* {
  box-sizing:border-box
}
html {
  scroll-behavior:smooth;
  scroll-padding-top:24px
}
body {
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:var(--body),sans-serif;
  font-size:17px;
  line-height:1.55
}
a {
  color:inherit
}
button,input {
  font:inherit
}
button,a,input,summary {
  -webkit-tap-highlight-color:transparent
}
button {
  cursor:pointer
}
button:disabled {
  cursor:default
}
button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible {
  outline:3px solid var(--accent);
  outline-offset:5px
}
button {
  color:inherit
}
h1,h2,h3,p {
  margin:0
}
h1,h2,h3 {
  font-family:var(--display),sans-serif;
  font-weight:400;
  line-height:1.08
}
h1 {
  font-size:clamp(48px,5.5vw,82px);
  letter-spacing:-.045em
}
h2 {
  font-size:48px;
  letter-spacing:-.025em
}
h3 {
  font-size:28px
}
p {
  max-width:65ch
}
svg {
  display:block;
  width:100%;
  height:auto
}
header {
  height:104px;
  margin:0 64px;
  border-bottom:1px solid var(--line);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px
}
.brand {
  font-family:var(--display);
  font-size:27px;
  text-decoration:none;
  line-height:1.1
}
nav {
  display:flex;
  gap:32px
}
nav a {
  text-decoration:none;
  font-size:15px;
  padding:12px 0
}
nav a:hover {
  text-decoration:underline
}
.hero {
  min-height:696px;
  margin:0 64px;
  position:relative
}
.button {
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:56px;
  padding:14px 25px;
  background:var(--accent);
  color:var(--button-ink,#fff);
  border:0;
  text-decoration:none;
  font-weight:600;
  text-align:center;
  line-height:1.35;
  max-width:100%
}
.button:hover {
  filter:brightness(.94)
}
.section {
  padding:90px 64px;
  scroll-margin-top:20px
}
.faq {
  display:grid;
  grid-template-columns:1fr 1.2fr;
  gap:100px;
  background:var(--panel)
}
.faq h2 {
  max-width:350px
}
.faq details {
  border-bottom:1px solid var(--line);
  padding:20px 0
}
.faq details:first-child {
  padding-top:0
}
.faq summary {
  cursor:pointer;
  font-weight:500;
  min-height:44px;
  padding-right:25px
}
.faq details p {
  font-size:15px;
  padding-top:10px;
  max-width:60ch
}
.request {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:100px
}
.request-copy p {
  margin-top:25px
}
.request-copy .demo-info {
  font-size:14px;
  margin-top:32px;
  color:var(--muted)
}
form {
  display:grid;
  gap:18px
}
form>label {
  font-size:14px;
  display:grid;
  gap:6px
}
input[type=text],input[type=tel] {
  border:1px solid var(--line);
  background:var(--bg);
  color:var(--ink);
  padding:13px 14px;
  min-height:52px;
  border-radius:0;
  width:100%
}
input[aria-invalid=true] {
  border:2px solid #A72B31
}
.error {
  color:var(--error,#A72B31);
  font-size:14px;
  min-height:0
}
.error:empty {
  display:none
}
.consent {
  display:flex;
  gap:12px;
  align-items:start;
  font-size:14px
}
.consent input {
  width:20px;
  height:20px;
  flex-shrink:0;
  margin:2px 0 0;
  accent-color:var(--accent)
}
.form-status {
  font-size:14px;
  padding:16px;
  border:1px solid var(--line);
  background:var(--panel)
}
.form-status:empty {
  display:none
}
.form-context {
  font-size:14px;
  color:var(--muted)
}
footer {
  padding:28px 64px;
  border-top:1px solid var(--line);
  display:flex;
  justify-content:space-between;
  gap:24px;
  font-size:14px;
  color:var(--muted)
}
.c1 .workbook {
  padding-top:52px
}
.workbook-top {
  display:flex;
  justify-content:space-between;
  align-items:end;
  gap:40px
}
.workbook-top h1 {
  font-size:74px
}
.workbook-top p {
  font-size:18px;
  margin-bottom:24px
}
.workpaper {
  background:#fff;
  margin-top:48px;
  border:1px solid #C8C8CF;
  box-shadow:10px 10px 0 #EAE5F3
}
.paper-head,.paper-foot {
  padding:18px 28px;
  display:flex;
  justify-content:space-between;
  gap:15px;
  font-size:14px
}
.paper-head {
  border-bottom:1px solid #C8C8CF
}
.formula {
  display:grid;
  grid-template-columns:1fr 70px 1fr 70px 1.5fr;
  align-items:center;
  padding:38px 30px
}
.formula>label,.formula>div {
  display:grid;
  gap:4px;
  font-size:14px
}
.formula input {
  width:100%;
  max-width:155px;
  border:0;
  border-bottom:2px solid #A82738;
  font-family:JetBrains Mono;
  font-size:68px;
  color:#202025;
  background:transparent;
  line-height:1.15;
  padding:0
}
.formula strong,.formula output {
  font-family:JetBrains Mono;
  font-size:68px;
  font-weight:400;
  white-space:nowrap;
  line-height:1.3
}
.formula small {
  font-size:14px;
  color:#6D627C
}
.operator {
  font-size:45px;
  text-align:center
}
.formula-result {
  background:#E6F29C;
  padding:17px 23px
}
.formula-result output {
  font-size:58px
}
.paper-foot {
  border-top:1px solid #E8E3F2;
  color:#71637F
}
.paper-foot span {
  font-size:14px
}
.hero-bottom {
  display:flex;
  justify-content:space-between;
  gap:20px;
  margin-top:35px;
  font-size:14px
}
@media(min-width:1600px) {
  .hero {
    max-width:1440px;
    margin-left:auto;
    margin-right:auto
  }
}
@media(max-width:1100px) {
  .hero {
    margin:0 32px
  }
  .workbook-top h1 {
    font-size:60px
  }
  .formula {
    grid-template-columns:1fr 40px 1fr 40px 1.5fr;
    padding:24px
  }
  .formula strong,.formula input {
    font-size:55px
  }
  .formula-result output {
    font-size:44px
  }
}
@media(max-width:760px) {
  .hero {
    margin:0 22px;
    min-height:auto
  }
  .button {
    min-height:54px;
    padding:14px 20px;
    font-size:15px
  }
  .c1 .workbook {
    padding-top:30px
  }
  .workbook-top {
    display:block
  }
  .workbook-top h1 {
    font-size:47px
  }
  .workbook-top p {
    font-size:16px;
    margin:22px 0
  }
  .workpaper {
    margin-top:30px;
    box-shadow:5px 5px 0 #EAE5F3
  }
  .paper-head {
    padding:14px;
    font-size:14px
  }
  .paper-head span:last-child {
    display:none
  }
  .formula {
    grid-template-columns:1fr 28px 1fr;
    padding:18px 16px;
    gap:14px 0
  }
  .formula>label,.formula>div {
    font-size:14px
  }
  .formula strong,.formula input {
    font-size:42px
  }
  .formula small {
    font-size:14px
  }
  .operator {
    font-size:28px
  }
  .formula>.operator:nth-of-type(2) {
    display:none
  }
  .formula-result {
    grid-column:1/-1;
    padding:12px 16px;
    grid-template-columns:1fr auto;
    align-items:center
  }
  .formula-result output {
    font-size:38px;
    grid-column:2;
    grid-row:1/3
  }
  .formula-result small {
    grid-column:1
  }
  .paper-foot {
    padding:12px 15px;
    display:block;
    font-size:14px
  }
  .paper-foot span {
    display:block;
    margin-top:6px;
    font-size:14px
  }
  .hero-bottom {
    display:block;
    font-size:14px;
    margin:25px 0 35px
  }
  .hero-bottom>span {
    display:block;
    margin-top:6px
  }
}
@media(max-width:360px) {
  .hero {
    margin-left:16px;
    margin-right:16px
  }
  .workbook-top h1 {
    font-size:40px
  }
  .formula-result output {
    font-size:30px
  }
}
.workpaper {
  box-shadow:none
}
.school-head {
  height:120px;
  border:0;
  align-items:center
}
.school-head .brand {
  border-left:7px solid #A82738;
  padding-left:16px
}
.school-head>span {
  font-size:14px;
  margin-right:auto
}
.school-head nav {
  gap:22px
}
.lesson {
  padding:80px 64px;
  background:#EEE9F7
}
.lesson-title {
  display:flex;
  gap:100px;
  align-items:end;
  margin-bottom:45px
}
.lesson-title h2 {
  flex:1
}
.lesson-title p {
  flex:1;
  max-width:44ch
}
.annotated-sheet {
  border:1px solid #BFB2D5;
  background:white
}
.sheet-row {
  display:grid;
  grid-template-columns:190px 1fr 300px;
  gap:28px;
  padding:28px;
  border-bottom:1px solid #DDD5EA;
  align-items:center
}
.sheet-row:last-child {
  border:0
}
.sheet-row>span {
  font-size:14px
}
.sheet-row strong {
  font-family:JetBrains Mono;
  font-weight:400;
  font-size:27px
}
.sheet-row aside {
  border-left:2px solid #A82738;
  padding-left:20px;
  font-size:15px;
  color:#645472
}
.sheet-check {
  background:#E6F29C
}
.sheet-check aside {
  color:#202025
}
.curriculum {
  padding:90px 64px
}
.curriculum ol {
  list-style:none;
  counter-reset:module;
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:60px;
  padding:0;
  margin:50px 0 0
}
.curriculum li {
  counter-increment:module;
  border-top:3px solid #A82738;
  padding-top:22px
}
.curriculum li:before {
  content:counter(module);
  font-family:JetBrains Mono;
  font-size:34px
}
.curriculum h3 {
  margin:15px 0
}
.study-kit {
  padding:60px 64px;
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:110px;
  background:#202025;
  color:#FFFFFF
}
.study-kit p {
  margin-top:22px
}
.study-kit ul {
  padding-left:22px;
  margin:0
}
.study-kit li {
  padding:14px 0;
  border-bottom:1px solid #73678E
}
.program-choice {
  padding:90px 64px;
  display:grid;
  grid-template-columns:1fr 1.3fr;
  gap:38px 80px
}
.program-choice p {
  margin-top:20px
}
.program-choice [role=group] {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:16px
}
.program-choice button {
  padding:25px;
  text-align:left;
  background:white;
  border:1px solid #C8C8CF;
  display:grid;
  gap:18px;
  align-content:start
}
.program-choice button strong {
  font-family:JetBrains Mono;
  font-size:30px;
  font-weight:400
}
.program-choice button span {
  font-size:15px
}
.program-choice button b {
  margin-top:15px
}
.program-choice [aria-pressed=true] {
  border:2px solid #A82738;
  background:#EAE4F5
}
.chosen {
  grid-column:2;
  display:flex;
  justify-content:space-between;
  border-top:1px solid #C8C8CF;
  padding-top:20px
}
.chosen output {
  font-size:30px;
  font-family:JetBrains Mono
}
.c1 .faq {
  display:block;
  padding:65px 14%;
  background:#EEE9F7
}
.faq h2 {
  max-width:none;
  margin-bottom:30px
}
.faq h2 br {
  display:none
}
.c1 .request {
  display:block;
  max-width:850px;
  margin:auto;
  padding:80px 64px
}
.request form {
  margin-top:35px
}
.school-foot {
  background:#E6F29C;
  color:#202025;
  padding:45px 64px;
  align-items:center;
  font-size:14px
}
.school-foot strong {
  font-family:JetBrains Mono;
  font-size:35px;
  font-weight:400
}
.school-foot p {
  margin-top:16px
}
@media(max-width:900px) {
  .school-head>span {
    display:none
  }
  .sheet-row {
    grid-template-columns:145px 1fr
  }
  .sheet-row aside {
    grid-column:2
  }
  .lesson-title {
    gap:35px
  }
  .school-head nav {
    gap:12px
  }
}
@media(max-width:760px) {
  .school-head {
    margin:0 22px;
    height:auto;
    padding:20px 0;
    align-items:start;
    flex-wrap:wrap
  }
  .school-head .brand {
    font-size:24px
  }
  .school-head nav {
    width:100%;
    flex-wrap:wrap;
    gap:6px 22px
  }
  .lesson,.curriculum,.study-kit,.program-choice {
    padding:50px 22px
  }
  .lesson-title {
    display:block
  }
  .lesson-title p {
    margin-top:25px
  }
  .sheet-row {
    padding:20px;
    grid-template-columns:1fr;
    gap:12px
  }
  .sheet-row aside {
    grid-column:auto
  }
  .sheet-row strong {
    font-size:24px
  }
  .curriculum ol {
    grid-template-columns:1fr;
    gap:30px;
    margin-top:30px
  }
  .study-kit,.program-choice {
    grid-template-columns:1fr;
    gap:30px
  }
  .program-choice [role=group] {
    grid-template-columns:1fr
  }
  .chosen {
    grid-column:auto;
    gap:20px
  }
  .c1 .faq {
    padding:45px 22px
  }
  .c1 .request {
    padding:50px 22px
  }
  .school-foot {
    display:block;
    padding:32px 22px
  }
  .school-foot>div {
    margin-top:25px
  }
  h2 {
    font-size:34px
  }
}
select {
  font:inherit
}
select:focus-visible {
  outline:3px solid var(--accent);
  outline-offset:4px
}
input,select,fieldset,form {
  min-width:0
}
input[type=number] {
  max-width:100%;
  min-height:44px
}
input[type=number][aria-invalid=true] {
  outline:2px solid var(--error,#A72B31)
}
button:disabled {
  opacity:.5
}
nav a {
  min-height:44px;
  display:inline-flex;
  align-items:center
}
details {
  min-width:0
}
summary {
  line-height:1.5
}
form .consent {
  min-height:44px;
  align-items:center
}
section {
  scroll-margin-top:20px
}

/* Owner review, November 2026 */
.paper-head,.paper-foot,.formula small,.hero-bottom{font-size:16px;color:#42394F}.formula>label,.formula>div{font-size:16px}.workbook h1{font-size:58px;letter-spacing:-.05em}.workpaper{border-width:2px}.paper-head{border-bottom:2px solid var(--ink)}@media(max-width:700px){.workbook h1{font-size:35px}.paper-head,.paper-foot,.formula small,.paper-foot span,.hero-bottom,.hero-bottom>span{font-size:14px}.formula>label,.formula>div{font-size:14px}.workbook-top{padding-top:20px}.workpaper{margin-top:22px}.formula-result output{font-size:29px}.paper-foot{padding:10px 14px}}

@media(min-width:761px){.hero{min-height:calc(100svh - 120px)}#details{min-height:100svh}}
@media(min-width:380px) and (max-width:700px){.hero{min-height:calc(100svh - 130px)}}
button:disabled{opacity:1;color:var(--ink);background:var(--bg);border:1px solid var(--ink)}
@media(max-width:700px){.school-head{padding:16px 0;height:auto;display:block}.school-head .brand{font-size:24px}.school-head .brand br{display:none}.school-head nav{margin-top:10px;gap:4px 16px;display:flex;flex-wrap:wrap}.school-head nav a{font-size:14px;min-height:36px}.workbook-top{padding-top:18px}.workbook h1{font-size:32px}.workbook-top>div p{margin:14px 0}.workbook-top>div{padding:0}.hero-bottom{margin:14px 0 0}}

@media(min-width:380px) and (max-width:700px){.hero{min-height:calc(100svh - 116.03125px)}}

/* Task 15 ? photography, first iteration */
.visual-opening{position:relative!important;isolation:isolate;display:grid!important;grid-template-columns:46% 54%;align-items:center!important;gap:0!important;padding:0!important;height:calc(100svh - var(--masthead,120px))!important;min-height:620px!important;max-width:none!important;overflow:hidden;margin:0!important}
.opening-image{margin:0;position:absolute;inset:0 0 0 44%;overflow:hidden;z-index:-1}
.opening-image img{display:block;width:100%;height:100%;object-fit:cover}
.opening-copy{grid-column:1;padding:40px clamp(24px,4vw,68px);background:var(--bg);position:relative;z-index:1}
.visual-opening .opening-copy h1{font-family:var(--display),sans-serif;font-size:clamp(42px,4.6vw,74px);line-height:1.04;letter-spacing:-.035em;margin:0 0 26px;color:var(--ink)}
.opening-copy p{font:400 18px/1.55 var(--body),sans-serif;max-width:34ch;margin:0 0 26px;color:var(--ink)}
.opening-copy .button{display:inline-flex;min-height:48px;align-items:center}
.explore-link{display:block;width:fit-content;margin-top:22px;font-size:16px;text-underline-offset:5px;color:var(--ink)}
.interactive-intro{min-height:0!important;height:auto!important;padding-top:70px!important;padding-bottom:70px!important}
.interactive-intro h2{font-family:var(--display),sans-serif;font-size:clamp(30px,4vw,54px);line-height:1.1}
.section-photo{margin:24px 0;min-width:0;overflow:hidden;grid-column:1/-1;position:relative}
.section-photo img{display:block;width:100%;height:280px;object-fit:cover;transition:transform 800ms ease}
.section-photo figcaption{font:400 14px/1.5 var(--body),sans-serif;margin-top:10px;color:var(--ink)}
#details{height:auto!important;min-height:100svh;align-content:start}
.photo-process{margin-top:0}
.photo-detail img{height:340px}
.visual-2 .opening-image,.visual-5 .opening-image,.visual-6 .opening-image,.visual-8 .opening-image,.visual-10 .opening-image{inset:0}
.visual-2 .opening-copy,.visual-5 .opening-copy,.visual-6 .opening-copy,.visual-8 .opening-copy,.visual-10 .opening-copy{margin:30px;background:var(--bg);align-self:end;padding:32px;max-width:550px}
.visual-2{grid-template-columns:50% 50%}
.visual-5{grid-template-columns:60% 40%}
.visual-5 .opening-copy{margin-bottom:42px}
.visual-6{grid-template-columns:54% 46%}
.visual-8{grid-template-columns:60% 40%}
.visual-8 .opening-copy{border-left:8px solid var(--accent)}
.visual-10 .opening-copy{margin-left:0;border-top:8px solid var(--accent)}
.visual-4 .opening-image{inset:0 0 0 42%}
.visual-7{grid-template-columns:43% 57%}
.visual-9 .opening-image{inset:0 0 0 47%}
.visual-3 .opening-image::after{content:"";position:absolute;inset:0;background:radial-gradient(circle at var(--light-x,50%) var(--light-y,50%),transparent,rgba(0,10,20,.35));pointer-events:none}
@media(prefers-reduced-motion:no-preference){
.visual-1 .opening-image img{animation:opening-focus 16s ease-in-out infinite alternate}
.visual-4 .opening-image img{animation:opening-float 9s ease-in-out infinite alternate}
.visual-7 .opening-image{animation:opening-reveal 1.2s ease both}
.visual-8 .opening-image{animation:opening-stage 1.4s ease both}
.visual-9 .opening-image img{animation:opening-track 18s ease-in-out infinite alternate}
.section-photo:hover img{transform:scale(1.035)}
}
@keyframes opening-focus{to{transform:scale(1.07)}}
@keyframes opening-float{to{transform:scale(1.04) translateY(-8px)}}
@keyframes opening-reveal{from{clip-path:inset(0 100% 0 0)}to{clip-path:inset(0)}}
@keyframes opening-stage{from{filter:brightness(.35)}to{filter:brightness(1)}}
@keyframes opening-track{from{transform:scale(1.08) translateX(-2%)}to{transform:scale(1.08) translateX(2%)}}
@media(max-width:760px){
.visual-opening{display:flex!important;flex-direction:column!important;height:calc(100svh - var(--masthead,120px))!important;min-height:650px!important;justify-content:flex-start!important}
.visual-opening .opening-image{position:relative;inset:auto!important;order:0;width:100%;height:45%;flex:1;min-height:220px;z-index:0}
.visual-opening .opening-copy{order:1;width:100%;max-width:none;margin:0!important;padding:24px!important;align-self:stretch}
.visual-opening .opening-copy h1{font-size:36px;margin-bottom:14px}
.visual-opening .opening-copy h1 br{display:none}
.opening-copy p{font-size:16px;line-height:1.4;margin-bottom:18px}
.explore-link{font-size:14px;margin-top:16px}
.interactive-intro{padding-top:36px!important;padding-bottom:36px!important}
.section-photo img,.photo-detail img{height:240px}
.section-photo{width:100%;margin:18px 0}
}
@media(prefers-reduced-motion:reduce){.visual-opening *,.section-photo *{animation:none!important;transition:none!important;transform:none!important;scroll-behavior:auto!important}}

/* Review 15. Caption contrast on independent section backgrounds. */
.section-photo figcaption{color:var(--ink);background:var(--bg);padding:8px 12px;margin-top:0}

/* Second review. Keep interactive illustrations within their section. */
.interactive-intro{padding:64px!important;overflow:hidden;max-width:100%;box-sizing:border-box}.interactive-intro h2{margin-bottom:20px}.section-photo{align-self:start}@media(max-width:760px){.interactive-intro{padding:32px 24px!important}}