/* Design tokens */
:root {
  --color-ink: #1C1C1C;
  --color-gold: #C8A96E;
  --color-parchment: #F7F4EF;
  --color-line: #E4DCC9;
  --color-white: #FFFFFF;
  --color-error: #C0392B;

  --text-hero: clamp(42px, 6vw, 72px);
  --text-h2: clamp(28px, 4vw, 44px);
  --text-h3: clamp(20px, 2.5vw, 28px);
  --text-body: 16px;
  --text-small: 13px;

  --section-gap: 100px;
  --card-gap: 28px;
  --max-width: 1200px;
  --border-radius: 4px;

  --font-display: "Playfair Display", Georgia, serif;
  --font-body: "Lato", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: 1.6;
  color: var(--color-ink);
  background-color: var(--color-parchment);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

button {
  font-family: inherit;
  cursor: pointer;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: var(--section-gap) 0;
}

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-parchment);
  border-bottom: 1px solid var(--color-line);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 16px;
}

.nav__logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  color: var(--color-gold);
  flex-shrink: 0;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border: none;
  background: transparent;
}

.nav__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-ink);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav__link {
  font-size: 14px;
  color: var(--color-ink);
  transition: color 0.2s ease;
}

.nav__link:hover {
  color: var(--color-gold);
}

.nav__lang {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
}

.nav__lang-btn {
  border: none;
  background: none;
  padding: 0;
  font-size: 14px;
  color: var(--color-ink);
  opacity: 0.45;
  transition: opacity 0.2s ease, color 0.2s ease;
}

.nav__lang-btn.is-active {
  font-weight: 700;
  opacity: 1;
}

.nav__lang-btn:hover {
  color: var(--color-gold);
}

.nav__lang-sep {
  opacity: 0.35;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  font-size: var(--text-body);
  font-weight: 700;
  border-radius: var(--border-radius);
  border: 1px solid transparent;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  text-align: center;
}

.btn--primary {
  background-color: var(--color-ink);
  color: var(--color-parchment);
}

.btn--primary:hover {
  background-color: var(--color-gold);
  color: var(--color-ink);
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-ink);
  border-color: var(--color-ink);
}

.btn--secondary:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
}

.btn--gold {
  background-color: var(--color-gold);
  color: var(--color-ink);
}

.btn--gold:hover {
  background-color: #d4b87e;
}

.btn--small {
  padding: 8px 16px;
  font-size: var(--text-small);
  font-weight: 400;
}

.btn--outline-small {
  padding: 8px 14px;
  font-size: var(--text-small);
  font-weight: 400;
  background: transparent;
  color: var(--color-ink);
  border: 1px solid var(--color-ink);
}

.btn--outline-small:hover {
  border-color: var(--color-gold);
  color: var(--color-gold);
}

/* Hero */
.hero {
  background-color: var(--color-parchment);
  padding: 120px 0 140px;
}

.hero__grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 64px;
  align-items: center;
}

.hero__content {
  padding: 24px 0;
}

.hero__eyebrow {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin: 0 0 24px;
}

.hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-hero);
  line-height: 1.1;
  margin: 0 0 28px;
  white-space: pre-line;
}

.hero__subtitle {
  font-size: var(--text-body);
  max-width: 42ch;
  margin: 0 0 40px;
  line-height: 1.7;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px;
}

.btn--hero {
  padding: 12px 26px;
  font-size: 15px;
  letter-spacing: 0.02em;
}

.hero__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--text-body);
  font-weight: 400;
  color: var(--color-ink);
  opacity: 0.85;
  transition: color 0.2s ease, opacity 0.2s ease;
}

.hero__link::after {
  content: "→";
  transition: transform 0.2s ease;
}

.hero__link:hover {
  color: var(--color-gold);
  opacity: 1;
}

.hero__link:hover::after {
  transform: translateX(3px);
}

.hero__visual {
  position: relative;
  width: 340px;
  height: 260px;
  flex-shrink: 0;
}

.hero__covers-item {
  position: absolute;
  bottom: 0;
  width: 160px;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: 0 16px 40px rgba(28, 28, 28, 0.14);
  transition: transform 0.3s ease;
}

.hero__covers-item .cover-card {
  width: 100%;
  aspect-ratio: 2 / 3;
}

.hero__covers-item--left {
  left: 0;
  transform: rotate(-5deg);
  z-index: 1;
}

.hero__covers-item--center {
  left: 50%;
  transform: translateX(-50%) rotate(0deg);
  z-index: 3;
}

.hero__covers-item--right {
  right: 0;
  transform: rotate(5deg);
  z-index: 2;
}

.hero__covers-item--left:hover {
  transform: rotate(-5deg) translateY(-4px);
}

.hero__covers-item--center:hover {
  transform: translateX(-50%) rotate(0deg) translateY(-6px);
}

.hero__covers-item--right:hover {
  transform: rotate(5deg) translateY(-4px);
}

/* Free workbook */
.free-workbook {
  background-color: var(--color-ink);
  color: var(--color-parchment);
}

.free-workbook__grid {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 48px;
  align-items: center;
}

.free-workbook__cover {
  width: 100%;
  max-width: 260px;
  aspect-ratio: 2 / 3;
  object-fit: cover;
  border-radius: var(--border-radius);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
}

.free-workbook__cover-wrap {
  width: 260px;
  max-width: 100%;
  flex-shrink: 0;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
}

.free-workbook__cover-wrap .cover-card {
  width: 100%;
  aspect-ratio: 2 / 3;
  border-radius: var(--border-radius);
}

.free-workbook__badge {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin: 0 0 16px;
}

.free-workbook__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-h2);
  line-height: 1.2;
  margin: 0 0 12px;
}

.free-workbook__subtitle {
  font-size: var(--text-body);
  margin: 0 0 16px;
  opacity: 0.9;
}

.free-workbook__text {
  font-size: var(--text-body);
  line-height: 1.8;
  margin: 0 0 28px;
  max-width: 52ch;
}

.free-workbook__note {
  font-size: var(--text-small);
  margin: 12px 0 0;
  opacity: 0.75;
}

/* Workbooks */
.workbooks__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.workbooks__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-h2);
  margin: 0;
}

.workbooks__filters-wrap {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
  max-width: 100%;
}

.filter-row {
  display: flex;
  gap: 8px;
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding-bottom: 4px;
  max-width: 100%;
}

.filter-row::-webkit-scrollbar {
  display: none;
}

.filter-row--sub {
  display: none;
}

.filter-row--sub.is-visible {
  display: flex;
}

.workbooks__filters {
  display: flex;
  gap: 8px;
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding-bottom: 4px;
}

.workbooks__filters::-webkit-scrollbar {
  display: none;
}

.filter-btn {
  flex-shrink: 0;
  padding: 8px 18px;
  font-size: var(--text-small);
  font-weight: 700;
  border: 1px solid var(--color-line);
  border-radius: 999px;
  background: var(--color-white);
  color: var(--color-ink);
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.filter-btn--sub {
  font-weight: 400;
  padding: 6px 14px;
  font-size: 12px;
}

.filter-btn.is-active {
  background-color: var(--color-gold);
  border-color: var(--color-gold);
  color: var(--color-ink);
}

.filter-btn:hover:not(.is-active) {
  border-color: var(--color-gold);
}

.workbooks__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--card-gap);
}

.workbooks__show-more {
  display: block;
  margin: 32px auto 0;
  padding: 12px 26px;
}

.workbooks__show-more[hidden] {
  display: none;
}

.workbook-card {
  border: 1px solid var(--color-line);
  border-radius: var(--border-radius);
  background: var(--color-white);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.workbook-card:hover {
  box-shadow: 0 8px 24px rgba(28, 28, 28, 0.08);
}

.cover-card {
  width: 100%;
  aspect-ratio: 1 / 1;
  background-color: var(--color-parchment);
  display: grid;
  grid-template-rows: auto 1fr auto;
  overflow: hidden;
  container-type: size;
}

.cover-card__label-top {
  padding: 5.5% 8% 0;
  font-family: var(--font-display);
  font-size: clamp(8px, 1.8cqw, 10px);
  font-weight: 700;
  text-align: center;
  color: var(--color-gold);
}

.cover-card__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 0 8%;
  text-align: center;
  gap: 0;
}

.cover-card__count {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(40px, 17.3cqw, 72px);
  line-height: 1;
  color: var(--color-ink);
  margin: 0 0 4%;
}

.cover-card__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(9px, 3.96cqw, 13px);
  line-height: 1.36;
  color: var(--color-ink);
  margin: 0;
  max-width: 100%;
  text-transform: uppercase;
}

.cover-card__subtitle {
  font-family: var(--font-body);
  font-size: clamp(7px, 1.98cqw, 11px);
  line-height: 1.4;
  color: var(--color-ink);
  margin: 3% 0 0;
  opacity: 0.6;
  max-width: 92%;
}

.cover-card__bar {
  width: 100%;
  height: 4.71cqh;
  min-height: 14px;
  background-color: var(--color-gold);
  display: flex;
  align-items: center;
  justify-content: center;
}

.cover-card__bar span {
  font-family: var(--font-display);
  font-size: clamp(7px, 1.98cqw, 11px);
  font-weight: 700;
  color: var(--color-parchment);
}

.workbook-card__body {
  padding: 16px;
}

.workbook-card__title {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.4;
  margin: 0 0 14px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 2.8em;
}

.workbook-card__countdown {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin: 0;
  font-size: var(--text-small);
  font-weight: 700;
  color: var(--color-gold);
}

.workbook-card__countdown-icon {
  flex-shrink: 0;
}

/* About */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-h2);
  margin: 0 0 24px;
}

.about__text {
  font-size: var(--text-body);
  line-height: 1.8;
  margin: 0 0 16px;
}

.about__content .about__text:last-of-type {
  margin-bottom: 28px;
}

.about__photo {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--border-radius);
  box-shadow: 0 8px 24px rgba(28, 28, 28, 0.12);
}

/* Contact */
.contact {
  text-align: center;
}

.contact__inner {
  max-width: 600px;
  margin: 0 auto;
}

.contact__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-h2);
  margin: 0 0 12px;
}

.contact__subtitle {
  margin: 0 0 36px;
  line-height: 1.7;
}

.contact__form {
  text-align: left;
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: var(--text-small);
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.form-input,
.form-textarea {
  width: 100%;
  padding: 12px;
  font-family: inherit;
  font-size: var(--text-body);
  color: var(--color-ink);
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--border-radius);
  transition: border-color 0.2s ease;
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-gold);
}

.form-textarea {
  min-height: 140px;
  resize: vertical;
}

.contact__submit {
  width: 100%;
  margin-top: 8px;
}

.contact__success {
  font-size: var(--text-body);
  font-style: italic;
  color: var(--color-gold);
  line-height: 1.7;
}

.contact__error {
  font-size: 14px;
  color: var(--color-error);
  margin-top: 16px;
}

.contact__status {
  display: none;
}

.contact__status.is-visible {
  display: block;
}

/* Footer */
.footer {
  background-color: var(--color-ink);
  color: var(--color-parchment);
  padding: 72px 0 0;
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
}

.footer__col {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.footer__logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  color: var(--color-gold);
  margin: 0 0 12px;
}

.footer__tagline {
  margin: 0 0 24px;
  font-size: var(--text-body);
  line-height: 1.6;
  opacity: 0.9;
  max-width: 28ch;
}

.footer__heading {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  color: var(--color-gold);
  margin: 0 0 20px;
  letter-spacing: 0.04em;
}

.footer__social {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer__link,
.footer__nav-link,
.footer__email {
  color: var(--color-parchment);
  font-size: var(--text-body);
  opacity: 0.9;
  transition: color 0.2s ease, opacity 0.2s ease;
}

.footer__link:hover,
.footer__nav-link:hover,
.footer__email:hover {
  color: var(--color-gold);
  opacity: 1;
}

.footer__social .footer__link {
  color: var(--color-gold);
  opacity: 1;
}

.footer__social .footer__link:hover {
  color: #d4b87e;
}

.footer__social-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.footer__icon {
  flex-shrink: 0;
}

.footer__text {
  margin: 0 0 16px;
  font-size: var(--text-body);
  line-height: 1.7;
  opacity: 0.85;
  max-width: 28ch;
}

.footer__cta {
  margin-bottom: 16px;
  color: var(--color-gold);
  opacity: 1;
}

.footer__cta:hover {
  color: #d4b87e;
}

.footer__email {
  font-size: var(--text-small);
  opacity: 0.75;
}

.footer__bottom {
  border-top: 1px solid var(--color-line);
  padding: 24px 0 32px;
}

.footer__copy {
  font-size: var(--text-small);
  opacity: 0.7;
  margin: 0;
}

/* Responsive: tablet */
@media (max-width: 1023px) {
  .workbooks__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }

  .footer__col:first-child {
    grid-column: 1 / -1;
  }
}

/* Responsive: mobile */
@media (max-width: 639px) {
  :root {
    --section-gap: 60px;
  }

  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background-color: var(--color-parchment);
    border-bottom: 1px solid var(--color-line);
    padding: 0 24px 24px;
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s ease, opacity 0.25s ease;
  }

  .nav__menu.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav__links {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    width: 100%;
  }

  .nav__links li {
    width: 100%;
    border-bottom: 1px solid var(--color-line);
  }

  .nav__link {
    display: block;
    padding: 16px 0;
    font-size: var(--text-body);
  }

  .nav__lang {
    padding-top: 20px;
    justify-content: center;
  }

  .hero {
    padding: 72px 0 80px;
  }

  .hero__grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero__content {
    padding: 0;
  }

  .hero__visual {
    width: 100%;
    max-width: 320px;
    height: 220px;
    margin: 0 auto;
  }

  .hero__covers-item {
    width: 140px;
  }

  .hero__actions {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .hero__actions .btn--hero {
    width: 100%;
  }

  .hero__link {
    justify-content: center;
    padding: 4px 0;
  }

  .free-workbook__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .free-workbook__cover,
  .free-workbook__cover-wrap {
    margin: 0 auto;
  }

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

  .workbooks__filters-wrap {
    width: 100%;
    align-items: flex-start;
  }

  .filter-row {
    width: 100%;
  }

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

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

  .about__photo {
    order: -1;
  }

  .footer__grid {
    grid-template-columns: 1fr;
    gap: 36px;
    padding-bottom: 36px;
  }

  .footer__tagline,
  .footer__text {
    max-width: none;
  }
}