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.composer.buttons-only .row {
  display: none;
}
.composer.buttons-only .buttons {
  margin-bottom: 0;
}
.buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}
.buttons button {
  background: #fff;
  color: var(--ink);
  border: 1px solid var(--line);
}
.row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  width: 100%;
}

.paywall {
  margin: 16px auto 0;
  width: var(--col);
  text-align: center;
}

@media (max-width: 640px) {
  .top { flex-direction: column; align-items: flex-start; }
  .bubble { padding: 16px 18px; }
}