/* ===== Cascade Layers ===== */
@layer reset, base, layout, components, utilities;

/* ===== Reset ===== */
@layer reset {
  *,
  *::before,
  *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  img {
    display: block;
    max-inline-size: 100%;
    block-size: auto;
  }

  ul,
  ol {
    list-style: none;
  }

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

/* ===== Base / Custom Properties ===== */
@layer base {
  :root {
    /* Colors — oklch */
    --color-bg: oklch(0.98 0 0);
    --color-surface: oklch(0.95 0 0);
    --color-text: oklch(0.2 0 0);
    --color-text-muted: oklch(0.45 0 0);
    --color-primary: oklch(0.35 0.08 30);
    --color-primary-light: oklch(0.45 0.08 30);
    --color-accent: oklch(0.55 0.15 30);
    --color-border: oklch(0.85 0 0);
    --color-hero-overlay: oklch(0.15 0.02 30 / 0.75);
    --color-white: oklch(1 0 0);

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 3rem;
    --space-xl: 5rem;

    /* Typography */
    --font-body: system-ui, -apple-system, sans-serif;
    --font-heading: system-ui, -apple-system, sans-serif;
    --text-sm: clamp(0.875rem, 0.8rem + 0.2vw, 1rem);
    --text-base: clamp(1rem, 0.9rem + 0.3vw, 1.125rem);
    --text-lg: clamp(1.25rem, 1rem + 0.8vw, 1.75rem);
    --text-xl: clamp(1.75rem, 1.2rem + 1.5vw, 2.75rem);
    --text-hero: clamp(2.25rem, 1.5rem + 2.5vw, 4rem);

    /* Layout */
    --max-width: 72rem;
    --border-radius: 0.5rem;
  }

  @media (prefers-color-scheme: dark) {
    :root {
      --color-bg: oklch(0.15 0 0);
      --color-surface: oklch(0.2 0.01 30);
      --color-text: oklch(0.9 0 0);
      --color-text-muted: oklch(0.65 0 0);
      --color-primary: oklch(0.55 0.1 30);
      --color-primary-light: oklch(0.65 0.1 30);
      --color-accent: oklch(0.6 0.15 30);
      --color-border: oklch(0.3 0 0);
      --color-hero-overlay: oklch(0.1 0.02 30 / 0.8);
    }
  }

  body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
  }

  h1,
  h2,
  h3 {
    font-family: var(--font-heading);
    line-height: 1.2;
    text-wrap: balance;
  }

  h1 { font-size: var(--text-hero); }
  h2 { font-size: var(--text-xl); }
  h3 { font-size: var(--text-lg); }

  :focus-visible {
    outline: 3px solid var(--color-accent);
    outline-offset: 3px;
  }
}

/* ===== Layout ===== */
@layer layout {
  .container {
    max-inline-size: var(--max-width);
    margin-inline: auto;
    padding-inline: var(--space-md);
  }

  .section {
    padding-block: var(--space-xl);
    content-visibility: auto;
  }
}

/* ===== Components ===== */
@layer components {

  /* --- Skip Link --- */
  .skip-link {
    position: absolute;
    inset-block-start: -100%;
    inset-inline-start: var(--space-sm);
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--border-radius);
    z-index: 100;

    &:focus {
      inset-block-start: var(--space-sm);
    }
  }

  /* --- Site Header / Nav --- */
  .site-header {
    position: sticky;
    inset-block-start: 0;
    z-index: 50;
    background: var(--color-bg);
    border-block-end: 1px solid var(--color-border);
  }

  .site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-block: var(--space-sm);
  }

  .site-logo {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: 0.02em;
  }

  /* Hamburger toggle (CSS-only) */
  .nav-toggle {
    display: none;
  }

  .nav-toggle-label {
    display: none;
    cursor: pointer;
    padding: var(--space-xs);
  }

  .nav-toggle-label span,
  .nav-toggle-label span::before,
  .nav-toggle-label span::after {
    display: block;
    inline-size: 1.5rem;
    block-size: 2px;
    background: var(--color-text);
    position: relative;
    transition: transform 0.3s ease;
  }

  .nav-toggle-label span::before,
  .nav-toggle-label span::after {
    content: "";
    position: absolute;
  }

  .nav-toggle-label span::before { inset-block-start: -0.5rem; }
  .nav-toggle-label span::after { inset-block-start: 0.5rem; }

  .nav-list {
    display: flex;
    gap: var(--space-md);
  }

  .nav-list a {
    font-weight: 500;
    font-size: var(--text-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding-block: var(--space-xs);
    transition: color 0.2s ease;

    &:hover,
    &:focus-visible {
      color: var(--color-accent);
    }
  }

  @media (max-width: 48rem) {
    .nav-toggle-label {
      display: block;
    }

    .nav-list {
      position: absolute;
      inset-block-start: 100%;
      inset-inline: 0;
      flex-direction: column;
      background: var(--color-bg);
      border-block-end: 1px solid var(--color-border);
      padding: var(--space-md);
      gap: var(--space-sm);
      transform: scaleY(0);
      transform-origin: top;
      transition: transform 0.3s ease;
    }

    .nav-toggle:checked ~ .nav-list {
      transform: scaleY(1);
    }
  }

  /* --- Hero --- */
  .hero {
    position: relative;
    min-block-size: 80vh;
    display: grid;
    place-items: center;
    justify-items: center;
    text-align: center;
    background: oklch(0.1 0 0);
    color: var(--color-white);
    padding: var(--space-lg);
    gap: var(--space-md);
  }

  .hero-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-lg);
    flex-wrap: wrap;
  }

  .hero-logo {
    max-block-size: 12rem;
    inline-size: auto;

    @media (min-width: 48rem) {
      max-block-size: 16rem;
    }
  }

  .hero-content h1 {
    margin: 0;
  }

  .hero-subtitle {
    font-size: var(--text-lg);
    opacity: 0.9;
  }

  .btn {
    display: inline-block;
    padding: var(--space-sm) var(--space-md);
    font-size: var(--text-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    border-radius: var(--border-radius);
    transition: background-color 0.2s ease, transform 0.2s ease;
  }

  .btn-primary {
    background: var(--color-accent);
    color: var(--color-white);

    &:hover,
    &:focus-visible {
      background: var(--color-primary-light);
      transform: translateY(-1px);
    }
  }

  .btn-outline {
    border: 2px solid var(--color-white);
    color: var(--color-white);

    &:hover,
    &:focus-visible {
      background: var(--color-white);
      color: var(--color-primary);
    }
  }

  /* --- About --- */
  .about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    align-items: center;

    @media (min-width: 48rem) {
      grid-template-columns: 1fr 1fr;
    }
  }

  .about-text h2 {
    margin-block-end: var(--space-sm);
    color: var(--color-primary);
  }

  .about-text p {
    margin-block-end: var(--space-sm);
    color: var(--color-text-muted);
  }

  .about-image {
    border-radius: var(--border-radius);
    overflow: hidden;
  }

  /* --- Training Cards --- */
  .training {
    background: var(--color-surface);
  }

  .section-heading {
    text-align: center;
    margin-block-end: var(--space-sm);
    color: var(--color-primary);
  }

  .section-intro {
    text-align: center;
    max-inline-size: 48rem;
    margin-inline: auto;
    margin-block-end: var(--space-lg);
    color: var(--color-text-muted);
  }

  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(18rem, 100%), 1fr));
    gap: var(--space-md);
  }

  .card {
    background: var(--color-bg);
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid var(--color-border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;

    &:hover {
      transform: translateY(-2px);
      box-shadow: 0 4px 20px oklch(0 0 0 / 0.1);
    }
  }

  /* --- Carousel --- */
  .carousel {
    position: relative;
    aspect-ratio: 3 / 2;
    overflow: hidden;
  }

  .carousel-slide {
    position: absolute;
    inset: 0;
    inline-size: 100%;
    block-size: 100%;
    object-fit: cover;
    opacity: 0;
    animation: carousel-fade 12s infinite;
  }

  .carousel-slide:first-child {
    position: relative;
  }

  .carousel-slide:nth-child(1) { animation-delay: 0s; }
  .carousel-slide:nth-child(2) { animation-delay: 4s; }
  .carousel-slide:nth-child(3) { animation-delay: 8s; }

  @keyframes carousel-fade {
    0%, 5% { opacity: 0; }
    8%, 33% { opacity: 1; }
    38%, 100% { opacity: 0; }
  }

  .card-body {
    padding: var(--space-md);
  }

  .card-body h3 {
    margin-block-end: var(--space-xs);
    color: var(--color-primary);
  }

  .card-body p {
    color: var(--color-text-muted);
    font-size: var(--text-sm);
  }

  /* --- Schedule (Accordion) --- */
  .schedule details {
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-block-end: var(--space-sm);
    overflow: hidden;
  }

  .schedule summary {
    padding: var(--space-sm) var(--space-md);
    font-weight: 600;
    cursor: pointer;
    background: var(--color-surface);
    transition: background-color 0.2s ease;

    &:hover {
      background: var(--color-border);
    }
  }

  .schedule .detail-content {
    padding: var(--space-sm) var(--space-md);
  }

  .schedule-table {
    inline-size: 100%;
    border-collapse: collapse;
  }

  .schedule-table th,
  .schedule-table td {
    text-align: start;
    padding: var(--space-xs) var(--space-sm);
    border-block-end: 1px solid var(--color-border);
  }

  .schedule-table th {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  /* --- Contact / Location --- */
  .contact-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);

    @media (min-width: 48rem) {
      grid-template-columns: 1fr 1fr;
    }
  }

  .contact-info h2 {
    margin-block-end: var(--space-sm);
    color: var(--color-primary);
  }

  .contact-info p {
    margin-block-end: var(--space-sm);
    color: var(--color-text-muted);
  }

  .contact-info address {
    font-style: normal;
    margin-block-end: var(--space-md);
  }

  .contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
  }

  .form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
  }

  .form-group label {
    font-weight: 600;
    font-size: var(--text-sm);
  }

  .form-group input,
  .form-group textarea {
    padding: var(--space-sm);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    font: inherit;
    background: var(--color-bg);
    color: var(--color-text);
    transition: border-color 0.2s ease;

    &:focus-visible {
      border-color: var(--color-accent);
      outline: none;
      box-shadow: 0 0 0 3px oklch(0.55 0.15 30 / 0.2);
    }
  }

  .form-group textarea {
    min-block-size: 8rem;
    resize: vertical;
  }

  /* --- Footer --- */
  .site-footer {
    background: var(--color-primary);
    color: var(--color-white);
    padding-block: var(--space-lg);
  }

  .footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-md);
  }

  .footer-nav {
    display: flex;
    gap: var(--space-md);
  }

  .footer-nav a {
    font-size: var(--text-sm);
    opacity: 0.8;
    transition: opacity 0.2s ease;

    &:hover {
      opacity: 1;
    }
  }

  .footer-copy {
    font-size: var(--text-sm);
    opacity: 0.7;
  }
}

/* ===== Utilities ===== */
@layer utilities {
  .visually-hidden {
    position: absolute;
    inline-size: 1px;
    block-size: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}