/* proto-b/assets/css/base.css — Functional */
*, *::before, *::after { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--color-navy-900);
  font-weight: 600;
  margin: 0 0 0.5em 0;
  line-height: 1.2;
}
h1 { font-size: 42px; }
h2 { font-size: 30px; }
h3 { font-size: 20px; }
h4 { font-size: 17px; }

p { margin: 0 0 1em 0; }

a {
  color: var(--color-navy-900);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--c-azure); }

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

button { font: inherit; cursor: pointer; border: 0; background: transparent; color: inherit; }

.container {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* Кнопки */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.01em;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition);
  white-space: nowrap;
  border: 1px solid transparent;
}
.btn--primary { background: var(--color-navy-900); color: #FFFFFF; }
.btn--primary:hover { background: var(--color-navy-700); color: #FFFFFF; }

.btn--secondary {
  background: var(--color-surface);
  color: var(--color-navy-900);
  border-color: var(--color-navy-900);
}
.btn--secondary:hover { background: var(--color-navy-900); color: #FFFFFF; }

.btn--ghost {
  background: var(--color-surface);
  color: var(--color-navy-900);
  border-color: var(--color-border);
}
.btn--ghost:hover { border-color: var(--color-navy-900); }

/* Универсальные секции */
.section { padding: 64px 0; }
.section--tight { padding: 40px 0; }

/* Заголовок секции */
.section-head { text-align: center; margin-bottom: 40px; }
.section-head h2 { margin-bottom: 12px; }
.section-head__lead {
  max-width: 720px;
  margin: 0 auto;
  color: var(--color-text-muted);
  font-size: 16px;
}

/* Иконки */
.icon { width: 24px; height: 24px; fill: currentColor; }
.icon-lg { width: 32px; height: 32px; }

/* Адаптив */
@media (max-width: 768px) {
  h1 { font-size: 28px; }
  h2 { font-size: 22px; }
  h3 { font-size: 18px; }
  .section { padding: 48px 0; }
  .container { padding: 0 16px; }
}