/* ==========================================================================
   Layout — Reset, Grid System, Responsive Breakpoints, Fluid Typography
   Specimen macrostructure: numbered section headers, generous editorial space
   ========================================================================== */

/* --- CSS Reset / Normalize --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  overflow-x: clip;
  scroll-behavior: smooth;
  /* Offset anchored jumps so the sticky nav doesn't cover section titles. */
  scroll-padding-top: var(--nav-offset, 6rem);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  overflow-x: clip;
  min-height: 100vh;
  line-height: var(--leading-relaxed);
  font-weight: var(--weight-body, 400);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-family: var(--font-body);
  color: var(--color-ink);
  background-color: var(--color-paper);
  /* Smooth theme switch — guarded by reduced-motion below */
  transition: background-color var(--duration-normal) var(--easing-default),
              color var(--duration-normal) var(--easing-default);
}

/* --- Fluid Typography --- */
body {
  font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  /* min 16px → max 18px */
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  line-height: var(--leading-tight);
  text-wrap: balance;
  overflow-wrap: anywhere;
  min-width: 0;
}

h1 { font-size: clamp(2.25rem, 1.6rem + 3vw, 4rem); }      /* 36 → 64px */
h2 { font-size: clamp(1.5rem, 1.25rem + 1.25vw, 2.25rem); }/* 24 → 36px */
h3 { font-size: clamp(1.25rem, 1.1rem + 0.75vw, 1.75rem); }/* 20 → 28px */
h4, h5, h6 { font-size: clamp(1.125rem, 1rem + 0.5vw, 1.375rem); }

/* --- Base Element Resets --- */
img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

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

a {
  color: inherit;
  text-decoration-skip-ink: auto;
}

ul, ol {
  list-style: none;
}

/* --- Overflow Protection for Narrow Viewports (240–319px) --- */
body {
  overflow-wrap: anywhere;
  word-break: normal;
}

/* --- Page Layout — single centered content column (Specimen, editorial) --- */
main {
  display: block;
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: var(--space-md);
  padding-block: var(--space-xl) var(--space-2xl);
}

/* Each section is a stacked block; rhythm comes from generous vertical gaps */
main > section {
  padding-block: var(--space-2xl);
  /* Anchored jumps land below the sticky nav, showing the section title. */
  scroll-margin-top: var(--nav-offset, 6rem);
}

main > section:first-child {
  padding-top: var(--space-lg);
}

/* --- Tablet Breakpoint (≥768px) --- */
@media (min-width: 768px) {
  main {
    padding-inline: var(--space-xl);
  }

  main > section {
    padding-block: var(--space-3xl);
  }
}

/* --- Desktop Breakpoint (≥1024px) --- */
@media (min-width: 1024px) {
  main {
    padding-inline: var(--space-2xl);
  }
}

/* --- Header / Navigation Layout --- */
.nav-edge {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-inline: var(--space-md);
  padding-block: var(--space-sm);
  width: 100%;
}

@media (min-width: 768px) {
  .nav-edge { padding-inline: var(--space-xl); }
}

@media (min-width: 1024px) {
  .nav-edge { padding-inline: var(--space-2xl); }
}

/* --- Footer Layout --- */
footer {
  padding-inline: var(--space-md);
  padding-block: var(--space-2xl);
}

@media (min-width: 768px) {
  footer { padding-inline: var(--space-xl); }
}

@media (min-width: 1024px) {
  footer { padding-inline: var(--space-2xl); }
}

/* --- Accessibility: Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  body { transition: none; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}