/* The Book Launch Playbook. Colours sampled from the cover (ART-DIRECTION.md). */
@font-face { font-family: 'Crimson Pro'; src: url(assets/fonts/crimson-pro-400.woff2) format('woff2'); font-weight: 400; font-display: swap; }
@font-face { font-family: 'Crimson Pro'; src: url(assets/fonts/crimson-pro-500.woff2) format('woff2'); font-weight: 500 600; font-display: swap; }
@font-face { font-family: 'Crimson Pro'; src: url(assets/fonts/crimson-pro-400i.woff2) format('woff2'); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: 'Archivo'; src: url(assets/fonts/archivo-700.woff2) format('woff2'); font-weight: 600 800; font-display: swap; }
@font-face { font-family: 'Inter'; src: url(assets/fonts/inter-400.woff2) format('woff2'); font-weight: 400; font-display: swap; }
@font-face { font-family: 'Inter'; src: url(assets/fonts/inter-600.woff2) format('woff2'); font-weight: 600 700; font-display: swap; }

:root {
	--teal: #038994;
	--teal-deep: #02727b;
	--yellow: #fcda17;
	--cream: #e5d9c1;
	--cream-2: #e1d0b6;
	--ink: #0b4e55;
	--serif: 'Crimson Pro', Garamond, Georgia, serif;
	--caps: 'Archivo', 'Helvetica Neue', Arial, sans-serif;
	--sans: 'Inter', 'Helvetica Neue', Arial, sans-serif;
	/* the stack photograph's shape, 860 x 1520 */
	--stack-ratio: .5658;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--teal); color: #fff; font: 400 17px/1.55 var(--sans); overflow-x: hidden; }
h1, h2, h3 { font-weight: 400; margin: 0; text-wrap: balance; }
p { margin: 0; }
a { color: inherit; }
img { max-width: 100%; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.wrap { width: min(1160px, 100% - 48px); margin: 0 auto; }
.narrow { width: min(760px, 100% - 48px); }
:focus-visible { outline: 3px solid var(--yellow); outline-offset: 3px; }
.paper :focus-visible { outline-color: var(--ink); }

.skip { position: absolute; left: 12px; top: -60px; z-index: 80; background: var(--yellow); color: #111; padding: 10px 14px; border-radius: 6px; font: 700 14px var(--sans); }
.skip:focus { top: 12px; }

/* The small buy tag that stays all page once the reader scrolls */
.buy-tag {
	position: fixed; top: 16px; right: 16px; z-index: 50; background: var(--yellow); color: #111; text-decoration: none;
	font: 800 12px/1 var(--caps); letter-spacing: .14em; text-transform: uppercase; padding: 12px 16px; border-radius: 4px;
	box-shadow: 0 10px 22px -10px rgba(0, 30, 35, .55); opacity: 0; pointer-events: none; transform: translateY(-8px);
	transition: opacity .25s, transform .25s;
}
.buy-tag.on { opacity: 1; pointer-events: auto; transform: none; }
html:not(.js) .buy-tag { opacity: 1; pointer-events: auto; transform: none; position: absolute; }

.btn {
	display: inline-flex; align-items: center; justify-content: center; min-height: 50px; padding: 14px 24px; border-radius: 4px;
	font: 800 13px/1 var(--caps); letter-spacing: .14em; text-transform: uppercase; text-decoration: none; cursor: pointer; border: 2px solid transparent;
	transition: transform .12s, box-shadow .2s, background .2s;
}
.btn-buy { background: var(--yellow); color: #111; box-shadow: 0 12px 24px -12px rgba(0, 25, 30, .6); }
.btn-buy:hover { transform: translateY(-1px); box-shadow: 0 16px 26px -12px rgba(0, 25, 30, .7); }
.btn-buy:active { transform: translateY(1px) scale(.98); }
.btn-quiet { border-color: rgba(255, 255, 255, .7); color: #fff; }
.btn-quiet:hover { background: rgba(255, 255, 255, .1); }
.btn-store { border: 2px dashed rgba(255, 255, 255, .7); color: #fff; letter-spacing: .06em; text-transform: none; font-weight: 700; font-size: 14px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }

/* Placeholders look like placeholders, in the page's own type */
.placeholder { display: inline-block; border: 1.5px dashed currentColor; border-radius: 4px; padding: 7px 12px; font: 600 13px/1.3 var(--sans); opacity: .9; }
.ph-dark { color: rgba(255, 255, 255, .85); }

/* ---------- The stack: one photograph, cut into its 11 books ---------- */
.stack { position: relative; aspect-ratio: 860 / 1520; }
.stack i { position: absolute; inset: 0; background: url(assets/stack/stack.webp) 0 0 / 100% 100% no-repeat; will-change: transform; }
.stack i:nth-child(1) { clip-path: polygon(0% 0%, 100% 0%, 100% 13.95%, 88.37% 13.68%, 44.19% 16.45%, 0% 16.45%); }
.stack i:nth-child(2) { clip-path: polygon(0% 16.45%, 44.19% 16.45%, 88.37% 13.68%, 100% 13.95%, 100% 21.71%, 46.51% 23.16%, 0% 23.16%); }
.stack i:nth-child(3) { clip-path: polygon(0% 23.16%, 46.51% 23.16%, 100% 21.71%, 100% 28.29%, 69.77% 28.55%, 45.93% 33.88%, 0% 33.22%); }
.stack i:nth-child(4) { clip-path: polygon(0% 33.22%, 45.93% 33.88%, 69.77% 28.55%, 100% 28.29%, 100% 38.55%, 0% 38.68%); }
.stack i:nth-child(5) { clip-path: polygon(0% 38.68%, 100% 38.55%, 100% 50%, 87.21% 49.47%, 69.77% 46.84%, 16.28% 47.24%, 0% 47.63%); }
.stack i:nth-child(6) { clip-path: polygon(0% 47.63%, 16.28% 47.24%, 69.77% 46.84%, 87.21% 49.47%, 100% 50%, 100% 56.32%, 93.02% 55.92%, 37.21% 53.03%, 0% 54.08%); }
.stack i:nth-child(7) { clip-path: polygon(0% 54.08%, 37.21% 53.03%, 93.02% 55.92%, 100% 56.32%, 100% 62.5%, 44.19% 60.39%, 0% 60.79%); }
.stack i:nth-child(8) { clip-path: polygon(0% 60.79%, 44.19% 60.39%, 100% 62.5%, 100% 68.68%, 0% 68.29%); }
.stack i:nth-child(9) { clip-path: polygon(0% 68.29%, 100% 68.68%, 100% 75.53%, 77.91% 75.79%, 62.79% 78.55%, 0% 77.63%); }
.stack i:nth-child(10) { clip-path: polygon(0% 77.63%, 62.79% 78.55%, 77.91% 75.79%, 100% 75.53%, 100% 84.34%, 78.14% 83.95%, 69.77% 89.74%, 0% 88.16%); }
.stack i:nth-child(11) { clip-path: polygon(0% 88.16%, 69.77% 89.74%, 78.14% 83.95%, 100% 84.34%, 100% 100%, 0% 100%); }

/* ---------- 1. The promise ---------- */
.promise { position: relative; min-height: 100vh; min-height: 100svh; overflow: hidden; display: flex; align-items: center; }
.promise-copy { position: relative; z-index: 2; width: min(720px, 56vw); padding: 64px 0 72px 6vw; }
.title { font-family: var(--serif); line-height: .92; letter-spacing: -.01em; }
.title .t1 { display: block; font-size: clamp(48px, 6.6vw, 104px); }
.title .t2 { display: block; color: var(--yellow); font-size: clamp(66px, 9.2vw, 148px); margin-top: .04em; }
.subtitle { text-wrap: balance; margin-top: 26px; font: 400 clamp(19px, 1.75vw, 26px)/1.3 var(--sans); letter-spacing: .06em; max-width: 30em; }
.subtitle .caps { display: block; font: 700 .9em/1.2 var(--caps); letter-spacing: .16em; text-transform: uppercase; margin-bottom: 4px; }
.subtitle em, .ki-bands em { font-family: var(--serif); font-size: 1.12em; letter-spacing: .03em; }
.promise-line { margin-top: 26px; font: 400 clamp(22px, 2vw, 30px)/1.25 var(--serif); }
.promise-line strong { font-weight: 500; position: relative; white-space: nowrap; color: var(--yellow); }
.promise-line strong::after { content: ''; position: absolute; left: 0; right: 0; bottom: -2px; height: 2px; background: var(--yellow); transform-origin: left; }
.js .promise-line strong::after { transform: scaleX(0); transition: transform .6s cubic-bezier(.3, .8, .3, 1); }
.js .promise-line strong.lit::after { transform: none; }
.byline { margin-top: 18px; font: 700 13px/1.3 var(--caps); letter-spacing: .18em; text-transform: uppercase; opacity: .92; }
.promise .actions { margin-top: 28px; }
.skip-inline { display: inline-block; margin-top: 14px; font: 600 14px var(--sans); opacity: .85; }
.promise .placeholder { display: block; width: max-content; max-width: 100%; margin-top: 22px; }

.promise-art { position: absolute; right: 0; bottom: 0; height: 100%; width: 48vw; z-index: 1; pointer-events: none; }
/* The stack stands where it stands on the cover: against the right edge, running off the bottom. */
.stack-hero { position: absolute; right: -1px; bottom: -6vh; height: 86vh; }
.book-stage { position: relative; margin: 0; }
.book-stage > img[data-book-fallback] { width: 100%; height: 100%; object-fit: contain; filter: drop-shadow(14px 22px 22px rgba(0, 40, 45, .4)); }
.book-stage canvas { display: block; filter: drop-shadow(16px 24px 24px rgba(0, 40, 45, .42)); }
/* The 3D book leans on the stack's lower books. */
#hero-book { position: absolute; bottom: -2vh; right: calc(86vh * var(--stack-ratio) * .93); width: min(25vw, 36vh); aspect-ratio: 2 / 3; transform: rotate(4deg); transform-origin: bottom right; }

/* ---------- 2. The problem ---------- */
.problem { position: relative; display: grid; grid-template-columns: minmax(200px, 34%) 1fr; align-items: end; gap: 6vw; padding: 16vh 6vw 14vh 0; background: linear-gradient(var(--teal), var(--teal-deep)); }
/* Only the bottom book, cropped clear of the books standing behind it */
.lone-book { position: relative; width: 100%; max-width: 420px; aspect-ratio: 630 / 243; overflow: hidden; justify-self: start; }
.lone-book .stack { position: absolute; left: 0; bottom: 0; width: 136.5%; }
.lone-book .stack i:not(:last-child) { display: none; }
.problem-lines { display: grid; gap: 28px; padding-bottom: 2vh; }
.problem-lines p { font: 400 clamp(24px, 2.6vw, 38px)/1.2 var(--serif); max-width: 22em; }
.problem-lines strong { font-weight: 500; color: #fff; border-bottom: 2px solid rgba(255, 255, 255, .5); }
.js [data-fade] { opacity: 0; transform: translateY(14px); transition: opacity .7s ease, transform .7s ease; }
.js [data-fade].seen { opacity: 1; transform: none; }

/* ---------- 3. The key idea ---------- */
.key-idea { position: relative; background: var(--teal-deep); }
.ki-sticky { padding: 9vh 6vw 8vh; }
.ki-head { display: flex; justify-content: space-between; align-items: baseline; gap: 24px; flex-wrap: wrap; }
.ki-head h2 { font: 400 clamp(32px, 3.4vw, 52px)/1.05 var(--serif); }
.ki-final { font: 500 clamp(28px, 3vw, 46px)/1 var(--serif); color: var(--yellow); }
.ki-final strong { font-weight: 500; font-size: 1.15em; }
.ki-board { --h: min(72vh, 680px); --gap: 36px; display: grid; grid-template-columns: 1fr calc(var(--h) * var(--stack-ratio)) minmax(120px, 1fr); gap: var(--gap); margin-top: 4vh; align-items: stretch; }
.ki-steps { position: relative; list-style: none; margin: 0; padding: 0; height: var(--h); }
.ki-steps li {
	position: absolute; right: 0; top: var(--mid); transform: translateY(-50%); white-space: nowrap;
	font: 600 15px/1.2 var(--sans); color: #fff; padding-right: 12px;
}
.ki-steps li::after {
	/* the thin yellow line from the label to its book */
	content: ''; position: absolute; top: 50%; left: 100%; height: 2px; background: var(--yellow);
	width: calc(var(--gap) + var(--left) * var(--h) * var(--stack-ratio) - 4px); transform-origin: left;
}
.ki-steps li.last { color: var(--yellow); font-weight: 700; }
.js .ki-steps li { color: rgba(255, 255, 255, .55); transition: color .3s; }
.js .ki-steps li::after { transform: scaleX(0); transition: transform .35s ease; }
.js .ki-steps li.on { color: #fff; }
.js .ki-steps li.on.last { color: var(--yellow); }
.js .ki-steps li.on::after { transform: none; }
.js .ki-final { opacity: .4; transition: opacity .4s, transform .4s; transform: translateY(6px); }
.js .ki-final.on { opacity: 1; transform: none; }
/* The photo stops where the cover stops; mid-page its cut side fades out instead. */
.stack-ki, .stack-buy { -webkit-mask: linear-gradient(90deg, #000 80%, transparent 99%); mask: linear-gradient(90deg, #000 80%, transparent 99%); }
.stack-ki { height: var(--h); }
.ki-bands { list-style: none; margin: 0; padding: 0 0 0 22px; position: relative; height: var(--h); border-left: 1.5px solid rgba(255, 255, 255, .3); }
.ki-bands li { position: absolute; left: 22px; transform: translateY(-50%); font-size: clamp(26px, 2.4vw, 36px); color: rgba(255, 255, 255, .55); }
.ki-bands li::before { content: ''; position: absolute; left: -29px; top: 50%; width: 13px; height: 13px; border-radius: 50%; background: var(--teal-deep); border: 1.5px solid rgba(255, 255, 255, .5); transform: translateY(-50%); }
.ki-bands .b-launch { top: 24%; }
.ki-bands .b-publish { top: 58%; }
.ki-bands .b-write { top: 84%; }
.ki-bands li.on { color: #fff; }
.ki-bands li.on::before { background: var(--yellow); border-color: var(--yellow); }
html:not(.js) .ki-bands li { color: #fff; }
html:not(.js) .ki-bands li::before { background: var(--yellow); border-color: var(--yellow); }
.ki-skip { margin-top: 3vh; }
/* Desktop: pinned for about 2.6 screens */
.key-idea.pinned { height: 260vh; }
.key-idea.pinned .ki-sticky { position: sticky; top: 0; height: 100vh; display: flex; flex-direction: column; justify-content: center; }

/* ---------- Paper parts ---------- */
.paper { background: var(--cream); color: var(--ink); }
.paper .placeholder { color: var(--ink); }
.paper h2 { font: 400 clamp(34px, 3.6vw, 54px)/1.05 var(--serif); }
.inside { padding: 0 0 12vh; }
/* The teal gives way to the cream of the cover's page edges. */
.inside::before { content: ''; display: block; height: 16vh; background: linear-gradient(var(--teal-deep), var(--cream-2) 70%, var(--cream)); margin-bottom: 6vh; }
.inside-list { list-style: none; margin: 40px 0 0; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 56px; counter-reset: step; }
.inside-list li { position: relative; padding: 20px 0 20px 48px; border-top: 1px solid rgba(11, 78, 85, .2); counter-increment: step; }
.inside-list li::before {
	content: ''; position: absolute; left: 0; top: 23px; width: 22px; height: 22px; border: 1.5px solid var(--ink); border-radius: 3px;
	background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7' fill='none' stroke='%23038994' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 18px no-repeat;
}
.inside-list h3 { font: 500 23px/1.2 var(--serif); }
.inside-list p { margin-top: 4px; font-size: 16px; opacity: .85; }
.inside-note { margin-top: 30px; font: 700 13px var(--caps); letter-spacing: .16em; text-transform: uppercase; }

.author { padding: 4vh 0 10vh; }
.author-grid { display: grid; grid-template-columns: minmax(200px, 300px) 1fr; gap: 56px; align-items: start; border-top: 1px solid rgba(11, 78, 85, .2); padding-top: 9vh; }
.placeholder-box { aspect-ratio: 4 / 5; border: 1.5px dashed var(--ink); border-radius: 6px; display: flex; align-items: center; justify-content: center; text-align: center; padding: 20px; font: 600 14px var(--sans); background: var(--cream-2); }
.creds { list-style: none; margin: 22px 0 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px; }
.creds li { border: 1.5px dashed var(--ink); border-radius: 4px; padding: 8px 12px; font: 600 13px/1.2 var(--sans); background: var(--cream-2); }
/* Authority, small: the tags slot in one after another, like books onto a short shelf. Nothing counts. */
.js .creds li { opacity: 0; transform: translateX(26px); transition: opacity .35s ease, transform .45s cubic-bezier(.2, 1.3, .4, 1); }
.js .creds.seen li { opacity: 1; transform: none; }
.js .creds.seen li:nth-child(2) { transition-delay: .18s; }
.js .creds.seen li:nth-child(3) { transition-delay: .36s; }
.bio { margin-top: 24px; font: 400 21px/1.45 var(--serif); max-width: 34em; }
.also { margin-top: 32px; display: flex; align-items: center; gap: 18px; }
.also img { width: 72px; height: auto; box-shadow: 0 8px 18px -8px rgba(0, 40, 45, .5); }
.also .label { display: block; font: 700 12px var(--caps); letter-spacing: .16em; text-transform: uppercase; opacity: .8; }
.also cite { font: italic 400 22px var(--serif); }

.proof { padding: 0 0 10vh; }
.proof-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.quote-card { margin: 0; min-height: 170px; border: 1.5px dashed var(--ink); border-radius: 6px; display: flex; align-items: center; justify-content: center; text-align: center; padding: 24px; font: 600 14px/1.4 var(--sans); }

.try { padding: 4vh 0 14vh; }
.try-grid { display: grid; grid-template-columns: minmax(280px, 420px) 1fr; gap: 64px; align-items: center; }
.sheet {
	background: #fbf7ee; color: var(--ink); padding: 34px 34px 40px; border-radius: 2px; transform: rotate(-1.2deg);
	box-shadow: 0 1px 0 rgba(0, 0, 0, .05), 0 24px 40px -22px rgba(0, 40, 45, .5);
	/* the torn edge at the top */
	-webkit-mask: radial-gradient(5px at 50% 0, #0000 98%, #000) 50% / 14px 100% repeat-x;
	mask: radial-gradient(5px at 50% 0, #0000 98%, #000) 50% / 14px 100% repeat-x;
}
.sheet-title { font: 700 13px var(--caps); letter-spacing: .18em; text-transform: uppercase; padding-bottom: 14px; border-bottom: 2px solid var(--teal); }
.ticks { list-style: none; margin: 8px 0 0; padding: 0; }
.ticks li { border-bottom: 1px solid rgba(11, 78, 85, .15); }
.ticks label { display: flex; align-items: center; gap: 14px; padding: 15px 0; font: 400 21px var(--serif); cursor: pointer; }
.ticks input { position: absolute; opacity: 0; }
.ticks .box { flex: none; width: 24px; height: 24px; border: 1.5px solid var(--ink); border-radius: 3px; position: relative; }
.ticks .box::after {
	content: ''; position: absolute; inset: 1px;
	background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7' fill='none' stroke='%23038994' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 20px no-repeat;
	clip-path: inset(0 100% 0 0); transition: clip-path .3s ease;
}
.ticks input:checked + .box::after { clip-path: inset(0); }
.ticks input:focus-visible + .box { outline: 3px solid var(--ink); outline-offset: 2px; }
.signup p { margin-top: 12px; max-width: 30em; }
.signup input[type=email] { display: block; width: 100%; max-width: 420px; margin-top: 22px; padding: 14px 16px; border-radius: 4px; border: 1.5px solid var(--ink); background: #fff; color: #111; font: 400 17px var(--sans); }
.signup .btn { margin-top: 12px; }
.small { font-size: 14px; opacity: .8; }
.form-done { font-weight: 600; }

/* ---------- 8. The buy moment ---------- */
.buy { position: relative; background: var(--teal); padding: 14vh 0 10vh; overflow: hidden; }
.buy-grid { display: grid; grid-template-columns: 1fr minmax(320px, 44%); gap: 48px; align-items: center; }
.buy h2 { font: 400 clamp(40px, 4.6vw, 72px)/1.02 var(--serif); }
.buy h2 strong { font-weight: 500; color: var(--yellow); }
.buy-panel { display: grid; gap: 22px; justify-items: start; }
.formats { border: 0; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px; }
.formats legend { font: 700 12px var(--caps); letter-spacing: .16em; text-transform: uppercase; margin-bottom: 10px; }
.formats label span { display: inline-block; padding: 12px 16px; border: 1.5px solid rgba(255, 255, 255, .6); border-radius: 4px; font: 600 15px var(--sans); cursor: pointer; transition: background .2s, color .2s; }
.formats input { position: absolute; opacity: 0; }
.formats input:checked + span { background: #fff; color: var(--ink); border-color: #fff; }
.formats input:focus-visible + span { outline: 3px solid var(--yellow); outline-offset: 2px; }
.notice { font: 600 16px/1.45 var(--sans); padding: 14px 16px; border-left: 4px solid var(--yellow); background: rgba(0, 40, 45, .22); max-width: 32em; }
.notice.flash { animation: flash 1s ease; }
@keyframes flash { 30% { background: rgba(252, 218, 23, .3); } }
.buy-art { position: relative; height: min(72vh, 700px); }
.stack-buy { position: absolute; right: 0; bottom: 0; height: 100%; }
/* On a wide screen the stack stands against the right edge, as on the cover. */
@media (min-width: 901px) { .stack-buy { right: calc((min(1160px, 100vw - 48px) - 100vw) / 2); -webkit-mask: none; mask: none; } }
.buy-book { position: absolute; z-index: 2; width: min(52%, 300px); aspect-ratio: 2 / 3; right: 46%; top: 16%; }
/* Before it comes forward, the 3D book waits where the top copy sits. */
.js .buy-book { opacity: 0; transform: translate(55%, -22%) scale(.6) rotate(8deg); transition: opacity .5s ease .25s, transform 1.1s cubic-bezier(.2, .9, .25, 1) .2s; }
.js .buy-art.out .buy-book { opacity: 1; transform: none; }
.js .stack-buy i:first-child { transition: transform .7s cubic-bezier(.3, .7, .3, 1), opacity .45s ease .25s; }
.js .buy-art.out .stack-buy i:first-child { transform: translate(-14%, -9%) rotate(-5deg); opacity: 0; }
.format-tag { position: absolute; z-index: 3; right: 44%; top: 14%; display: inline-flex; align-items: center; gap: 8px; background: #fff; color: var(--ink); border-radius: 30px; padding: 8px 14px 8px 10px; font: 700 13px var(--sans); box-shadow: 0 10px 20px -10px rgba(0, 40, 45, .6); animation: pop .25s cubic-bezier(.3, 1.6, .5, 1); }
.format-tag[hidden] { display: none; }
.format-tag svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
@keyframes pop { from { transform: scale(.6); opacity: 0; } }

/* ---------- 9. Groups ---------- */
.groups { background: var(--teal); padding: 2vh 0 8vh; }
.label-h { font: 700 13px var(--caps); letter-spacing: .18em; text-transform: uppercase; margin-bottom: 20px; }
.group-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.group-card { display: flex; flex-direction: column; justify-content: space-between; gap: 24px; min-height: 150px; padding: 24px; border-radius: 6px; background: var(--teal-deep); text-decoration: none; border: 1.5px solid transparent; transition: border-color .2s; }
.group-card.dashed { background: transparent; border: 1.5px dashed rgba(255, 255, 255, .7); }
.group-card:hover { border-color: var(--yellow); }
.group-card h3 { font: 500 24px/1.2 var(--serif); }
.group-card span { font: 700 12px var(--caps); letter-spacing: .14em; text-transform: uppercase; color: var(--yellow); }
.groups .placeholder { margin-top: 22px; }

/* ---------- 10. Questions ---------- */
.questions { padding: 0 0 12vh; }
/* The teal band gives way to the cream again, and the cream to the teal at the buy moment. */
.questions::before { content: ''; display: block; height: 12vh; background: linear-gradient(var(--teal), var(--cream)); margin-bottom: 8vh; }
.buy::before { content: ''; position: absolute; left: 0; right: 0; top: 0; height: 12vh; background: linear-gradient(var(--cream), var(--teal)); }
.questions h2 { margin-bottom: 26px; }
details { border-top: 1px solid rgba(11, 78, 85, .25); }
details:last-of-type { border-bottom: 1px solid rgba(11, 78, 85, .25); }
summary { list-style: none; cursor: pointer; padding: 22px 44px 22px 0; position: relative; font: 500 22px/1.3 var(--serif); }
summary::-webkit-details-marker { display: none; }
summary::after { content: '+'; position: absolute; right: 6px; top: 50%; transform: translateY(-50%); font: 400 28px var(--sans); color: var(--teal); }
details[open] summary::after { content: '\2212'; }
details p { padding: 0 0 22px; max-width: 40em; }
details p.placeholder { padding: 7px 12px; margin-bottom: 22px; }

/* ---------- 11. The end ---------- */
.end { background: var(--teal-deep); padding: 10vh 0 calc(80px + env(safe-area-inset-bottom)); }
.end-grid { display: grid; grid-template-columns: 1fr auto; gap: 40px; align-items: end; }
.flat-book { width: 150px; height: 31px; overflow: hidden; margin-bottom: 26px; }
.flat-book .stack { width: 200px; margin-top: -213px; }
.flat-book .stack i:not(:nth-child(8)) { display: none; }
.end h2 { font: 400 clamp(28px, 2.6vw, 38px)/1.1 var(--serif); }
.field-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: stretch; margin-top: 18px; }
.end-signup input[type=email] { margin: 0; flex: 1 1 240px; max-width: 360px; border-color: transparent; }
.end-signup .btn { margin: 0; }
.end-links { display: grid; gap: 10px; justify-items: end; }
.end-notes { margin-top: 8vh; padding-top: 22px; border-top: 1px solid rgba(255, 255, 255, .2); font-size: 14px; display: flex; justify-content: space-between; gap: 18px; flex-wrap: wrap; opacity: .9; }
.credit a { color: var(--yellow); }

/* ---------- Tablet ---------- */
@media (max-width: 1100px) {
	.promise-copy { width: 62vw; }
	.promise-art { width: 50vw; }
	.stack-hero { height: 62vh; bottom: -4vh; }
	#hero-book { right: calc(62vh * var(--stack-ratio) * .9); width: min(28vw, 30vh); }
	.try-grid { grid-template-columns: 1fr; }
	.sheet { max-width: 460px; }
}
@media (max-width: 900px) {
	.promise { align-items: flex-start; }
	.promise-copy { width: 100%; padding: 40px 24px 0; }
	.promise-art { position: relative; width: 100%; height: 44vh; min-height: 300px; margin-top: 24px; }
	.promise { flex-direction: column; }
	.stack-hero { height: 100%; bottom: -6%; }
	#hero-book { right: calc(44vh * var(--stack-ratio) * .92); width: 34vw; max-width: 200px; bottom: 2%; }
	.problem { grid-template-columns: 1fr; padding: 10vh 24px; gap: 30px; }
	.lone-book { order: 2; max-width: 300px; margin-left: -24px; }
	.ki-sticky { padding: 10vh 24px 8vh; }
	.ki-board { --h: 420px; --gap: 18px; grid-template-columns: 1fr calc(var(--h) * var(--stack-ratio)); }
	.ki-bands { display: none; }
	.inside-list { grid-template-columns: 1fr; }
	.author-grid { grid-template-columns: 1fr; gap: 28px; }
	.portrait { max-width: 220px; }
	.proof-row, .group-row { grid-template-columns: 1fr; }
	.quote-card { min-height: 110px; }
	.buy-grid { grid-template-columns: 1fr; }
	.buy-art { height: 420px; order: -1; }
	.stack-buy { right: -24px; -webkit-mask: none; mask: none; }
	.end-grid { grid-template-columns: 1fr; }
	.end-links { justify-items: start; }
}
@media (max-width: 560px) {
	body { font-size: 16px; }
	.title .t1 { font-size: 44px; }
	.title .t2 { font-size: 64px; }
	.subtitle { margin-top: 16px; font-size: 16px; }
	.promise-line { margin-top: 16px; font-size: 21px; }
	.byline { margin-top: 12px; font-size: 11px; }
	.promise .actions { margin-top: 18px; gap: 10px; }
	.promise .btn { min-height: 46px; padding: 12px 16px; font-size: 12px; }
	.promise .placeholder { margin-top: 14px; }
	/* clear of the preview tape at the bottom */
	.promise { padding-bottom: 56px; }
	.promise-art { height: 270px; }
	.stack-hero { height: 320px; bottom: -40px; }
	#hero-book { right: 158px; width: 116px; }
	/* Phones: the steps as a plain list beside the stack, not pinned */
	.ki-board { --h: 380px; grid-template-columns: 1fr calc(var(--h) * var(--stack-ratio)); gap: 12px; }
	.ki-steps { height: auto; display: grid; gap: 8px; align-content: center; }
	.ki-steps li { position: static; transform: none; white-space: normal; padding: 0; font-size: 14px; }
	.ki-steps li::after { display: none; }
	.ki-head h2 { font-size: 30px; }
	.buy-art { height: 340px; }
	.buy-book { width: 150px; right: 40%; }
	.sheet { padding: 26px 22px 30px; }
	.ticks label { font-size: 19px; }
}

/* ---------- Concept preview tape (from templates/cloudflare/PLAYBOOK.md) ---------- */
.preview-notice { position: fixed; left: 0; right: 0; bottom: 0; z-index: 60; pointer-events: none; padding-bottom: env(safe-area-inset-bottom); }
.preview-tape { overflow: hidden; background: repeating-linear-gradient(-45deg, rgba(255, 214, 0, .94) 0 22px, rgba(255, 203, 0, .94) 22px 44px); color: #111; border-top: 2px solid #111; border-bottom: 2px solid #111; height: 34px; display: flex; align-items: center; }
.preview-tape-track { display: flex; width: max-content; animation: tape 40s linear infinite; }
.preview-tape-group { display: flex; }
.preview-tape-group span { white-space: nowrap; font: 800 12px/1 var(--caps); letter-spacing: .1em; text-transform: uppercase; padding-right: 28px; }
.preview-tape-group i { font-style: normal; margin: 0 10px; }
@keyframes tape { to { transform: translateX(-50%); } }
.preview-tape-controls { position: absolute; right: 10px; bottom: calc(40px + env(safe-area-inset-bottom)); display: flex; gap: 8px; pointer-events: auto; }
.preview-tape-controls a, .preview-tape-pause { background: #111; color: #ffd600; border-radius: 8px; padding: 6px 10px; display: flex; align-items: center; gap: 8px; text-decoration: none; font: 700 12px/1.1 var(--sans); cursor: pointer; }
.preview-cta-copy small { display: block; font-weight: 500; opacity: .85; }
.preview-tape-pause input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.preview-tape-pause svg { fill: currentColor; }
.preview-tape-pause .i-play { display: none; }
.preview-tape-pause:has(input:checked) .i-play { display: block; }
.preview-tape-pause:has(input:checked) .i-pause { display: none; }
.preview-notice:has(input:checked) .preview-tape-track { animation-play-state: paused; }
.preview-tape-pause:focus-within { outline: 3px solid #111; outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) { .preview-tape-track { animation: none; } }