/* ==========================================================================
   Brain of Reese — design system (no CDN; system fonts only)
   ========================================================================== */

:root {
  /* Palette — all text/background pairs meet WCAG 2.1 AA (>= 4.5:1) */
  --bg: #f4f5fb;
  --surface: #ffffff;
  --ink: #1c2130;            /* 14.9:1 on --surface */
  --ink-soft: #4a5168;       /*  7.6:1 on --surface */
  --line: #e3e6f0;
  --brand: #4f46e5;          /* white on brand: 6.3:1 */
  --brand-soft: #eef0fe;
  --brand-ink: #3730a3;
  --accent-bg: #fff7e8;
  --accent-ink: #92400e;     /* 8.7:1 on --accent-bg */
  --accent-line: #f59e0b;
  --ok-ink: #15803d;
  --ok-bg: #f0fdf4;
  --err-ink: #b91c1c;
  --err-bg: #fef2f2;
  --err-line: #fecaca;

  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgb(28 33 48 / 0.06), 0 4px 16px rgb(28 33 48 / 0.07);
  --shadow-lg: 0 4px 10px rgb(28 33 48 / 0.08), 0 12px 32px rgb(28 33 48 / 0.12);

  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --header-h: 64px;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

.container {
  width: 100%;
  max-width: 72rem;
  margin-inline: auto;
  padding-inline: 1.25rem;
}

/* ---------- Accessibility helpers ---------- */
/* The `hidden` attribute must always win — some components set an explicit
   `display` (e.g. .kb-banner { display: flex }) which would otherwise override
   the UA stylesheet's `[hidden] { display: none }` and leave the element visible. */
[hidden] { display: none !important; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--brand);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: 0 0 var(--radius-sm) 0;
  z-index: 100;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--brand);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- Header ---------- */
.app-header {
  height: var(--header-h);
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 1.125rem;
  color: var(--ink);
  text-decoration: none;
}
.brand-mark { font-size: 1.4rem; }
.brand-text strong { color: var(--brand-ink); font-weight: 700; }

.app-nav { display: flex; gap: 0.25rem; }
.nav-link {
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink-soft);
  font-weight: 600;
  font-size: 0.95rem;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}
.nav-link:hover { background: var(--brand-soft); color: var(--brand-ink); }
.nav-link.is-active { background: var(--brand); color: #fff; }

/* ---------- Main frame ---------- */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding-block: 1.25rem;
}

/* Chat is a vertical conversation: a centered, capped column is the
   correct layout here (PLAN §UI/UX). The surrounding frame keeps it
   from collapsing into a hairline on wide screens. */
.chat-shell {
  max-width: 46rem;
  margin-inline: auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  flex: 1;
}

.messages {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  min-height: 200px;
}

/* ---------- Messages ---------- */
.msg { display: flex; gap: 0.6rem; max-width: 100%; }
.msg .avatar {
  flex: 0 0 auto;
  width: 34px; height: 34px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 1.05rem;
  background: var(--brand-soft);
  border: 1px solid var(--line);
}
.msg-body {
  max-width: 85%;
  /* min-width: 0 — as a flex item this overrides min-width:auto so a
     long unbroken token can wrap (overflow-wrap: anywhere) instead of
     widening the bubble past the column (AC7, phase 07). */
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.bubble {
  padding: 0.7rem 1rem;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  overflow-wrap: anywhere;
}
.bubble p { margin: 0.2rem 0; }
.bubble pre {
  background: #10131c;
  color: #e6e9f2;
  padding: 0.7rem 0.9rem;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  font-size: 0.85rem;
  font-family: var(--mono);
}
.bubble code { font-family: var(--mono); font-size: 0.88em; background: var(--brand-soft); padding: 0.08em 0.35em; border-radius: 5px; }
.bubble pre code { background: none; padding: 0; }

.msg.user { justify-content: flex-end; }
.msg.user .msg-body { align-items: flex-end; }
.msg.user .bubble {
  background: var(--brand);
  border-color: var(--brand);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.msg.user .bubble code { background: rgb(255 255 255 / 0.18); }

.msg.brain .bubble { border-bottom-left-radius: 4px; }
.msg.brain.is-deflected .bubble {
  background: var(--accent-bg);
  border-color: var(--accent-line);
}

.msg-meta {
  font-size: 0.75rem;
  color: var(--ink-soft);
  padding-inline: 0.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}
.source-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  background: var(--brand-soft);
  color: var(--brand-ink);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.15rem 0.6rem;
  text-decoration: none;
  max-width: 100%;
  /* min-width: 0 so the nowrap pill ellipsizes instead of widening its row */
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.source-chip:hover { background: #e2e5fd; }

/* "Maybe try" chips under a deflected bubble (phase 04). Unlike the
   onboarding row (which scrolls horizontally on mobile), this group wraps
   at every width: the chips are the actionable follow-up, not decoration.
   The pills themselves reuse .suggestion-chip (>=44px, brand-soft/ink). */
.maybe-try {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.45rem;
  padding-inline: 0.25rem;
}
/* As flex items these chips must be allowed to shrink (min-width:auto
   would let a long title-derived chip exceed the column on phones —
   phase 07 overflow fix); the label text then wraps inside the pill. */
.maybe-try .suggestion-chip {
  min-width: 0;
  max-width: 100%;
}

/* typing indicator */
.typing { display: inline-flex; gap: 5px; padding: 0.9rem 1rem; }
.typing span {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ink-soft);
  opacity: 0.5;
  animation: typing 1.2s infinite ease-in-out;
}
.typing span:nth-child(2) { animation-delay: 0.15s; }
.typing span:nth-child(3) { animation-delay: 0.3s; }
@keyframes typing {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
  30% { transform: translateY(-5px); opacity: 1; }
}
@media (prefers-reduced-motion: reduce) {
  .typing span { animation: none; opacity: 0.7; }
}

/* ---------- Empty state & suggestions ---------- */
.empty-state {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2.5rem 1.75rem;
  text-align: center;
  margin-top: 1rem;
}
.empty-state-emoji { font-size: 2.6rem; line-height: 1; }
.empty-state-title { margin: 0.8rem 0 0.4rem; font-size: 1.5rem; color: var(--ink); }
.empty-state-sub { margin: 0 auto 1.25rem; max-width: 34rem; color: var(--ink-soft); }
.empty-state-sub code { font-family: var(--mono); font-size: 0.85em; background: var(--brand-soft); padding: 0.1em 0.35em; border-radius: 5px; }

.suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  list-style: none;
  margin: 0;
  padding: 0;
}
.suggestion-chip {
  font: inherit;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--brand-ink);
  background: var(--brand-soft);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.55rem 1rem;
  min-height: 44px;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.05s ease;
}
.suggestion-chip:hover { background: #e2e5fd; }
.suggestion-chip:active { transform: scale(0.98); }

/* ---------- Composer ---------- */
.composer {
  display: flex;
  align-items: flex-end;
  gap: 0.6rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 0.6rem;
}
.composer:focus-within { border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft), var(--shadow); }
.composer textarea {
  flex: 1;
  font: inherit;
  color: var(--ink);
  border: 0;
  resize: none;
  max-height: 12rem;
  padding: 0.55rem 0.5rem;
  background: transparent;
}
.send-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-width: 84px;
  min-height: 44px;
  border: 0;
  border-radius: var(--radius-sm);
  background: var(--brand);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  padding-inline: 1rem;
}
.send-btn:hover:not(:disabled) { background: #4338ca; }
.send-btn:disabled { background: #a5b4fc; cursor: not-allowed; }

.spinner {
  width: 16px; height: 16px;
  border: 2.5px solid rgb(255 255 255 / 0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) {
  .spinner { animation-duration: 2s; }
}

/* ---------- Banners ---------- */
.kb-banner {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent-bg);
  color: var(--accent-ink);
  border: 1px solid var(--accent-line);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.9rem;
  font-size: 0.92rem;
  font-weight: 600;
}
.kb-banner.is-error { background: var(--err-bg); color: var(--err-ink); border-color: var(--err-line); }

/* ---------- Sources page ---------- */
.sources-shell {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  flex: 1;
}
.page-head h1 { margin: 0 0 0.25rem; font-size: 1.7rem; }
.page-sub { margin: 0; color: var(--ink-soft); }
.page-sub code { font-family: var(--mono); font-size: 0.85em; background: var(--brand-soft); padding: 0.1em 0.35em; border-radius: 5px; }

.stat-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.9rem;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}
.stat-value { font-size: 2rem; font-weight: 800; color: var(--brand-ink); line-height: 1.1; }
.stat-value-sm { font-size: 1.15rem; font-weight: 700; }
.stat-label { color: var(--ink-soft); font-size: 0.88rem; font-weight: 600; }

.table-wrap {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow-x: auto;
}
.docs-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
  font-size: 0.93rem;
}
.docs-table th, .docs-table td {
  text-align: left;
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
.docs-table th {
  background: var(--brand-soft);
  color: var(--brand-ink);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  position: sticky;
  top: 0;
}
.docs-table td:nth-child(2) { font-family: var(--mono); font-size: 0.82rem; max-width: 30rem; overflow: hidden; text-overflow: ellipsis; }
.docs-table tbody tr:hover { background: var(--bg); }
.docs-table tbody tr:last-child td { border-bottom: 0; }

/* ---------- Footer ---------- */
.app-footer {
  border-top: 1px solid var(--line);
  background: var(--surface);
  padding-block: 0.8rem;
  margin-top: 1rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  color: var(--ink-soft);
  font-size: 0.85rem;
}

/* ---------- Responsive (mobile-first adjustments) ---------- */
@media (max-width: 640px) {
  :root { --header-h: 58px; }
  .container { padding-inline: 0.9rem; }
  .brand-text { font-size: 1rem; }
  .nav-link { padding: 0.45rem 0.7rem; font-size: 0.9rem; }
  .msg-body { max-width: 92%; }
  .empty-state { padding: 1.75rem 1.1rem; margin-top: 0.25rem; }
  .empty-state-title { font-size: 1.25rem; }
  .suggestions { flex-wrap: nowrap; overflow-x: auto; justify-content: flex-start;
    padding-bottom: 0.4rem; -webkit-overflow-scrolling: touch; scrollbar-width: thin; }
  .suggestion-chip { flex: 0 0 auto; }
  .composer { padding: 0.5rem; }
  .footer-inner { flex-direction: column; gap: 0.2rem; text-align: center; }
  main { padding-bottom: env(safe-area-inset-bottom, 0); }
}