:root {
  --ink: #0a0a0b; --line: #26262b; --line-2: #3a3a41; --text: #ecebe6; --muted: #8a8a90;
  --red: #ff4646; --green: #72e872; color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--ink); color: var(--text); font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; overflow-x: hidden; }
a { color: inherit; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.hw { display: block; height: 100%; width: auto; max-width: 100%; overflow: visible; }
.hw path, .hw-w path, .board path { fill: none; stroke-linecap: round; stroke-linejoin: round; }

.top { display: flex; align-items: center; justify-content: space-between; padding: 18px clamp(16px, 4vw, 40px); max-width: 1200px; margin: 0 auto; }
.logo { display: block; height: 34px; }
.top-cta { color: var(--muted); font-size: 14px; text-decoration: none; border-bottom: 1px solid var(--line-2); padding-bottom: 2px; }
.top-cta:hover { color: var(--text); border-color: var(--text); }
.top-links { display: flex; align-items: center; gap: 22px; }
.top-in { color: #5f5f66; font-size: 14px; text-decoration: none; }
.top-in:hover { color: var(--text); }

main { max-width: 1200px; margin: 0 auto; padding: 0 clamp(16px, 4vw, 40px); }
section { scroll-margin-top: 16px; }

/* hero */
.hero { text-align: center; padding: clamp(18px, 4vw, 44px) 0 24px; }
.headline { margin: 0; font-weight: normal; }
.hl { display: block; line-height: 1.12; }
.hl-1 { font-size: clamp(40px, 7vw, 86px); }
.hl-2 { font-size: clamp(27px, 4vw, 52px); margin-top: .1em; }
.hw-w { display: inline-block; height: 1em; width: auto; margin: 0 .09em; vertical-align: top; overflow: visible; }
.tagline { margin: 14px auto 0; color: var(--muted); font-size: clamp(16px, 1.7vw, 19px); }
.lede { max-width: 560px; margin: 10px auto 24px; color: #c9c9c4; font-size: clamp(16px, 1.5vw, 18px); }
.btn { display: inline-block; background: var(--text); color: var(--ink); border: 0; border-radius: 10px; padding: 13px 20px; font: inherit; font-weight: 600; text-decoration: none; cursor: pointer; }
.btn:hover { background: #fff; }
.btn:disabled { opacity: .5; cursor: default; }
.cta { font-size: 17px; padding: 14px 24px; }
.cta-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }
.btn.ghost { background: none; color: var(--text); box-shadow: inset 0 0 0 1px var(--line-2); }
.btn.ghost:hover { background: none; box-shadow: inset 0 0 0 1px var(--text); }
.board-wrap { max-width: 1040px; margin: 30px auto 0; }
.board { display: block; width: 100%; aspect-ratio: 16 / 9; background: var(--ink); border: 1px solid #1d1d21; border-radius: 12px; }
.board .hit { fill: transparent; }
.board .pen-tip { opacity: 0; transition: opacity .35s; stroke: #ffffffcc; stroke-width: 1.5; filter: drop-shadow(0 0 5px #fff6); }
.board .pen-tip.on { opacity: .95; transition: opacity .1s; }
.caption { min-height: 3em; margin-top: 12px; color: #d9d9d4; font-size: 15px; transition: opacity .3s; }
.caption.small { min-height: 2.8em; margin-top: 10px; font-size: 14px; color: #b9b9b4; }

/* the hero board's try-it picker and subtitles live inside its frame, over the bottom edge */
.board-wrap { scroll-margin-top: 12px; }
.stage { position: relative; }
.subs, .picker { position: absolute; left: 1px; right: 1px; bottom: 1px; border-radius: 0 0 11px 11px; transition: opacity .25s; }
.subs { padding: 56px 28px 16px; background: linear-gradient(#0a0a0b00, #0a0a0bd0 45%, #0a0a0bf2); text-align: center; opacity: 0; pointer-events: none; }
.subs.on { opacity: 1; }
.subs .asked { color: #7df0c4; font-size: 14px; }
.subs .asked:empty { display: none; }
.subs .caption { min-height: 0; max-width: 820px; margin: 4px auto 0; color: var(--text); font-size: 16px; line-height: 1.45; }
.picker { padding: 48px 20px 12px; background: linear-gradient(#0a0a0b00, #0a0a0bd0 38%, #0a0a0bf2); }
.picker.away { opacity: 0; pointer-events: none; }
.sheet { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 8px 14px; }
.subjects { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px; }
.subjects button { background: none; border: 1px solid var(--line-2); border-radius: 999px; padding: 5px 12px; font: inherit; font-size: 13px; color: var(--muted); cursor: pointer; }
.subjects button[aria-selected="true"] { background: var(--text); border-color: var(--text); color: var(--ink); font-weight: 600; }
.chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; }
.chips button { display: none; background: #141416e6; border: 1px solid var(--line); border-radius: 10px; padding: 7px 12px; font: inherit; font-size: 14px; line-height: 1.35; color: var(--text); text-align: left; cursor: pointer; }
.chips button:hover { background: #1b1b1f; border-color: var(--line-2); }
.chips button.on { border-color: #3c6f5d; color: #7df0c4; }
.chips[data-show="math"] [data-sub="math"], .chips[data-show="physics"] [data-sub="physics"],
.chips[data-show="chemistry"] [data-sub="chemistry"], .chips[data-show="biology"] [data-sub="biology"] { display: block; }
.ask { display: flex; align-items: center; gap: 10px; max-width: 560px; margin: 8px auto 0; padding: 6px 6px 6px 16px; background: #0e0e10; border: 1px solid var(--line); border-radius: 12px; text-align: left; cursor: default; }
.ask-text { flex: 1; min-width: 0; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; color: #5f5f66; font-size: 14px; }
.ask.typing .ask-text { color: var(--text); }
.ask-send { display: grid; place-items: center; width: 28px; height: 28px; flex: none; border-radius: 50%; background: #222226; color: var(--muted); font-size: 14px; transition: background .2s, color .2s; }
.ask.typing .ask-send { background: var(--text); color: var(--ink); }
.qs-toggle { display: none; }
.try-note { flex-basis: 100%; margin: 0; color: #6a6a70; font-size: 12px; line-height: 1.4; text-align: center; }
.again { position: absolute; top: 12px; right: 12px; background: #0a0a0bcc; border: 1px solid var(--line-2); border-radius: 999px; padding: 5px 13px; font: inherit; font-size: 13px; color: var(--text); cursor: pointer; opacity: 0; pointer-events: none; transition: opacity .25s; }
.again.on { opacity: 1; pointer-events: auto; }
.again:hover { border-color: var(--text); }

.sec-title { height: clamp(38px, 5vw, 60px); display: flex; justify-content: center; }

/* before / after */
.ba { text-align: center; padding: 64px 0 8px; }
.ba-grid { display: grid; grid-template-columns: 1fr auto 1fr; gap: 18px; align-items: start; max-width: 1100px; margin: 26px auto 0; text-align: left; }
.ba-side { margin: 0; min-width: 0; }
.ba-side figcaption { color: var(--muted); font-size: 14px; margin-bottom: 8px; }
.ba-side figcaption span { color: #5f5f66; }
.ba-arrow { align-self: center; color: var(--muted); font-size: 28px; padding-bottom: 12px; }
.ba .board { border-radius: 8px; }
.ba .caption { text-align: left; }
.slide { container-type: inline-size; aspect-ratio: 16 / 9; background: #f7f7f4; color: #1e1e1e; border-radius: 8px; padding: 5.5% 6.5%; font-family: Calibri, Carlito, "Segoe UI", Arial, sans-serif; overflow: hidden; }
.slide-title { font-size: 18px; font-size: 5cqw; font-weight: 700; line-height: 1.15; margin-bottom: 4%; }
.slide ul { margin: 0; padding-left: 1.1em; font-size: 14px; font-size: 3.7cqw; line-height: 1.5; }
.slide sup { font-size: .65em; line-height: 0; }

/* three points */
.points { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(18px, 3vw, 36px); padding: 64px 0 24px; }
.pt-title { height: 34px; margin-bottom: 10px; }
.point p { margin: 0; color: #b9b9b4; font-size: 15px; }

/* from your phone */
.phone { text-align: center; padding: 56px 0 8px; border-top: 1px solid #17171a; margin-top: 40px; }
.phone-grid { display: grid; grid-template-columns: 1fr 1.15fr; gap: clamp(20px, 4vw, 48px); align-items: center; max-width: 1040px; margin: 26px auto 0; text-align: left; }
.phone-list { list-style: none; margin: 0; padding: 0; }
.phone-list li { margin: 0 0 16px; color: #b9b9b4; font-size: 15.5px; }
.phone-list li:last-child { margin-bottom: 0; }
.phone-list b { color: var(--text); font-weight: 600; }
.phone-board { margin: 0; }
.phone-board .board { border-radius: 10px; }
.phone-board figcaption { margin-top: 10px; color: var(--muted); font-size: 14px; }
.tick { color: var(--green); }
.miss { color: var(--red); }

/* pricing */
.pricing { text-align: center; padding: 56px 0 8px; border-top: 1px solid #17171a; margin-top: 48px; }
.anchor { max-width: 620px; margin: 16px auto 0; color: var(--muted); font-size: clamp(16px, 1.7vw, 19px); }
.anchor .ln { display: block; }
.anchor b { color: var(--text); font-weight: 500; }
[data-cad] { white-space: nowrap; }
.cur-toggle { display: inline-flex; margin: 18px 0 22px; border: 1px solid var(--line-2); border-radius: 8px; overflow: hidden; }
.cur-toggle button { background: none; border: 0; padding: 5px 14px; font: inherit; font-size: 13px; color: var(--muted); cursor: pointer; }
.cur-toggle button.on { background: var(--text); color: var(--ink); font-weight: 600; }
.founding { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 14px 28px; max-width: 980px; margin: 0 auto 22px; padding: 18px 24px; border: 1px solid #6a2c2c; border-radius: 12px; background: #ff46460b; text-align: left; }
.founding-title { height: 40px; }
.founding p { margin: 0; color: #d9d9d4; font-size: 15.5px; }
.founding p b { color: var(--text); font-weight: 600; }
.founding .btn { white-space: nowrap; }
.tiers { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(14px, 2vw, 24px); max-width: 980px; margin: 0 auto; text-align: left; }
.tier { position: relative; border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; }
.tier.main { border-color: #6a2c2c; }
.tag { position: absolute; top: 16px; right: 16px; color: var(--red); font-size: 12px; border: 1px solid #6a2c2c; border-radius: 999px; padding: 1px 9px; }
.tier-name { height: 38px; }
.tier-price { margin: 8px 0 2px; color: #d9d9d4; }
.tier-price b { font-size: 22px; font-weight: 600; color: var(--text); }
.tier-alt { color: var(--muted); font-size: 14px; }
.tier-founding { margin-top: 4px; color: #ffb3b3; font-size: 14px; }
.tier ul { margin: 12px 0 0; padding-left: 18px; color: #b9b9b4; font-size: 15px; line-height: 1.7; }

/* faq */
.faq { max-width: 720px; margin: 0 auto; padding: 56px 0 8px; }
.faq .sec-title { margin-bottom: 18px; }
.faq details { border-bottom: 1px solid var(--line); }
.faq details:first-of-type { border-top: 1px solid var(--line); }
.faq summary { display: flex; justify-content: space-between; gap: 16px; padding: 14px 2px; cursor: pointer; list-style: none; font-weight: 600; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; color: var(--muted); font-weight: 400; }
.faq details[open] summary::after { content: '–'; }
.faq details p { margin: 0 2px 16px; color: #b9b9b4; font-size: 15.5px; }
.faq details a { color: var(--text); text-underline-offset: 3px; }

/* waitlist */
.join { text-align: center; padding: 56px 0 72px; border-top: 1px solid #17171a; margin-top: 48px; }
.join p { color: #b9b9b4; max-width: 520px; margin: 14px auto 26px; }
.form { display: grid; gap: 14px; max-width: 440px; margin: 0 auto; }
.form input { background: none; border: 0; border-bottom: 1px solid var(--line-2); padding: 11px 2px; font: inherit; color: var(--text); outline: none; text-align: center; min-width: 0; }
.form input:focus { border-color: var(--text); }
.form input::placeholder { color: #5f5f66; }
.form .btn { margin-top: 8px; padding: 13px; }
.hp { position: absolute; left: -9999px; }
.msg { min-height: 24px; font-size: 14px; color: var(--muted); }
.msg.ok { color: var(--green); }
.msg.bad { color: #ff8a8a; }
.foot { text-align: center; color: #55555b; font-size: 13px; padding: 24px 16px 40px; }
.foot a { color: #77777d; text-decoration: none; }
.foot a:hover { color: var(--text); }

/* terms + privacy */
.legal { max-width: 720px; padding-bottom: 40px; }
.page-title { height: clamp(44px, 7vw, 64px); margin: 18px 0 14px; }
.legal .draft { margin: 0 0 10px; padding: 12px 16px; border: 1px solid #5a2a2a; border-radius: 10px; background: #ff46460d; color: #ffb3b3; font-size: 14px; }
.legal .updated { margin: 0 0 8px; color: var(--muted); font-size: 13px; }
.legal h2 { margin: 34px 0 8px; font-size: 18px; font-weight: 600; }
.legal p, .legal li { color: #c9c9c4; font-size: 15.5px; }
.legal ul { padding-left: 20px; }
.legal li { margin: 4px 0; }
.legal a { color: var(--text); text-underline-offset: 3px; }

/* phone: the board is ~200px tall, so only a slim ask bar sits in the frame; questions open in a sheet above it,
   and the subtitles go under the board instead of over it */
@media (max-width: 600px) {
  .picker { padding: 26px 6px 6px; background: linear-gradient(#0a0a0b00, #0a0a0be0 55%); }
  .ask { margin: 0; padding: 4px; gap: 8px; cursor: pointer; }
  .ask-text { font-size: 13px; }
  .ask-send { width: 26px; height: 26px; font-size: 13px; }
  .qs-toggle { display: block; flex: none; background: var(--text); border: 0; border-radius: 999px; padding: 4px 10px; font: inherit; font-size: 12.5px; font-weight: 600; color: var(--ink); cursor: pointer; }
  .sheet { display: none; position: absolute; left: 6px; right: 6px; bottom: calc(100% - 20px); flex-direction: column; align-items: stretch; gap: 8px; padding: 10px; background: #111113f5; border: 1px solid var(--line-2); border-radius: 12px; }
  .picker.open .sheet { display: flex; }
  .chips { flex-direction: column; gap: 6px; }
  .chips button { font-size: 13.5px; padding: 7px 10px; }
  .try-note { font-size: 11px; }
  .subs { position: static; display: none; padding: 10px 0 0; background: none; border-radius: 0; }
  .subs.on { display: block; }
  .subs .caption { font-size: 14.5px; color: #d9d9d4; }
  .again { top: 8px; right: 8px; padding: 3px 10px; font-size: 12px; }
}

@media (max-width: 760px) {
  .logo { height: 28px; }
  .top-links { gap: 16px; }
  .ba-grid, .phone-grid { grid-template-columns: 1fr; }
  .ba-arrow { transform: rotate(90deg); justify-self: center; padding: 0; line-height: 1; }
  .points { grid-template-columns: 1fr; padding-top: 44px; }
  .tiers { grid-template-columns: 1fr; }
  .founding { grid-template-columns: 1fr; text-align: center; justify-items: center; padding: 18px 16px; }
  .founding-title { display: flex; justify-content: center; }
}