/* ============================================================
   Material Design 3 — Android Compose Interview Guide
   Shared stylesheet
   ============================================================ */

/* ---------- MD3 Tokens ---------- */
:root {
  --primary:               #6750A4;
  --on-primary:            #FFFFFF;
  --primary-container:     #EADDFF;
  --on-primary-container:  #21005D;
  --secondary:             #625B71;
  --secondary-container:   #E8DEF8;
  --on-secondary-container:#1D192B;
  --tertiary:              #7D5260;
  --surface:               #FFFBFE;
  --surface-variant:       #E7E0EC;
  --on-surface:            #1C1B1F;
  --on-surface-variant:    #49454F;
  --outline:               #79747E;
  --outline-variant:       #CAC4D0;
  --background:            #FFFBFE;
  --error:                 #B3261E;
  --error-container:       #F9DEDC;
  --success:               #386A20;
  --success-container:     #C3E7AD;

  --header-height:   64px;
  --sidebar-width:   255px;
  --radius:          12px;
  --radius-sm:       8px;
  --transition:      0.18s ease;
}

[data-theme="dark"] {
  --primary:               #D0BCFF;
  --on-primary:            #381E72;
  --primary-container:     #4F378B;
  --on-primary-container:  #EADDFF;
  --secondary:             #CCC2DC;
  --secondary-container:   #4A4458;
  --on-secondary-container:#E8DEF8;
  --tertiary:              #EFB8C8;
  --surface:               #1C1B1F;
  --surface-variant:       #49454F;
  --on-surface:            #E6E1E5;
  --on-surface-variant:    #CAC4D0;
  --outline:               #938F99;
  --outline-variant:       #49454F;
  --background:            #1C1B1F;
  --error:                 #F2B8B5;
  --error-container:       #8C1D18;
  --success:               #A8D5A2;
  --success-container:     #1E4620;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--background);
  color: var(--on-surface);
  line-height: 1.65;
  transition: background var(--transition), color var(--transition);
}

a { color: var(--primary); }

/* ---------- Top Nav ---------- */
.top-nav {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-height);
  background: var(--surface);
  border-bottom: 1px solid var(--outline-variant);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 20px;
  z-index: 200;
  box-shadow: 0 1px 4px rgba(0,0,0,.1);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--primary);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
}

.nav-brand .brand-icon {
  width: 32px; height: 32px;
  background: var(--primary);
  color: var(--on-primary);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: .9rem; font-weight: 800;
}

.nav-tabs {
  display: flex;
  gap: 2px;
  overflow-x: auto;
  flex: 1;
  min-width: 0;          /* allow flex child to shrink and scroll */
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}
.nav-tabs::-webkit-scrollbar { display: none; }

.nav-tab {
  padding: 6px 13px;
  border: none;
  background: transparent;
  color: var(--on-surface-variant);
  cursor: pointer;
  border-radius: 20px;
  font-size: .82rem;
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
  font-family: inherit;
  text-decoration: none;
  display: inline-block;
}
.nav-tab:hover { background: var(--surface-variant); color: var(--on-surface); }
.nav-tab.active {
  background: var(--primary-container);
  color: var(--on-primary-container);
  font-weight: 600;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

/* Search */
.search-wrap {
  position: relative;
  display: flex;
  align-items: center;
}
.search-wrap svg {
  position: absolute;
  left: 10px;
  color: var(--on-surface-variant);
  pointer-events: none;
}
.search-input {
  padding: 6px 12px 6px 34px;
  border: 1px solid var(--outline);
  border-radius: 20px;
  background: var(--surface-variant);
  color: var(--on-surface);
  font-size: .85rem;
  width: 190px;
  outline: none;
  transition: all var(--transition);
  font-family: inherit;
}
.search-input:focus { width: 250px; border-color: var(--primary); background: var(--surface); }

/* Theme toggle */
.theme-btn {
  width: 38px; height: 38px;
  border: none;
  background: var(--surface-variant);
  color: var(--on-surface);
  border-radius: 50%;
  cursor: pointer;
  font-size: 17px;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--transition);
}
.theme-btn:hover { background: var(--outline-variant); }

/* Search dropdown */
.search-dropdown {
  position: fixed;
  top: calc(var(--header-height) + 6px);
  right: 20px;
  width: 380px;
  max-height: 55vh;
  overflow-y: auto;
  background: var(--surface);
  border: 1px solid var(--outline);
  border-radius: var(--radius);
  box-shadow: 0 6px 24px rgba(0,0,0,.15);
  z-index: 300;
  display: none;
}
.search-dropdown.open { display: block; }
.search-result {
  padding: 10px 14px;
  border-bottom: 1px solid var(--outline-variant);
  cursor: pointer;
  transition: background var(--transition);
}
.search-result:last-child { border-bottom: none; }
.search-result:hover { background: var(--surface-variant); }
.sr-section { font-size: .7rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; color: var(--primary); }
.sr-title { font-size: .88rem; font-weight: 600; color: var(--on-surface); }
.sr-snippet { font-size: .78rem; color: var(--on-surface-variant); margin-top: 2px; }
.sr-snippet mark { background: var(--primary-container); color: var(--on-primary-container); border-radius: 2px; padding: 0 2px; }
.search-empty { padding: 20px; text-align: center; color: var(--on-surface-variant); font-size: .88rem; }

/* ---------- Layout ---------- */
.layout {
  display: flex;
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
}

/* ---------- Sidebar ---------- */
.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  position: sticky;
  top: var(--header-height);
  height: calc(100vh - var(--header-height));
  overflow-y: auto;
  border-right: 1px solid var(--outline-variant);
  background: var(--surface);
  padding: 12px 0 24px;
  scrollbar-width: thin;
  scrollbar-color: var(--outline-variant) transparent;
}

.sidebar-heading {
  padding: 10px 16px 4px;
  font-size: .7rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--on-surface-variant);
}

.sidebar a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px 6px 20px;
  color: var(--on-surface-variant);
  text-decoration: none;
  font-size: .82rem;
  border-radius: 0 20px 20px 0;
  margin-right: 12px;
  transition: all var(--transition);
}
.sidebar a:hover { background: var(--surface-variant); color: var(--on-surface); }
.sidebar a.active {
  background: var(--primary-container);
  color: var(--on-primary-container);
  font-weight: 600;
}

/* ---------- Main Content ---------- */
.content {
  flex: 1;
  min-width: 0;
  padding: 28px 36px 60px;
  max-width: 860px;
}

/* Section hero */
.page-hero {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 2px solid var(--primary-container);
}
.page-hero h1 {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 6px;
}
.page-hero p {
  color: var(--on-surface-variant);
  font-size: .95rem;
}

/* Subsections */
.subsection {
  margin-bottom: 44px;
  scroll-margin-top: calc(var(--header-height) + 12px);
}

.sub-header {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}
.sub-header h2 {
  font-size: 1.25rem;
  color: var(--on-surface);
}

.doc-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  background: var(--primary-container);
  color: var(--on-primary-container);
  border-radius: 12px;
  font-size: .72rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity var(--transition);
}
.doc-link:hover { opacity: .75; }

.sub-desc {
  color: var(--on-surface-variant);
  font-size: .9rem;
  margin-bottom: 12px;
}

/* Inline code */
code:not([class*="language"]) {
  background: var(--surface-variant);
  color: var(--primary);
  padding: 1px 5px;
  border-radius: 4px;
  font-family: 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  font-size: .85em;
}

/* ---------- Code Cards ---------- */
.code-card {
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 12px;
  border: 1px solid var(--outline-variant);
}

.code-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 7px 12px;
  background: var(--primary-container);
  border-bottom: 1px solid var(--outline-variant);
}

.code-lang {
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--on-primary-container);
}

.code-btns {
  display: flex;
  gap: 6px;
}

.btn-sm {
  padding: 3px 10px;
  border: 1px solid var(--outline);
  background: var(--surface);
  color: var(--on-surface-variant);
  border-radius: 10px;
  cursor: pointer;
  font-size: .73rem;
  font-family: inherit;
  transition: all var(--transition);
}
.btn-sm:hover { background: var(--surface-variant); color: var(--on-surface); }
.btn-sm.copied { background: var(--success-container); border-color: var(--success); color: var(--success); }

.code-card pre[class*="language-"] {
  margin: 0 !important;
  border-radius: 0 !important;
  padding: 14px 16px !important;
  font-size: .8rem !important;
  line-height: 1.55 !important;
  background: #f8f8f8 !important;
}

[data-theme="dark"] .code-card pre[class*="language-"] {
  background: #1e1e2e !important;
}

.code-expanded { display: none; border-top: 1px solid var(--outline-variant); }
.code-expanded.open { display: block; }

/* ---------- Deep Dive ---------- */
details.deep-dive {
  border-top: 1px solid var(--outline-variant);
  background: var(--surface);
}
details.deep-dive summary {
  padding: 9px 14px;
  cursor: pointer;
  font-size: .83rem;
  font-weight: 600;
  color: var(--primary);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}
details.deep-dive summary::-webkit-details-marker { display: none; }
details.deep-dive summary::before {
  content: '▶';
  font-size: .6rem;
  transition: transform var(--transition);
  flex-shrink: 0;
}
details.deep-dive[open] summary::before { transform: rotate(90deg); }
.deep-content {
  padding: 14px 16px;
  border-top: 1px solid var(--outline-variant);
  font-size: .88rem;
  color: var(--on-surface-variant);
}
.deep-content p { margin-bottom: 10px; }
.deep-content ul, .deep-content ol {
  margin-left: 18px;
  margin-bottom: 10px;
}
.deep-content li { margin-bottom: 4px; }
.deep-content strong { color: var(--on-surface); }
.deep-content .code-card { margin-top: 10px; }

/* ---------- Callout Boxes ---------- */
/* ---------- Icon category reference blocks ---------- */
.icon-category {
  background: var(--surface-variant);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  margin-bottom: 10px;
  font-size: .82rem;
  line-height: 1.8;
  color: var(--on-surface);
  word-break: break-word;
}
.icon-category strong {
  display: block;
  font-size: .75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--primary);
  margin-bottom: 4px;
}
[data-theme="dark"] .icon-category {
  background: #2a2435;
}

.callout {
  padding: 11px 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  font-size: .86rem;
  border-left: 4px solid;
  line-height: 1.5;
}
.callout.tip   { background: rgba(103,80,164,.1); border-color: var(--primary); }
.callout.warn  { background: rgba(255,152,0,.1);  border-color: #FF9800; }
.callout.info  { background: rgba(66,133,244,.1); border-color: #4285F4; }
.callout.deprecated { background: var(--error-container); border-color: var(--error); }
.callout strong { font-weight: 700; }

.interview-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  background: var(--secondary-container);
  color: var(--on-secondary-container);
  border-radius: 12px;
  font-size: .75rem;
  font-weight: 700;
  margin-bottom: 10px;
}

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; margin: 12px 0; }
table { width: 100%; border-collapse: collapse; font-size: .85rem; }
th {
  background: var(--primary-container);
  color: var(--on-primary-container);
  padding: 9px 12px;
  text-align: left;
  font-weight: 700;
}
td { padding: 8px 12px; border-bottom: 1px solid var(--outline-variant); }
tr:hover td { background: var(--surface-variant); }

/* ---------- Footer ---------- */
footer {
  margin-top: 48px;
  padding: 28px 36px;
  border-top: 1px solid var(--outline-variant);
  color: var(--on-surface-variant);
  font-size: .85rem;
  background: var(--surface);
}
footer h4 { color: var(--on-surface); margin-bottom: 10px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 14px; }
.footer-links a { color: var(--primary); text-decoration: none; }
.footer-links a:hover { text-decoration: underline; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--outline-variant); border-radius: 3px; }

/* ---------- Responsive ---------- */
@media (max-width: 780px) {
  .sidebar { display: none; }
  .content { padding: 18px 16px 48px; }
  .search-input { width: 130px; }
  .search-input:focus { width: 170px; }
  .search-dropdown { width: calc(100vw - 32px); right: 16px; }
}