:root {
  --accent: #7c3aed;
  --accent-dark: #6d28d9;
  --accent-soft: #ede9fe;
  --bg: #ffffff;
  --bg-soft: #fafafb;
  --text: #1f2937;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --code-bg: #f6f4ff;
  --code-border: #e4d9fb;
  --serif-ar: "Amiri", "Scheherazade New", "Noto Naskh Arabic", "Traditional Arabic", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

html[lang="ar"] body {
  font-family: var(--serif-ar);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1.5rem;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.back-link {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  white-space: nowrap;
}

.back-link:hover {
  text-decoration: underline;
}

.header-title {
  flex: 1 1 auto;
  min-width: 200px;
}

.header-title h1 {
  margin: 0;
  font-size: 1.35rem;
  color: var(--accent);
}

.subtitle {
  margin: 0.1rem 0 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#search {
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  min-width: 220px;
}

#search:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

#search-clear {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  border-radius: 8px;
  padding: 0.45rem 0.75rem;
  cursor: pointer;
  font-size: 0.85rem;
}

#lang-toggle {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 0.45rem 0.9rem;
  cursor: pointer;
  font-size: 0.9rem;
}

#lang-toggle:hover {
  background: var(--accent-dark);
}

.layout {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 2rem;
  max-width: 1080px;
  margin: 0 auto;
  padding: 1.5rem;
}

.sidebar {
  position: sticky;
  top: 92px;
  align-self: start;
  max-height: calc(100vh - 110px);
  overflow-y: auto;
  border-right: 1px solid var(--border);
  padding-right: 1rem;
}

html[dir="rtl"] .sidebar {
  border-right: none;
  border-left: 1px solid var(--border);
  padding-right: 0;
  padding-left: 1rem;
}

.sidebar-heading {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin: 0 0 0.5rem;
}

#topic-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

#topic-nav li {
  margin-bottom: 0.25rem;
}

#topic-nav a {
  display: block;
  padding: 0.35rem 0.6rem;
  border-radius: 6px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.92rem;
}

#topic-nav a:hover {
  background: var(--accent-soft);
  color: var(--accent);
}

.main {
  min-width: 0;
}

.topic-card {
  scroll-margin-top: 90px;
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.topic-anchor {
  display: block;
  position: relative;
  top: -90px;
  visibility: hidden;
}

.topic-title {
  font-size: 1.4rem;
  color: var(--accent);
  margin: 0 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--accent-soft);
}

.topic-points,
.topic-tips {
  margin: 0.5rem 0 1rem;
  padding-left: 1.4rem;
}

html[dir="rtl"] .topic-points,
html[dir="rtl"] .topic-tips {
  padding-left: 0;
  padding-right: 1.4rem;
}

.topic-card h3 {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin: 1.2rem 0 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  margin: 0.5rem 0 1rem;
  direction: ltr;
  text-align: left;
}

pre code {
  font-family: "Cascadia Code", "Consolas", "Menlo", monospace;
  font-size: 0.85rem;
  line-height: 1.5;
  color: #3b0764;
}

.topic-tips li {
  margin-bottom: 0.3rem;
}

.empty-state {
  color: var(--text-muted);
  padding: 2rem 0;
}

.site-footer {
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 1rem;
}

@media (max-width: 820px) {
  .layout {
    grid-template-columns: 1fr;
    gap: 1rem;
    padding: 1rem;
  }

  .sidebar {
    position: static;
    top: auto;
    max-height: none;
    border-right: none;
    border-left: none;
    border-bottom: 1px solid var(--border);
    padding: 0 0 0.75rem;
    overflow: visible;
  }

  html[dir="rtl"] .sidebar {
    border-left: none;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 0 0 0.75rem;
  }

  .sidebar-heading {
    margin-bottom: 0.25rem;
  }

  #topic-nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 0.75rem;
  }

  #topic-nav li {
    margin-bottom: 0;
  }

  #search {
    min-width: 140px;
    flex: 1;
  }

  .header-actions {
    width: 100%;
  }
}