:root {
  color-scheme: light dark;
  --bg: #101214;
  --panel: #1b2025;
  --panel-2: #252c33;
  --text: #f6f1e8;
  --muted: #a8b0b7;
  --accent: #59c7a4;
  --border: #343d46;
  --danger: #ff8a80;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  min-height: 100vh;
  background:
    linear-gradient(135deg, rgba(89, 199, 164, 0.16), transparent 32%),
    linear-gradient(315deg, rgba(255, 199, 87, 0.10), transparent 38%),
    var(--bg);
  color: var(--text);
}
button, input, textarea { font: inherit; }
button {
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #061310;
  cursor: pointer;
  font-weight: 800;
}
button:disabled { cursor: wait; opacity: 0.65; }
.zki-shell {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 24px;
}
.zki-login, .zki-chat {
  width: min(100%, 960px);
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(27, 32, 37, 0.95);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.3);
}
.zki-login {
  max-width: 520px;
  padding: 34px;
}
.zki-chat {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: min(820px, calc(100vh - 48px));
  overflow: hidden;
}
.zki-chat header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--border);
  padding: 18px 20px;
}
.actions {
  display: flex;
  gap: 8px;
}
.actions button {
  background: var(--panel-2);
  color: var(--text);
  min-height: 38px;
  padding: 0 12px;
}
.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}
h1 {
  margin: 0;
  color: var(--text);
  font-size: 30px;
  letter-spacing: 0;
}
.muted {
  margin: 10px 0 24px;
  color: var(--muted);
  line-height: 1.5;
}
label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
}
.login-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}
input, textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #101417;
  color: var(--text);
  outline: none;
}
input {
  min-height: 44px;
  padding: 10px 12px;
}
.login-row button, .composer button {
  min-height: 44px;
  padding: 0 16px;
}
.error {
  min-height: 22px;
  color: var(--danger);
}
.messages {
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow-y: auto;
  padding: 20px;
}
.message {
  max-width: min(78ch, 88%);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
  line-height: 1.48;
  white-space: pre-wrap;
}
.message.user {
  align-self: flex-end;
  border-color: rgba(89, 199, 164, 0.55);
  background: rgba(89, 199, 164, 0.12);
}
.message.assistant {
  align-self: flex-start;
  background: var(--panel-2);
}
.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  border-top: 1px solid var(--border);
  padding: 14px;
}
textarea {
  max-height: 180px;
  min-height: 46px;
  resize: none;
  padding: 12px;
  line-height: 1.4;
}
@media (max-width: 640px) {
  .zki-shell { padding: 0; }
  .zki-login, .zki-chat {
    width: 100%;
    min-height: 100vh;
    border: 0;
    border-radius: 0;
  }
  .zki-chat header {
    align-items: flex-start;
    flex-direction: column;
  }
  .login-row, .composer {
    grid-template-columns: 1fr;
  }
  .message {
    max-width: 100%;
  }
}