/* ===== Reset & Base ===== */

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

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

body {
  font-family: var(--font-body);
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-tap-highlight-color: transparent;
}

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

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition);
}

/* Focus-visible: keyboard focus ring without affecting mouse clicks */
:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 3px;
  border-radius: 4px;
}

:focus:not(:focus-visible) {
  outline: none;
}

a:hover {
  color: var(--accent-cyan);
}

ul, ol {
  list-style: none;
}

/* ===== Typography ===== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 6vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.8rem, 4vw, 2.8rem); letter-spacing: -0.01em; }
h3 { font-size: clamp(1.3rem, 3vw, 1.6rem); }
h4 { font-size: 1.2rem; }

p {
  color: var(--text-secondary);
  line-height: 1.8;
}

.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.mono {
  font-family: var(--font-mono);
}

/* ===== Layout ===== */

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

section {
  padding: var(--section-py) 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  margin-bottom: 16px;
}

.section-header p {
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.1rem;
}

.section-divider {
  width: 60px;
  height: 3px;
  background: var(--gradient-main);
  border-radius: 3px;
  margin: 16px auto 0;
}

/* ===== Utilities ===== */

.text-center { text-align: center; }
.text-start { text-align: start; }

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

/* Skip to content link — visible on focus for keyboard users */
.skip-link {
  position: fixed;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10000;
  padding: 12px 24px;
  background: var(--gradient-main);
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top 0.3s ease;
}

.skip-link:focus {
  top: 12px;
  color: #fff;
}