.topbar {
  position: sticky;
  z-index: 100;
  top: 0;
  min-height: var(--topbar-height);
  background: var(--surface);
  border-bottom: 1px solid var(--separator);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  backdrop-filter: blur(24px) saturate(180%);
}

.topbar__inner {
  width: min(calc(100% - 2rem), var(--page-width));
  min-height: var(--topbar-height);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.68rem;
  border-radius: 0.8rem;
  font-weight: 680;
  letter-spacing: -0.012em;
}

.brand__mark {
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  border-radius: 0.62rem;
  background: var(--text);
  color: var(--canvas);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  box-shadow: var(--shadow-sm);
}

.topbar__actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.privacy-note {
  color: var(--text-tertiary);
  font-size: 0.78rem;
}

.icon-button,
.button,
.copy-button,
.filter-chip,
.segmented-control button {
  border: 0;
  cursor: pointer;
  transition:
    transform var(--duration-fast) ease-out,
    background-color var(--duration-medium) var(--ease-fluid),
    color var(--duration-medium) var(--ease-fluid),
    box-shadow var(--duration-medium) var(--ease-fluid),
    opacity var(--duration-fast) ease-out;
}

.icon-button:active,
.button:active,
.copy-button:active,
.filter-chip:active,
.segmented-control button:active { transform: scale(0.97); }

.icon-button {
  width: 2.75rem;
  height: 2.75rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-muted);
}
.icon-button:hover { background: var(--separator); }

.button {
  min-height: 2.75rem;
  padding: 0.68rem 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 650;
}
.button--primary { background: var(--blue); color: #fff; }
.button--secondary { background: var(--surface-solid); box-shadow: inset 0 0 0 1px var(--separator), var(--shadow-sm); }
.button--quiet { background: var(--surface-muted); }
.button svg { width: 1rem; height: 1rem; }

.search-box {
  width: min(100%, 42rem);
  min-height: 3.5rem;
  margin-top: 2rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.75rem;
  padding: 0.45rem 0.55rem 0.45rem 1rem;
  border: 1px solid var(--separator);
  border-radius: 1rem;
  background: var(--surface-strong);
  box-shadow: var(--shadow-md);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  transition: box-shadow var(--duration-medium) var(--ease-fluid), border-color var(--duration-medium) var(--ease-fluid), transform var(--duration-medium) var(--ease-fluid);
}
.search-box:focus-within {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px var(--focus-ring), var(--shadow-md);
  transform: translateY(-1px);
}
.search-box__icon { color: var(--text-tertiary); }
.search-box input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-size: 1rem;
}
.search-box input::placeholder { color: var(--text-tertiary); }
.search-box__shortcut {
  padding: 0.35rem 0.55rem;
  border: 1px solid var(--separator);
  border-radius: 0.5rem;
  background: var(--surface-muted);
  color: var(--text-tertiary);
  font-family: var(--font-sans);
  font-size: 0.72rem;
  white-space: nowrap;
  box-shadow: inset 0 -1px 0 var(--separator-strong);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}
.section-heading h2 {
  margin-bottom: 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
  line-height: 1.12;
  letter-spacing: -0.025em;
}
.section-heading--compact { margin-bottom: 1rem; }
.result-count { margin: 0; color: var(--text-tertiary); font-size: 0.9rem; }

.filter-row {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.25rem 0.15rem 0.75rem;
  scrollbar-width: none;
}
.filter-row::-webkit-scrollbar { display: none; }
.filter-chip {
  flex: 0 0 auto;
  min-height: 2.5rem;
  padding: 0.52rem 0.9rem;
  border-radius: 999px;
  background: var(--surface-muted);
  color: var(--text-secondary);
  font-size: 0.86rem;
  font-weight: 650;
}
.filter-chip:hover { color: var(--text); }
.filter-chip.is-active { background: var(--text); color: var(--canvas); box-shadow: var(--shadow-sm); }

.command-card {
  position: relative;
  min-height: 22rem;
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--separator);
  border-radius: var(--radius-lg);
  background: var(--surface-strong);
  box-shadow: var(--shadow-sm);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
  transition:
    transform var(--duration-medium) var(--ease-fluid),
    box-shadow var(--duration-medium) var(--ease-fluid),
    border-color var(--duration-medium) var(--ease-fluid);
}
.command-card::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.65;
  background: radial-gradient(circle at 10% 0%, var(--card-accent-soft), transparent 52%);
}
.command-card:hover {
  transform: translateY(-4px);
  border-color: var(--separator-strong);
  box-shadow: var(--shadow-md);
}
.command-card:active { transform: scale(0.985); }
.command-card--blue { --card-accent: var(--blue); --card-accent-soft: var(--blue-soft); }
.command-card--green { --card-accent: var(--green); --card-accent-soft: var(--green-soft); }
.command-card--orange { --card-accent: var(--orange); --card-accent-soft: var(--orange-soft); }
.command-card__top,
.command-card__body,
.command-card__tags { position: relative; z-index: 1; }
.command-card__top { display: flex; align-items: center; justify-content: space-between; }
.command-card__icon {
  width: 3rem;
  height: 3rem;
  display: grid;
  place-items: center;
  border-radius: 1rem;
  background: var(--card-accent-soft);
  color: var(--card-accent);
}
.command-card__icon svg { width: 1.45rem; height: 1.45rem; }
.command-card__arrow {
  width: 2.5rem;
  height: 2.5rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-muted);
  color: var(--text-tertiary);
  transition: transform var(--duration-medium) var(--ease-fluid), color var(--duration-medium) var(--ease-fluid), background-color var(--duration-medium) var(--ease-fluid);
}
.command-card:hover .command-card__arrow { transform: translateX(3px); color: var(--card-accent); background: var(--card-accent-soft); }
.command-card__body { margin-top: 2.25rem; }
.command-card__category { margin-bottom: 0.5rem; color: var(--card-accent); font-size: 0.76rem; font-weight: 750; letter-spacing: 0.06em; text-transform: uppercase; }
.command-card h3 { margin-bottom: 0.2rem; font-family: var(--font-mono); font-size: clamp(1.25rem, 2vw, 1.55rem); letter-spacing: -0.025em; }
.command-card__label { margin-bottom: 0.9rem; color: var(--text); font-weight: 650; }
.command-card__description { margin-bottom: 0; color: var(--text-secondary); font-size: 0.94rem; }
.command-card__tags { margin-top: auto; padding-top: 1.5rem; display: flex; flex-wrap: wrap; gap: 0.45rem; }
.tag { padding: 0.35rem 0.58rem; border: 1px solid var(--separator); border-radius: 999px; background: var(--surface-muted); color: var(--text-secondary); font-size: 0.72rem; font-weight: 600; }

.empty-state,
.error-state,
.loading-state {
  padding: clamp(3rem, 10vw, 7rem) 1rem;
  text-align: center;
}
.empty-state__icon,
.error-state__icon {
  width: 3.5rem;
  height: 3.5rem;
  margin: 0 auto 1rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-muted);
  color: var(--text-tertiary);
}
.empty-state h3,
.error-state h1 { margin-bottom: 0.45rem; }
.empty-state p,
.error-state p { margin-bottom: 1.4rem; color: var(--text-secondary); }
.loading-state__icon {
  width: 2rem;
  height: 2rem;
  margin: 0 auto 1rem;
  border: 2px solid var(--separator-strong);
  border-top-color: var(--blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.content-card {
  scroll-margin-top: calc(var(--topbar-height) + 1.25rem);
  padding: clamp(1.25rem, 4vw, 2rem);
  border: 1px solid var(--separator);
  border-radius: var(--radius-lg);
  background: var(--surface-strong);
  box-shadow: var(--shadow-sm);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
}
.content-card + .content-card { margin-top: 1rem; }
.content-card--accent { background: linear-gradient(145deg, var(--blue-soft), var(--surface-strong) 48%); }
.content-card__heading { display: flex; align-items: flex-start; gap: 0.9rem; margin-bottom: 1rem; }
.content-card__heading h2 { margin-bottom: 0; font-size: clamp(1.25rem, 3vw, 1.65rem); line-height: 1.15; letter-spacing: -0.02em; }
.content-card__icon {
  flex: 0 0 auto;
  width: 2.6rem;
  height: 2.6rem;
  display: grid;
  place-items: center;
  border-radius: 0.85rem;
  background: var(--blue-soft);
  color: var(--blue);
}
.content-card__icon--success { background: var(--green-soft); color: var(--green); }

.code-stack { display: grid; gap: 0.8rem; margin-top: 1rem; }
.code-panel { overflow: hidden; border: 1px solid rgba(255,255,255,0.09); border-radius: 1rem; background: var(--code-bg); color: var(--code-text); box-shadow: inset 0 1px 0 rgba(255,255,255,0.05); }
.code-panel__header {
  min-height: 2.9rem;
  padding: 0.55rem 0.65rem 0.55rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.09);
  color: var(--code-muted);
  font-size: 0.76rem;
  font-weight: 650;
  letter-spacing: 0.02em;
}
.code-panel pre { margin: 0; padding: 1.1rem; overflow-x: auto; font-size: 0.86rem; line-height: 1.7; }
.code-panel code { white-space: pre; }
.copy-button {
  min-height: 2rem;
  padding: 0.35rem 0.62rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border-radius: 0.55rem;
  background: rgba(255,255,255,0.09);
  color: var(--code-text);
  font-size: 0.72rem;
  font-weight: 650;
}
.copy-button:hover { background: rgba(255,255,255,0.15); }
.copy-button:disabled { cursor: not-allowed; opacity: 0.38; }
.copy-button.is-copied { background: rgba(69,199,128,0.18); color: #7ee2a9; }
.copy-button svg { width: 0.95rem; height: 0.95rem; }

.form-grid { display: grid; gap: 0.9rem; margin-top: 1.25rem; }
.form-grid--two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.form-grid--three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.field { min-width: 0; display: flex; flex-direction: column; gap: 0.35rem; }
.field__label { font-size: 0.88rem; font-weight: 700; }
.field__hint { min-height: 1.25rem; color: var(--text-tertiary); font-size: 0.75rem; }
.field input {
  width: 100%;
  min-height: 3rem;
  padding: 0.7rem 0.8rem;
  border: 1px solid var(--separator-strong);
  border-radius: 0.75rem;
  outline: 0;
  background: var(--surface-solid);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  transition: border-color var(--duration-fast) ease-out, box-shadow var(--duration-fast) ease-out, background-color var(--duration-fast) ease-out;
}
.field input:focus { border-color: var(--blue); box-shadow: 0 0 0 4px var(--focus-ring); }
.field input.is-invalid { border-color: var(--red); background: var(--red-soft); }
.field--explanation { justify-content: center; padding: 0.8rem 1rem; border: 1px solid var(--separator); border-radius: 0.75rem; background: var(--surface-muted); }

.builder-options { margin-top: 1rem; display: grid; border: 1px solid var(--separator); border-radius: 1rem; overflow: hidden; }
.switch-row {
  position: relative;
  min-height: 4.3rem;
  padding: 0.8rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: var(--surface-muted);
  cursor: pointer;
}
.switch-row + .switch-row { border-top: 1px solid var(--separator); }
.switch-row--standalone { margin: 1rem 0; border: 1px solid var(--separator); border-radius: 1rem; }
.switch-row > span:first-child { display: grid; gap: 0.15rem; }
.switch-row strong { font-size: 0.86rem; }
.switch-row small { color: var(--text-tertiary); font-size: 0.74rem; }
.switch-row input { position: absolute; opacity: 0; pointer-events: none; }
.switch-control {
  flex: 0 0 auto;
  width: 2.85rem;
  height: 1.75rem;
  padding: 0.16rem;
  border-radius: 999px;
  background: var(--separator-strong);
  transition: background-color var(--duration-medium) var(--ease-fluid);
}
.switch-control::after {
  content: "";
  width: 1.43rem;
  height: 1.43rem;
  display: block;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,0.25);
  transition: transform var(--duration-medium) var(--ease-fluid);
}
.switch-row input:checked + .switch-control { background: var(--green); }
.switch-row input:checked + .switch-control::after { transform: translateX(1.1rem); }
.switch-row input:focus-visible + .switch-control { outline: 3px solid var(--focus-ring); outline-offset: 3px; }

.inline-validation { min-height: 1.4rem; margin-top: 0.8rem; font-size: 0.78rem; font-weight: 620; }
.inline-validation--success { color: var(--green); }
.inline-validation--warning { color: var(--red); }

.meaning-card { margin-top: 1rem; padding: 1rem; border: 1px solid var(--separator); border-radius: 1rem; background: var(--surface-muted); }
.meaning-card span { display: block; margin-bottom: 0.25rem; color: var(--text-tertiary); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; }
.meaning-card p { margin: 0; }

.notice { margin-top: 1rem; padding: 1rem; display: grid; grid-template-columns: auto 1fr; gap: 0.75rem; border-radius: 1rem; }
.notice > span { margin-top: 0.12rem; }
.notice strong { display: block; margin-bottom: 0.15rem; }
.notice p { margin: 0; color: var(--text-secondary); font-size: 0.86rem; }
.notice--warning { background: var(--orange-soft); color: var(--orange); }
.notice--warning p { color: var(--text-secondary); }
.notice--info { background: var(--blue-soft); color: var(--blue); }
.notice--info p { color: var(--text-secondary); }

.segmented-control {
  width: min(100%, 28rem);
  margin-top: 1rem;
  padding: 0.25rem;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.2rem;
  border: 1px solid var(--separator);
  border-radius: 0.85rem;
  background: var(--surface-muted);
}
.segmented-control button { min-height: 2.5rem; border-radius: 0.65rem; background: transparent; color: var(--text-secondary); font-size: 0.86rem; font-weight: 650; }
.segmented-control button.is-active { background: var(--surface-solid); color: var(--text); box-shadow: var(--shadow-sm); }
.builder-panel { padding-top: 0.25rem; }

.use-case-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 0.6rem; margin-top: 1rem; }
.use-case-grid span { padding: 0.8rem; border: 1px solid var(--separator); border-radius: 0.75rem; background: var(--surface-muted); font-family: var(--font-mono); font-size: 0.84rem; }
.comparison-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 0.75rem; }
.comparison-card { padding: 1rem; border: 1px solid var(--separator); border-radius: 1rem; background: var(--green-soft); }
.comparison-card--warning { background: var(--orange-soft); }
.comparison-card strong { display: block; margin-bottom: 0.3rem; }
.comparison-card p { margin: 0; color: var(--text-secondary); font-size: 0.86rem; }

.diagram { margin: 1rem 0; padding: 1.2rem; border-radius: 1rem; background: var(--code-bg); color: var(--code-text); font-size: 0.9rem; line-height: 1.7; }
blockquote { margin: 1rem 0 0; padding: 0.85rem 1rem; border-left: 3px solid var(--blue); border-radius: 0 0.8rem 0.8rem 0; background: var(--blue-soft); color: var(--text-secondary); }
.example-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.75rem; margin-top: 1rem; }
.reference-list { display: grid; gap: 0.65rem; }
.reference-list > div { padding: 0.9rem 1rem; display: grid; grid-template-columns: minmax(8rem, 0.65fr) 1.35fr; align-items: center; gap: 1rem; border: 1px solid var(--separator); border-radius: 0.85rem; background: var(--surface-muted); }
.reference-list span { color: var(--text-secondary); font-size: 0.84rem; }
.reference-list code { overflow-wrap: anywhere; }

.toast {
  position: fixed;
  z-index: 200;
  left: 50%;
  bottom: 1.4rem;
  max-width: min(90vw, 28rem);
  padding: 0.75rem 1rem;
  border: 1px solid rgba(255,255,255,0.10);
  border-radius: 999px;
  background: rgba(28, 28, 30, 0.88);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 620;
  box-shadow: var(--shadow-float);
  opacity: 0;
  transform: translate(-50%, calc(100% + 2rem)) scale(0.96);
  pointer-events: none;
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  transition: opacity var(--duration-medium) var(--ease-fluid), transform var(--duration-medium) var(--ease-fluid);
}
.toast.is-visible { opacity: 1; transform: translate(-50%, 0) scale(1); }
.toast[data-type="error"] { background: rgba(120, 0, 18, 0.92); }

@media (max-width: 48rem) {
  .privacy-note { display: none; }
  .form-grid--three, .form-grid--two, .comparison-grid, .example-pair { grid-template-columns: 1fr; }
  .reference-list > div { grid-template-columns: 1fr; gap: 0.3rem; }
}

@media (max-width: 34rem) {
  .brand__name { display: none; }
  .topbar__home { padding-inline: 0.75rem; }
  .search-box__shortcut { display: none; }
  .search-box { grid-template-columns: auto 1fr; }
  .use-case-grid { grid-template-columns: 1fr; }
  .switch-row { align-items: flex-start; }
}

@media (prefers-reduced-transparency: reduce) {
  .topbar, .search-box, .command-card, .content-card { background: var(--surface-solid); -webkit-backdrop-filter: none; backdrop-filter: none; }
  .toast { background: #1c1c1e; -webkit-backdrop-filter: none; backdrop-filter: none; }
}

@media (prefers-contrast: more) {
  .topbar, .search-box, .command-card, .content-card { background: var(--surface-solid); border-color: var(--text-secondary); }
  .button--secondary, .filter-chip, .tag { border: 1px solid var(--text-secondary); }
}