:root {
  --ink: #0e1a24;
  --ink-soft: #243447;
  --paper: #e8eef3;
  --paper-dim: #c5d0db;
  --signal: #c45c26;
  --signal-soft: #e8a37a;
  --line: rgba(14, 26, 36, 0.14);
  --glow: rgba(196, 92, 38, 0.18);
  --font-display: "Literata", Georgia, serif;
  --font-body: "IBM Plex Sans", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.5;
}

.atmosphere {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, var(--glow), transparent 55%),
    radial-gradient(ellipse 60% 40% at 90% 10%, rgba(36, 52, 71, 0.12), transparent 50%),
    linear-gradient(165deg, #f4f7fa 0%, #d9e3ec 45%, #cfd9e4 100%);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.1rem 1.5rem;
  border-bottom: 1px solid var(--line);
}

.brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav {
  display: flex;
  gap: 1.25rem;
}

.nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.95rem;
}

.nav a:hover {
  color: var(--signal);
}

.hero {
  max-width: 42rem;
  margin: 0 auto;
  padding: clamp(3rem, 12vh, 6rem) 1.5rem 2rem;
  animation: rise 0.7s ease-out both;
}

.brand-mark {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 7vw, 3.8rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 0 0 1rem;
  color: var(--ink);
}

.headline {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 1.15rem;
  margin: 0 0 0.6rem;
  color: var(--ink-soft);
}

.lede {
  margin: 0 0 2rem;
  color: var(--ink-soft);
  max-width: 36rem;
}

.ask-form textarea {
  width: 100%;
  resize: vertical;
  min-height: 6rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.55);
  color: var(--ink);
  font: inherit;
  font-size: 1.05rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ask-form textarea:focus {
  border-color: var(--signal);
  box-shadow: 0 0 0 3px var(--glow);
}

.ask-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: flex-end;
  margin-top: 1rem;
  justify-content: flex-end;
}

.cta {
  margin-left: auto;
  appearance: none;
  border: none;
  background: var(--ink);
  color: var(--paper);
  font: inherit;
  font-weight: 600;
  padding: 0.75rem 1.4rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

.cta:hover {
  background: var(--signal);
  transform: translateY(-1px);
}

.cta:disabled {
  opacity: 0.55;
  cursor: wait;
  transform: none;
}

.status {
  margin-top: 1rem;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.answer-panel {
  max-width: 42rem;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
  animation: rise 0.45s ease-out both;
}

.answer-panel h2,
.answer-panel h3 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.answer-body {
  white-space: pre-wrap;
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
}

.sources {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.source {
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--line);
  animation: rise 0.4s ease-out both;
}

.source .source-title {
  color: var(--ink);
  font-weight: 600;
  margin: 0;
}

.source .meta {
  font-size: 0.85rem;
  color: var(--ink-soft);
  margin: 0.25rem 0 0.5rem;
}

.source .excerpt {
  font-size: 0.92rem;
  color: var(--ink-soft);
}

.ghost {
  margin-top: 2rem;
  appearance: none;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  font: inherit;
  padding: 0.6rem 1rem;
  cursor: pointer;
}

.ghost:hover {
  border-color: var(--signal);
  color: var(--signal);
}

.nav-user {
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.nav-linkish {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-size: 0.95rem;
  cursor: pointer;
  padding: 0;
}

.nav-linkish:hover {
  color: var(--signal);
}

.auth-tabs {
  display: flex;
  gap: 1rem;
  margin: 1.5rem 0 0.5rem;
}

.auth-tab {
  appearance: none;
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  font: inherit;
  font-weight: 600;
  color: var(--ink-soft);
  padding: 0.35rem 0;
  cursor: pointer;
}

.auth-tab.active {
  color: var(--ink);
  border-bottom-color: var(--signal);
}

.auth-form label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 0.9rem;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

.auth-form input {
  font: inherit;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
}

.usage-line {
  margin: 0 0 1rem;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

.auth-footnote {
  margin-top: 1rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.results-split {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 2rem;
  margin-top: 1.5rem;
  align-items: start;
}

.results-col h3 {
  margin-top: 0;
}

.related-hint {
  margin: 0 0 0.85rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.related-topics {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.topic-chip {
  appearance: none;
  text-align: left;
  font: inherit;
  font-size: 0.95rem;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.45);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease, transform 0.15s ease;
}

.topic-chip:hover {
  border-color: var(--signal);
  color: var(--signal);
  transform: translateX(2px);
}

.answer-actions {
  margin: 1.25rem 0 0.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.action-chip {
  appearance: none;
  font: inherit;
  font-size: 0.9rem;
  padding: 0.55rem 0.85rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.55);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.action-chip:hover:not(:disabled) {
  border-color: var(--signal);
  color: var(--signal);
}

.action-chip:disabled {
  opacity: 0.5;
  cursor: wait;
}

.followup-form {
  margin-top: 1rem;
}

.followup-form textarea {
  width: 100%;
  font: inherit;
  padding: 0.75rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
  resize: vertical;
  min-height: 4rem;
}

.thread {
  margin: 0 0 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}

.thread-turn {
  margin: 0 0 0.85rem;
}

.thread-q {
  margin: 0 0 0.25rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.thread-n {
  color: var(--ink-soft);
  font-weight: 500;
}

.thread-a {
  margin: 0;
  font-size: 0.88rem;
  color: var(--ink-soft);
  white-space: pre-wrap;
}

@media (max-width: 800px) {
  .results-split {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

.about {
  max-width: 40rem;
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}

.about h1 {
  font-family: var(--font-display);
  font-size: 2rem;
  margin-bottom: 1rem;
}

.about p,
.about li {
  color: var(--ink-soft);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}

@media (max-width: 640px) {
  .cta {
    margin-left: 0;
    width: 100%;
  }
  .ask-actions {
    flex-direction: column;
    align-items: stretch;
  }
}