:root {
  --ink: #1a1a1a;
  --soft-ink: #555;
  --muted: #767676;
  --accent: #4b2e83;
  --line: #e8e8e8;
  --paper: #f5f4f1;
  --font-heading: "Instrument Serif", serif;
  --grain-svg: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.55'/%3E%3C/svg%3E");
}

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

html,
body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.7;
  mix-blend-mode: multiply;
  background-image: var(--grain-svg);
  background-size: 180px 180px;
}

.unsure-main {
  position: relative;
  z-index: 0;
  width: min(56rem, 92vw);
  margin: 0 auto;
  padding: 3rem 0 3.5rem;
}

.unsure-back {
  display: inline-block;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.unsure-back:hover,
.unsure-back:focus-visible {
  color: var(--accent);
  border-bottom-color: color-mix(in srgb, var(--accent) 35%, transparent);
}

.unsure-title {
  margin: 0 0 0.75rem;
  font-family: var(--font-heading);
  font-size: clamp(1.45rem, 2.4vw, 1.9rem);
  font-weight: 400;
}

.unsure-lead {
  margin: 0 0 1.25rem;
  color: var(--soft-ink);
  line-height: 1.7;
}

.unsure-calc {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.56);
  padding: 1rem;
}

.unsure-input {
  width: 100%;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font-size: 1rem;
  margin-bottom: 0.8rem;
}

.unsure-grid {
  display: grid;
  grid-template-columns: minmax(260px, 340px) 1fr;
  gap: 1rem;
}

.unsure-keypad {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  padding: 0.65rem;
}

.unsure-keypad-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.45rem;
}

.unsure-key {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 0.95rem;
  padding: 0.5rem;
  cursor: pointer;
}

.unsure-key:hover,
.unsure-key:focus-visible {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
}

.unsure-key.unsure-key-op {
  color: var(--accent);
  font-weight: 600;
}

.unsure-output {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  padding: 0.8rem;
}

.unsure-result {
  margin: 0 0 0.7rem;
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--ink);
}

.unsure-error {
  margin: 0 0 0.7rem;
  color: #8a2e2e;
  font-size: 0.92rem;
  display: none;
}

.unsure-error.is-visible {
  display: block;
}

.unsure-section-title {
  margin: 0.6rem 0 0.35rem;
  color: var(--muted);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.unsure-pre {
  margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.75rem;
  line-height: 1.38;
  white-space: pre;
  overflow: auto;
  color: var(--soft-ink);
}

.unsure-help {
  margin-top: 1rem;
  color: var(--soft-ink);
  line-height: 1.7;
}

.unsure-help h2 {
  margin: 1.65rem 0 0.6rem;
  color: var(--ink);
  font-size: 1rem;
}

.unsure-help ul {
  margin: 0 0 1.25rem;
  padding-left: 1.25rem;
}

.unsure-help li {
  margin: 0 0 0.45rem;
}

.unsure-help a {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: color-mix(in srgb, var(--soft-ink) 55%, transparent);
}

.unsure-help a:hover,
.unsure-help a:focus-visible {
  color: var(--accent);
  text-decoration-color: color-mix(in srgb, var(--accent) 55%, transparent);
}

.unsure-help code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
}

@media (max-width: 900px) {
  .unsure-grid {
    grid-template-columns: 1fr;
  }
}