/* =====================================================================
   Ζέττα — Από την άκρη στο κέντρο (πρόταση 3) · styles.css
   Tokens live in css/theme.css (exported from v4/DESIGN.md). This file
   adds fluid sizes, layout, components and motion. No hex codes here.
   ===================================================================== */

:root {
  --fs-xl:       clamp(3.2rem, 1.4rem + 5.4vw, 5.75rem);
  --fs-lg:       clamp(2.2rem, 1.3rem + 3vw, 3.75rem);
  --fs-parts:    clamp(1.7rem, 1.1rem + 2.2vw, 2.75rem);
  --fs-title:    clamp(2rem, 1.3rem + 1.9vw, 2.375rem);
  --fs-card:     1.625rem;
  --fs-lead:     clamp(1.15rem, 1.05rem + .35vw, 1.3125rem);
  --fs-body:     1.125rem;
  --fs-small:    1rem;
  --fs-label:    .875rem;

  --hair:        color-mix(in srgb, var(--color-primary) 16%, transparent);
  --hair-light:  color-mix(in srgb, var(--color-surface) 24%, transparent);
  --on-deep-soft: color-mix(in srgb, var(--color-surface) 82%, var(--color-primary));
  --tap:         color-mix(in srgb, var(--color-secondary) 22%, transparent);

  --max: 1280px;
  --head: 4.75rem;
  --offset: 14px;
  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light; scroll-behavior: smooth; scroll-padding-top: calc(var(--head) + 1rem); -webkit-text-size-adjust: 100%; background: var(--color-neutral); }
body {
  margin: 0; background: var(--color-neutral); color: var(--color-primary);
  font-family: var(--font-body-md), system-ui, sans-serif; font-size: var(--fs-body); line-height: 1.62;
  text-wrap: pretty; -webkit-tap-highlight-color: var(--tap); overflow-x: clip;
}
img, svg, picture { display: block; max-width: 100%; }
img { height: auto; }
h1, h2, h3 { margin: 0; font-weight: 400; text-wrap: balance; }
p, ul, ol, figure { margin: 0; padding: 0; }
ul, ol { list-style: none; }
a { color: var(--color-secondary); text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { color: var(--color-primary); }
button, input, textarea { font: inherit; color: inherit; }
button { cursor: pointer; touch-action: manipulation; }
label, summary, a { touch-action: manipulation; }
:focus-visible { outline: 2px solid var(--color-secondary); outline-offset: 3px; border-radius: var(--radius-md); }
[id] { scroll-margin-top: calc(var(--head) + 1rem); }
p { max-width: 62ch; }

.skip { position: absolute; left: var(--spacing-sm); top: -100%; z-index: 100; padding: .7rem 1.1rem; border-radius: var(--radius-full); background: var(--color-primary); color: var(--color-surface); text-decoration: none; font-weight: 600; }
.skip:focus { top: var(--spacing-sm); }

.wrap { width: min(100% - 2 * var(--spacing-gutter), var(--max)); margin-inline: auto; }
.section { padding-block: var(--spacing-xxl); }
.section--flush { padding-block: var(--spacing-xl); }

/* ---------- type ---------- */
.eyebrow { font-size: var(--fs-label); font-weight: 600; letter-spacing: var(--tracking-label-md); color: var(--color-secondary); margin-bottom: var(--spacing-md); display: flex; align-items: center; gap: .7rem; }
.eyebrow::before { content: ""; width: 10px; height: 10px; border-radius: 50%; border: 1.5px solid currentColor; flex: none; }
.eyebrow--light { color: var(--color-tertiary); }
.eyebrow--gold { color: var(--color-tertiary); }
.section-title { font-family: var(--font-headline-md), serif; font-weight: var(--font-weight-headline-md); font-size: var(--fs-title); line-height: 1.14; max-width: 20ch; margin-bottom: var(--spacing-lg); }
.lead { font-size: var(--fs-lead); line-height: 1.5; }
.note { font-size: var(--fs-small); color: var(--color-muted); line-height: 1.55; }
.more { display: inline-block; margin-top: var(--spacing-md); font-weight: 600; text-decoration: none; border-bottom: 1px solid currentColor; padding-bottom: .1rem; }
.more::after { content: " →"; }

/* ---------- buttons ---------- */
.btn {
  display: inline-grid; place-items: center; padding: 1.05rem 1.7rem; border-radius: var(--radius-full);
  background: var(--color-secondary); color: var(--color-on-secondary); border: 1.5px solid var(--color-secondary);
  font-weight: 600; font-size: var(--fs-small); letter-spacing: .02em; text-decoration: none; white-space: nowrap; line-height: 1.1;
  transition: background-color .3s var(--ease), border-color .3s, color .3s, transform .3s var(--ease);
}
.btn:hover { background: var(--color-primary); border-color: var(--color-primary); color: var(--color-on-secondary); }
.btn--ghost { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn--ghost:hover { background: var(--color-primary); color: var(--color-surface); }
.btn--sm { padding: .7rem 1.2rem; }
.btn--block { width: 100%; position: relative; overflow: hidden; white-space: normal; text-align: center; }
.btn > span { grid-area: 1 / 1; transition: opacity .3s, transform .4s var(--ease); }
.btn__done { opacity: 0; transform: translateY(8px); }
.btn.is-sent { background: var(--color-primary); border-color: var(--color-primary); pointer-events: none; }
.btn.is-sent .btn__label { opacity: 0; }
.btn.is-sent .btn__done { opacity: 1; transform: none; }
.actions { display: flex; flex-wrap: wrap; gap: var(--spacing-sm); margin-top: var(--spacing-lg); }

/* ---------- header ---------- */
.top { position: sticky; top: 0; z-index: 50; background: var(--color-neutral); border-bottom: 1px solid transparent; transition: border-color .3s; }
.top.is-scrolled { border-bottom-color: var(--hair); }
.top__in { height: var(--head); display: flex; align-items: center; justify-content: space-between; gap: var(--spacing-md); }
.brand { display: inline-flex; align-items: center; gap: .7rem; color: var(--color-primary); text-decoration: none; }
.brand__mark { display: grid; place-items: center; width: 48px; height: 48px; border-radius: var(--radius-md); background: var(--color-primary); flex: none; }
.brand__mark img { width: 34px; height: 34px; }
.brand__name { display: flex; flex-direction: column; font-family: var(--font-title), serif; font-weight: 400; font-size: 1.55rem; line-height: 1; letter-spacing: .01em; }
.brand__name small { font-family: var(--font-label-md), sans-serif; font-size: var(--fs-label); font-weight: 600; letter-spacing: var(--tracking-label-md); color: var(--color-secondary); margin-top: .25rem; }
.nav ul { display: flex; align-items: center; gap: var(--spacing-md); }
.nav a:not(.btn) { color: var(--color-primary); text-decoration: none; font-weight: 600; font-size: var(--fs-small); padding: .35rem 0; background: linear-gradient(currentColor, currentColor) 0 100% / 0 1.5px no-repeat; transition: background-size .35s var(--ease); }
.nav a:not(.btn):hover { background-size: 100% 1.5px; }
.menu-toggle { display: none; }

/* ---------- hero ---------- */
.hero { padding-block: var(--spacing-lg) var(--spacing-xxl); overflow: clip; }
.hero__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); column-gap: var(--spacing-xl); align-items: center; }
.hero__title { font-family: var(--font-display-xl), serif; font-weight: var(--font-weight-display-xl); font-size: var(--fs-xl); line-height: 1.02; letter-spacing: var(--tracking-display-xl); margin-bottom: var(--spacing-lg); }
.hero__title span { display: block; }
.hero__title span:nth-child(2) { padding-left: .9em; }
.hero__title span:nth-child(3) { padding-left: 1.8em; }
.hero__title em { font-style: italic; font-weight: 300; color: var(--color-secondary); }
.hero__copy .lead { max-width: 46ch; }
.hero__copy .note { margin-top: var(--spacing-md); }

.spiral { position: relative; width: min(640px, 46vw); aspect-ratio: 1; margin-right: calc(-1 * clamp(0px, 6vw, 120px)); justify-self: end; }
.spiral__turn { position: absolute; inset: 0; }
.spiral__svg { width: 100%; height: 100%; overflow: visible;
  -webkit-mask-image: radial-gradient(circle at 50% 50%, transparent 0 21%, var(--color-primary) 52%);
          mask-image: radial-gradient(circle at 50% 50%, transparent 0 21%, var(--color-primary) 52%); }
.spiral__guide { fill: none; stroke: none; }
.spiral__line { fill: none; stroke: var(--color-tertiary); stroke-width: 1.2; stroke-linecap: round; opacity: .9; }
.spiral__text { font-family: var(--font-spiral), sans-serif; font-size: 17px; font-weight: 500; fill: var(--color-primary); letter-spacing: .02em; }
.spiral__center { position: absolute; inset: 31.5%; border-radius: var(--radius-full); background: var(--color-secondary); overflow: hidden; box-shadow: 0 0 0 2px var(--color-neutral), 0 0 0 4px var(--color-tertiary); }
.spiral__center img { width: 100%; height: 135%; object-fit: cover; object-position: 50% 6%; }

/* ---------- parts ---------- */
.parts { margin: var(--spacing-md) 0 var(--spacing-xl); border-top: 1px solid var(--hair); }
.part { display: flex; align-items: baseline; gap: 1.1rem; padding: var(--spacing-md) 0; border-bottom: 1px solid var(--hair); font-family: var(--font-parts), serif; font-weight: var(--font-weight-parts); font-size: var(--fs-parts); line-height: 1.18; max-width: 30ch; text-wrap: balance; }
.part__mark { flex: none; width: .5em; height: .5em; border-radius: 50%; border: 1.5px solid var(--color-secondary); transform: translateY(-.05em); }
.part--2 .part__mark { background: linear-gradient(90deg, var(--color-secondary) 50%, transparent 50%); }
.part--3 .part__mark { background: var(--color-secondary); }
.cols { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--spacing-lg); max-width: 1000px; }

/* ---------- photo + text pairs ---------- */
.pair { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); column-gap: var(--spacing-xl); row-gap: var(--spacing-lg); align-items: center; }
.pair--reverse { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.pair--portrait { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.photo--portrait { justify-self: start; }
.photo--portrait img { aspect-ratio: 3 / 4; object-fit: cover; object-position: 50% 30%; max-height: 82svh; width: auto; max-width: 100%; }
.pair--reverse .photo { order: 2; }
.pair__text > p + p { margin-top: var(--spacing-sm); }
.photo { position: relative; margin: 0; }
.photo::before { content: ""; position: absolute; inset: 0; translate: var(--offset) var(--offset); border-radius: var(--radius-lg); background: var(--color-line); }
.photo img { position: relative; width: 100%; border-radius: var(--radius-lg); }
.photo--tall img { aspect-ratio: 4 / 5; object-fit: cover; object-position: 50% 20%; }
.creds { margin-top: var(--spacing-lg); border-top: 1px solid var(--hair); columns: 2; column-gap: var(--spacing-lg); }
.creds li { break-inside: avoid; padding: .65rem 0; border-bottom: 1px solid var(--hair); font-size: var(--fs-small); color: var(--color-muted); }

/* ---------- how ---------- */
.how { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); column-gap: var(--spacing-xl); align-items: start; }
.how__head { position: sticky; top: calc(var(--head) + var(--spacing-lg)); }
.how__head .note { margin-bottom: var(--spacing-md); max-width: 36ch; }
.steps { border-top: 1px solid var(--hair); }
.step { display: grid; grid-template-columns: 4.5rem 1fr; gap: var(--spacing-md); padding: var(--spacing-lg) 0; border-bottom: 1px solid var(--hair); }
.step__num { font-family: var(--font-display-lg), serif; font-weight: 300; font-size: 3rem; line-height: .9; color: var(--color-secondary); }
.step h3 { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.5rem; line-height: 1.22; margin-bottom: .6rem; }
.step p { color: var(--color-muted); }

/* ---------- sessions band ---------- */
.band { background: var(--color-primary); color: var(--color-surface); padding-block: var(--spacing-xxl); overflow: clip; }
.band a { color: var(--color-surface); }
.band__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); column-gap: var(--spacing-xl); align-items: center; }
.band .section-title { color: var(--color-surface); }
.band p { color: var(--on-deep-soft); }
.facts { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); margin-bottom: var(--spacing-lg); border-top: 1px solid var(--hair-light); border-bottom: 1px solid var(--hair-light); }
.facts li { padding: var(--spacing-md) var(--spacing-sm) var(--spacing-md) 0; }
.facts li + li { padding-left: var(--spacing-sm); border-left: 1px solid var(--hair-light); }
.facts b { display: block; font-family: var(--font-display-lg), serif; font-weight: 300; font-size: clamp(2rem, 1.3rem + 1.9vw, 3rem); white-space: nowrap; line-height: 1; font-variant-numeric: tabular-nums; }
.facts span { display: block; margin-top: .5rem; font-size: var(--fs-label); letter-spacing: .03em; color: var(--on-deep-soft); }
.notfor { margin-top: var(--spacing-lg); padding-top: var(--spacing-md); border-top: 1px solid var(--hair-light); }
.notfor h3 { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.45rem; margin-bottom: .6rem; }
.notfor h3 strong { font-weight: 500; letter-spacing: .06em; color: var(--color-tertiary); }
.notfor li { position: relative; padding: .35rem 0 .35rem 1.3rem; font-size: var(--fs-small); color: var(--on-deep-soft); }
.notfor li::before { content: ""; position: absolute; left: 0; top: .95em; width: 7px; height: 7px; border-radius: 50%; background: var(--color-tertiary); }
.photo--room { margin-right: calc(-1 * clamp(0px, 6vw, 120px)); }
.photo--room::before { background: var(--color-tertiary); }
.facts li:nth-child(3) b { font-style: italic; font-size: clamp(1.6rem, 1.05rem + 1.5vw, 2.4rem); line-height: 1.25; }
.photo--room img { aspect-ratio: 9 / 11; object-fit: cover; }

/* ---------- concepts: ten tiles ---------- */
.concepts__head { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); column-gap: var(--spacing-xl); align-items: end; margin-bottom: var(--spacing-lg); }
.concepts__head .section-title { margin-bottom: 0; }
.tiles { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: var(--spacing-md); }
.tiles > li { display: grid; grid-row: span 4; grid-template-rows: subgrid; row-gap: 0; }
.tile { display: grid; grid-row: span 4; grid-template-rows: subgrid; row-gap: 0; padding: 24px 22px; border-radius: var(--radius-md); background: var(--color-surface); color: var(--color-on-surface); text-decoration: none; transition: transform .45s var(--ease), background-color .3s; }
@supports not (grid-template-rows: subgrid) {
  .tiles > li, .tile { display: flex; flex-direction: column; }
  .tile__title { min-height: 3.6em; }
  .tile__line { flex: 1; }
}
.tile__num { font-family: var(--font-title), serif; font-size: 1.05rem; color: var(--color-muted); font-variant-numeric: tabular-nums; }
.tile__title { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.375rem; line-height: 1.18; padding-top: var(--spacing-md); margin-bottom: .55rem; overflow-wrap: break-word; }
.tile__line { font-size: .9375rem; color: var(--color-muted); line-height: 1.5; }
.tile__go { align-self: end; margin-top: var(--spacing-md); font-weight: 600; font-size: var(--fs-small); color: var(--color-secondary); display: inline-flex; align-items: center; gap: .4rem; }
.tile__go::after { content: "→"; transition: transform .45s var(--ease); }
.tile:hover { color: var(--color-on-surface); }

/* ---------- faq ---------- */
.faq { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); column-gap: var(--spacing-xl); align-items: start; }
.faq__head { position: sticky; top: calc(var(--head) + var(--spacing-lg)); }
.faq .section-title { margin-bottom: var(--spacing-sm); }
.qas { display: grid; gap: var(--spacing-sm); }
.qa { background: var(--color-surface); border-radius: var(--radius-md); padding: 0 28px; }
.qa summary { list-style: none; cursor: pointer; display: grid; grid-template-columns: 1fr 28px; gap: var(--spacing-sm); align-items: center; padding: 22px 0; }
.qa summary::-webkit-details-marker { display: none; }
.qa summary h3 { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.3rem; line-height: 1.28; }
.qa summary::after { content: ""; width: 28px; height: 28px; border-radius: 50%; border: 1.5px solid var(--color-secondary);
  background: linear-gradient(var(--color-secondary), var(--color-secondary)) center / 11px 1.5px no-repeat, linear-gradient(var(--color-secondary), var(--color-secondary)) center / 1.5px 11px no-repeat;
  transition: transform .35s var(--ease); }
.qa[open] summary::after { transform: rotate(45deg); }
.qa p { padding-bottom: 24px; color: var(--color-muted); }

/* ---------- close (deep band) ---------- */
.close { position: relative; background: var(--color-primary); color: var(--color-surface); padding-block: var(--spacing-xxl); overflow: clip; isolation: isolate; }
.close__spiral { position: absolute; z-index: -1; width: min(900px, 80vw); left: -18vw; top: 50%; translate: 0 -50%; opacity: .5; }
.close__spiral path { fill: none; stroke: var(--color-tertiary); stroke-width: 1; }
.close__grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); column-gap: var(--spacing-xl); row-gap: var(--spacing-lg); align-items: start; }
.close__title { font-family: var(--font-display-lg), serif; font-weight: var(--font-weight-display-lg); font-size: var(--fs-lg); line-height: 1.08; margin-bottom: var(--spacing-md); max-width: 14ch; }
.close__text p { color: var(--on-deep-soft); }
.next { margin-top: var(--spacing-lg); border-top: 1px solid var(--hair-light); }
.next li { display: grid; grid-template-columns: 2.4rem 1fr; padding: .8rem 0; border-bottom: 1px solid var(--hair-light); color: var(--on-deep-soft); font-size: var(--fs-small); }
.next b { font-family: var(--font-title), serif; font-weight: 300; font-size: 1.2rem; color: var(--color-tertiary); line-height: 1.2; }
.form { display: grid; gap: var(--spacing-sm); padding: 32px; border-radius: var(--radius-lg); background: var(--color-surface); color: var(--color-on-surface); }
.form p { max-width: none; }
.form__intro { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.6rem; line-height: 1.15; }
.form__privacy { font-size: var(--fs-label); color: var(--color-muted); margin: -.4rem 0 var(--spacing-xs); }
.field { display: grid; gap: .4rem; }
.field__label { font-size: var(--fs-small); font-weight: 600; }
.field__label small { font-weight: 400; color: var(--color-muted); font-size: inherit; }
.field input, .field textarea { width: 100%; padding: .85rem 1rem; border-radius: var(--radius-md); background: var(--color-surface); border: 1px solid var(--color-line); transition: border-color .2s; }
.field input::placeholder, .field textarea::placeholder { color: var(--color-muted); opacity: .75; }
.field input:focus-visible, .field textarea:focus-visible { outline: 2px solid var(--color-secondary); outline-offset: 1px; border-color: var(--color-secondary); }
.field textarea { resize: vertical; min-height: 4.5rem; }
.field.is-invalid input, .field.is-invalid textarea { border-color: var(--color-error); border-width: 2px; }
.field__error { display: none; font-size: var(--fs-label); font-weight: 600; color: var(--color-error); }
.field.is-invalid .field__error, .check.is-invalid .field__error { display: block; }
.check { display: grid; grid-template-columns: 1.2rem 1fr; gap: .3rem .75rem; align-items: start; font-size: var(--fs-small); color: var(--color-muted); cursor: pointer; }
.check input { width: 1.2rem; height: 1.2rem; margin: .2rem 0 0; accent-color: var(--color-secondary); }
.check .field__error { grid-column: 2; }
.hp { position: absolute; left: -9999px; }
.turnstile { min-height: 65px; }
.form__status { font-size: var(--fs-small); color: var(--color-error); }
.form__status:empty { display: none; }

/* ---------- footer ---------- */
.foot { background: var(--color-primary); color: var(--on-deep-soft); padding-block: var(--spacing-lg); border-top: 1px solid var(--hair-light); }
.foot p { font-size: var(--fs-label); max-width: none; }
.foot p + p { margin-top: .5rem; }
.foot b { color: var(--color-surface); font-weight: 600; }
.foot a { color: var(--color-surface); }

/* ---------- inner pages (about, concepts, faq, privacy, 404) ---------- */
.nav a[aria-current="page"] { background-size: 100% 1.5px; }
.section--tight { padding-block: var(--spacing-xl); }

.page-head { padding-block: var(--spacing-xl) var(--spacing-lg); }
.page-head .lead { max-width: 58ch; margin-top: var(--spacing-md); }
.page-head .note { margin-top: var(--spacing-sm); }
.page-title { font-family: var(--font-display-lg), serif; font-weight: var(--font-weight-display-lg); font-size: var(--fs-lg); line-height: 1.08; letter-spacing: var(--tracking-display-lg); max-width: 20ch; }
.page-title em { font-style: italic; color: var(--color-secondary); }
.page-head__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); column-gap: var(--spacing-xl); align-items: center; }
.page-head__photo img { max-height: 78svh; width: auto; max-width: 100%; aspect-ratio: 4 / 5; object-fit: cover; object-position: 50% 20%; }
.page-head--404 { min-height: 60svh; display: grid; align-content: center; }

/* about */
.prose-grid { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr); column-gap: var(--spacing-xl); align-items: start; }
.prose-grid .section-title { position: sticky; top: calc(var(--head) + var(--spacing-lg)); }
.prose p + p { margin-top: var(--spacing-sm); }
.pullquote { margin: var(--spacing-lg) 0; padding: var(--spacing-md) 0 var(--spacing-md) var(--spacing-md); border-left: 2px solid var(--color-tertiary); }
.pullquote p { font-family: var(--font-headline-md), serif; font-weight: 300; font-size: clamp(1.4rem, 1.1rem + 1vw, 1.9rem); line-height: 1.3; max-width: 30ch; }
.edu-head { max-width: 760px; margin-bottom: var(--spacing-lg); }
.edu-head .section-title { margin-bottom: var(--spacing-md); }
.edu { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--spacing-md); align-items: start; }
.edu__card { background: var(--color-surface); border-radius: var(--radius-md); padding: 28px; }
.edu__card h3 { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.5rem; line-height: 1.2; margin-bottom: var(--spacing-sm); }
.edu__group { font-size: var(--fs-label); font-weight: 600; letter-spacing: var(--tracking-label-md); color: var(--color-secondary); margin-bottom: .2rem; }
.edu__list li { padding: .7rem 0; border-bottom: 1px solid var(--hair); font-size: var(--fs-small); line-height: 1.45; }
.edu__list li:last-child { border-bottom: 0; }
.edu__list span { display: block; margin-top: .15rem; color: var(--color-muted); font-size: .9375rem; }
.edu__list--more { margin-top: var(--spacing-sm); border-top: 1px solid var(--hair); }
.pair--quiet .pair__text > p + p { margin-top: var(--spacing-sm); }
.pair--quiet .photo--tall img { aspect-ratio: 4 / 5; object-fit: cover; object-position: 50% 25%; max-height: 80svh; }

/* sidebar layout (concepts, faq) */
.sidebar-layout { display: grid; grid-template-columns: minmax(0, 3fr) minmax(0, 8fr); column-gap: var(--spacing-xl); align-items: start; }
.sidebar { position: sticky; top: calc(var(--head) + var(--spacing-lg)); }
.sidebar__list { border-top: 1px solid var(--hair); }
.sidebar__list li { border-bottom: 1px solid var(--hair); }
.sidebar__list a { display: flex; gap: .8rem; align-items: baseline; padding: .6rem 0; color: var(--color-primary); text-decoration: none; font-size: var(--fs-small); line-height: 1.3; transition: color .25s, transform .35s var(--ease); }
.sidebar__list a b { font-family: var(--font-title), serif; font-weight: 400; color: var(--color-muted); font-variant-numeric: tabular-nums; min-width: 1.6rem; }
.sidebar__list a:hover, .sidebar__list a.is-current { color: var(--color-secondary); }
.sidebar__list a.is-current { font-weight: 600; }
.sidebar__list a.is-current b { color: var(--color-secondary); }
.sidebar__cta { margin-top: var(--spacing-md); }

/* concepts */
.concept { padding-block: var(--spacing-lg); border-top: 1px solid var(--hair); scroll-margin-top: calc(var(--head) + var(--spacing-md)); }
.concept:first-child { border-top: 0; padding-top: 0; }
.concept__num { font-family: var(--font-title), serif; font-size: 1.05rem; color: var(--color-muted); font-variant-numeric: tabular-nums; }
.concept__title { font-family: var(--font-display-lg), serif; font-weight: 300; font-size: clamp(2rem, 1.4rem + 1.8vw, 2.75rem); line-height: 1.1; margin: .3rem 0 .6rem; }
.concept__sub { font-family: var(--font-headline-md), serif; font-style: italic; font-weight: 300; font-size: clamp(1.2rem, 1.05rem + .5vw, 1.45rem); line-height: 1.35; color: var(--color-secondary); max-width: 40ch; margin-bottom: var(--spacing-md); }
.concept > p:not([class]) { max-width: 64ch; }
.concept > p:not([class]) + p:not([class]) { margin-top: var(--spacing-sm); }
.wonder { margin-top: var(--spacing-lg); padding: 24px 28px; border-radius: var(--radius-md); background: var(--color-surface); max-width: 64ch; }
.wonder__label { font-size: var(--fs-label); font-weight: 600; letter-spacing: var(--tracking-label-md); color: var(--color-secondary); }
.wonder__q { font-family: var(--font-title), serif; font-weight: 400; font-size: 1.3rem; line-height: 1.3; margin: .4rem 0 .2rem; }
.wonder .more { margin-top: .6rem; }

/* faq page */
.faq-group + .faq-group { margin-top: var(--spacing-xl); }
.faq-group { scroll-margin-top: calc(var(--head) + var(--spacing-md)); }
.group-title { font-family: var(--font-headline-md), serif; font-weight: 400; font-size: clamp(1.6rem, 1.3rem + 1vw, 2rem); margin-bottom: var(--spacing-md); }
.qa { scroll-margin-top: calc(var(--head) + var(--spacing-md)); }
.qa p a { font-weight: 600; }

/* privacy */
.legal { max-width: 70ch; }
.legal h2 { font-family: var(--font-headline-md), serif; font-weight: 400; font-size: 1.5rem; margin: var(--spacing-lg) 0 var(--spacing-xs); }
.legal h2:first-child { margin-top: 0; }
.legal p + p { margin-top: var(--spacing-sm); }
.todo { background: var(--color-surface); border: 1px dashed var(--color-tertiary); border-radius: 4px; padding: 0 .3em; color: var(--color-error); font-weight: 600; }

@media (max-width: 900px) {
  .page-head__grid, .prose-grid, .sidebar-layout, .edu { grid-template-columns: minmax(0, 1fr); }
  .page-head__photo { max-width: 420px; margin-top: var(--spacing-lg); }
  .prose-grid .section-title { position: static; }
  .sidebar { position: static; margin-bottom: var(--spacing-lg); }
  .page-concepts .sidebar__list { columns: 2; column-gap: var(--spacing-md); border-top: 0; }
  .page-concepts .sidebar__list li { break-inside: avoid; }
}
@media (max-width: 560px) {
  .page-concepts .sidebar__list { columns: 1; }
  .edu__card, .wonder { padding: 22px; }
}

/* ---------- responsive ---------- */
@media (max-width: 1180px) {
  .tiles { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 1080px) {
  .nav ul { gap: var(--spacing-sm); }
  .nav li:nth-child(1) { display: none; }
}
@media (max-width: 900px) {
  :root { --head: 4.25rem; --spacing-xxl: 88px; --spacing-xl: 48px; }
  .hero__grid, .pair, .pair--reverse, .how, .band__grid, .concepts__head, .faq, .close__grid, .cols { grid-template-columns: minmax(0, 1fr); }
  .spiral { width: min(520px, calc(100vw - 2 * var(--spacing-gutter))); margin: var(--spacing-xl) auto 0; justify-self: center; }
  .pair--reverse .photo { order: 0; }
  .how__head, .faq__head { position: static; margin-bottom: var(--spacing-md); }
  .photo--room { margin-right: 0; max-width: 460px; margin-top: var(--spacing-lg); }
  .facts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .facts li:nth-child(3) { padding-left: 0; border-left: 0; }
  .facts li:nth-child(n+3) { border-top: 1px solid var(--hair-light); }
  .creds { columns: 1; }
  .tiles { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .pair--portrait { grid-template-columns: minmax(0, 1fr); }
  .photo--portrait { max-width: 460px; }
  .photo--portrait img { max-height: none; width: 100%; aspect-ratio: 4 / 5; }
  .close__spiral { width: 140vw; left: -50vw; top: 0; translate: 0 0; opacity: .35; }

  .menu-toggle { position: relative; display: inline-flex; padding: .55rem 1.1rem; border-radius: var(--radius-full); border: 1.5px solid var(--color-primary); font-weight: 600; font-size: var(--fs-small); cursor: pointer; }
  .menu-toggle input { position: absolute; inset: 0; width: 100%; height: 100%; margin: 0; opacity: 0; cursor: pointer; }
  .menu-toggle:focus-within { outline: 2px solid var(--color-secondary); outline-offset: 3px; }
  .nav { display: none; position: absolute; left: 0; right: 0; top: var(--head); background: var(--color-neutral); border-bottom: 1px solid var(--hair); padding: var(--spacing-sm) var(--spacing-gutter) var(--spacing-lg); }
  .top:has(.menu-toggle input:checked) .nav { display: block; }
  .nav ul { flex-direction: column; align-items: stretch; gap: 0; }
  .nav li { border-bottom: 1px solid var(--hair); }
  .nav li:nth-child(1) { display: block; }
  .nav li:last-child { border: 0; padding-top: var(--spacing-md); }
  .nav a:not(.btn) { display: block; padding: .9rem 0; font-size: var(--fs-body); }
  .nav__cta .btn { width: 100%; }
}
@media (max-width: 560px) {
  :root { --spacing-gutter: 18px; }
  .hero__title span:nth-child(2), .hero__title span:nth-child(3) { padding-left: 0; }
  .actions .btn { width: 100%; }
  .part { font-size: 1.6rem; }
  .form { padding: 22px; }
  .qa { padding: 0 20px; }
  .tiles { grid-template-columns: minmax(0, 1fr); gap: var(--spacing-sm); }
  .tiles > li, .tile { grid-row: auto; display: flex; flex-direction: column; }
  .tile__title { padding-top: var(--spacing-xs); }
  .tile__go { align-self: flex-start; }
  .brand__name small { display: none; }
}

/* ---------- motion ---------- */
@media (prefers-reduced-motion: no-preference) {
  /* 1. first screen: the lines arrive, the spiral turns in */
  .hero__copy > * { opacity: 0; translate: 0 16px; animation: arrive 1s var(--ease) forwards; }
  .hero__copy > :nth-child(1) { animation-delay: .05s; }
  .hero__copy > :nth-child(2) { animation-delay: .15s; }
  .hero__copy > :nth-child(3) { animation-delay: .45s; }
  .hero__copy > :nth-child(4) { animation-delay: .6s; }
  .hero__copy > :nth-child(5) { animation-delay: .7s; }
  .spiral__svg { opacity: 0; rotate: 35deg; animation: wind-in 2.4s var(--ease) .1s forwards; }
  .spiral__center { opacity: 0; scale: .92; animation: arrive 1.2s var(--ease) .9s forwards; }

  /* 1b. the spiral keeps turning with the scroll */
  @supports (animation-timeline: scroll()) {
    .spiral__turn { animation: turn linear both; animation-timeline: scroll(root); animation-range: 0 120vh; }
  }

  /* 2. the parts come into line */
  @supports (animation-timeline: view()) {
    .part { animation: align linear both; animation-timeline: view(); animation-range: entry 10% cover 45%; }
    .part--1 { --from: 0px; }
    .part--2 { --from: clamp(24px, 6vw, 96px); }
    .part--3 { --from: clamp(48px, 12vw, 192px); }
    .part__mark { animation: settle-mark linear both; animation-timeline: view(); animation-range: entry 10% cover 45%; }
  }

  /* 3. the repeated object: tiles lift, the arrow moves */
  .tile:hover, .tile:focus-visible { transform: translateY(-6px); }
  .tile:hover .tile__go::after, .tile:focus-visible .tile__go::after { transform: translateX(5px); }

  @keyframes arrive { to { opacity: 1; translate: 0 0; scale: 1; } }
  @keyframes wind-in { to { opacity: 1; rotate: 0deg; } }
  @keyframes turn { to { rotate: -55deg; } }
  @keyframes align { from { translate: var(--from) 0; opacity: .45; } to { translate: 0 0; opacity: 1; } }
  @keyframes settle-mark { from { rotate: -180deg; } to { rotate: 0deg; } }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition-duration: .01ms !important; }
}

/* ---------- print ---------- */
@media print {
  .top, .spiral, .close__spiral, .form, .skip { display: none !important; }
  html, body, .band, .close, .foot { background: var(--color-surface) !important; color: var(--color-primary) !important; }
  .band p, .close__text p, .facts span, .notfor li, .next li, .foot p { color: var(--color-primary) !important; }
  .tiles { display: block; }
  .section, .band, .close { padding-block: 1.5rem; }
  details:not([open]) > *:not(summary) { display: block; }
}