:root {
  color-scheme: light;
  --ink: #18313b;
  --muted: #5f727a;
  --navy: #123b4a;
  --blue: #0878b9;
  --blue-soft: #e8f4fa;
  --green: #0c8068;
  --green-soft: #e4f5ef;
  --line: #d8e3e7;
  --surface: #ffffff;
  --surface-alt: #f4f8f9;
  --warning: #fff6df;
  --warning-line: #e8c86a;
  --shadow: 0 18px 50px rgba(18, 59, 74, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 5.5rem; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--surface-alt);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
}
a { color: var(--blue); }
a:focus-visible, summary:focus-visible { outline: 3px solid #f0ac2c; outline-offset: 3px; border-radius: 4px; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 99; padding: .7rem 1rem; color: white; background: var(--navy); }
.skip-link:focus { top: 1rem; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: 4.6rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .75rem clamp(1rem, 4vw, 3rem);
  color: white;
  background: rgba(18, 59, 74, .97);
  border-bottom: 1px solid rgba(255,255,255,.12);
  backdrop-filter: blur(14px);
}
.brand { display: flex; align-items: center; gap: .75rem; color: white; text-decoration: none; line-height: 1.15; }
.brand-mark { display: grid; place-items: center; width: 2.5rem; height: 2.5rem; font-weight: 800; background: var(--green); border-radius: .7rem .7rem .7rem .2rem; }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 1rem; letter-spacing: .01em; }
.brand small { margin-top: .22rem; color: #c6d9df; font-size: .78rem; }
.store-link, .closing > a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: .6rem 1rem;
  color: white;
  background: var(--green);
  border-radius: .6rem;
  font-weight: 700;
  text-decoration: none;
}
.store-link:hover, .closing > a:hover { background: #0a6e5b; }

.page-shell { width: min(1240px, 100%); margin: 0 auto; display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 2rem; padding: 2rem clamp(1rem, 4vw, 3rem) 4rem; }
.sidebar { position: sticky; top: 6.5rem; align-self: start; max-height: calc(100vh - 8rem); overflow: auto; padding: 1rem; background: var(--surface); border: 1px solid var(--line); border-radius: 1rem; box-shadow: var(--shadow); }
.nav-label { margin: 0 0 .55rem; color: var(--muted); font-size: .78rem; font-weight: 800; letter-spacing: .11em; text-transform: uppercase; }
.sidebar nav { display: grid; gap: .1rem; }
.sidebar a { padding: .42rem .55rem; color: #3d555e; border-radius: .45rem; font-size: .9rem; text-decoration: none; }
.sidebar a:hover { color: var(--navy); background: var(--blue-soft); }

main { min-width: 0; }
.intro, .section, .closing { background: var(--surface); border: 1px solid var(--line); box-shadow: var(--shadow); }
.intro { position: relative; overflow: hidden; padding: clamp(2rem, 6vw, 4.5rem); border-radius: 1.4rem; }
.intro::after { content: ""; position: absolute; width: 18rem; height: 18rem; right: -8rem; top: -9rem; border: 3rem solid var(--blue-soft); border-radius: 50%; pointer-events: none; }
.eyebrow { margin: 0 0 .35rem; color: var(--green); font-size: .78rem; font-weight: 850; letter-spacing: .13em; text-transform: uppercase; }
h1, h2, h3 { margin-top: 0; line-height: 1.17; color: var(--navy); }
h1 { position: relative; z-index: 1; max-width: 16ch; margin-bottom: 1rem; font-size: clamp(2.3rem, 6vw, 4.4rem); letter-spacing: -.045em; }
h2 { margin-bottom: .4rem; font-size: clamp(1.7rem, 3vw, 2.35rem); letter-spacing: -.025em; }
h3 { margin-bottom: .45rem; font-size: 1.1rem; }
p { margin: .65rem 0 0; }
.intro-copy { max-width: 65ch; color: var(--muted); font-size: 1.12rem; }
.formula { position: relative; z-index: 1; margin-top: 2rem; padding: 1rem; display: flex; flex-wrap: wrap; align-items: center; gap: .65rem; background: var(--navy); color: white; border-radius: .85rem; }
.formula span, .formula strong { padding: .32rem .58rem; background: rgba(255,255,255,.1); border-radius: .4rem; }
.formula strong { background: var(--green); }
.formula b { color: #89d6c4; }
.quick-links { display: flex; flex-wrap: wrap; gap: .65rem; margin-top: 1rem; }
.quick-links a { padding: .45rem .8rem; color: var(--navy); background: var(--blue-soft); border-radius: 999px; font-weight: 700; text-decoration: none; }

.section { margin-top: 1.15rem; padding: clamp(1.4rem, 4vw, 2.5rem); border-radius: 1.1rem; }
.section-heading { display: flex; align-items: center; gap: 1rem; padding-bottom: 1.15rem; border-bottom: 1px solid var(--line); }
.section-heading .eyebrow { margin-bottom: .2rem; }
.section-heading h2 { margin: 0; }
.step-number { display: grid; place-items: center; flex: 0 0 3rem; height: 3rem; color: white; background: var(--navy); border-radius: .8rem .8rem .8rem .25rem; font-size: .82rem; font-weight: 800; letter-spacing: .05em; }
.steps { margin: 1.35rem 0 0; padding: 0; list-style: none; counter-reset: tutorial-step; display: grid; gap: .75rem; }
.steps li { counter-increment: tutorial-step; position: relative; padding: .85rem 1rem .85rem 3.4rem; background: var(--surface-alt); border-radius: .7rem; }
.steps li::before { content: counter(tutorial-step); position: absolute; left: 1rem; top: .8rem; display: grid; place-items: center; width: 1.55rem; height: 1.55rem; color: white; background: var(--green); border-radius: 50%; font-size: .75rem; font-weight: 800; }
.steps.compact { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.note, .warning { margin-top: 1.25rem; padding: 1rem 1.1rem; border-left: 4px solid var(--green); background: var(--green-soft); border-radius: 0 .65rem .65rem 0; }
.warning { border-left-color: var(--warning-line); background: var(--warning); }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .85rem; margin-top: 1.25rem; }
.card-grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.feature-card { padding: 1.15rem; background: var(--surface-alt); border: 1px solid var(--line); border-radius: .8rem; }
.feature-card p { color: var(--muted); }
.calculation { margin-top: 1.25rem; display: grid; grid-template-columns: 1fr auto; border: 1px solid var(--line); border-radius: .8rem; overflow: hidden; }
.calculation span, .calculation strong { padding: .8rem 1rem; }
.calculation span { background: var(--surface-alt); }
.calculation strong { color: var(--green); border-left: 1px solid var(--line); }
.split-panel { display: grid; grid-template-columns: repeat(2, 1fr); gap: .8rem; margin-top: 1.25rem; }
.split-panel > div { padding: 1rem; color: white; background: var(--navy); border-radius: .75rem; }
.split-panel small, .split-panel strong { display: block; }
.split-panel small { margin-bottom: .25rem; color: #bcd4dc; }
.app-shot { width: min(100%, 29rem); margin: 1.4rem auto 0; padding: .6rem; background: var(--surface-alt); border: 1px solid var(--line); border-radius: 1rem; box-shadow: 0 18px 45px rgba(29, 51, 58, .12); }
.app-shot.app-shot-wide { width: min(100%, 33rem); }
.app-shot img { display: block; width: 100%; height: auto; border-radius: .65rem; }
.app-shot figcaption { padding: .8rem .55rem .35rem; color: var(--muted); font-size: .88rem; line-height: 1.5; text-align: center; }
.table-wrap { overflow-x: auto; margin-top: 1.25rem; border: 1px solid var(--line); border-radius: .75rem; }
table { width: 100%; min-width: 640px; border-collapse: collapse; }
th, td { padding: .78rem .9rem; text-align: left; border-bottom: 1px solid var(--line); }
th { color: white; background: var(--navy); font-size: .88rem; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:nth-child(even) { background: var(--surface-alt); }
code { padding: .15rem .35rem; background: var(--blue-soft); border-radius: .3rem; font-size: .92em; }
.faq-list { margin-top: 1.25rem; display: grid; gap: .65rem; }
details { padding: .9rem 1rem; background: var(--surface-alt); border: 1px solid var(--line); border-radius: .7rem; }
summary { cursor: pointer; color: var(--navy); font-weight: 750; }
details p { color: var(--muted); }
.closing { margin-top: 1.15rem; padding: clamp(1.5rem, 4vw, 2.6rem); display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; border-radius: 1.1rem; background: var(--navy); }
.closing h2, .closing p { color: white; }
.closing .eyebrow { color: #82dbc5; }
.closing > a { flex: 0 0 auto; }
.site-footer { display: flex; justify-content: space-between; gap: 1rem; padding: 1.4rem max(1rem, calc((100vw - 1180px) / 2)); color: var(--muted); background: white; border-top: 1px solid var(--line); }
.site-footer p { margin: 0; }
.support-cta, .support-submit { display: inline-flex; align-items: center; justify-content: center; min-height: 3rem; padding: .7rem 1.1rem; color: white; background: var(--green); border: 0; border-radius: .65rem; font: inherit; font-weight: 750; text-decoration: none; cursor: pointer; }
.support-cta:hover, .support-submit:hover { background: #0a6e5b; }
.support-shell { width: min(920px, calc(100% - 2rem)); margin: 2rem auto 4rem; }
.support-intro, .support-form { padding: clamp(1.4rem, 4vw, 2.5rem); background: var(--surface); border: 1px solid var(--line); border-radius: 1.1rem; box-shadow: var(--shadow); }
.support-intro h1 { max-width: 18ch; font-size: clamp(2.3rem, 6vw, 4rem); }
.support-preview { width: min(340px, 100%); margin: 1.5rem auto 0; }
.support-preview img { display: block; width: 100%; border: 1px solid var(--line); border-radius: 1rem; box-shadow: var(--shadow); }
.support-preview figcaption { margin-top: .6rem; color: var(--muted); font-size: .86rem; text-align: center; }
.support-form { margin-top: 1.15rem; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.form-grid label { display: grid; gap: .4rem; color: var(--navy); font-weight: 700; }
.form-grid label.full { grid-column: 1 / -1; }
.form-grid label small, .field-help { color: var(--muted); font-size: .85rem; font-weight: 500; }
.form-grid input, .form-grid select, .form-grid textarea { width: 100%; min-height: 3rem; padding: .72rem .8rem; color: var(--ink); background: white; border: 1px solid #b9c9cf; border-radius: .58rem; font: inherit; }
.form-grid textarea { resize: vertical; }
.form-grid input:focus, .form-grid select:focus, .form-grid textarea:focus { outline: 3px solid rgba(8, 120, 185, .2); border-color: var(--blue); }
.file-field { padding: 1rem; background: var(--surface-alt); border-radius: .7rem; }
.honeypot { position: absolute; left: -10000px; }
.support-submit { margin-top: 1.2rem; }
.support-submit:disabled { cursor: wait; opacity: .65; }
.form-status { margin-top: 1rem; padding: 0; }
.form-status.success, .form-status.error { padding: .85rem 1rem; border-radius: .6rem; }
.form-status.success { color: #075947; background: var(--green-soft); }
.form-status.error { color: #8b2f23; background: #fff0ed; }
.support-alternative { color: var(--muted); font-size: .92rem; }

@media (max-width: 900px) {
  .page-shell { grid-template-columns: 1fr; }
  .sidebar { position: static; max-height: none; }
  .sidebar nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .card-grid.three { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  html { scroll-padding-top: 7rem; }
  .topbar { align-items: flex-start; }
  .store-link { min-height: 2.4rem; padding: .5rem .7rem; font-size: .8rem; text-align: center; }
  .page-shell { padding-top: 1rem; }
  .sidebar { padding: .8rem; overflow-x: auto; }
  .sidebar nav { display: flex; width: max-content; }
  .sidebar a { white-space: nowrap; background: var(--surface-alt); }
  .intro { padding: 1.5rem; }
  .intro::after { display: none; }
  h1 { font-size: 2.35rem; }
  .formula { align-items: stretch; }
  .formula span, .formula strong { flex: 1 1 42%; text-align: center; }
  .formula b { align-self: center; }
  .steps.compact, .card-grid, .split-panel { grid-template-columns: 1fr; }
  .calculation { grid-template-columns: 1fr; }
  .calculation strong { border-left: 0; border-top: 1px solid var(--line); }
  .closing { align-items: stretch; flex-direction: column; }
  .site-footer { flex-direction: column; }
  .form-grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}