:root {
  color-scheme: dark;
  font-family: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
  color: #d6e9e5;
  background: #112b31;
  --ink: #e5f1ec;
  --muted: #bfd0cb;
  --line: #37616a;
  --paper: #17363d;
  --cyan: #83e4d5;
  --orange: #ffb46e;
  --display: Georgia, "Times New Roman", serif;
}
* { box-sizing: border-box; }
body { margin: 0; min-width: 320px; background-color: #112b31; background-image: linear-gradient(#83e4d50d 1px, transparent 1px), linear-gradient(90deg, #83e4d50d 1px, transparent 1px); background-size: 24px 24px; }
.shell { width: min(1120px, calc(100% - 44px)); margin: 0 auto; }
header { min-height: 76px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
header a { color: #d6e9e5; font-size: .76rem; text-decoration: none; }
header > a:last-child { color: #c5d8d3; }
header > a:last-child span { margin-left: 7px; color: var(--cyan); }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .15em; }
.brand-icon { display: grid; place-items: center; width: 35px; height: 30px; border: 1px solid var(--cyan); color: var(--cyan); font: 800 .62rem ui-monospace, monospace; }
.hero { min-height: 365px; display: grid; grid-template-columns: 1fr .65fr; align-items: center; padding: 42px 7%; border-bottom: 1px solid var(--line); background: radial-gradient(ellipse at 78% 48%, #23606a 0, transparent 35%); }
.eyebrow { margin: 0 0 12px; color: var(--cyan); font: 700 .64rem ui-monospace, monospace; letter-spacing: .14em; }
.hero h1 { margin: 0; color: #e5f1ec; font: 700 clamp(3.7rem, 7.7vw, 6.5rem)/.9 Georgia, serif; letter-spacing: -.065em; }
.hero h1 i { color: var(--orange); font-weight: 400; }
.hero > div:first-child > p:last-child { max-width: 480px; margin: 19px 0 0; color: #c5d8d3; font-size: .94rem; line-height: 1.7; }
.hero-mark { width: 225px; height: 215px; position: relative; display: grid; place-items: center; justify-self: center; }
.square { position: absolute; width: 105px; height: 105px; border: 1px solid #83e4d5; border-radius: 2px; transform: rotate(45deg); }
.square-one { top: 38px; left: 9px; background: #16383c; }
.square-two { top: 31px; right: 6px; border-color: var(--orange); background: #284347; }
.square-three { bottom: 8px; left: 52px; border-color: #74a7a3; background: #1c4145; }
.hero-mark span { position: relative; color: #e5f1ec; text-align: center; font: 800 .66rem/1.55 ui-monospace, monospace; letter-spacing: .1em; }
.checker { width: min(920px, calc(100% - 18px)); margin: -20px auto 70px; padding: clamp(23px, 4vw, 42px); border: 1px solid #47717a; background: #17363d; box-shadow: 10px 10px 0 #0b2025; }
.checker-head { display: flex; align-items: end; justify-content: space-between; gap: 15px; margin-bottom: 27px; padding-bottom: 20px; border-bottom: 1px solid var(--line); }
.checker-head h2, .limits h2 { margin: 0; color: #e5f1ec; font: 600 clamp(1.8rem, 4vw, 2.5rem)/1.1 Georgia, serif; letter-spacing: -.04em; }
.checker-head > span { color: var(--cyan); font: 700 .6rem ui-monospace, monospace; }
.form-section { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; padding: 20px 0; border-top: 1px dashed #47717a; }
.form-section h3 { grid-column: 1 / -1; margin: 0; color: var(--orange); font: 700 .74rem ui-monospace, monospace; letter-spacing: .07em; text-transform: uppercase; }
.form-section > label { display: grid; gap: 7px; color: #d1e1dc; font-size: .73rem; font-weight: 650; }
.form-section select, .form-section input[type="number"] { width: 100%; min-height: 45px; padding: 0 11px; border: 1px solid #517780; border-radius: 2px; background: #102b31; color: #eff7f2; font: inherit; }
.form-section input::placeholder { color: #a9c0bb; }
.form-section select:focus, .form-section input:focus { outline: 3px solid var(--cyan); outline-offset: 2px; }
fieldset { margin: 0; padding: 0; border: 0; }
legend { margin-bottom: 8px; color: #d1e1dc; font-size: .73rem; font-weight: 650; }
.checks { display: flex; flex-wrap: wrap; gap: 8px; }
.checks label { padding: 8px 9px; border: 1px solid #517780; color: #d1e1dc; font-size: .69rem; }
.checks input { accent-color: var(--cyan); }
.button { min-height: 48px; padding: 0 19px; border: 0; border-radius: 2px; background: var(--cyan); color: #102b31; font-weight: 900; cursor: pointer; }
.button:hover { background: #b2fff1; }
.button span { margin-left: 15px; }
.result { margin-top: 25px; padding: 22px; border: 1px solid #5a8e87; background: #1d4548; }
.result[hidden] { display: none; }
.result h3 { margin: 0 0 15px; color: #e5f1ec; font: 600 1.4rem Georgia, serif; }
.check-list { display: grid; gap: 9px; }
.check-item { display: grid; grid-template-columns: 27px 1fr; gap: 10px; padding: 13px; border: 1px solid #426b70; background: #153940; }
.check-mark { width: 24px; height: 24px; display: grid; place-items: center; background: var(--cyan); color: #102b31; font-weight: 900; }
.check-item.fail .check-mark { background: var(--orange); color: #392411; }
.check-item.unknown .check-mark { background: #bccbd0; color: #263c42; }
.check-item strong { display: block; color: #e5f1ec; font-size: .78rem; }
.check-item p { margin: 4px 0; color: #bfd0cb; font-size: .72rem; line-height: 1.55; }
.overall { margin-bottom: 17px; color: #d1e1dc; font-size: .8rem; line-height: 1.6; }
.limits { padding: 0 8% 65px; }
.limits h2 { max-width: 510px; margin-bottom: 20px; }
.limits-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.limits-grid p { padding-top: 13px; border-top: 1px solid #47717a; color: #c5d8d3; font-size: .78rem; line-height: 1.7; }
.privacy-note { margin-top: 20px; color: #bfd0cb; font-size: .72rem; }
footer { display: flex; justify-content: space-between; gap: 15px; padding: 20px 0 28px; border-top: 1px solid var(--line); color: #bfd0cb; font-size: .68rem; }
a { color: var(--cyan); }
:focus-visible { outline: 3px solid var(--orange); outline-offset: 3px; }
@media (max-width: 900px) {
  .shell { width: calc(100% - 28px); }
  .hero { grid-template-columns: 1fr; padding: 36px 4%; gap: 8px; }
  .hero h1 { font-size: clamp(3.7rem, 14vw, 5.7rem); }
  .hero-mark { height: 160px; transform: scale(.82); }
  .form-section { grid-template-columns: 1fr; }
  .form-section h3 { grid-column: auto; }
  .checker-head { align-items: flex-start; flex-direction: column; }
  .limits { padding-inline: 4%; }
  .limits-grid { grid-template-columns: 1fr; gap: 0; }
  footer { flex-direction: column; }
}

/* Shared responsive geometry across the utility suite. */
:root { --layout-max: 1180px; --layout-inline-space: clamp(32px, 8vw, 96px); }
.shell { width: min(var(--layout-max), calc(100% - var(--layout-inline-space))); }
.checker { width: 100%; max-width: none; margin-left: 0; margin-right: 0; }
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; min-height: 0; gap: 12px; padding: clamp(30px, 6vw, 56px) clamp(20px, 5vw, 56px); }
  .hero-mark { width: min(225px, 100%); }
  .limits-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .hero { padding: 32px 0 24px; }
  .hero h1 { font-size: clamp(3rem, 12vw, 4.5rem); }
  .checker { margin-top: 24px; padding: 22px clamp(16px, 5vw, 24px); }
  .form-section, .limits-grid { grid-template-columns: 1fr; }
  .form-section h3 { grid-column: auto; }
  .limits { padding-inline: 0; }
  footer { flex-direction: column; }
}
@media (max-width: 400px) {
  header { min-height: 64px; height: auto; flex-wrap: wrap; row-gap: 8px; padding-block: 12px; }
  .hero h1 { font-size: clamp(2.8rem, 11vw, 3.4rem); }
}