/**
 * Application Layout, Visualizers, and Interactive Sandbox Styles
 */

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

/* Material Symbols needs ligature rendering, otherwise names like account_tree
   appear as oversized fallback text while the web font is loading. */
.material-symbols-outlined {
  display: inline-block;
  width: 1em;
  height: 1em;
  overflow: hidden;
  font-family: 'Material Symbols Outlined';
  font-weight: 400;
  font-style: normal;
  font-size: 24px;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-feature-settings: 'liga';
  -webkit-font-smoothing: antialiased;
  font-feature-settings: 'liga';
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
}

/*
 * 主题切换期间屏蔽所有过渡与动画。
 * 由 theme-switcher.js 在切换 data-theme / data-palette 的同一帧添加，两帧后移除。
 * 目的：规避 WebKit 中「transition 属性取值来自 CSS 自定义属性」时变量更新
 * 不触发重新求值、导致颜色固化在旧主题的缺陷。
 */
.theme-switching,
.theme-switching *,
.theme-switching *::before,
.theme-switching *::after {
  transition: none !important;
  animation: none !important;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--md-ref-typeface-plain);
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--md-sys-color-surface);
}

/* ==========================================================================
   App Shell Layout (Desktop Navigation Rail + Main Content)
   ========================================================================== */
.app-shell {
  display: flex;
  min-height: 100vh;
  width: 100vw;
  background-color: var(--md-sys-color-surface);
}

/* Desktop Navigation Rail (80px wide per MD3 spec) */
.nav-rail {
  width: 96px;
  background-color: var(--md-sys-color-surface-container);
  border-right: 1px solid var(--md-sys-color-outline-variant);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px 0;
  gap: 12px;
  flex-shrink: 0;
  position: sticky;
  top: 0;
  height: 100vh;
  z-index: 100;
  overflow-y: auto;
  scrollbar-width: none;
}
.nav-rail::-webkit-scrollbar {
  display: none;
}

.rail-header {
  margin-bottom: 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}
.rail-logo {
  width: 44px;
  height: 44px;
  border-radius: var(--md-sys-shape-corner-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-tertiary));
  color: var(--md-sys-color-on-primary);
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
}

.rail-destinations {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  align-items: center;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  width: 80px;
  padding: 4px 0;
  border-radius: var(--md-sys-shape-corner-medium);
  background: transparent;
  border: none;
  cursor: pointer;
  text-decoration: none;
  color: var(--md-sys-color-on-surface-variant);
  font: var(--md-sys-typescale-label-small);
  /*
   * 仅过渡真正由交互态驱动的属性。原先的 `transition: all` 会把 color 一并纳入，
   * 而 color 取值来自 CSS 自定义属性 —— WebKit 在变量更新时不会重新求值被过渡
   * 覆盖的属性，导致主题切换后导航文字仍是旧主题颜色。
   */
  transition: background-color var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard),
              font-weight var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
  position: relative;
}

.nav-indicator {
  width: 56px;
  height: 32px;
  border-radius: var(--md-sys-shape-corner-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: transparent;
  transition: background-color var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard),
              width var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
}

.nav-item .material-symbols-outlined {
  font-size: 22px;
  color: var(--md-sys-color-on-surface-variant);
  transition: color var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
}

.nav-label {
  font: var(--md-sys-typescale-label-small);
  text-align: center;
  max-width: 76px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.nav-item:hover .nav-indicator {
  background-color: var(--md-sys-color-surface-container-highest);
}

.nav-item.active {
  color: var(--md-sys-color-on-surface);
  font-weight: 700;
}
.nav-item.active .nav-indicator {
  background-color: var(--md-sys-color-secondary-container);
}
.nav-item.active .material-symbols-outlined {
  color: var(--md-sys-color-on-secondary-container);
}

/* Bottom Nav for Compact Mobile */
.bottom-nav {
  display: none;
}

/* ==========================================================================
   Main Content Area & Top App Bar
   ========================================================================== */
.main-viewport {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
  overflow-y: auto;
  position: relative;
}

.top-app-bar {
  position: sticky;
  top: 0;
  height: 68px;
  background-color: var(--md-sys-color-surface);
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  z-index: 90;
  backdrop-filter: blur(12px);
  /*
   * 此处刻意不加 background-color 过渡。顶栏没有任何 hover / active 态，
   * 该过渡唯一作用就是主题切换时的渐变，但 WebKit 在「transition 覆盖的属性
   * 取值来自 CSS 自定义属性」时不会随变量更新重新求值，会把背景色固化在
   * 旧主题（浅色下顶栏仍为深色）。去掉过渡即彻底消除该缺陷。
   */
}

.top-app-bar__headline {
  display: flex;
  align-items: center;
  gap: 12px;
}

.top-app-bar__title {
  font: var(--md-sys-typescale-title-large);
  font-weight: 700;
  color: var(--md-sys-color-on-surface);
  letter-spacing: -0.2px;
}

.top-app-bar__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Content Container - Constrained to 1280px for readibility per MD3 */
.content-wrapper {
  max-width: 1240px;
  width: 100%;
  margin: 0 auto;
  padding: 36px 32px 120px 32px;
  display: flex;
  flex-direction: column;
  gap: 48px;
}

/* Section Containers */
.doc-section {
  display: flex;
  flex-direction: column;
  gap: 24px;
  scroll-margin-top: 96px;
}

.section-header {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-bottom: 2px solid var(--md-sys-color-surface-container-highest);
  padding-bottom: 16px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--md-sys-color-primary);
  font: var(--md-sys-typescale-label-medium);
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.section-title {
  font: var(--md-sys-typescale-headline-medium);
  color: var(--md-sys-color-on-surface);
  font-weight: 700;
  letter-spacing: -0.3px;
}

.section-desc {
  font: var(--md-sys-typescale-body-large);
  color: var(--md-sys-color-on-surface-variant);
  line-height: 1.6;
  max-width: 900px;
}

/* ==========================================================================
   Code Surfaces & Code Snippets
   ========================================================================== */
.code-surface {
  background-color: var(--code-bg);
  color: var(--code-fg);
  border: 1px solid var(--code-border);
  border-radius: var(--md-sys-shape-corner-medium);
  overflow: hidden;
  margin: 16px 0;
  box-shadow: 0 4px 12px rgba(0,0,0,0.12);
  display: flex;
  flex-direction: column;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  background-color: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--code-border);
  font: var(--md-sys-typescale-label-medium);
  color: #A5A2B5;
}

.code-lang-tag {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--md-ref-typeface-code);
  font-weight: 600;
  font-size: 12px;
  color: var(--md-sys-color-primary-container);
}

.code-copy-btn {
  background: transparent;
  border: none;
  color: #A5A2B5;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font: var(--md-sys-typescale-label-small);
  padding: 4px 8px;
  border-radius: var(--md-sys-shape-corner-small);
  transition: all var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
}
.code-copy-btn:hover {
  background-color: rgba(255,255,255,0.1);
  color: #FFFFFF;
}

.code-body {
  padding: 16px 20px;
  overflow-x: auto;
  font: var(--md-sys-typescale-code-large);
  line-height: 1.6;
}

.code-body code {
  font-family: var(--md-ref-typeface-code);
}

/* Inline code chip */
code.inline-code {
  font-family: var(--md-ref-typeface-code);
  font-size: 0.88em;
  background-color: var(--md-sys-color-surface-container-highest);
  color: var(--md-sys-color-primary);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--md-sys-color-outline-variant);
  font-weight: 500;
}

/* ==========================================================================
   Tables & Matrices
   ========================================================================== */
.table-container {
  overflow-x: auto;
  border-radius: var(--md-sys-shape-corner-large);
  border: 1px solid var(--md-sys-color-outline-variant);
  background-color: var(--md-sys-color-surface);
  margin: 16px 0;
}

.md3-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font: var(--md-sys-typescale-body-medium);
}

.md3-table th {
  background-color: var(--md-sys-color-surface-container);
  color: var(--md-sys-color-on-surface);
  font: var(--md-sys-typescale-title-small);
  font-weight: 700;
  padding: 14px 18px;
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  white-space: nowrap;
}

.md3-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  color: var(--md-sys-color-on-surface);
  vertical-align: middle;
}

.md3-table tr:last-child td {
  border-bottom: none;
}

.md3-table tr:hover td {
  background-color: var(--md-sys-color-surface-container-low);
}

/* ==========================================================================
   Visualizer 1: 0xBA Opcode Breakdown
   ========================================================================== */
.opcode-visualizer {
  display: flex;
  flex-direction: column;
  gap: 16px;
  background-color: var(--md-sys-color-surface-container-low);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-large);
  padding: 24px;
}

.opcode-bytes-row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
}

.opcode-byte-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 16px 8px;
  border-radius: var(--md-sys-shape-corner-medium);
  background-color: var(--md-sys-color-surface);
  border: 2px solid var(--md-sys-color-outline-variant);
  transition: all var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
  text-align: center;
}
.opcode-byte-card.active {
  border-color: var(--md-sys-color-primary);
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}

.byte-hex {
  font-family: var(--md-ref-typeface-code);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--md-sys-color-primary);
  margin-bottom: 4px;
}
.opcode-byte-card.active .byte-hex {
  color: var(--md-sys-color-on-primary-container);
}

.byte-name {
  font: var(--md-sys-typescale-label-medium);
  font-weight: 700;
  margin-bottom: 2px;
}

.byte-role {
  font: var(--md-sys-typescale-body-small);
  color: var(--md-sys-color-on-surface-variant);
}

/* ==========================================================================
   Visualizer 2: Interactive Stepper (indy Execution Debugger)
   ========================================================================== */
.stepper-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  background-color: var(--md-sys-color-surface-container);
  border-radius: var(--md-sys-shape-corner-extra-large);
  padding: 28px;
  border: 1px solid var(--md-sys-color-outline-variant);
}

.stepper-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
}

.stepper-timeline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  margin: 20px 0;
  padding: 0 20px;
}
.stepper-timeline::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 30px;
  right: 30px;
  height: 4px;
  background-color: var(--md-sys-color-outline-variant);
  z-index: 1;
  transform: translateY(-50%);
}

.timeline-progress-bar {
  position: absolute;
  top: 50%;
  left: 30px;
  height: 4px;
  background-color: var(--md-sys-color-primary);
  z-index: 2;
  transform: translateY(-50%);
  transition: width var(--md-sys-motion-duration-medium2) var(--md-sys-motion-easing-emphasized);
}

.timeline-step {
  position: relative;
  z-index: 3;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--md-sys-color-surface);
  border: 3px solid var(--md-sys-color-outline-variant);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 13px;
  color: var(--md-sys-color-on-surface-variant);
  cursor: pointer;
  transition: all var(--md-sys-motion-duration-short3) var(--md-sys-motion-easing-standard);
}

.timeline-step.completed {
  border-color: var(--md-sys-color-primary);
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
}

.timeline-step.current {
  border-color: var(--md-sys-color-primary);
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  transform: scale(1.2);
  box-shadow: 0 0 0 6px rgba(103, 80, 164, 0.2);
}

.stepper-display-card {
  background-color: var(--md-sys-color-surface);
  border-radius: var(--md-sys-shape-corner-large);
  padding: 24px;
  border: 1px solid var(--md-sys-color-outline-variant);
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.stepper-state-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.state-pane {
  background-color: var(--md-sys-color-surface-container-low);
  border-radius: var(--md-sys-shape-corner-medium);
  padding: 16px;
  border: 1px solid var(--md-sys-color-outline-variant);
}

.state-pane-title {
  font: var(--md-sys-typescale-title-small);
  color: var(--md-sys-color-primary);
  font-weight: 700;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ==========================================================================
   Visualizer 3: Duck Typing / CallSite Mutation Simulator
   ========================================================================== */
.duck-simulator {
  display: flex;
  flex-direction: column;
  gap: 20px;
  background-color: var(--md-sys-color-surface-container-low);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-large);
  padding: 24px;
}

.receiver-selection-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.receiver-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--md-sys-shape-corner-full);
  border: 1px solid var(--md-sys-color-outline);
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  font: var(--md-sys-typescale-label-large);
  cursor: pointer;
  transition: all var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
}
.receiver-btn:hover {
  background-color: var(--md-sys-color-surface-container-high);
}
.receiver-btn.active {
  background-color: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  border-color: var(--md-sys-color-primary);
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.callsite-flowchart {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 20px;
  background-color: var(--md-sys-color-surface);
  border-radius: var(--md-sys-shape-corner-medium);
  border: 1px solid var(--md-sys-color-outline-variant);
}

.flow-node {
  padding: 16px;
  border-radius: var(--md-sys-shape-corner-medium);
  background-color: var(--md-sys-color-surface-container);
  border: 1px solid var(--md-sys-color-outline-variant);
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.flow-node.highlight {
  border-color: var(--md-sys-color-primary);
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  box-shadow: 0 0 0 3px rgba(103, 80, 164, 0.25);
}

.flow-arrow {
  color: var(--md-sys-color-outline);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ==========================================================================
   Visualizer 4: Quiz Challenge
   ========================================================================== */
.quiz-card {
  background-color: var(--md-sys-color-surface-container-low);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-large);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  border-radius: var(--md-sys-shape-corner-medium);
  border: 1px solid var(--md-sys-color-outline-variant);
  background-color: var(--md-sys-color-surface);
  color: var(--md-sys-color-on-surface);
  cursor: pointer;
  font: var(--md-sys-typescale-body-large);
  transition: all var(--md-sys-motion-duration-short2) var(--md-sys-motion-easing-standard);
}
.quiz-option:hover {
  background-color: var(--md-sys-color-surface-container-high);
}
.quiz-option.correct {
  background-color: #E8F5E9;
  border-color: #2E7D32;
  color: #1B5E20;
}
[data-theme="dark"] .quiz-option.correct {
  background-color: #1B3820;
  border-color: #81C784;
  color: #C8E6C9;
}
.quiz-option.wrong {
  background-color: #FFEBEE;
  border-color: #C62828;
  color: #B71C1C;
}
[data-theme="dark"] .quiz-option.wrong {
  background-color: #3C1C1C;
  border-color: #E57373;
  color: #FFCDD2;
}

/* ==========================================================================
   Responsive Adaptations
   ========================================================================== */
@media (max-width: 840px) {
  .nav-rail {
    display: none;
  }

  .bottom-nav {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 64px;
    padding: 0;
    background-color: var(--md-sys-color-surface-container);
    border-top: 1px solid var(--md-sys-color-outline-variant);
    z-index: 100;
    justify-content: space-around;
    align-items: stretch;
    overflow: hidden;
  }

  .bottom-nav .nav-item {
    min-width: 0;
    width: 20%;
    flex: 1 1 20%;
    height: 100%;
    padding: 4px 0 2px;
    gap: 2px;
    justify-content: center;
    overflow: hidden;
  }

  .bottom-nav .nav-indicator {
    flex: 0 0 32px;
    width: 56px;
    max-width: calc(100% - 8px);
  }

  .bottom-nav .nav-label {
    display: block;
    width: 100%;
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    line-height: 16px;
  }

  .bottom-nav .material-symbols-outlined {
    flex: 0 0 22px;
    width: 22px;
    height: 22px;
    font-size: 22px;
  }

  .content-wrapper {
    width: 100%;
    max-width: 100%;
    min-width: 0;
    padding: 20px 16px 90px;
    gap: 36px;
    overflow: hidden;
  }

  .top-app-bar {
    width: 100%;
    min-width: 0;
    height: auto;
    min-height: 68px;
    padding: 10px 16px;
    gap: 8px;
    align-items: center;
  }

  .top-app-bar__headline {
    min-width: 0;
    flex: 1 1 auto;
    overflow: hidden;
  }

  .top-app-bar__title {
    min-width: 0;
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 16px;
    line-height: 24px;
  }

  .top-app-bar__actions {
    flex: 0 0 auto;
    gap: 6px;
    margin-left: auto;
  }

  #paletteSelector {
    gap: 5px !important;
    margin-right: 0 !important;
  }

  #paletteSelector .palette-dot {
    width: 18px !important;
    height: 18px !important;
    flex: 0 0 18px;
  }

  .top-app-bar__actions > .md3-icon-btn {
    flex: 0 0 40px;
  }

  .doc-section {
    min-width: 0;
    width: 100%;
  }

  .section-header,
  .section-tag,
  .section-title,
  .section-desc {
    min-width: 0;
    max-width: 100%;
  }

  .section-tag {
    flex-wrap: wrap;
  }

  .section-title {
    font-size: 1.75rem;
    line-height: 1.3;
  }

  .section-desc {
    font-size: 1rem;
    line-height: 1.65;
  }

  .table-container {
    width: 100%;
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .md3-table {
    min-width: 760px;
  }

  .opcode-visualizer,
  .md3-card,
  .code-surface {
    max-width: 100%;
    min-width: 0;
  }

  .stepper-state-grid,
  .callsite-flowchart,
  .opcode-bytes-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 420px) {
  .top-app-bar__title {
    font-size: 14px;
  }

  #paletteSelector .palette-dot {
    width: 16px !important;
    height: 16px !important;
    flex-basis: 16px;
  }

  #paletteSelector {
    gap: 3px !important;
  }

  .content-wrapper {
    padding-left: 12px;
    padding-right: 12px;
  }

  .section-title {
    font-size: 1.5rem;
  }
}