*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  /* offset in-page anchors so section tops are not hidden */
  scroll-padding-top: 2rem;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

p {
  color: var(--text-2);
}

/* --- helpers --- */
.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.04em;
}

.hl {
  color: var(--blue);
  font-weight: 600;
}

.hl-warm {
  color: var(--amber);
  font-weight: 600;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 1000;
  padding: 0.6rem 1rem;
  background: var(--surface-2);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-sm);
  transform: translateY(-160%);
  transition: transform var(--t) var(--ease);
}
.skip-link:focus {
  transform: translateY(0);
}

/* --- background --- */
.bg-layer {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
  background: var(--bg);
}

.bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.45;
}

/* --- top scroll progress bar --- */
.scroll-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 900;
  background: transparent;
}
.scroll-bar span {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(
    90deg,
    var(--accent),
    color-mix(in srgb, var(--accent) 40%, #fff)
  );
  box-shadow: 0 0 12px color-mix(in srgb, var(--accent) 60%, transparent);
  transition: width 0.1s linear;
}

/* --- reveal on scroll --- */
[data-reveal] {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.6s var(--ease-out), transform 0.7s var(--ease-out);
  will-change: opacity, transform;
}
[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}