/* ============================================================
   Duckingo — tuckzed visual system
   Monochrome minimalism · Comic Relief · light mode
   ============================================================ */

:root {
  --white:      #FFFFFF;
  --black:      #000000;
  --gray-50:    #F4F4F4;
  --gray-100:   #E5E5E5;
  --gray-200:   #CCCCCC;
  --gray-300:   #B0B0B0;
  --gray-400:   #888888;
  --gray-500:   #6E6E6E;
  --gray-600:   #555555;
  --gray-700:   #3A3A3A;
  --gray-800:   #222222;
  --gray-900:   #111111;

  --font:       "Comic Relief", cursive, system-ui, sans-serif;
  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg:  16px;
  --shadow-sm:  0 1px 3px rgba(0,0,0,.08);
  --shadow-md:  0 4px 16px rgba(0,0,0,.12);
  --shadow-lg:  0 8px 32px rgba(0,0,0,.16);
  --transition: 160ms ease;
  --nav-h:      64px;
  --sidebar-w:  280px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; height: 100%; }

body {
  font-family: var(--font);
  background: var(--white);
  color: var(--black);
  line-height: 1.6;
  min-height: 100%;
  height: 100%;
  word-break: break-word;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font-family: var(--font); }
button { cursor: pointer; }

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--black);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: 0;
  left: 16px;
  z-index: 400;
  padding: 10px 16px;
  background: var(--black);
  color: var(--white);
  font-weight: 700;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  transform: translateY(-120%);
  transition: transform var(--transition);
}
.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); }

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

.app {
  position: relative;
  min-height: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  background: var(--white);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  background: var(--white);
  color: var(--black);
  font-size: .875rem;
  font-weight: 700;
  transition: background var(--transition), color var(--transition), transform var(--transition);
  white-space: nowrap;
}
.btn:hover { background: var(--black); color: var(--white); }
.btn:active { transform: scale(.97); }
.btn:disabled {
  opacity: .55;
  cursor: not-allowed;
  pointer-events: none;
  transform: none;
}
.btn--primary { background: var(--black); color: var(--white); }
.btn--primary:hover { background: var(--gray-900); }
.btn--ghost {
  border-color: var(--gray-200);
  color: var(--gray-600);
}
.btn--ghost:hover { border-color: var(--black); color: var(--black); background: var(--white); }
.btn--sm { padding: 6px 14px; font-size: .8rem; }
.btn--icon {
  width: 42px;
  height: 42px;
  padding: 0;
}

.badge {
  display: inline-block;
  padding: 3px 10px;
  border: 1.5px solid var(--black);
  border-radius: 999px;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  background: var(--white);
}
.badge--muted {
  border-color: var(--gray-200);
  color: var(--gray-600);
  background: var(--gray-50);
}

/* ── Navigation ─────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  border-bottom: 2px solid var(--black);
  flex-shrink: 0;
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--nav-h);
  padding: 8px 0;
  gap: 8px;
}
.nav__logo {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -.01em;
}
.nav__logo span { font-weight: 400; }
.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}
.nav__link {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: .875rem;
  font-weight: 700;
  transition: background var(--transition);
}
.nav__link:hover { background: var(--gray-50); }
.nav__link.is-active {
  background: var(--black);
  color: var(--white);
}
.nav__menu-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  background: var(--white);
}

/* ── Workspace ──────────────────────────────────────────────── */
.workspace {
  flex: 1;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: 0;
}

.sidebar {
  border-right: 2px solid var(--black);
  background: var(--white);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: auto;
  padding: 20px 16px;
  flex-shrink: 0;
  min-width: var(--sidebar-w);
}
.sidebar__new {
  width: 100%;
  margin-bottom: 28px;
}
.sidebar__label {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--gray-500);
  padding: 0 6px 10px;
}
.tool-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.tool-item {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 12px 12px;
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--black);
  text-align: left;
  font-size: .9rem;
  font-weight: 700;
  transition: background var(--transition), border-color var(--transition);
}
.tool-item:hover { background: var(--gray-50); border-color: var(--gray-200); }
.tool-item.is-active {
  border-color: var(--black);
  background: var(--white);
}
.tool-item.is-soon {
  color: var(--gray-500);
  cursor: default;
}
.tool-item.is-soon:hover { background: transparent; border-color: transparent; }
.tool-item__icon {
  width: 32px;
  height: 32px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  background: var(--white);
}
.tool-item.is-soon .tool-item__icon {
  border-color: var(--gray-200);
  color: var(--gray-400);
}
.tool-item__meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.tool-item__name { line-height: 1.2; }
.tool-item__hint {
  font-size: .72rem;
  font-weight: 400;
  color: var(--gray-500);
}
.sidebar__foot {
  margin-top: auto;
  padding-top: 20px;
  font-size: .75rem;
  color: var(--gray-400);
}

.sidebar-toggle {
  position: absolute;
  top: calc(var(--nav-h) + 14px);
  left: calc(var(--sidebar-w) - 16px);
  z-index: 120;
  width: 32px;
  height: 32px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  background: var(--white);
  color: var(--black);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1;
  box-shadow: var(--shadow-sm);
  transition: left var(--transition), background var(--transition), color var(--transition);
}
.sidebar-toggle:hover {
  background: var(--black);
  color: var(--white);
}
.sidebar {
  flex-shrink: 0;
  min-width: var(--sidebar-w);
}
.app.sidebar-collapsed .workspace {
  grid-template-columns: 72px minmax(0, 1fr);
}
.app.sidebar-collapsed .sidebar {
  min-width: 72px;
  width: 72px;
  padding: 12px 8px;
  overflow: hidden;
}
.app.sidebar-collapsed .sidebar__label,
.app.sidebar-collapsed .sidebar__foot,
.app.sidebar-collapsed .tool-item__meta {
  display: none;
}
.app.sidebar-collapsed .sidebar__new-label {
  display: none;
}
.app.sidebar-collapsed .sidebar__new {
  padding: 10px 0;
  font-size: 1.15rem;
}
.app.sidebar-collapsed .tool-item {
  justify-content: center;
  padding: 10px 6px;
}
.app.sidebar-collapsed .sidebar-toggle {
  left: 56px;
}

/* ── Chat ───────────────────────────────────────────────────── */
.chat {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background: var(--white);
}
.chat__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 28px;
  border-bottom: 2px solid var(--black);
  flex-shrink: 0;
}
.chat__identity {
  display: flex;
  align-items: center;
  gap: 12px;
}
.mark {
  width: 40px;
  height: 40px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  background: var(--black);
  color: var(--white);
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 1.15rem;
  flex-shrink: 0;
}
.chat__title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.2;
}
.chat__sub {
  font-size: .78rem;
  color: var(--gray-500);
  font-weight: 400;
}

.chat__thread {
  flex: 1;
  overflow: auto;
  padding: 32px 24px 12px;
}
.chat__inner {
  width: min(100%, 760px);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-height: 100%;
}

.empty {
  margin: auto;
  text-align: center;
  max-width: 560px;
  padding: 24px 8px 40px;
}
.empty__eyebrow {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gray-500);
  margin-bottom: 14px;
}
.empty__title {
  font-size: clamp(2rem, 5vw, 3.1rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 14px;
}
.empty__lead {
  color: var(--gray-600);
  font-size: 1.05rem;
  margin-bottom: 28px;
}
.suggest-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  text-align: left;
}
.suggest {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 16px 14px;
  border: 2px solid var(--black);
  border-radius: var(--radius-md);
  background: var(--white);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  cursor: pointer;
}
.suggest:hover {
  background: var(--black);
  color: var(--white);
  box-shadow: var(--shadow-md);
}
.suggest:hover .suggest__hint { color: var(--gray-200); }
.suggest__label { font-weight: 700; font-size: .92rem; }
.suggest__hint { font-size: .78rem; color: var(--gray-500); font-weight: 400; }

.msg {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  max-width: 100%;
  animation: msgIn 220ms ease;
}
.msg--user {
  flex-direction: row-reverse;
}
.msg__avatar {
  width: 34px;
  height: 34px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-size: .78rem;
  font-weight: 700;
  flex-shrink: 0;
  background: var(--white);
}
.msg--assistant .msg__avatar {
  background: var(--black);
  color: var(--white);
}
.msg__stack { max-width: min(100% - 46px, 620px); }
.msg__who {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--gray-500);
  margin-bottom: 6px;
}
.msg--user .msg__who { text-align: right; color: var(--gray-500); }
.msg--user .msg__stack { display: flex; flex-direction: column; align-items: flex-end; }
.msg__bubble {
  padding: 14px 16px;
  border: 2px solid var(--black);
  border-radius: var(--radius-md);
  background: var(--gray-50);
  font-size: .95rem;
  line-height: 1.55;
}
.msg--user .msg__bubble {
  background: var(--black);
  color: var(--white);
}
.msg__bubble p + p { margin-top: 10px; }

.typing {
  display: inline-flex;
  gap: 5px;
  align-items: center;
  height: 16px;
}
.typing span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--black);
  animation: blink 1s ease-in-out infinite;
}
.typing span:nth-child(2) { animation-delay: .15s; }
.typing span:nth-child(3) { animation-delay: .3s; }

@keyframes blink {
  0%, 80%, 100% { opacity: .2; transform: translateY(0); }
  40% { opacity: 1; transform: translateY(-2px); }
}
@keyframes msgIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

.composer {
  flex-shrink: 0;
  padding: 16px 24px 22px;
}
.composer__box {
  width: min(100%, 760px);
  margin: 0 auto;
  border: 2px solid var(--black);
  border-radius: var(--radius-md);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  padding: 10px 10px 10px 16px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: end;
  transition: box-shadow var(--transition);
}
.composer__box:focus-within { box-shadow: 0 0 0 3px rgba(0,0,0,.12); }
.composer__input {
  width: 100%;
  border: 0;
  resize: none;
  background: transparent;
  color: var(--black);
  font-size: .95rem;
  line-height: 1.5;
  max-height: 160px;
  min-height: 44px;
  padding: 10px 0;
}
.composer__input::placeholder { color: var(--gray-400); }
.composer__send {
  width: 44px;
  height: 44px;
  border: 2px solid var(--black);
  border-radius: var(--radius-sm);
  background: var(--black);
  color: var(--white);
  display: grid;
  place-items: center;
  transition: background var(--transition), transform var(--transition);
}
.composer__send:hover { background: var(--gray-900); }
.composer__send:active { transform: scale(.97); }
.composer__send:disabled {
  background: var(--gray-100);
  color: var(--gray-400);
  border-color: var(--gray-200);
  cursor: not-allowed;
}
.composer__note {
  width: min(100%, 760px);
  margin: 8px auto 0;
  font-size: .75rem;
  color: var(--gray-400);
  text-align: center;
}

/* ── 404 ────────────────────────────────────────────────────── */
.not-found-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 64px 24px;
  text-align: center;
}
.not-found-card {
  border: 2px solid var(--black);
  border-radius: var(--radius-lg);
  padding: 48px;
  max-width: 480px;
  background: var(--white);
  box-shadow: var(--shadow-lg);
}
.not-found-code { font-size: 3.5rem; font-weight: 700; line-height: 1; margin-bottom: 16px; }
.not-found-sub { color: var(--gray-600); margin-bottom: 28px; }
.hero__actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

@media (max-width: 860px) {
  .workspace { grid-template-columns: 1fr; }
  .sidebar-toggle { display: none; }
  .app.sidebar-collapsed .workspace { grid-template-columns: 1fr; }
  .app.sidebar-collapsed .sidebar {
    width: min(100%, 320px);
    min-width: 0;
    padding: 20px 16px;
    overflow: auto;
  }
  .app.sidebar-collapsed .sidebar__label,
  .app.sidebar-collapsed .sidebar__foot,
  .app.sidebar-collapsed .tool-item__meta { display: revert; }
  .app.sidebar-collapsed .tool-item { justify-content: flex-start; padding: 12px; }
  .app.sidebar-collapsed .sidebar__new-label { display: inline; }
  .app.sidebar-collapsed .sidebar__new { font-size: .875rem; padding: 10px 20px; }
  .sidebar {
    display: none;
    position: absolute;
    top: var(--nav-h);
    left: 0;
    bottom: 0;
    width: min(100%, 320px);
    z-index: 80;
    border-right: 2px solid var(--black);
    box-shadow: var(--shadow-lg);
  }
  .app.nav-open .sidebar { display: flex; }
  .nav__menu-btn { display: inline-flex; }
  .nav__links { display: none; }
  .app.nav-open .nav__links {
    display: flex;
    position: absolute;
    top: var(--nav-h);
    right: 0;
    left: 0;
    background: var(--white);
    border-bottom: 2px solid var(--black);
    flex-direction: column;
    padding: 12px 16px;
    z-index: 90;
  }
  .suggest-grid { grid-template-columns: 1fr; }
  .chat__header, .chat__thread, .composer { padding-left: 16px; padding-right: 16px; }
  .nav__logo { font-size: 1.15rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}