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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

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

a {
  color: var(--color-brand);
}

a:hover {
  color: var(--color-brand-dark);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: var(--color-brand);
  color: #fff;
}

.skip-link:focus {
  left: 0;
}

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(6px);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.75rem;
}

.brand {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  text-decoration: none;
  color: var(--color-text);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9375rem;
}

.nav-toggle {
  display: none;
  border: 1px solid var(--color-border);
  background: #fff;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius);
  font: inherit;
  cursor: pointer;
}

.section {
  padding-block: 4rem;
}

.section--alt {
  background: var(--color-surface);
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  margin: 0 0 0.5rem;
  color: var(--color-brand);
}

.section-title::after {
  content: "";
  display: block;
  width: 3rem;
  height: 3px;
  margin-top: 0.5rem;
  background: var(--color-brand);
}

.section-lead {
  margin: 0 0 2rem;
  color: var(--color-muted);
  max-width: 42rem;
}

.hero {
  position: relative;
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  color: #fff;
  background: var(--color-brand) center / cover no-repeat;
  background-image: linear-gradient(
      rgba(26, 52, 72, 0.55),
      rgba(26, 52, 72, 0.45)
    ),
    url("../images/jpeg/hero-mermaid.jpg");
}

.hero__inner {
  padding: 3rem 1rem;
  max-width: 40rem;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 6vw, 3rem);
  margin: 0 0 0.75rem;
  line-height: 1.15;
  text-transform: lowercase;
}

.hero p {
  margin: 0 0 1.5rem;
  font-size: 1.25rem;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 700;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  font: inherit;
}

.btn--primary {
  background: #fff;
  color: var(--color-brand-dark);
}

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

.btn--outline {
  background: transparent;
  border-color: var(--color-brand);
  color: var(--color-brand);
}

.btn--outline:hover {
  background: var(--color-brand);
  color: #fff;
}

.about-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}

@media (min-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.about-grid img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.gallery-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(14rem, 1fr));
}

.gallery-grid figure {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.gallery-grid img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.courses-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
}

.course-card {
  margin: 0;
  padding: 1.25rem;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.course-card h3 {
  font-family: var(--font-heading);
  margin: 0;
  font-size: 1.125rem;
}

.course-meta {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.9375rem;
}

.course-price {
  margin: 0;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-brand);
}

.course-card .btn {
  margin-top: auto;
  align-self: flex-start;
}

.book-note {
  margin-top: 1.5rem;
  font-size: 0.9375rem;
  color: var(--color-muted);
}

.faq-list {
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: 48rem;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item button {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0;
  border: none;
  background: none;
  font: inherit;
  font-family: var(--font-heading);
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  color: var(--color-text);
}

.faq-item button::after {
  content: "+";
  font-size: 1.25rem;
  color: var(--color-brand);
  flex-shrink: 0;
}

.faq-item.is-open button::after {
  content: "−";
}

.faq-answer {
  display: none;
  padding: 0 0 1rem;
  color: var(--color-muted);
}

.faq-item.is-open .faq-answer {
  display: block;
}

.contact-grid {
  display: grid;
  gap: 2rem;
}

@media (min-width: 768px) {
  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.contact-form label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  margin-bottom: 1rem;
  padding: 0.5rem 0.65rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font: inherit;
}

.hours-table {
  width: 100%;
  border-collapse: collapse;
}

.hours-table th,
.hours-table td {
  text-align: left;
  padding: 0.5rem 0.75rem 0.5rem 0;
  border-bottom: 1px solid var(--color-border);
}

.site-footer {
  padding: 2rem 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
}

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    flex-direction: column;
    width: 100%;
    padding-top: 0.5rem;
  }

  .site-header.is-open .site-nav {
    display: flex;
  }

  .site-header .container {
    flex-wrap: wrap;
  }
}