/* Backsolved — one stylesheet, no framework, no build step, no webfont.
   Loads in a single round trip on a 3G connection in an Indian metro,
   which is the only performance target that matters here. */

:root {
  --paper: #FAF9F6;
  --paper-2: #F2F0EA;
  --card: #FFFFFF;
  --ink: #17161A;
  --ink-2: #3C3A42;
  --muted: #6E6B75;
  --rule: #E2DFD6;
  --rule-2: #CFCBBF;
  --ok: #1B6B4C;
  --ok-bg: #E8F2ED;
  --bad: #A93B24;
  --bad-bg: #FBEDE9;
  --accent: #1F3D7A;
  --accent-soft: #E9EDF6;

  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --max: 1080px;
  --measure: 68ch;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

@media (max-width: 640px) { body { font-size: 16px; } }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* .narrow keeps prose to a readable measure WITHOUT re-centring the column —
   a page that alternates between a flush-left edge and a centred one reads as
   two different templates stitched together. One left edge, everywhere. */
.wrap.narrow > *,
.wrap.narrow > section > * { max-width: 760px; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--ink); }

h1, h2, h3 { line-height: 1.15; letter-spacing: -0.021em; margin: 0 0 .5em; font-weight: 700; }
h1 { font-size: clamp(2.1rem, 5.2vw, 3.4rem); }
h2 { font-size: clamp(1.5rem, 3.2vw, 2.05rem); margin-top: 2.4em; }
h3 { font-size: 1.12rem; margin-top: 2em; }
p { margin: 0 0 1.1em; max-width: var(--measure); }
ul, ol { max-width: var(--measure); padding-left: 1.2em; }
li { margin-bottom: .45em; }
strong { font-weight: 650; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 3rem 0; }

.lede { font-size: 1.16rem; color: var(--ink-2); }
.small { font-size: .88rem; color: var(--muted); }
.mono { font-family: var(--mono); font-size: .93em; }

/* ---------- header ---------- */
.site-head {
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
  position: sticky; top: 0; z-index: 20;
}
.site-head .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 20px; min-height: 64px;
}
.brand {
  font-weight: 700; font-size: 1.08rem; letter-spacing: -0.02em;
  color: var(--ink); text-decoration: none; display: inline-flex; align-items: center; gap: 9px;
}
.brand svg { display: block; }
.nav { display: flex; gap: 22px; align-items: center; }
.nav a { color: var(--ink-2); text-decoration: none; font-size: .95rem; }
.nav a:hover { color: var(--ink); text-decoration: underline; }
@media (max-width: 720px) {
  .nav a.hide-sm { display: none; }
  .site-head .wrap { padding: 0 18px; }
}

/* ---------- buttons ---------- */
.btn {
  display: inline-block; padding: 13px 22px; border-radius: 7px;
  background: var(--ink); color: var(--paper); text-decoration: none;
  font-weight: 600; font-size: .97rem; border: 1px solid var(--ink);
  transition: transform .08s ease, background .15s ease;
}
.btn:hover { background: #000; color: #fff; transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--rule-2); }
.btn-ghost:hover { background: var(--paper-2); color: var(--ink); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin: 1.6em 0 .8em; }

/* ---------- notice strip ---------- */
.strip {
  background: var(--accent-soft); border-bottom: 1px solid #D5DCEC;
  font-size: .9rem; color: #23325C;
}
.strip .wrap { padding-top: 9px; padding-bottom: 9px; }
.strip p { margin: 0; max-width: none; }

/* ---------- hero ---------- */
.hero { padding: 72px 0 8px; }
.hero h1 { max-width: 16ch; }
.hero .lede { max-width: 54ch; }
@media (max-width: 640px) { .hero { padding: 44px 0 4px; } }

.kicker {
  font-family: var(--mono); font-size: .78rem; letter-spacing: .09em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 18px;
}

/* ---------- the verifier motif ---------- */
.check {
  background: var(--card); border: 1px solid var(--rule);
  border-radius: 10px; padding: 0; overflow: hidden;
  box-shadow: 0 1px 2px rgba(20,18,14,.04), 0 8px 24px -18px rgba(20,18,14,.35);
  margin: 2.2em 0;
}
.check-head {
  padding: 10px 18px; border-bottom: 1px solid var(--rule);
  background: var(--paper-2); font-family: var(--mono);
  font-size: .74rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted);
}
.check-body { padding: 18px; overflow-x: auto; }
.check-row {
  display: grid; grid-template-columns: 1fr auto; gap: 8px 18px;
  align-items: start; padding: 12px 0; border-bottom: 1px dashed var(--rule);
}
.check-row:last-child { border-bottom: 0; }
.check-said { font-family: var(--mono); font-size: .95rem; color: var(--ink); white-space: nowrap; }
.check-note { grid-column: 1 / -1; font-size: .88rem; color: var(--muted); }
.tag {
  font-family: var(--mono); font-size: .76rem; font-weight: 600;
  padding: 3px 9px; border-radius: 20px; white-space: nowrap;
}
.tag-ok { background: var(--ok-bg); color: var(--ok); }
.tag-bad { background: var(--bad-bg); color: var(--bad); }
.check-note b { color: var(--bad); font-weight: 650; }
.check-note em { color: var(--ok); font-style: normal; font-weight: 650; }

/* ---------- grids ---------- */
.grid { display: grid; gap: 22px; margin: 1.8em 0; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 820px) { .grid-3, .grid-2 { grid-template-columns: 1fr; } }

.card {
  background: var(--card); border: 1px solid var(--rule);
  border-radius: 10px; padding: 22px;
}
.card h3 { margin-top: 0; font-size: 1.02rem; }
.card p:last-child { margin-bottom: 0; }
.card .num {
  font-family: var(--mono); font-size: .78rem; color: var(--muted);
  display: block; margin-bottom: 10px; letter-spacing: .08em;
}

/* ---------- comparison ---------- */
table { border-collapse: collapse; width: 100%; margin: 1.6em 0; font-size: .95rem; }
th, td { text-align: left; padding: 13px 14px; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-weight: 650; font-size: .82rem; letter-spacing: .04em; text-transform: uppercase; color: var(--muted); }
td:first-child { font-weight: 600; }
.tbl-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }

/* ---------- pricing ---------- */
.price-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; margin: 2em 0; align-items: start; }
@media (max-width: 760px) { .price-grid { grid-template-columns: 1fr; } }
.price {
  border: 1px solid var(--rule); border-radius: 12px; padding: 26px; background: var(--card);
}
.price.featured { border-color: var(--ink); border-width: 1.5px; }
.price .amt { font-size: 2.1rem; font-weight: 700; letter-spacing: -0.03em; margin: 6px 0 2px; }
.price .amt small { font-size: .95rem; font-weight: 500; color: var(--muted); letter-spacing: 0; }
.price ul { list-style: none; padding: 0; margin: 18px 0 0; }
.price li { padding-left: 22px; position: relative; font-size: .95rem; color: var(--ink-2); }
.price li::before {
  content: "→"; position: absolute; left: 0; color: var(--muted); font-family: var(--mono); font-size: .85rem;
}

/* ---------- faq ---------- */
details {
  border-bottom: 1px solid var(--rule); padding: 16px 0;
}
summary {
  cursor: pointer; font-weight: 600; list-style: none;
  display: flex; justify-content: space-between; gap: 16px; align-items: baseline;
}
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; color: var(--muted); font-family: var(--mono); font-weight: 400; }
details[open] summary::after { content: "−"; }
details p { margin: 12px 0 2px; color: var(--ink-2); }

/* ---------- legal / long-form ---------- */
.legal { padding: 48px 0 20px; }
.legal h2 { font-size: 1.22rem; margin-top: 2.2em; }
.legal p, .legal li { color: var(--ink-2); }
.legal .updated {
  font-family: var(--mono); font-size: .8rem; color: var(--muted);
  border: 1px solid var(--rule); border-radius: 6px; padding: 10px 14px;
  display: inline-block; margin-bottom: 2em;
}
.callout {
  border-left: 3px solid var(--rule-2); padding: 4px 0 4px 18px;
  margin: 1.6em 0; color: var(--ink-2);
}

/* ---------- sections & footer ---------- */
section { padding: 6px 0; }
.band { background: var(--paper-2); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); margin-top: 4rem; padding: 8px 0 40px; }

.site-foot { border-top: 1px solid var(--rule); margin-top: 4rem; padding: 40px 0 60px; font-size: .92rem; }
.foot-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; }
@media (max-width: 720px) { .foot-grid { grid-template-columns: 1fr 1fr; } }
.site-foot h4 { font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 12px; font-weight: 650; }
.site-foot ul { list-style: none; padding: 0; margin: 0; }
.site-foot li { margin-bottom: 7px; }
.site-foot a { color: var(--ink-2); text-decoration: none; }
.site-foot a:hover { color: var(--ink); text-decoration: underline; }
.site-foot .colophon { margin-top: 34px; padding-top: 22px; border-top: 1px solid var(--rule); color: var(--muted); font-size: .85rem; }
.site-foot .colophon p { max-width: none; }

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: var(--paper); padding: 10px 16px; z-index: 50;
}
.skip:focus { left: 8px; top: 8px; }

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