/*
 * Navigation & Scroll Enhancements for OpenJudge Documentation
 * Phase 1: 导航滚动修复
 *
 * Features:
 * - 侧边栏滚动优化
 * - 当前页面高亮
 * - 滚动时侧边栏固定
 * - 目录 (TOC) 滚动跟随
 * - 平滑滚动
 */

/* ========================================
   Global Smooth Scroll
   ======================================== */

html {
  scroll-behavior: smooth;
}

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

/* ========================================
   Sidebar Navigation
   ======================================== */

/* Sidebar container - sticky positioning */
nav.sidebar,
.md-sidebar,
.nav-sidebar,
aside.sidebar {
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
  overflow-x: hidden;
  /* Hide scrollbar by default, show on hover */
  scrollbar-width: none;
  scrollbar-color: var(--muted-foreground, #d1d5db) transparent;
}

/* Show scrollbar on hover (Firefox) */
nav.sidebar:hover,
.md-sidebar:hover,
.nav-sidebar:hover,
aside.sidebar:hover {
  scrollbar-width: thin;
}

/* Custom scrollbar for sidebar (Webkit - hidden by default) */
nav.sidebar::-webkit-scrollbar,
.md-sidebar::-webkit-scrollbar,
.nav-sidebar::-webkit-scrollbar,
aside.sidebar::-webkit-scrollbar {
  width: 0;
}

/* Show scrollbar on hover (Webkit) */
nav.sidebar:hover::-webkit-scrollbar,
.md-sidebar:hover::-webkit-scrollbar,
.nav-sidebar:hover::-webkit-scrollbar,
aside.sidebar:hover::-webkit-scrollbar {
  width: 4px;
}

nav.sidebar::-webkit-scrollbar-track,
.md-sidebar::-webkit-scrollbar-track,
.nav-sidebar::-webkit-scrollbar-track,
aside.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

nav.sidebar::-webkit-scrollbar-thumb,
.md-sidebar::-webkit-scrollbar-thumb,
.nav-sidebar::-webkit-scrollbar-thumb,
aside.sidebar::-webkit-scrollbar-thumb {
  background: var(--muted-foreground, #d1d5db);
  border-radius: 2px;
}

nav.sidebar::-webkit-scrollbar-thumb:hover,
.md-sidebar::-webkit-scrollbar-thumb:hover,
.nav-sidebar::-webkit-scrollbar-thumb:hover,
aside.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--foreground, #9ca3af);
}

/* ========================================
   Navigation Links
   ======================================== */

/* Base nav link styles */
nav.sidebar a,
.md-sidebar a,
.nav-sidebar a,
aside.sidebar a,
.md-nav__link {
  display: block;
  padding: 0.5rem 0.75rem;
  color: var(--muted-foreground, #6b7280);
  text-decoration: none;
  border-radius: 0.375rem;
  transition: all 0.15s ease;
  font-size: 0.875rem;
  line-height: 1.5;
}

/* Hover state */
nav.sidebar a:hover,
.md-sidebar a:hover,
.nav-sidebar a:hover,
aside.sidebar a:hover,
.md-nav__link:hover {
  color: var(--foreground, #1f2937);
  background: var(--muted, rgba(0, 0, 0, 0.04));
}

/* ========================================
   Current Page Highlight
   ======================================== */

/* Active/current page indicator */
nav.sidebar a.active,
nav.sidebar a[aria-current="page"],
.md-sidebar a.active,
.md-sidebar a[aria-current="page"],
.nav-sidebar a.active,
.nav-sidebar a[aria-current="page"],
aside.sidebar a.active,
aside.sidebar a[aria-current="page"],
.md-nav__link--active,
.md-nav__item--active > .md-nav__link {
  color: var(--primary, #3b82f6);
  background: rgba(59, 130, 246, 0.1);
  font-weight: 500;
  position: relative;
}

/* Active indicator bar */
nav.sidebar a.active::before,
nav.sidebar a[aria-current="page"]::before,
.md-sidebar a.active::before,
.md-sidebar a[aria-current="page"]::before,
.nav-sidebar a.active::before,
aside.sidebar a.active::before,
.md-nav__link--active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 1.25rem;
  background: var(--primary, #3b82f6);
  border-radius: 0 2px 2px 0;
}

/* ========================================
   Table of Contents (TOC)
   ======================================== */

/* TOC container */
.toc,
.md-sidebar--secondary,
.table-of-contents,
nav.toc {
  position: sticky;
  top: 1rem;
  max-height: calc(100vh - 2rem);
  overflow-y: auto;
  padding-right: 0.5rem;
}

/* TOC title */
.toc-title,
.md-sidebar--secondary .md-nav__title,
.table-of-contents-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted-foreground, #9ca3af);
  margin-bottom: 0.75rem;
  padding: 0 0.5rem;
}

/* TOC links */
.toc a,
.md-sidebar--secondary a,
.table-of-contents a,
nav.toc a {
  display: block;
  padding: 0.375rem 0.5rem;
  font-size: 0.8125rem;
  color: var(--muted-foreground, #6b7280);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.15s ease;
  line-height: 1.4;
}

.toc a:hover,
.md-sidebar--secondary a:hover,
.table-of-contents a:hover,
nav.toc a:hover {
  color: var(--foreground, #1f2937);
  border-left-color: var(--muted-foreground, #d1d5db);
}

/* Active TOC item (scroll spy) */
.toc a.active,
.toc a[aria-current="true"],
.md-sidebar--secondary a.active,
.table-of-contents a.active,
nav.toc a.active {
  color: var(--primary, #3b82f6);
  border-left-color: var(--primary, #3b82f6);
  font-weight: 500;
}

/* Nested TOC levels */
.toc ul ul a,
.md-sidebar--secondary .md-nav--secondary a,
.table-of-contents ul ul a {
  padding-left: 1rem;
  font-size: 0.75rem;
}

.toc ul ul ul a,
.table-of-contents ul ul ul a {
  padding-left: 1.5rem;
}

/* ========================================
   Scroll Progress Indicator
   ======================================== */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--primary, #3b82f6);
  z-index: 9999;
  transition: width 0.1s ease-out;
}

/* ========================================
   Scroll to Top Button
   ======================================== */

.scroll-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--background, #fff);
  border: 1px solid var(--border, #e5e7eb);
  border-radius: 50%;
  color: var(--muted-foreground, #6b7280);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  z-index: 100;
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top:hover {
  color: var(--foreground, #1f2937);
  border-color: var(--primary, #3b82f6);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* ========================================
   Header Offset for Anchor Links
   ======================================== */

/* Offset for fixed header when jumping to anchors */
:target::before {
  content: '';
  display: block;
  height: 80px;
  margin-top: -80px;
  visibility: hidden;
  pointer-events: none;
}

/* Alternative using scroll-margin */
h1[id], h2[id], h3[id], h4[id], h5[id], h6[id],
[id]:target {
  scroll-margin-top: 80px;
}

/* ========================================
   Dark Mode
   ======================================== */

/* Dark mode scrollbar */
.dark nav.sidebar::-webkit-scrollbar-thumb,
.dark .md-sidebar::-webkit-scrollbar-thumb,
.dark .nav-sidebar::-webkit-scrollbar-thumb,
.dark aside.sidebar::-webkit-scrollbar-thumb,
.dark nav.sidebar::-webkit-scrollbar-thumb,
.dark .md-sidebar::-webkit-scrollbar-thumb {
  background: var(--muted-foreground, #4b5563);
}

/* Dark mode nav links */
.dark nav.sidebar a,
.dark .md-sidebar a,
.dark .nav-sidebar a,
.dark aside.sidebar a,
.dark nav.sidebar a,
.dark .md-sidebar a {
  color: var(--muted-foreground, #9ca3af);
}

.dark nav.sidebar a:hover,
.dark .md-sidebar a:hover,
.dark .nav-sidebar a:hover,
.dark aside.sidebar a:hover,
.dark nav.sidebar a:hover,
.dark .md-sidebar a:hover {
  color: var(--foreground, #f3f4f6);
  background: rgba(255, 255, 255, 0.05);
}

/* Dark mode active state */
.dark nav.sidebar a.active,
.dark nav.sidebar a[aria-current="page"],
.dark .md-sidebar a.active,
.dark .md-nav__link--active,
.dark nav.sidebar a.active,
.dark .md-sidebar a.active {
  color: var(--primary, #60a5fa);
  background: rgba(96, 165, 250, 0.1);
}

/* Dark mode TOC */
.dark .toc a,
.dark .md-sidebar--secondary a,
.dark .table-of-contents a,
.dark .toc a,
.dark .md-sidebar--secondary a {
  color: var(--muted-foreground, #9ca3af);
}

.dark .toc a:hover,
.dark .md-sidebar--secondary a:hover,
.dark .toc a:hover,
.dark .md-sidebar--secondary a:hover {
  color: var(--foreground, #f3f4f6);
  border-left-color: var(--muted-foreground, #6b7280);
}

.dark .toc a.active,
.dark .md-sidebar--secondary a.active,
.dark .toc a.active,
.dark .md-sidebar--secondary a.active {
  color: var(--primary, #60a5fa);
  border-left-color: var(--primary, #60a5fa);
}

/* Dark mode scroll to top */
.dark .scroll-to-top,
.dark .scroll-to-top {
  background: var(--background, #1f2937);
  border-color: var(--border, #374151);
  color: var(--muted-foreground, #9ca3af);
}

.dark .scroll-to-top:hover,
.dark .scroll-to-top:hover {
  color: var(--foreground, #f3f4f6);
  border-color: var(--primary, #60a5fa);
}

/* ========================================
   Mobile Navigation
   ======================================== */

@media (max-width: 768px) {
  /* Mobile sidebar - only apply custom positioning if sidebar has .mobile-drawer class */
  nav.sidebar.mobile-drawer,
  .md-sidebar.mobile-drawer,
  .nav-sidebar.mobile-drawer,
  aside.sidebar.mobile-drawer {
    position: fixed;
    top: 0;
    left: 0;
    width: 280px;
    height: 100vh;
    max-height: 100vh;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 1000;
    background: var(--background, #fff);
    border-right: 1px solid var(--border, #e5e7eb);
    padding: 1rem;
  }

  /* Open state for drawer navigation */
  nav.sidebar.mobile-drawer.open,
  .md-sidebar.mobile-drawer.open,
  .nav-sidebar.mobile-drawer.open,
  aside.sidebar.mobile-drawer.open {
    transform: translateX(0);
  }

  /* Mobile TOC - hidden by default */
  .toc,
  .md-sidebar--secondary,
  .table-of-contents {
    display: none;
  }

  /* Scroll to top - smaller on mobile */
  .scroll-to-top {
    bottom: 1rem;
    right: 1rem;
    width: 2.25rem;
    height: 2.25rem;
  }

  /* Reduce scroll margin for smaller header */
  h1[id], h2[id], h3[id], h4[id], h5[id], h6[id],
  [id]:target {
    scroll-margin-top: 60px;
  }
}

/* Dark mode mobile sidebar */
@media (max-width: 768px) {
  .dark nav.sidebar.mobile-drawer,
  .dark .md-sidebar.mobile-drawer,
  .dark .nav-sidebar.mobile-drawer,
  .dark aside.sidebar.mobile-drawer,
  .dark nav.sidebar.mobile-drawer,
  .dark .md-sidebar.mobile-drawer {
    background: var(--background, #111827);
    border-right-color: var(--border, #374151);
  }
}

/* ========================================
   Overlay for Mobile Menu
   ======================================== */

.nav-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
}

.nav-overlay.visible {
  opacity: 1;
  visibility: visible;
}