/* ============================================
   BASE.CSS — Типографика и базовые стили
   ============================================ */

html {
  overflow-x: hidden;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- Grain Overlay --- */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: var(--z-overlay);
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='1'/%3E%3C/svg%3E");
  background-size: 200px 200px;
  animation: grain 8s steps(10) infinite;
}

@keyframes grain {
  0%, 100% { transform: translate(0, 0); }
  10% { transform: translate(-2%, -2%); }
  20% { transform: translate(2%, 2%); }
  30% { transform: translate(-2%, 2%); }
  40% { transform: translate(2%, -2%); }
  50% { transform: translate(-1%, 1%); }
  60% { transform: translate(1%, -1%); }
  70% { transform: translate(-1%, -1%); }
  80% { transform: translate(1%, 1%); }
  90% { transform: translate(-2%, 1%); }
}

/* --- Типографика --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.1;
  color: var(--text-white);
  letter-spacing: -0.02em;
}

h1 { font-size: var(--text-h1); }
h2 { font-size: var(--text-h2); }
h3 { font-size: var(--text-h3); }
h4 { font-size: var(--text-h4); }

p {
  color: var(--text-secondary);
  line-height: 1.7;
}

strong {
  color: var(--text-white);
  font-weight: 600;
}

/* --- Контейнер --- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  width: 100%;
}

.container--narrow {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* --- Сетки --- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
}

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

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

/* --- Разделитель --- */
.divider {
  height: 1px;
  background: var(--gradient-divider);
  border: none;
  margin: 0;
}

/* --- Метки секций --- */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-blue-light);
  margin-bottom: var(--space-lg);
}

.section-label::before {
  content: '';
  display: block;
  width: 24px;
  height: 1px;
  background: var(--accent-blue-light);
}

/* --- Заголовки секций --- */
.section-title {
  font-size: var(--text-h2);
  font-family: var(--font-display);
  font-weight: 800;
  color: var(--text-white);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.section-subtitle {
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.7;
}

/* --- Акцентный текст --- */
.text-accent {
  color: var(--accent-blue-light);
}

.text-amber {
  color: var(--accent-amber);
}

.text-gradient {
  background: linear-gradient(135deg, var(--accent-blue-light), var(--accent-amber));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* --- Анимации появления --- */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Световые пятна (ambient light) --- */
.ambient-light {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(80px);
  z-index: 0;
}

.ambient-light--blue {
  background: radial-gradient(circle, rgba(37, 99, 235, 0.2) 0%, transparent 70%);
}

.ambient-light--amber {
  background: radial-gradient(circle, rgba(245, 158, 11, 0.15) 0%, transparent 70%);
}

/* --- Скроллбар --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* --- Выделение текста --- */
::selection {
  background: var(--accent-blue);
  color: var(--text-white);
}

/* --- Служебные классы --- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.no-overflow {
  overflow: hidden;
}

.relative {
  position: relative;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}