:root {
  --font-sans: "Inter", "Noto Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "Fira Code", "SFMono-Regular", Menlo, Consolas, monospace;
  --color-bg: #f5f7ff;
  --color-surface: #ffffff;
  --color-surface-alt: #edf0ff;
  --color-primary: #4b5cff;
  --color-primary-accent: #7f8aff;
  --color-accent: #0ec5a3;
  --color-text: #10163a;
  --color-muted: #5b5f75;
  --color-border: rgba(46, 64, 153, 0.12);
  --max-width: 1140px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --shadow-soft: 0 28px 60px rgba(79, 92, 255, 0.15);
  --shadow-card: 0 18px 42px rgba(16, 21, 58, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background: radial-gradient(circle at -10% -20%, rgba(141, 156, 255, 0.4), transparent 55%),
              radial-gradient(circle at 110% 20%, rgba(14, 197, 163, 0.25), transparent 60%),
              var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}

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

a:hover,
a:focus {
  color: var(--color-primary-accent);
}

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

main {
  display: block;
}

.section {
  padding: 72px 24px;
}

.section-dark {
  background: rgba(0, 0, 0, 0.25);
}

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

h1,
h2,
h3,
h4 {
  color: var(--color-text);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 16px;
}

h1 {
  font-size: clamp(2.25rem, 4vw, 3.25rem);
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
}

p {
  margin: 0 0 16px;
  color: var(--color-muted);
}

ul,
ol {
  padding-left: 20px;
  color: var(--color-muted);
}

blockquote {
  margin: 0;
  padding: 16px 24px;
  background: var(--color-surface-alt);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
}

button,
input,
select {
  font-family: inherit;
}

input,
select,
textarea {
  background: var(--color-surface-alt);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  padding: 12px 14px;
  transition: border 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--color-primary);
  outline: none;
  box-shadow: 0 0 0 4px rgba(108, 92, 231, 0.2);
}

@media (max-width: 768px) {
  .section {
    padding: 56px 18px;
  }

  :root {
    --radius-lg: 18px;
    --radius-md: 14px;
  }
}