/* Academic Writing Tutorial - DHCraft Design System */

:root {
  /* Colors - Main palette (from DHCraft) */
  --color-slate: #607D8B;
  --color-slate-light: rgba(96, 125, 139, 0.1);
  --color-slate-muted: rgba(96, 125, 139, 0.6);
  --color-terracotta: #BF5B3E;
  --color-terracotta-dark: #a04d34;
  --color-terracotta-light: rgba(191, 91, 62, 0.1);
  --color-white: #FFFFFF;
  --color-black: #1A1A1A;
  --color-background: #E8E8E8;

  /* Code */
  --color-code-bg: #f5f5f5;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

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

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 2px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 60px; /* Offset for fixed header */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-black);
  background-color: var(--color-background);
  max-width: 100vw;
  overflow-x: hidden;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 90;
  background: rgba(232, 232, 232, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(96, 125, 139, 0.1);
}

.header-content {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-lg);
  max-width: 1200px;
  margin: 0 auto;
}

.back-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--color-black);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: color 0.2s ease;
  flex-shrink: 0;
}

.back-link:hover {
  color: var(--color-terracotta);
}

.back-link svg {
  width: 16px;
  height: 16px;
  color: var(--color-slate);
}

.title-group {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-grow: 1;
}

.step-separator {
  color: var(--color-slate);
  opacity: 0.5;
}

.current-page {
  font-size: 0.9rem;
  color: var(--color-terracotta);
  font-weight: 500;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav-link {
  font-size: 0.8rem;
  color: var(--color-slate);
  text-decoration: none;
  padding: 4px 12px;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--color-terracotta);
  background: rgba(191, 91, 62, 0.1);
}

/* Layout */
.page-layout {
  min-height: 100dvh;
}

.container {
  display: flex;
  max-width: 1400px;
  margin: 0 auto;
  padding-top: 50px; /* Header height */
}

/* Sidebar */
nav.sidebar {
  width: 260px;
  height: calc(100vh - 50px);
  position: sticky;
  top: 50px;
  padding: var(--space-lg) var(--space-md);
  overflow-y: auto;
  flex-shrink: 0;
  border-right: 1px solid rgba(96, 125, 139, 0.1);
}

nav.sidebar h2 {
  font-size: 0.85rem;
  margin: 0 0 var(--space-md) 0;
  color: var(--color-terracotta);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

nav.sidebar ul {
  list-style: none;
}

nav.sidebar li {
  margin: var(--space-xs) 0;
}

nav.sidebar a {
  color: var(--color-black);
  text-decoration: none;
  font-size: 0.9rem;
  display: block;
  padding: 4px 8px;
  border-radius: 4px;
  transition: all 0.2s ease;
}

nav.sidebar a:hover {
  color: var(--color-terracotta);
  background: rgba(191, 91, 62, 0.08);
}

nav.sidebar a.active {
  color: var(--color-terracotta);
  background: rgba(191, 91, 62, 0.12);
  font-weight: 500;
}

nav.sidebar .section-title {
  font-weight: 600;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-slate);
  padding: 0 8px;
}

/* Main content */
main {
  flex: 1;
  max-width: 800px;
  padding: var(--space-xl);
  margin: 0 auto;
}

/* Text card - main content wrapper */
.text-card {
  background: rgba(255, 255, 255, 0.9);
  padding: var(--space-lg);
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  margin-bottom: var(--space-lg);
}

/* Typography */
h1 {
  font-size: clamp(2rem, 5vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-terracotta);
  margin-bottom: var(--space-md);
}

h2 {
  font-size: clamp(1.3rem, 3vw, 1.6rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-slate);
  margin: var(--space-xl) 0 var(--space-md) 0;
  padding-top: var(--space-md);
  border-top: 2px solid var(--color-terracotta);
}

h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-black);
  margin: var(--space-lg) 0 var(--space-sm) 0;
}

h4 {
  font-size: 1rem;
  font-weight: 600;
  margin: var(--space-md) 0 var(--space-sm) 0;
}

p {
  margin: var(--space-md) 0;
  line-height: 1.7;
}

a {
  color: var(--color-terracotta);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-terracotta-dark);
  text-decoration: underline;
}

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

/* Hero */
.hero {
  text-align: center;
  padding: var(--space-lg) 0 var(--space-xl);
  margin-bottom: var(--space-lg);
}

.hero h1 {
  margin-bottom: var(--space-sm);
}

.hero .tagline {
  font-size: 1.1rem;
  color: var(--color-slate);
  margin: var(--space-sm) 0 var(--space-lg);
}

.hero .actions {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--color-terracotta);
  color: white;
}

.btn-primary:hover {
  background: var(--color-terracotta-dark);
  text-decoration: none;
}

.btn-secondary {
  border: 1px solid var(--color-slate);
  color: var(--color-slate);
}

.btn-secondary:hover {
  border-color: var(--color-terracotta);
  color: var(--color-terracotta);
  text-decoration: none;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
  margin: var(--space-lg) 0;
}

.card {
  background: var(--color-white);
  border-radius: 8px;
  padding: var(--space-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(96, 125, 139, 0.1);
}

.card h4 {
  margin: 0 0 var(--space-sm) 0;
  color: var(--color-slate);
}

.card ul {
  margin: 0;
  padding-left: var(--space-md);
}

.card li {
  margin: var(--space-xs) 0;
}

/* Code */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

pre {
  background: var(--color-code-bg);
  padding: var(--space-md);
  border-radius: 8px;
  overflow-x: auto;
  margin: var(--space-lg) 0;
  border: 1px solid rgba(96, 125, 139, 0.1);
}

pre code {
  background: none;
  padding: 0;
  font-size: 0.85rem;
  line-height: 1.5;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-lg) 0;
  font-size: 0.95rem;
}

th, td {
  text-align: left;
  padding: var(--space-sm);
  border-bottom: 1px solid rgba(96, 125, 139, 0.2);
}

th {
  background: var(--color-slate-light);
  font-weight: 600;
  color: var(--color-slate);
}

/* Asides - using DHCraft patterns */
.aside {
  padding: var(--space-md) var(--space-md);
  border-radius: 8px;
  margin: var(--space-lg) 0;
  border-left: 3px solid;
  text-align: left;
}

.aside-caution {
  background: var(--color-terracotta-light);
  border-color: var(--color-terracotta);
}

.aside-note {
  background: var(--color-slate-light);
  border-color: var(--color-slate);
}

.aside .aside-title {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin: 0 0 var(--space-sm) 0;
  display: flex;
  align-items: center;
  gap: 0.5em;
}

.aside .aside-title::before {
  font-size: 1.1em;
}

.aside-caution .aside-title {
  color: var(--color-terracotta);
}

.aside-caution .aside-title::before {
  content: "⚠";
}

.aside-note .aside-title {
  color: var(--color-slate);
}

.aside-note .aside-title::before {
  content: "ℹ";
}

.aside p {
  font-size: 0.9rem;
  margin: 0;
  line-height: 1.6;
  color: var(--color-black);
}

/* Steps */
.steps {
  counter-reset: step;
  padding-left: 0;
  list-style: none;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding-left: 3rem;
  margin: var(--space-lg) 0;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 2rem;
  height: 2rem;
  background: var(--color-terracotta);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 600;
}

/* Diagram figures */
figure.diagram {
  margin: var(--space-lg) 0;
  text-align: center;
}

figure.diagram img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: var(--shadow-md);
}

/* Placeholder images */
.placeholder {
  background: rgba(96, 125, 139, 0.08);
  border: 2px dashed var(--color-slate-muted);
  padding: var(--space-lg);
  text-align: center;
  margin: var(--space-lg) 0;
  border-radius: 8px;
}

.placeholder p {
  margin: 0;
  color: var(--color-slate);
  font-size: 0.9rem;
}

.placeholder strong {
  display: block;
  margin-bottom: var(--space-sm);
  color: var(--color-slate);
}

/* Blockquote */
blockquote {
  border-left: 3px solid var(--color-terracotta);
  margin: var(--space-lg) 0;
  padding: var(--space-sm) var(--space-md);
  font-style: italic;
  background: var(--color-slate-light);
  border-radius: 0 8px 8px 0;
}

/* Lists */
ul, ol {
  padding-left: var(--space-lg);
}

li {
  margin: var(--space-xs) 0;
}

/* Footer */
footer {
  margin-top: var(--space-xl);
  padding: var(--space-lg) 0;
  border-top: 1px solid rgba(96, 125, 139, 0.2);
  text-align: center;
  font-size: 0.9rem;
  color: var(--color-slate);
}

/* Mobile */
@media (max-width: 900px) {
  .header-content {
    padding: var(--space-xs) var(--space-md);
  }

  .header-nav {
    display: none;
  }

  .container {
    flex-direction: column;
    width: 100%;
  }

  nav.sidebar {
    display: none;
  }

  main {
    padding: var(--space-md);
    width: 100%;
    max-width: 100%;
  }

  .hero {
    width: 100%;
  }

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

/* Print */
@media print {
  .site-header,
  nav.sidebar {
    display: none;
  }

  .container {
    padding-top: 0;
  }

  main {
    max-width: 100%;
    padding: 0;
  }

  .placeholder {
    border-style: solid;
  }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}