@layer reset, tokens, base, layout, components, utilities;

@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  * { margin: 0; }
  p, h1, h2, h3, h4 { overflow-wrap: break-word; }
}

@layer tokens {
  :root {
    color-scheme: dark;
    --hue: 258;
    --brand: oklch(56% 0.21 var(--hue));
    --brand-hover: oklch(from var(--brand) calc(l - 0.06) c h);
    --accent: oklch(74% 0.13 calc(var(--hue) - 78));

    --surface:        light-dark(oklch(98.6% 0.006 var(--hue)), oklch(17% 0.018 var(--hue)));
    --surface-raised: light-dark(oklch(100% 0 0),               oklch(22% 0.022 var(--hue)));
    --text:           light-dark(oklch(23% 0.025 var(--hue)),   oklch(93% 0.012 var(--hue)));
    --text-muted:     color-mix(in oklch, var(--text) 64%, var(--surface));
    --border:         color-mix(in oklch, var(--text) 13%, var(--surface));
    --brand-subtle:   color-mix(in oklch, var(--brand) 9%, var(--surface));
    --on-brand:       oklch(99% 0.01 var(--hue));

    --space:    clamp(1rem, 0.6rem + 1.6vw, 1.75rem);
    --space-lg: clamp(2.5rem, 1.5rem + 4vw, 5.5rem);
    --step--1: clamp(0.83rem, 0.80rem + 0.15vw, 0.94rem);
    --step-0:  clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --step-1:  clamp(1.25rem, 1.12rem + 0.65vw, 1.55rem);
    --step-2:  clamp(1.56rem, 1.32rem + 1.2vw, 2.15rem);
    --step-3:  clamp(1.95rem, 1.55rem + 2vw, 2.9rem);
    --step-4:  clamp(2.44rem, 1.8rem + 3.2vw, 4.2rem);

    --radius: 14px;
    --shadow: 0 1px 2px oklch(20% 0.03 var(--hue) / 0.08),
              0 10px 32px oklch(20% 0.03 var(--hue) / 0.11);
    --shadow-lg: 0 2px 4px oklch(20% 0.03 var(--hue) / 0.10),
                 0 24px 64px -12px oklch(20% 0.03 var(--hue) / 0.22);
  }

  @supports (color: contrast-color(red)) {
    :root { --on-brand: contrast-color(var(--brand)); }
  }

  html:has(#theme-switch:checked) { color-scheme: light; }
}

@layer base {
  html { scrollbar-gutter: stable; font-family: system-ui, sans-serif; }
  @media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
  body {
    background: var(--surface); color: var(--text);
    font-size: var(--step-0); line-height: 1.6;
    transition: background-color 0.4s, color 0.4s;
  }
}

@layer layout {
  .site-header {
    display: flex; justify-content: center; align-items: center;
    padding: var(--space); position: relative;
    max-inline-size: 64rem; margin-inline: auto;
  }
  .nav-links { display: flex; gap: var(--space); }
  .nav-links a { 
    text-decoration: none; color: var(--text-muted); 
    font-weight: 500; font-size: var(--step--1);
  }
  .nav-links a:hover { color: var(--text); }
  
  main {
    max-inline-size: 64rem; margin-inline: auto; padding-inline: var(--space);
    display: flex; flex-direction: column; gap: var(--space-lg);
  }

  .hero {
    text-align: center; padding-block: var(--space-lg);
    display: flex; flex-direction: column; gap: var(--space); align-items: center;
  }
  .hero h1 { 
    font-size: var(--step-4); font-weight: 850; 
    letter-spacing: -0.03em; line-height: 1.1; 
  }
  .gradient-text {
    background: linear-gradient(135deg, var(--brand), var(--accent));
    -webkit-background-clip: text; color: transparent;
  }
  .subtitle { font-size: var(--step-1); color: var(--text-muted); max-inline-size: 40ch; }
}

@layer components {
  /* Theme toggle */
  .theme-toggle-btn {
    position: absolute; right: var(--space);
    cursor: pointer; padding: 0.5rem; border-radius: 50%;
    background: var(--surface-raised); border: 1px solid var(--border);
    color: var(--text); box-shadow: var(--shadow);
    display: flex; justify-content: center; align-items: center;
  }
  .moon-icon { display: none; }
  html:has(#theme-switch:checked) .sun-icon { display: none; }
  html:has(#theme-switch:checked) .moon-icon { display: block; }

  /* Feature Grid */
  .feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(17rem, 100%), 1fr));
    gap: var(--space); list-style: none; padding: 0;
  }
  .feature {
    padding: clamp(1.25rem, 3cqi, 2rem);
    background: var(--surface-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: translate 0.2s ease-out, box-shadow 0.2s, border-color 0.2s;
    display: flex; align-items: center; justify-content: center; text-align: center;
    min-block-size: 140px;
  }
  .feature h3 { font-size: var(--step-0); }
  @media (hover: hover) and (pointer: fine) {
    .feature:hover {
      translate: 0 -3px; box-shadow: var(--shadow-lg);
      border-color: color-mix(in oklch, var(--brand) 30%, var(--border));
    }
  }

  /* FAQ Accordion (Projects Timeline) */
  .faq-list { display: grid; gap: 0.75rem; }
  .faq-list details {
    background: var(--surface-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: border-color 0.2s;
  }
  .faq-list summary {
    display: flex; align-items: center; justify-content: space-between; gap: 1rem;
    padding: 1.1rem 1.3rem; font-weight: 650; cursor: pointer; list-style: none;
    min-block-size: 44px; font-size: var(--step-0);
  }
  .faq-list summary::-webkit-details-marker { display: none; }
  .faq-list summary::after {
    content: ""; flex-shrink: 0; inline-size: 0.6rem; aspect-ratio: 1;
    border-inline-end: 2px solid var(--brand); border-block-end: 2px solid var(--brand);
    rotate: 45deg; translate: 0 -2px;
    transition: rotate 0.25s ease-out, translate 0.25s ease-out;
  }
  .faq-list details[open] summary::after { rotate: 225deg; translate: 0 2px; }
  .faq-list details[open] { border-color: color-mix(in oklch, var(--brand) 35%, var(--border)); }
  .faq-list details::details-content {
    opacity: 0; block-size: 0; overflow-y: clip;
    transition: content-visibility 0.3s allow-discrete, opacity 0.3s ease-out, block-size 0.3s ease-out;
  }
  .faq-list details[open]::details-content { opacity: 1; block-size: auto; }
  .answer { padding: 0 1.3rem 1.2rem; color: var(--text-muted); font-size: var(--step--1); }
  
  .section-title { font-size: var(--step-3); font-weight: 800; margin-block-end: var(--space); text-align: center;}

  /* Contact CTA */
  .section-contact { padding-block-end: var(--space-lg); }
  .cta-final {
    position: relative; overflow: clip;
    border-radius: calc(var(--radius) * 1.4);
    padding: var(--space-lg) clamp(1.25rem, 4vw, 3rem);
    text-align: center;
    background: radial-gradient(40rem 22rem at 50% -30%, color-mix(in oklch, var(--brand) 20%, transparent), transparent 70%), var(--surface);
    border: 1px solid var(--border);
    display: grid; justify-items: center; gap: 1rem;
  }
  .cta-final h2 { font-size: var(--step-2); font-weight: 800;}
  .cta-final p { color: var(--text-muted); font-size: var(--step-0); }
  .contact-links {
    display: flex; flex-wrap: wrap; justify-content: center; gap: 1rem; margin-block-start: 1rem;
  }
  .contact-btn {
    text-decoration: none; font-weight: 600; font-size: var(--step--1);
    color: var(--text); background: var(--surface-raised);
    padding: 0.65rem 1.4rem; border-radius: 99px;
    border: 1px solid var(--border);
    transition: all 0.3s;
  }
  .contact-btn:hover {
    background: var(--brand); color: var(--on-brand); border-color: var(--brand);
    transform: translateY(-2px); box-shadow: var(--shadow);
  }
}

footer {
  text-align: center; padding-block: var(--space-lg);
  color: var(--text-muted); font-size: var(--step--1); border-block-start: 1px solid var(--border);
}