:root {
  --navy-deep: #0A1B30;
  --navy: #0F2540;
  --navy-light: #16324f;
  --grid-line: rgba(143,193,232,0.07);
  --grid-line-strong: rgba(143,193,232,0.16);
  --ink: #EAF2FA;
  --ink-muted: #96ACC6;
  --ink-faint: #5F7793;
  --amber: #FF8B42;
  --amber-soft: rgba(255,139,66,0.14);
  --teal: #52D6C9;
  --paper: #F6F8FA;
  --paper-line: #DCE3EA;
  --ink-dark: #16232F;
  --ink-dark-muted: #57677A;
  --radius: 10px;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'IBM Plex Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink-dark);
  background: var(--paper);
  line-height: 1.6;
}

img, svg { max-width: 100%; }

:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 3px;
}

.wrap {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */
header.site {
  background: var(--navy-deep);
  border-bottom: 1px solid var(--grid-line-strong);
}
.site-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  max-width: 1040px;
  margin: 0 auto;
  gap: 16px;
  flex-wrap: wrap;
}
.logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
  letter-spacing: -0.01em;
  text-decoration: none;
  display: flex;
  align-items: baseline;
  gap: 2px;
}
.logo .dot { color: var(--amber); }
nav.site-nav {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}
nav.site-nav a {
  color: var(--ink-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
}
nav.site-nav a:hover { color: var(--ink); }

/* ---------- Hero (homepage) ---------- */
.hero {
  background:
    linear-gradient(var(--navy), var(--navy)),
    repeating-linear-gradient(0deg, transparent, transparent 27px, var(--grid-line) 27px, var(--grid-line) 28px),
    repeating-linear-gradient(90deg, transparent, transparent 27px, var(--grid-line) 27px, var(--grid-line) 28px);
  color: var(--ink);
  padding: 56px 0 64px;
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
}
.eyebrow .blip {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 0 4px rgba(82,214,201,0.18);
}
h1 {
  font-family: var(--font-display);
  font-size: clamp(34px, 5.2vw, 56px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
  max-width: 14ch;
}
.hero-sub {
  font-size: clamp(15px, 1.7vw, 18px);
  color: var(--ink-muted);
  max-width: 46ch;
  margin: 0 0 40px;
}

.instrument-grid {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 20px;
  align-items: stretch;
}
@media (max-width: 780px) {
  .instrument-grid { grid-template-columns: 1fr; }
}

.panel {
  background: var(--navy-light);
  border: 1px solid var(--grid-line-strong);
  border-radius: var(--radius);
  padding: 26px 24px;
  position: relative;
}
.tick {
  position: absolute;
  width: 12px; height: 12px;
  border-color: var(--amber);
  border-style: solid;
  opacity: 0.85;
}
.tick.tl { top: -1px; left: -1px; border-width: 2px 0 0 2px; }
.tick.tr { top: -1px; right: -1px; border-width: 2px 2px 0 0; }
.tick.bl { bottom: -1px; left: -1px; border-width: 0 0 2px 2px; }
.tick.br { bottom: -1px; right: -1px; border-width: 0 2px 2px 0; }

.readout-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  padding: 14px 0;
  border-bottom: 1px solid var(--grid-line-strong);
  gap: 12px;
  flex-wrap: wrap;
}
.readout-row:first-of-type { padding-top: 2px; }
.readout-row:last-of-type { border-bottom: none; padding-bottom: 2px; }
.readout-label {
  font-size: 13px;
  color: var(--ink-muted);
  font-weight: 500;
}
.readout-label small {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 2px;
}
.readout-value {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(22px, 3.4vw, 30px);
  color: var(--ink);
  letter-spacing: -0.01em;
}
.ratio-badge {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--amber);
  background: var(--amber-soft);
  border-radius: 100px;
  padding: 3px 10px;
  margin-left: 10px;
  white-space: nowrap;
}

.chip-row {
  display: flex;
  gap: 10px;
  margin-top: 18px;
  flex-wrap: wrap;
}
.chip {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-muted);
  border: 1px solid var(--grid-line-strong);
  border-radius: 100px;
  padding: 6px 12px;
}
.chip b { color: var(--ink); font-weight: 600; }

.resize-note {
  margin-top: 18px;
  font-size: 13px;
  color: var(--ink-faint);
  display: flex;
  gap: 8px;
  align-items: flex-start;
}

.diagram-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.diagram-caption {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 22px;
}
.diagram-stage {
  position: relative;
  width: 100%;
  min-height: 170px;
  display: flex;
  align-items: center;
  justify-content: center;
}
#ratio-diagram {
  border: 1.5px dashed var(--teal);
  background: rgba(82,214,201,0.06);
  border-radius: 3px;
  transition: width 0.15s ease, height 0.15s ease;
  position: relative;
}
.dim-label {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--teal);
  white-space: nowrap;
}
.dim-label.dim-w { top: -24px; left: 50%; transform: translateX(-50%); }
.dim-label.dim-h {
  inset-inline-start: -12px; top: 50%;
  transform: translateY(-50%) rotate(-90deg);
  transform-origin: center;
}
.diagram-ratio-big {
  margin-top: 22px;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 600;
  color: var(--ink);
}
.diagram-ratio-big span { color: var(--amber); }

/* ---------- Page banner (inner pages) ---------- */
.page-banner {
  background:
    linear-gradient(var(--navy), var(--navy)),
    repeating-linear-gradient(0deg, transparent, transparent 27px, var(--grid-line) 27px, var(--grid-line) 28px),
    repeating-linear-gradient(90deg, transparent, transparent 27px, var(--grid-line) 27px, var(--grid-line) 28px);
  color: var(--ink);
  padding: 44px 0 48px;
}
.page-banner h1 {
  margin: 0;
  max-width: none;
  font-size: clamp(28px, 4vw, 40px);
}

/* ---------- Content sections ---------- */
main { background: var(--paper); }
section.content {
  padding: 56px 0;
  border-bottom: 1px solid var(--paper-line);
}
section.content:last-of-type { border-bottom: none; }
.section-label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #1a8a7e;
  margin: 0 0 10px;
}
h2 {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
  color: var(--ink-dark);
}
section.content p {
  max-width: 68ch;
  color: #3b4a5a;
  font-size: 15.5px;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  margin-top: 8px;
}
@media (max-width: 720px) {
  .two-col { grid-template-columns: 1fr; }
}
.howto-card {
  background: #fff;
  border: 1px solid var(--paper-line);
  border-radius: var(--radius);
  padding: 22px 24px;
}
.howto-card h3 {
  font-family: var(--font-display);
  font-size: 16.5px;
  margin: 0 0 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.howto-card ol {
  margin: 0;
  padding-left: 20px;
  color: #3b4a5a;
  font-size: 14.5px;
}
.howto-card li { margin-bottom: 8px; }
.howto-card li:last-child { margin-bottom: 0; }
.howto-tip {
  margin-top: 14px;
  font-size: 13px;
  color: var(--ink-dark-muted);
  padding-top: 12px;
  border-top: 1px dashed var(--paper-line);
}

table.res-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 8px;
  font-size: 14.5px;
}
table.res-table th, table.res-table td {
  text-align: left;
  padding: 11px 14px;
  border-bottom: 1px solid var(--paper-line);
}
table.res-table th {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-dark-muted);
  font-weight: 500;
}
table.res-table td:nth-child(2), table.res-table td:nth-child(3) {
  font-family: var(--font-mono);
  color: #1f2f3f;
}
table.res-table tr:last-child td { border-bottom: none; }

.faq-item {
  border-bottom: 1px solid var(--paper-line);
  padding: 16px 0;
}
.faq-item:first-of-type { padding-top: 0; }
.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 15.5px;
  color: var(--ink-dark);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 20px;
  color: #1a8a7e;
  flex-shrink: 0;
}
.faq-item[open] summary::after { content: "–"; }
.faq-item p {
  margin: 12px 0 0;
  font-size: 14.5px;
  color: #3b4a5a;
}

/* ---------- Prose pages (About / Privacy / Terms / Contact) ---------- */
.prose-page { padding: 56px 0 72px; background: var(--paper); }
.prose-page .wrap { max-width: 760px; }
.prose-page .updated {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-dark-muted);
  margin: 0 0 28px;
}
.prose-page h2 {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  margin: 36px 0 12px;
  color: var(--ink-dark);
}
.prose-page h2:first-of-type { margin-top: 0; }
.prose-page p {
  color: #3b4a5a;
  font-size: 15.5px;
  max-width: 68ch;
  margin: 0 0 14px;
}
.prose-page ul {
  color: #3b4a5a;
  font-size: 15.5px;
  padding-left: 20px;
  margin: 0 0 14px;
}
.prose-page li { margin-bottom: 6px; }
.contact-email {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 15.5px;
  color: #12766c;
  text-decoration: none;
  border: 1px solid var(--paper-line);
  border-radius: 8px;
  padding: 12px 18px;
  margin-top: 6px;
  background: #fff;
}
.contact-email:hover { border-color: #12766c; }

/* ---------- Footer ---------- */
footer.site {
  background: var(--navy-deep);
  color: var(--ink-muted);
  padding: 40px 0 28px;
}
.footer-cols {
  display: flex;
  gap: 56px;
  flex-wrap: wrap;
  padding-top: 4px;
}
.footer-heading {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 14px;
}
.footer-col a {
  display: block;
  color: var(--ink-muted);
  text-decoration: none;
  font-size: 13.5px;
  margin-bottom: 9px;
}
.footer-col a:hover { color: var(--ink); }
.footer-col-langs { flex: 1; min-width: 260px; }
.lang-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
}
.lang-grid a { margin-bottom: 0; }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 13px;
  padding-top: 24px;
  margin-top: 24px;
  border-top: 1px solid var(--grid-line-strong);
}