:root {
  color-scheme: dark;
  --bg: #080b10;
  --panel: rgba(19, 24, 32, 0.9);
  --panel-strong: #151b24;
  --line: rgba(255, 255, 255, 0.1);
  --text: #f5f7fa;
  --muted: #aab4c2;
  --lime: #c8ff45;
  --cyan: #59e4ff;
  --shadow: rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background:
    radial-gradient(circle at 50% 8%, rgba(89, 228, 255, 0.12), transparent 28rem),
    radial-gradient(circle at 20% 35%, rgba(200, 255, 69, 0.07), transparent 24rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

button, a { -webkit-tap-highlight-color: transparent; }
a { color: var(--cyan); }
.site-nav, .site-footer, .content { width: min(100% - 2rem, 760px); margin-inline: auto; }
.site-nav { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-block: 1rem; }
.site-name { color: var(--text); font-weight: 850; text-decoration: none; }
.site-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: .65rem 1rem; }
.site-links a { color: var(--muted); font-size: .86rem; text-decoration: none; }
.site-links a:hover, .site-links a[aria-current="page"] { color: var(--cyan); }

.hero { min-height: calc(100svh - 68px); display: grid; place-items: center; padding: 1.5rem 1rem 2.5rem; }
.tool { width: min(100%, 760px); text-align: center; }
.eyebrow { margin: 0 0 .35rem; color: var(--lime); font-size: .75rem; font-weight: 800; letter-spacing: .2em; text-transform: uppercase; }
h1 { margin: 0; font-size: clamp(2.3rem, 8vw, 5.2rem); line-height: 1; letter-spacing: -.055em; }
.subtitle { margin: .75rem auto 1.7rem; max-width: 42rem; color: var(--muted); font-size: clamp(1rem, 2.5vw, 1.2rem); }
.tap-button {
  position: relative; display: grid; place-items: center; width: clamp(13rem, 44vw, 18rem); aspect-ratio: 1;
  margin: 0 auto 1.4rem; border: 1px solid rgba(200,255,69,.7); border-radius: 50%;
  background: radial-gradient(circle at 35% 28%, rgba(255,255,255,.18), transparent 23%), linear-gradient(145deg,#d8ff74,#9fd62e);
  color: #0a0e08; box-shadow: 0 1.4rem 4rem rgba(157,218,41,.18), inset 0 -.6rem 1rem rgba(47,76,0,.18), inset 0 .12rem 0 rgba(255,255,255,.5);
  cursor: pointer; touch-action: manipulation; user-select: none; transition: transform 90ms ease, box-shadow 90ms ease, filter 90ms ease;
}
.tap-button:hover { filter: brightness(1.06); }
.tap-button:active, .tap-button.is-tapping { transform: scale(.965); box-shadow: 0 .7rem 2rem rgba(157,218,41,.16), inset 0 .4rem 1rem rgba(47,76,0,.24); }
.tap-button:focus-visible, .reset-button:focus-visible, a:focus-visible { outline: 3px solid var(--cyan); outline-offset: 5px; }
.tap-main { display: block; font-size: clamp(2.15rem,8vw,4rem); font-weight: 900; letter-spacing: -.05em; line-height: 1; }
.tap-hint { display: block; margin-top: .55rem; font-size: .78rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; opacity: .72; }
.results { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: .8rem; margin: 0 auto; }
.metric { min-height: 8rem; display: grid; align-content: center; padding: 1rem; border: 1px solid var(--line); border-radius: 1.15rem; background: var(--panel); box-shadow: 0 1rem 3rem var(--shadow); backdrop-filter: blur(12px); }
.metric-label { color: var(--muted); font-size: .76rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.metric-value { margin-top: .2rem; font-variant-numeric: tabular-nums; font-size: clamp(2rem,7vw,3.5rem); font-weight: 850; letter-spacing: -.05em; line-height: 1; }
.metric:first-child .metric-value { color: var(--lime); }
.metric:last-child .metric-value { color: var(--cyan); }

.content { padding: 3rem 0 5rem; }
.panel { padding: clamp(1.15rem,4vw,2rem); border: 1px solid var(--line); border-radius: 1.25rem; background: var(--panel-strong); box-shadow: 0 1.25rem 4rem var(--shadow); }
.panel + .panel { margin-top: 1rem; }
h2 { margin: 0 0 .8rem; font-size: clamp(1.25rem,4vw,1.65rem); letter-spacing: -.025em; }
h3 { margin: 1.35rem 0 .35rem; font-size: 1.05rem; }
.panel p, .panel li { color: var(--muted); }
.panel p { margin: .55rem 0; }
.instructions { display: grid; gap: .55rem; margin: 0; padding: 0; list-style: none; counter-reset: steps; }
.instructions li { counter-increment: steps; display: grid; grid-template-columns: 2rem 1fr; align-items: start; gap: .7rem; }
.instructions li::before { content: counter(steps); display: grid; place-items: center; width: 1.8rem; height: 1.8rem; border-radius: 50%; background: rgba(200,255,69,.12); color: var(--lime); font-size: .8rem; font-weight: 850; }
.intervals { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: .55rem; margin: 0; padding: 0; list-style: none; }
.intervals li { padding: .7rem .5rem; border: 1px solid var(--line); border-radius: .7rem; background: rgba(255,255,255,.025); color: var(--muted); font-variant-numeric: tabular-nums; text-align: center; }
.controls { display: flex; justify-content: center; margin-top: 1rem; }
.reset-button { padding: .65rem 1rem; border: 1px solid var(--line); border-radius: .65rem; background: transparent; color: var(--text); font: inherit; font-weight: 700; cursor: pointer; }
.reset-button:hover { background: rgba(255,255,255,.06); }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; text-align: left; }
th, td { padding: .8rem .7rem; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; }
td { color: var(--muted); }
td:last-child { color: var(--lime); font-weight: 800; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
.formula { padding: .8rem 1rem; border-left: 3px solid var(--lime); background: rgba(200,255,69,.06); color: var(--text) !important; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.privacy { text-align: center; font-size: .86rem; color: var(--muted); }
.site-footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .75rem 1.5rem; padding-block: 1.5rem 2rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
.site-footer p { margin: 0; }

@media (max-width: 540px) {
  .site-nav { align-items: flex-start; }
  .site-links { gap: .5rem .75rem; }
  .hero { min-height: auto; padding-block: 1.25rem 2.5rem; }
  .subtitle { margin-bottom: 1.2rem; }
  .tap-button { width: min(62vw,14.5rem); margin-bottom: 1rem; }
  .metric { min-height: 6.5rem; padding: .8rem; }
  .intervals { grid-template-columns: repeat(2,minmax(0,1fr)); }
  th, td { padding-inline: .5rem; }
}

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; } }