/*
  CSS controls presentation: color, spacing, layout, and interaction states.
  The HTML gives each part a class (for example .hero or .price-card); these
  selectors use those class names to style the matching elements.
*/

/* 1. Shared design tokens: update these values to change the whole theme. */
:root {
  --ink: #172235;
  --muted: #627087;
  --paper: #f4f7fb;
  --white: #ffffff;
  --soft-blue: #c6d5e7;
  --deep: #1b3b63;
  --accent: #9eb5d1;
  --line: #dce4ee;
  --serif: Georgia, 'Times New Roman', serif;
  --header-clearance: 72px;
}

/* The box-sizing rule makes width calculations easier to reason about. */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'DM Sans', sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select,
textarea {
  font: inherit;
}

.page-wrap {
  width: min(1160px, calc(100% - 48px));
  margin-inline: auto;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* 2. Header: flex aligns the logo, section links, and language selector. */
.site-header {
  position: static;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 72px;
  padding: 8px max(20px, calc((100vw - 1160px) / 2));
  border-bottom: 1px solid #29496e;
  background: rgba(20, 45, 77, 0.97);
  backdrop-filter: blur(12px);
  box-shadow: 0 5px 16px rgba(12, 29, 50, 0.12);
}

.brand {
  flex: 0 0 auto;
  font: 800 26px/1 Manrope, sans-serif;
  letter-spacing: -1.5px;
}

.brand span {
  color: var(--deep);
}

.brand-image {
  display: block;
  width: 112px;
  height: 56px;
  overflow: hidden;
  border-radius: 8px;
  background: #142d4d;
}

.brand-image img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(10px, 1.8vw, 22px);
  color: #e7edf5;
  font-size: 12px;
}

.main-nav a:not(.nav-cta):hover,
.main-nav a:not(.nav-cta):focus-visible {
  color: #a9c7e9;
}

.text-link:hover {
  color: var(--deep);
}

.nav-cta {
  padding: 8px 12px;
  border-radius: 99px;
  background: #ffffff;
  color: #142d4d;
  white-space: nowrap;
  font-weight: 600;
}

.nav-cta:hover,
.button:hover {
  background: #d9e5f2;
  color: #142d4d;
  transform: translateY(-2px);
}

.language-control {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
  padding: 4px 0;
  color: #fff;
}

.language-option {
  padding: 4px 2px;
  border: 0;
  background: transparent;
  color: #b7c4d5;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: color 160ms ease, transform 160ms ease;
}

.language-option:hover,
.language-option:focus-visible,
.language-option[aria-pressed="true"] {
  color: #ffffff;
}

.language-option:hover {
  transform: translateY(-1px);
}

.language-option:focus-visible {
  outline: 2px solid #c5d8ef;
  outline-offset: 4px;
  border-radius: 3px;
}

.language-divider {
  width: 2px;
  height: 22px;
  background: #e4ecf6;
}

/* Shared button style keeps all primary actions consistent. */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 21px;
  border: 0;
  border-radius: 99px;
  background: var(--deep);
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, background 0.2s;
}

/* 3. Hero: CSS Grid creates a copy column and an illustration column. */
.hero {
  display: grid;
  grid-template-columns: 1fr 0.95fr;
  align-items: center;
  gap: 62px;
  padding-top: 68px;
  padding-bottom: 82px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 13px;
  color: var(--deep);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 22px;
  height: 1px;
  background: var(--accent);
  content: '';
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  font-family: Manrope, sans-serif;
}

h1 {
  max-width: 650px;
  margin-bottom: 23px;
  font-size: clamp(48px, 6vw, 75px);
  font-weight: 600;
  letter-spacing: -4px;
  line-height: 1.04;
}

h1 em {
  color: var(--deep);
  font-family: var(--serif);
  font-weight: 400;
}

.lead {
  max-width: 560px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.7;
}

.small-note {
  margin-top: 19px;
  color: var(--muted);
  font-size: 13px;
}

/* The hero illustration is built from CSS shapes as a replaceable placeholder. */
.hero-art {
  position: relative;
  min-height: 440px;
  overflow: hidden;
  border-radius: 180px 180px 24px 24px;
  background: #dce7f3;
}

.hero-art::before {
  position: absolute;
  right: -12%;
  bottom: -13%;
  left: -12%;
  height: 40%;
  border-radius: 50% 50% 0 0;
  background: #b9cde4;
  content: '';
}

.window-shape {
  position: absolute;
  top: 18%;
  left: 10%;
  width: 28%;
  height: 42%;
  border: 12px solid #f6f8fb;
  background: linear-gradient(90deg, transparent 48%, #f6f8fb 48% 53%, transparent 53%), linear-gradient(transparent 48%, #f6f8fb 48% 53%, transparent 53%), #c5d6e9;
}

.tutor-shape,
.student-shape {
  position: absolute;
  bottom: 22%;
  width: 23%;
  height: 37%;
  border-radius: 48% 48% 8% 8%;
}

.tutor-shape {
  left: 32%;
  background: #244a76;
  transform: rotate(-5deg);
}

.student-shape {
  right: 16%;
  bottom: 21%;
  width: 20%;
  height: 30%;
  background: #829dbd;
  transform: rotate(4deg);
}

.tutor-shape::before,
.student-shape::before {
  position: absolute;
  top: -28%;
  left: 28%;
  width: 52%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: #d6a382;
  content: '';
}

.student-shape::before {
  background: #ba8466;
}

.tutor-shape span,
.student-shape span {
  position: absolute;
  z-index: 2;
  top: -32%;
  left: 23%;
  width: 62%;
  height: 27%;
  border-radius: 50% 50% 30% 30%;
  background: #172d49;
}

.desk-shape {
  position: absolute;
  z-index: 3;
  right: 13%;
  bottom: 20%;
  left: 23%;
  height: 12px;
  border-radius: 4px;
  background: #607d9e;
}

.desk-shape::before {
  position: absolute;
  top: -34px;
  left: 38%;
  width: 22%;
  height: 32px;
  border-radius: 3px;
  background: #f8fbff;
  content: '';
  transform: rotate(-5deg);
}

.desk-shape i {
  position: absolute;
  top: 10px;
  width: 9px;
  height: 52px;
  background: #456487;
}

.desk-shape i:first-child {
  left: 8%;
}

.desk-shape i:last-child {
  right: 8%;
}

.art-note {
  position: absolute;
  z-index: 4;
  right: 16px;
  bottom: 16px;
  left: 16px;
  padding: 11px 14px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.94);
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

/* 4. Reusable section and card styles. */
.section {
  padding-top: 100px;
  padding-bottom: 100px;
  scroll-margin-top: 90px;
}

/* Keep About, the science feature, reviews, and prices visually connected. */
#about,
#science-communication,
#recension,
#prices {
  padding-block: clamp(40px, 5vw, 56px);
}

.section-heading {
  max-width: 700px;
  margin: 0 auto 42px;
  text-align: center;
}

.section-heading h2,
.booking-layout h2 {
  margin-bottom: 16px;
  font-size: clamp(34px, 4vw, 50px);
  font-weight: 600;
  letter-spacing: -2.2px;
  line-height: 1.1;
}

.section-heading > p:last-child {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 17px;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.info-card,
.price-card,
.detail-card,
.review-card {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--white);
}

.info-card {
  min-height: 205px;
  padding: 25px;
}

.card-index {
  display: grid;
  width: 34px;
  height: 34px;
  margin-bottom: 20px;
  place-items: center;
  border-radius: 50%;
  background: #e8eff7;
  color: var(--deep);
  font-size: 12px;
  font-weight: 700;
}

.info-card h3,
.price-card h3,
.detail-card h3,
.about-copy h3,
.video-copy h3,
.reviews-heading h3 {
  margin-bottom: 9px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.3px;
}

.info-card p,
.detail-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

/* Pin this full-screen story while its heading and coaching message reveal on scroll. */
.approach-story {
  position: relative;
  min-height: 260svh;
  margin: clamp(52px, 8vh, 100px) calc(50% - 50vw);
  padding-inline: max(24px, calc((100vw - 1160px) / 2));
  overflow: clip;
  background:
    radial-gradient(circle at 78% 48%, rgba(91, 133, 184, 0.28), transparent 34%),
    linear-gradient(135deg, #10233a 0%, #18395f 58%, #10233a 100%);
  color: #fff;
  scroll-margin-top: 0;
}

.approach-stage {
  position: sticky;
  top: 0;
  display: flex;
  min-height: 100svh;
  align-items: center;
  overflow: hidden;
  padding-block: clamp(48px, 8vh, 94px);
}

.approach-content {
  position: relative;
  z-index: 1;
  width: min(100%, 1030px);
  padding-bottom: 10px;
}

.approach-eyebrow {
  margin-bottom: clamp(22px, 4vh, 42px);
  color: #b9cce3;
}

.approach-title {
  max-width: 1020px;
  margin: 0;
  color: #fff;
  font-size: clamp(54px, 9vw, 126px);
  font-weight: 600;
  letter-spacing: -0.075em;
  line-height: 0.98;
  text-wrap: balance;
}

.approach-text {
  max-width: 700px;
  margin: clamp(28px, 5vh, 54px) 0 0;
  color: #d9e4f1;
  font-size: clamp(18px, 2vw, 23px);
  line-height: 1.55;
}

.approach-story.is-scroll-driven .approach-eyebrow,
.approach-story.is-scroll-driven .approach-title,
.approach-story.is-scroll-driven .approach-text {
  opacity: var(--story-opacity, 1);
  transform: translateY(var(--story-lift, 0px));
  will-change: opacity, transform;
}

.approach-orbit {
  position: absolute;
  top: 50%;
  right: -8%;
  width: min(56vw, 700px);
  aspect-ratio: 1;
  border: 1px solid rgba(223, 236, 252, 0.18);
  border-radius: 50%;
  opacity: 0.72;
  pointer-events: none;
  transform: translateY(-50%);
}

.approach-orbit::before,
.approach-orbit::after {
  position: absolute;
  inset: 12%;
  border: 1px solid rgba(223, 236, 252, 0.15);
  border-radius: 50%;
  content: '';
}

.approach-orbit::after {
  inset: 26%;
}

.approach-orbit span {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 38%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(176, 208, 244, 0.26), rgba(176, 208, 244, 0.015) 70%);
  transform: translate(-50%, -50%);
}

.approach-progress {
  position: absolute;
  right: 0;
  bottom: 25px;
  left: 0;
  height: 2px;
  overflow: hidden;
  background: rgba(228, 238, 250, 0.2);
}

.approach-progress span {
  display: block;
  width: 100%;
  height: 100%;
  background: #c2d9f4;
  transform: scaleX(var(--approach-progress, 0));
  transform-origin: left center;
}

/* The video stays in a responsive 16:9 frame; the link also opens the source page. */
.video-card {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  align-items: center;
  gap: 30px;
  margin-top: 22px;
  padding: 28px;
  border-radius: 20px;
  background: #eef2f7;
}

.video-copy p:not(.eyebrow) {
  color: var(--muted);
}

.text-link {
  color: var(--deep);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.video-frame {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 14px;
  background: #142d4d;
}

.video-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  transition: transform 220ms ease;
}

.video-frame:hover img,
.video-frame:focus-visible img {
  transform: scale(1.035);
}

.video-frame:focus-visible {
  outline: 3px solid var(--soft-blue);
  outline-offset: 4px;
}

.video-play {
  position: absolute;
  top: 50%;
  left: 50%;
  display: grid;
  width: 66px;
  height: 66px;
  place-items: center;
  padding-left: 4px;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: #fff;
  color: #1b3b63;
  font-size: 22px;
  box-shadow: 0 4px 20px rgb(0 0 0 / 24%);
  transition: transform 220ms ease;
}

.video-frame:hover .video-play,
.video-frame:focus-visible .video-play {
  transform: translate(-50%, -50%) scale(1.08);
}

/* 5. Price section: featured hourly rate and add-on costs. */
.prices-section {
  background: #e8eef6;
}

.price-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.price-card {
  padding: 30px;
}

.price-featured {
  border-color: #b4c7dd;
  box-shadow: 0 14px 36px rgba(27, 59, 99, 0.08);
}

.price {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 5px 0 24px;
  color: var(--muted);
}

.price strong {
  color: var(--ink);
  font: 700 50px/1 Manrope, sans-serif;
  letter-spacing: -2px;
}

.price-card ul,
.compact-list {
  display: grid;
  gap: 10px;
  padding-left: 20px;
  color: var(--muted);
  font-size: 14px;
}

.price-card li::marker,
.compact-list li::marker {
  color: var(--deep);
}

.extra-price,
.rate-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  border-top: 1px solid var(--line);
  padding: 14px 0;
}

.extra-price {
  margin-top: 20px;
  color: var(--muted);
  font-size: 14px;
}

.extra-price strong,
.rate-row strong {
  color: var(--deep);
  white-space: nowrap;
}

.rate-row:first-of-type {
  margin-top: 16px;
}

.rate-row small {
  color: var(--muted);
  font-size: 11px;
  font-weight: 400;
}

.card-footnote {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.details-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 18px;
}

.detail-card {
  padding: 23px;
}

.compact-list {
  gap: 5px;
  margin-bottom: 0;
}

/* 6. About and reputation: two-column biography, interview, and review cards. */
.left-heading {
  margin-left: 0;
  text-align: left;
}

.about-grid {
  display: grid;
  grid-template-columns: 0.6fr 1.4fr;
  align-items: center;
  gap: 58px;
}

.about-mark {
  position: relative;
  display: grid;
  min-height: 320px;
  overflow: hidden;
  place-items: center;
  border-radius: 24px;
  background: #e1eaf4;
}

.about-mark span {
  color: var(--deep);
  font: 800 210px/1 Manrope, sans-serif;
  letter-spacing: -20px;
}

.about-mark i {
  position: absolute;
  right: 22px;
  bottom: 18px;
  color: #738cab;
  font: 600 44px var(--serif);
}

.about-copy {
  max-width: 700px;
}

.about-copy p {
  color: var(--muted);
}

.about-copy h3:not(:first-child) {
  margin-top: 26px;
}

.signature {
  color: var(--deep) !important;
  font: italic 22px var(--serif);
}

.interview-details {
  margin-top: 38px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.interview-details summary {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  color: var(--deep);
  font: 700 17px Manrope, sans-serif;
  cursor: pointer;
  list-style: none;
}

.interview-details summary::after {
  content: '+';
  font-size: 23px;
  font-weight: 400;
}

.interview-details[open] summary::after {
  content: '−';
}

.interview-list {
  display: grid;
  gap: 20px;
  padding-top: 22px;
}

.interview-item h4 {
  margin: 0 0 6px;
  font: 700 15px Manrope, sans-serif;
}

.interview-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.reviews-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 25px;
  margin: 65px 0 22px;
}

.reviews-heading h3 {
  margin: 0;
  font-size: 30px;
  letter-spacing: -1px;
}

.rating-summary {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 14px;
  border-radius: 12px;
  background: #eef3fa;
  white-space: nowrap;
}

.rating-summary span {
  color: #e9a800;
  letter-spacing: 1px;
}

.rating-summary small {
  color: var(--muted);
  font-size: 11px;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.review-card {
  padding: 20px;
}

.review-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
  font-weight: 700;
}

.review-stars {
  color: #e9a800;
  font-size: 13px;
  letter-spacing: 1px;
}

.review-card p {
  margin: 0;
  color: #465a73;
  font-size: 14px;
}

/* 7. Booking form: labels sit above their inputs; grid makes two columns on desktop. */
.booking-section {
  padding: 88px 0;
  background: #1b3b63;
  color: white;
  scroll-margin-top: 86px;
}

.booking-layout {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  align-items: start;
  gap: 65px;
}

.booking-layout .eyebrow,
.booking-layout h2 {
  color: white;
}

.booking-layout > div > p:not(.eyebrow) {
  color: #d9e4f1;
}

.booking-email a {
  color: white;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.booking-form {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 15px;
  padding: 27px;
  border-radius: 20px;
  background: var(--white);
  color: var(--ink);
}

.booking-form label {
  display: grid;
  gap: 7px;
  font-size: 13px;
  font-weight: 600;
}

.format-field {
  grid-column: 1 / -1;
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.format-field legend {
  margin-bottom: 7px;
  padding: 0;
  font-size: 13px;
  font-weight: 600;
}

.format-options {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.booking-form .format-option {
  position: relative;
  display: flex;
  gap: 0;
  cursor: pointer;
}

.booking-form .format-option input {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  clip-path: inset(50%);
}

.format-option span {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  padding: 8px 15px;
  border: 1px solid #dce4ee;
  border-radius: 999px;
  background: #fff;
  color: var(--muted);
  transition: border-color 160ms ease, background-color 160ms ease, color 160ms ease;
}

.format-option:hover span {
  border-color: var(--deep);
  color: var(--deep);
}

.format-option input:checked + span {
  border-color: var(--deep);
  background: var(--deep);
  color: #fff;
}

.format-option input:focus-visible + span {
  outline: 3px solid rgba(27, 59, 99, 0.2);
  outline-offset: 2px;
}

.booking-form input,
.booking-form select,
.booking-form textarea {
  width: 100%;
  padding: 12px 13px;
  border: 1px solid #dce4ee;
  border-radius: 9px;
  outline: none;
  background: white;
  color: var(--ink);
}

.booking-form input:focus,
.booking-form select:focus,
.booking-form textarea:focus {
  border-color: var(--deep);
  box-shadow: 0 0 0 3px rgba(27, 59, 99, 0.12);
}

.booking-form textarea {
  resize: vertical;
}

.full-field,
.booking-form .button,
.form-note {
  grid-column: 1 / -1;
}

.booking-form .button {
  justify-self: start;
}

.form-note {
  margin: -4px 0 0;
  color: var(--muted);
  font-size: 11px;
}

.form-note[data-state="success"] {
  color: #245b43;
  font-size: 14px;
  font-weight: 700;
}

.form-note[data-state="error"] {
  color: #9b2d2d;
  font-size: 13px;
  font-weight: 600;
}

.form-note[data-state="sending"] {
  color: var(--deep);
}

.booking-form .button:disabled {
  cursor: wait;
  opacity: 0.72;
  transform: none;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 24px max(24px, calc((100vw - 1160px) / 2));
  color: var(--muted);
  font-size: 12px;
}

.site-footer > span a {
  color: var(--deep);
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 40;
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 13px 20px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  background: #080a0d;
  color: #fff;
  box-shadow: 0 8px 24px rgba(10, 20, 34, 0.28);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 180ms ease, transform 180ms ease, visibility 180ms ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top.footer-visible {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(8px);
}

.back-to-top:hover {
  background: var(--deep);
}

.back-to-top:focus-visible {
  outline: 3px solid #a9c7e9;
  outline-offset: 4px;
}

.back-to-top-arrow {
  font-size: 25px;
  font-weight: 500;
}

/* Keep anchored sections visible below the compact navigation bar. */
main > section[id] {
  scroll-margin-top: 78px;
}

/* 8. Responsive rules override desktop layouts at smaller viewport widths. */
@media (max-width: 900px) {
  .site-header {
    gap: 12px;
  }

  .main-nav {
    gap: 10px;
    font-size: 11px;
  }

  .hero {
    gap: 35px;
  }

  .hero-art {
    min-height: 370px;
  }

  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 700px) {
  :root {
    --header-clearance: 92px;
  }

  .page-wrap {
    width: min(100% - 36px, 600px);
  }

  .site-header {
    position: static;
    flex-wrap: wrap;
    gap: 0 12px;
    padding: 6px 14px;
  }

  .brand {
    margin-right: auto;
  }

  .brand-image {
    width: 92px;
    height: 46px;
  }

  .main-nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    gap: 8px;
    overflow-x: auto;
    padding-top: 2px;
    scrollbar-width: none;
  }

  .main-nav::-webkit-scrollbar {
    display: none;
  }

  .main-nav a {
    flex: 0 0 auto;
    white-space: nowrap;
  }

  .main-nav .nav-cta {
    padding: 5px 9px;
  }

  main > section[id] {
    scroll-margin-top: 96px;
  }

  .back-to-top {
    right: 15px;
    bottom: max(16px, env(safe-area-inset-bottom));
    gap: 10px;
    padding: 12px 17px;
    font-size: 16px;
  }

  .back-to-top-arrow {
    font-size: 22px;
  }

  .hero,
  .video-card,
  .price-layout,
  .about-grid,
  .booking-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 48px;
    padding-bottom: 60px;
  }

  h1 {
    font-size: 54px;
    letter-spacing: -3px;
  }

  .hero-art {
    min-height: 350px;
    border-radius: 140px 140px 22px 22px;
  }

  .approach-story {
    min-height: 250svh;
    padding-inline: 20px;
  }

  .approach-stage {
    padding-block: 38px 54px;
  }

  .approach-title {
    font-size: clamp(48px, 13vw, 82px);
  }

  .approach-text {
    max-width: 560px;
    font-size: 18px;
  }

  .approach-orbit {
    right: -58%;
    width: 110vw;
    opacity: 0.42;
  }

  .section {
    padding-top: 72px;
    padding-bottom: 72px;
  }

  .info-grid,
  .details-grid {
    grid-template-columns: 1fr;
  }

  .video-card {
    gap: 20px;
    padding: 23px;
  }

  .about-grid {
    gap: 28px;
  }

  .about-mark {
    min-height: 220px;
  }

  .about-mark span {
    font-size: 160px;
  }

  .reviews-heading {
    align-items: start;
    flex-direction: column;
    margin-top: 45px;
  }

  .booking-layout {
    gap: 30px;
  }
}

@media (max-width: 480px) {
  .page-wrap {
    width: calc(100% - 32px);
  }

  .main-nav {
    font-size: 11px;
  }

  .nav-cta {
    padding: 8px 10px;
  }

  h1 {
    font-size: 47px;
  }

  .lead {
    font-size: 16px;
  }

  .price-card {
    padding: 23px;
  }

  .reviews-grid {
    grid-template-columns: 1fr;
  }

  .rating-summary {
    flex-wrap: wrap;
  }

  .booking-form {
    grid-template-columns: 1fr;
    padding: 21px;
  }

  .full-field,
  .booking-form .button,
  .form-note {
    grid-column: 1;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  .approach-story {
    min-height: 100svh;
  }

  .approach-story.is-scroll-driven .approach-title,
  .approach-story.is-scroll-driven .approach-text {
    opacity: 1 !important;
    transform: none !important;
  }
}

/* Keep the approved math and physics marks close to the general-information heading. */
#general > .section-heading {
  position: relative;
  margin-bottom: 28px;
  z-index: 0;
}
#general > .section-heading h2,
#general > .section-heading > p {
  position: relative;
  z-index: 1;
}
.science-watermarks {
  position: absolute;
  inset: -72px -92px auto;
  height: 72px;
  pointer-events: none;
}
.watermark-math,
.watermark-physics {
  position: absolute;
  top: 0;
  width: 42%;
  height: 72px;
  color: var(--deep);
  font-family: Georgia, 'Times New Roman', serif;
}
.watermark-math { left: 2%; }
.watermark-physics { right: 2%; }
.watermark-math > span,
.watermark-physics > span {
  position: absolute;
  display: block;
  white-space: nowrap;
  opacity: .16;
}
.watermark-math .sum { top: 1px; left: 8%; font-size: 42px; }
.watermark-math .frac { top: 2px; left: 60%; width: 38px; text-align: center; font-size: 20px; }
.watermark-math .frac small,
.watermark-math .lim small { display: block; border-top: 1px solid currentColor; font-size: 10px; line-height: 1.3; }
.watermark-math .lim { top: 39px; left: 70%; text-align: center; font-size: 18px; }
.watermark-math .integral { top: 5px; left: 91%; font-size: 50px; }
.watermark-physics .force { top: 4px; left: 10%; font-size: 24px; }
.watermark-physics .atom { top: 13px; left: 46%; width: 44px; height: 44px; }
.watermark-physics .atom i { position: absolute; inset: 14px 0; border: 1.5px solid currentColor; border-radius: 50%; }
.watermark-physics .atom i:nth-child(2) { transform: rotate(60deg); }
.watermark-physics .atom i:nth-child(3) { transform: rotate(-60deg); }
.watermark-physics .atom b { position: absolute; inset: 19px; border-radius: 50%; background: currentColor; }
.watermark-physics .action { top: 43px; left: 69%; font-size: 13px; }
.about-mark { overflow: hidden; background: #e1eaf4; }
.about-mark img { display: block; width: 100%; height: 100%; min-height: 320px; object-fit: cover; object-position: center 36%; }
.rating-summary small a { text-decoration: underline; text-underline-offset: 3px; }
@media (max-width: 900px) {
  .science-watermarks { inset-inline: -54px; transform: scale(.82); transform-origin: bottom center; }
}
@media (max-width: 560px) {
  .science-watermarks { inset-inline: -25px; transform: scale(.6); transform-origin: bottom center; }
  #general > .section-heading { margin-bottom: 38px; }
  .about-mark img { min-height: 280px; }
}