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

html { min-width: 320px; background: var(--background); }
body.useful-page {
  min-width: 320px;
  min-height: 100svh;
  margin: 0;
  background: var(--background);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}

a { -webkit-tap-highlight-color: transparent; }
h1, h2, p { margin: 0; }
[hidden] { display: none !important; }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 12px 20px;
  transform: translateY(-160%);
  background: #fff;
  color: var(--blue);
}
.skip-link:focus { transform: none; }

.useful-main { width: min(100%, 1180px); margin: 0 auto; padding: 32px 32px 52px; }
.useful-intro { max-width: 640px; margin-bottom: 24px; color: var(--muted); }

.useful-jump { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 32px; }
.useful-jump a { padding: 6px 12px; border: 1px solid #cfdcf3; border-radius: 4px; background: #f9f9fb; color: var(--blue); text-decoration: none; }
.useful-jump a:hover { border-color: var(--blue); }
.useful-jump a:focus-visible { outline: 3px solid var(--blue); outline-offset: 3px; }
.useful-group { margin-bottom: 44px; }
.useful-group-head { display: grid; gap: 8px; max-width: 720px; margin-bottom: 20px; }
.useful-group-head h2 { scroll-margin-top: 16px; font-family: 'OffBit', monospace; font-size: 24px; font-weight: 700; line-height: 1.2; letter-spacing: 0; }
.useful-group-link { display: inline-flex; align-items: center; gap: 8px; justify-self: start; color: var(--blue); text-decoration: underline; text-underline-offset: 4px; }
.useful-group-link:focus-visible { outline: 3px solid var(--blue); outline-offset: 4px; }

.useful-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; margin: 0; padding: 0; list-style: none; }
.useful-grid > li { display: flex; min-width: 0; }
.useful-card {
  position: relative;
  display: flex;
  flex: 1;
  flex-direction: column;
  min-width: 0;
  padding: 24px;
  border: 1px solid #fff;
  border-radius: 10px;
  background: #f9f9fb;
  color: inherit;
  text-decoration: none;
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
  animation: useful-card-enter .65s ease backwards;
}
.useful-card:hover { transform: translateY(-5px); border-color: var(--blue); box-shadow: 0 12px 30px #17171708; }
.useful-card:focus-visible { outline: 3px solid var(--blue); outline-offset: 6px; }
.useful-badge { align-self: flex-start; padding: 2px 8px; border: 1px solid #d5d7dc; border-radius: 4px; color: var(--muted); font-size: 12px; line-height: 18px; letter-spacing: .3px; }
.useful-card h3 { margin: 14px 0 10px; font-family: 'OffBit', monospace; font-size: 29px; font-weight: 700; line-height: 1.05; letter-spacing: 0; overflow-wrap: anywhere; }
.useful-kicker { display: block; margin-bottom: 4px; color: var(--muted); font-size: 16px; line-height: 1.2; }
.useful-description { margin-bottom: 10px; overflow-wrap: anywhere; }
.useful-platforms { margin-bottom: 20px; color: var(--muted); }
.useful-action { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: auto; padding-top: 16px; border-top: 1px solid #dedfe4; color: var(--blue); font-size: 14px; line-height: 22px; overflow-wrap: anywhere; }
.useful-arrow { display: block; flex: none; width: 18px; height: 18px; transition: transform .2s ease; }
.useful-card:hover .useful-arrow { transform: translate(3px, -3px); }

.useful-disclaimer { display: flex; align-items: flex-start; gap: 9px; max-width: 640px; margin-top: 26px; color: var(--muted); }
.useful-disclaimer svg { display: block; flex: none; width: 15px; height: 15px; margin-top: 3px; color: var(--blue); }

@keyframes useful-card-enter {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1050px) {
  .useful-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 800px) {
  .useful-main { padding-inline: 24px; }
  .useful-grid { gap: 18px; }
}
@media (max-width: 600px) {
  .useful-main { padding: 24px 16px 40px; }
  .useful-grid { grid-template-columns: 1fr; gap: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}