:root {
  --bg: #111315;
  --fg: #e3e6e8;
  --muted: #9da4aa;
  --panel: #1a1d20;
  --line: #2c3136;
  --accent: #3d8a6b;
  --accent-fg: #f4faf7;
  --ease-smooth: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast: 640ms;
  --dur-mid: 1040ms;
  --dur-slow: 1520ms;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: var(--fg);
  background: radial-gradient(circle at 10% 10%, #1a1d20, var(--bg));
}

.shell {
  min-height: 100vh;
  padding: 56px 24px 80px;
}

.hero {
  max-width: 760px;
  margin: 0 auto;
  text-align: left;
}

h1 {
  font-size: clamp(1.8rem, 3.2vw, 2.8rem);
  line-height: 1.2;
  margin: 0 0 24px;
}

h1 span {
  display: block;
  white-space: nowrap;
}

.primary,
.ghost {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 16px;
  cursor: pointer;
  font: inherit;
  transition:
    background-color var(--dur-mid) var(--ease-smooth),
    border-color var(--dur-mid) var(--ease-smooth),
    color var(--dur-mid) var(--ease-smooth),
    filter var(--dur-mid) var(--ease-smooth),
    transform var(--dur-fast) var(--ease-smooth);
}

.primary {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}

.primary:hover {
  filter: brightness(1.05);
}

.ghost {
  background: transparent;
  color: var(--fg);
}

.contacts {
  margin-top: 20px;
  display: flex;
  justify-content: flex-start;
  gap: 12px;
  flex-wrap: wrap;
}

.contacts a {
  color: #c8ced3;
  transition: color var(--dur-mid) var(--ease-smooth);
}

.chat-inline {
  width: 100%;
  margin-top: 18px;
  display: block;
  opacity: 0;
  transform: translateY(8px);
  max-height: 0;
  visibility: hidden;
  overflow: hidden;
  pointer-events: none;
  transition:
    opacity var(--dur-mid) var(--ease-smooth),
    transform calc(var(--dur-mid) + 120ms) var(--ease-smooth),
    max-height calc(var(--dur-slow) + 60ms) var(--ease-smooth),
    visibility 0ms linear calc(var(--dur-slow) + 60ms);
}

.chat-inline.open {
  opacity: 1;
  transform: translateY(0);
  max-height: 3000px;
  visibility: visible;
  pointer-events: auto;
  transition:
    opacity var(--dur-mid) var(--ease-smooth),
    transform calc(var(--dur-mid) + 120ms) var(--ease-smooth),
    max-height calc(var(--dur-slow) + 60ms) var(--ease-smooth),
    visibility 0ms;
}

.starter-prompts {
  padding: 10px 0;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.prompt-chip {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  background: #171a1d;
  color: var(--fg);
  cursor: pointer;
  font-size: 0.85rem;
  transition:
    background-color var(--dur-mid) var(--ease-smooth),
    border-color var(--dur-mid) var(--ease-smooth),
    color var(--dur-mid) var(--ease-smooth),
    transform var(--dur-fast) var(--ease-smooth);
}

.prompt-chip:hover {
  background: #1d2125;
  transform: translateY(-1px);
}

.messages {
  padding: 6px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.msg {
  padding: 10px 12px;
  border-radius: 12px;
  max-width: 90%;
  white-space: pre-wrap;
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity var(--dur-mid) var(--ease-smooth),
    transform calc(var(--dur-mid) + 120ms) var(--ease-smooth);
}

.msg.show {
  opacity: 1;
  transform: translateY(0);
}

.msg.user {
  align-self: flex-end;
  background: #23292e;
  transition-duration: var(--dur-mid), calc(var(--dur-mid) + 120ms);
}

.msg.ai {
  align-self: flex-start;
  background: #1f2327;
  transition-duration: var(--dur-slow), calc(var(--dur-slow) + 180ms);
}

.msg small {
  display: block;
  margin-top: 6px;
  color: var(--muted);
}

.chat-form {
  display: flex;
  gap: 8px;
  padding: 10px 0 0;
}

.chat-form input {
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font: inherit;
  color: var(--fg);
  background: #14171a;
}

.muted {
  color: var(--muted);
}

@media (max-width: 700px) {
  h1 {
    font-size: clamp(1.15rem, 4.2vw, 1.8rem);
  }

  .chat-form {
    flex-direction: column;
  }
}