/* ================================================
   SIDE B - Stylesheet
   Dark theme, mobile-first, accessible
   ================================================ */

/* --- CSS Variables --- */
:root {
  --color-bg: #1a1a1a;
  --color-text: #e8e8e8;
  --color-accent: #E63946;
  --color-accent-hover: #ff4d5a;
  --color-border: #333333;
  --color-surface: #242424;
  --color-muted: #999999;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

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

  --max-width: 1200px;
  --sidebar-width: 250px;
}

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

/* --- Base --- */
html {
  font-size: 100%;
  scroll-behavior: smooth;
}

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

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Skip Link --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  background-color: var(--color-accent);
  color: #ffffff;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.875rem;
  font-weight: 700;
  text-decoration: none;
  z-index: 1000;
  border-radius: 0 0 4px 4px;
}

.skip-link:focus {
  top: 0;
  outline: 3px solid #ffffff;
  outline-offset: 2px;
}

/* --- Focus Styles --- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* --- Links --- */
a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 0.15em;
  transition: color 0.15s ease;
}

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

/* --- Headings --- */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  font-weight: 700;
  color: #ffffff;
}

h1 {
  font-size: 2rem;
  margin-bottom: var(--space-lg);
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.4rem;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-accent);
}

h3 {
  font-size: 1.15rem;
  margin-bottom: var(--space-sm);
  color: var(--color-accent);
}

/* --- Paragraphs --- */
p {
  margin-bottom: var(--space-md);
}

p:last-child {
  margin-bottom: 0;
}

/* --- Site Header --- */
.site-header {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md) var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

.site-logo-link {
  text-decoration: none;
}

.site-name {
  font-size: 1.75rem;
  font-weight: 900;
  color: #ffffff;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: inline-block;
}

.site-logo-link:hover .site-name {
  color: var(--color-accent);
}

.site-tagline {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-top: var(--space-xs);
  margin-bottom: 0;
  font-style: italic;
}

/* --- Navigation --- */
.site-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--color-border);
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.site-nav li {
  margin: 0;
}

.site-nav a {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  color: var(--color-text);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* --- Layout: Single Column --- */
.layout-single {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md);
}

/* --- Content Blocks --- */
.content-block {
  margin-bottom: var(--space-xl);
}

.content-block:last-child {
  margin-bottom: 0;
}

/* --- Hero Section (Home) --- */
.hero {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
}

.hero h1 {
  font-size: 2.25rem;
  max-width: 40ch;
  color: var(--color-accent);
}

.hero p {
  font-size: 1.1rem;
  max-width: 65ch;
  color: var(--color-muted);
}

/* --- Lists inside main content --- */
main ul,
main ol {
  padding-left: 1.6rem;
  margin-bottom: var(--space-md);
}

main li {
  margin-bottom: var(--space-sm);
}

/* --- Footer --- */
.site-footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-xl);
  text-align: center;
}

.site-footer p {
  font-size: 0.8rem;
  color: var(--color-muted);
  margin-bottom: var(--space-xs);
}

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

/* --- Selection --- */
::selection {
  background-color: var(--color-accent);
  color: #ffffff;
}

/* --- Responsive --- */
@media (min-width: 48em) {
  h1 {
    font-size: 2.5rem;
  }

  .hero h1 {
    font-size: 2.75rem;
  }

  .site-header {
    padding: var(--space-xl) var(--space-lg) var(--space-md);
  }

  .site-nav {
    padding: var(--space-sm) var(--space-lg);
  }

  .layout-single {
    padding: var(--space-xl) var(--space-lg);
  }

  .site-footer {
    padding: var(--space-lg);
  }

  .site-nav a {
    padding: var(--space-sm) var(--space-md);
  }
}

@media (min-width: 64em) {
  .site-name {
    font-size: 2rem;
  }

  .hero h1 {
    font-size: 3rem;
  }
}