/* INFINITE Digital Security — Design System
   Colors derived from logo: black, metallic silver, accent red */

:root {
  --color-bg: #0a0a0a;
  --color-bg-elevated: #121212;
  --color-bg-card: #161616;
  --color-bg-hover: #1c1c1c;
  --color-border: #2a2a2a;
  --color-border-light: #3a3a3a;
  --color-text: #f0f0f0;
  --color-text-muted: #9a9a9a;
  --color-text-subtle: #6b6b6b;
  --color-accent: #c41e3a;
  --color-accent-hover: #e02445;
  --color-accent-glow: rgba(196, 30, 58, 0.25);
  --color-accent-subtle: rgba(196, 30, 58, 0.12);
  --color-silver: #b8b8b8;
  --color-silver-light: #d4d4d4;
  --color-success: #2d8a4e;
  --color-error: #c41e3a;
  --color-focus: #e02445;

  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 24px var(--color-accent-glow);

  --header-height: 123px;
  --container-max: 1200px;
  --container-narrow: 800px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

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

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.2;
  font-weight: 600;
  color: var(--color-text);
}

h1 {
  font-size: clamp(1.875rem, 5vw, 3rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  letter-spacing: -0.01em;
}

h3 {
  font-size: clamp(1.125rem, 2.5vw, 1.5rem);
}

p {
  color: var(--color-text-muted);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-lg);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: 10000;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-md);
}

main {
  flex: 1;
}

.section {
  padding-block: var(--space-3xl);
}

.section--hero {
  padding-block: var(--space-4xl) var(--space-3xl);
}

.section-title {
  margin-bottom: var(--space-md);
}

.section-subtitle {
  font-size: clamp(1rem, 2vw, 1.125rem);
  max-width: 640px;
  margin-bottom: var(--space-2xl);
}

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

.text-center .section-subtitle {
  margin-inline: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  min-height: 48px;
  min-width: 48px;
  padding: 0.75rem 1.5rem;
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-base), color var(--transition-base),
    box-shadow var(--transition-base), transform var(--transition-fast);
  text-decoration: none;
}

.btn:active {
  transform: scale(0.98);
}

.btn--primary {
  background: var(--color-accent);
  color: #fff;
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  color: #fff;
  box-shadow: var(--shadow-glow);
}

.btn--secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
}

.btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn--full {
  width: 100%;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  border-color: var(--color-border-light);
  box-shadow: var(--shadow-md);
}

.card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-subtle);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
  color: var(--color-accent);
}

.card__title {
  margin-bottom: var(--space-sm);
}

.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid--2 {
  grid-template-columns: 1fr;
}

.grid--3 {
  grid-template-columns: 1fr;
}

.grid--4 {
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .grid--2 {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid--3 {
    grid-template-columns: repeat(3, 1fr);
  }

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

@media (min-width: 1024px) {
  .grid--4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

.divider {
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--color-border-light) 20%,
    var(--color-accent) 50%,
    var(--color-border-light) 80%,
    transparent
  );
  margin-block: var(--space-2xl);
  opacity: 0.6;
}

.page-header {
  padding-block: var(--space-3xl) var(--space-xl);
  background: linear-gradient(180deg, var(--color-bg-elevated) 0%, var(--color-bg) 100%);
  border-bottom: 1px solid var(--color-border);
}

.page-header__title {
  margin-bottom: var(--space-md);
}

.page-header__intro {
  font-size: clamp(1rem, 2vw, 1.125rem);
  max-width: 720px;
}

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

.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }
}