/* ============================================================
   Base: reset, типографика, сетка, утилиты
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
ul, ol { list-style: none; }

h1, h2, h3 { line-height: 1.2; letter-spacing: -0.02em; font-weight: 700; }
h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

/* Читаемость: текстовые блоки не растягиваются шире 68 символов */
p { max-width: 68ch; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

.section { padding: var(--section-pad) 0; }
.section-alt { background: var(--bg-elevated); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-head p { margin: 14px auto 0; color: var(--text-secondary); font-size: 1.06rem; }

.grid { display: grid; gap: var(--gap); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .section-head { margin-bottom: 32px; }
}

.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }

/* Появление секций при скролле; отключается по prefers-reduced-motion */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation: none !important; }
}