/* ===== 全局样式 - 考研408计算机网络可视化 ===== */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700;900&display=swap');

:root {
  /* 主色调 */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e3a5f;
  --bg-card-hover: #264a73;
  --bg-surface: #0f172aee;

  /* 文字色 */
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* 强调色 */
  --accent-green: #10b981;
  --accent-green-dim: #10b98133;
  --accent-amber: #f59e0b;
  --accent-amber-dim: #f59e0b33;
  --accent-red: #ef4444;
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-cyan: #06b6d4;

  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
  --shadow-glow-green: 0 0 20px rgba(16,185,129,0.3);
  --shadow-glow-amber: 0 0 20px rgba(245,158,11,0.3);

  /* 导航栏 */
  --nav-width: 260px;

  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: 
    radial-gradient(ellipse at 20% 20%, rgba(16,185,129,0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(6,182,212,0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(59,130,246,0.05) 0%, transparent 70%),
    linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(16,185,129,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16,185,129,0.03) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: conic-gradient(
    from 0deg,
    transparent 0deg 340deg,
    rgba(16,185,129,0.02) 340deg 360deg
  );
  animation: rotate-conic 60s linear infinite;
  pointer-events: none;
  z-index: 0;
}

@keyframes rotate-conic {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

#particle-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

#particle-bg canvas {
  display: block;
}

.main-content, .sidebar, .menu-toggle {
  position: relative;
  z-index: 10;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--accent-green);
}

/* ===== 侧边导航 ===== */
.sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: var(--nav-width);
  height: 100vh;
  background: var(--bg-secondary);
  border-right: 1px solid rgba(255,255,255,0.06);
  padding: var(--spacing-lg);
  overflow-y: auto;
  z-index: 100;
  transition: transform var(--transition-normal);
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.sidebar-logo h2 {
  font-size: 1.1rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sidebar-logo .logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 900;
  color: var(--bg-primary);
  flex-shrink: 0;
}

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

.sidebar-nav li {
  margin-bottom: var(--spacing-xs);
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.sidebar-nav a:hover {
  background: rgba(255,255,255,0.05);
  color: var(--text-primary);
}

.sidebar-nav a.active {
  background: var(--accent-green-dim);
  color: var(--accent-green);
}

.sidebar-nav a .nav-num {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.sidebar-nav a.active .nav-num {
  background: var(--accent-green);
  color: var(--bg-primary);
}

/* 侧边栏章节内目录 */
.sidebar-toc {
  margin-top: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255,255,255,0.08);
}

.sidebar-toc h4 {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 1px;
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-md);
}

.sidebar-toc a {
  display: block;
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: 0.8rem;
  color: var(--text-muted);
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.sidebar-toc a:hover,
.sidebar-toc a.active {
  color: var(--accent-green);
  border-left-color: var(--accent-green);
  background: rgba(16,185,129,0.05);
}

/* ===== 主内容区 ===== */
.main-content {
  margin-left: var(--nav-width);
  min-height: 100vh;
  padding: var(--spacing-xl) var(--spacing-2xl);
}

/* ===== Hero区域 ===== */
.hero {
  text-align: center;
  padding: var(--spacing-2xl) 0;
  margin-bottom: var(--spacing-2xl);
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 900;
  margin-bottom: var(--spacing-md);
  background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== 章节卡片网格 ===== */
.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.chapter-card {
  background: linear-gradient(135deg, rgba(30,58,95,0.6), rgba(30,41,59,0.8));
  backdrop-filter: blur(20px);
  border: 1px solid rgba(16,185,129,0.15);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.chapter-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-cyan));
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.chapter-card::after {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(16,185,129,0.08) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.chapter-card:hover {
  transform: translateY(-4px);
  border-color: rgba(16,185,129,0.4);
  box-shadow: 0 8px 32px rgba(16,185,129,0.15), 0 0 0 1px rgba(16,185,129,0.2);
}

.chapter-card:hover::before {
  opacity: 1;
}

.chapter-card:hover::after {
  opacity: 1;
}

.chapter-card .card-num {
  font-size: 3rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.3;
  line-height: 1;
}

.chapter-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: var(--spacing-sm) 0;
}

.chapter-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.chapter-card .card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
}

.card-tag {
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: 600;
}

.card-tag.hot {
  background: var(--accent-amber-dim);
  color: var(--accent-amber);
}

.card-tag.anim {
  background: var(--accent-green-dim);
  color: var(--accent-green);
}

/* ===== 章节页标题 ===== */
.chapter-header {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.chapter-header .chapter-num {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-green);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-xs);
}

.chapter-header h1 {
  font-size: 2rem;
  font-weight: 900;
  margin-bottom: var(--spacing-sm);
}

.chapter-header p {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ===== 知识点卡片 ===== */
.section-block {
  margin-bottom: var(--spacing-2xl);
  scroll-margin-top: var(--spacing-xl);
}

.section-block h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.section-block h2 .sec-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--accent-green-dim);
  color: var(--accent-green);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.kp-card {
  background: linear-gradient(135deg, rgba(30,41,59,0.8), rgba(15,23,42,0.9));
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-fast);
}

.kp-card:hover {
  border-color: rgba(16,185,129,0.2);
  box-shadow: 0 4px 20px rgba(16,185,129,0.08);
}

.kp-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--accent-green), transparent);
}

.kp-card.important::before {
  background: linear-gradient(180deg, var(--accent-amber), transparent);
}

.kp-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.kp-card h3 .badge {
  padding: 1px 8px;
  border-radius: 4px;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
}

.kp-card h3 .badge.hot {
  background: var(--accent-amber-dim);
  color: var(--accent-amber);
}

.kp-card h3 .badge.key {
  background: var(--accent-green-dim);
  color: var(--accent-green);
}

.kp-card p, .kp-card li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.kp-card ul, .kp-card ol {
  padding-left: var(--spacing-lg);
  margin-top: var(--spacing-sm);
}

.kp-card li {
  margin-bottom: var(--spacing-xs);
}

.kp-card strong {
  color: var(--text-primary);
}

.kp-card code {
  background: rgba(255,255,255,0.08);
  padding: 1px 6px;
  border-radius: 3px;
  font-size: 0.85em;
  color: var(--accent-cyan);
}

.kp-card .formula {
  background: rgba(16,185,129,0.05);
  border: 1px solid rgba(16,185,129,0.15);
  border-radius: var(--radius-sm);
  padding: var(--spacing-md);
  margin: var(--spacing-md) 0;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  color: var(--accent-green);
  text-align: center;
}

/* ===== 对比表格 ===== */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--spacing-md) 0;
  font-size: 0.85rem;
}

.compare-table th {
  background: rgba(16,185,129,0.1);
  color: var(--accent-green);
  padding: var(--spacing-sm) var(--spacing-md);
  text-align: left;
  font-weight: 700;
  border-bottom: 2px solid var(--accent-green);
}

.compare-table td {
  padding: var(--spacing-sm) var(--spacing-md);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  color: var(--text-secondary);
}

.compare-table tr:hover td {
  background: rgba(255,255,255,0.02);
}

/* ===== 动画演示区 ===== */
.anim-section {
  background: var(--bg-secondary);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg);
  margin: var(--spacing-lg) 0;
  overflow: hidden;
}

.anim-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-lg);
  background: rgba(16,185,129,0.05);
  border-bottom: 1px solid rgba(16,185,129,0.1);
}

.anim-header h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-green);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.anim-canvas-wrapper {
  position: relative;
  width: 100%;
  min-height: 400px;
  background: #0a0f1e;
  display: flex;
  align-items: center;
  justify-content: center;
}

.anim-canvas-wrapper canvas {
  display: block;
}

.anim-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: rgba(0,0,0,0.2);
  border-top: 1px solid rgba(255,255,255,0.06);
}

.anim-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.05);
  color: var(--text-primary);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
}

.anim-btn:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--accent-green);
}

.anim-btn.primary {
  background: var(--accent-green);
  color: var(--bg-primary);
  border-color: var(--accent-green);
}

.anim-btn.primary:hover {
  background: #0ea372;
}

.anim-step-info {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.anim-step-info span {
  color: var(--accent-green);
  font-weight: 700;
}

.anim-desc {
  padding: var(--spacing-md) var(--spacing-lg);
  border-top: 1px solid rgba(255,255,255,0.06);
  font-size: 0.85rem;
  color: var(--text-secondary);
  min-height: 40px;
}

.anim-desc .step-desc {
  color: var(--accent-cyan);
  font-weight: 500;
}

/* ===== 交互式组件 ===== */
.interactive-panel {
  background: var(--bg-secondary);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin: var(--spacing-md) 0;
}

.interactive-panel label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
}

.interactive-panel input,
.interactive-panel select {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--bg-primary);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.9rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition-fast);
}

.interactive-panel input:focus,
.interactive-panel select:focus {
  border-color: var(--accent-green);
}

.interactive-panel .result-box {
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  background: rgba(16,185,129,0.05);
  border: 1px solid rgba(16,185,129,0.15);
  border-radius: var(--radius-sm);
  font-family: 'Courier New', monospace;
  font-size: 0.85rem;
  color: var(--accent-green);
  white-space: pre-wrap;
}

/* ===== 分层模型图 ===== */
.layer-model {
  display: flex;
  gap: var(--spacing-2xl);
  justify-content: center;
  align-items: stretch;
  margin: var(--spacing-xl) 0;
  flex-wrap: wrap;
}

.layer-stack {
  min-width: 280px;
  flex: 1;
  max-width: 360px;
}

.layer-stack h3 {
  text-align: center;
  margin-bottom: var(--spacing-md);
  font-size: 1rem;
  font-weight: 700;
}

.layer-item {
  padding: var(--spacing-md) var(--spacing-lg);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-sm);
  margin-bottom: var(--spacing-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
}

.layer-item:hover {
  background: rgba(255,255,255,0.05);
  border-color: var(--accent-green);
}

.layer-item.active {
  background: var(--accent-green-dim);
  border-color: var(--accent-green);
}

.layer-item .layer-num {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 600;
}

.layer-item .layer-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

.layer-item .layer-desc {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* ===== 移动端菜单按钮 ===== */
.menu-toggle {
  display: none;
  position: fixed;
  top: var(--spacing-md);
  left: var(--spacing-md);
  z-index: 200;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  border: 1px solid rgba(255,255,255,0.12);
  color: var(--text-primary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

/* ===== 响应式 ===== */
@media (max-width: 1200px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .main-content {
    margin-left: 0;
    padding: var(--spacing-xl) var(--spacing-lg);
  }
  .menu-toggle {
    display: flex;
  }
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 1.8rem;
  }
  .chapter-grid {
    grid-template-columns: 1fr;
  }
  .layer-model {
    flex-direction: column;
    align-items: center;
  }
  .anim-canvas-wrapper {
    min-height: 300px;
  }
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.12);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255,255,255,0.2);
}

/* ===== 页面过渡 ===== */
.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== 脉冲动画 ===== */
@keyframes pulse-green {
  0%, 100% { box-shadow: 0 0 0 0 rgba(16,185,129,0.4); }
  50% { box-shadow: 0 0 0 8px rgba(16,185,129,0); }
}

.pulse {
  animation: pulse-green 2s infinite;
}

/* ===== CRC计算器样式 ===== */
.crc-calculator {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--spacing-lg);
}

.crc-input-section {
  background: rgba(0,0,0,0.2);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
}

.crc-input-section .input-group {
  margin-bottom: var(--spacing-md);
}

.crc-input-section label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.crc-input-section input,
.crc-input-section select {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background: rgba(0,0,0,0.3);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: 'Monaco', 'Menlo', monospace;
  font-size: 0.95rem;
  margin-bottom: var(--spacing-xs);
}

.crc-input-section input:focus,
.crc-input-section select:focus {
  outline: none;
  border-color: var(--accent-green);
  box-shadow: 0 0 0 3px rgba(16,185,129,0.1);
}

.crc-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}

.crc-btn:hover {
  background: rgba(255,255,255,0.12);
}

.crc-btn.primary {
  background: var(--accent-green);
  border-color: var(--accent-green);
  color: #000;
  font-weight: 600;
}

.crc-btn.primary:hover {
  background: var(--accent-green-light);
}

.crc-btn.secondary {
  background: rgba(59,130,246,0.2);
  border-color: rgba(59,130,246,0.4);
  color: var(--accent-blue);
}

.crc-btn.active {
  background: var(--accent-green);
  color: #000;
}

.crc-action-btns {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.crc-action-btns .crc-btn {
  flex: 1;
  padding: var(--spacing-sm) var(--spacing-md);
}

.crc-result-section {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.crc-step {
  background: rgba(0,0,0,0.15);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  border-left: 3px solid var(--accent-blue);
}

.crc-step h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.crc-step-content {
  font-size: 0.85rem;
  line-height: 1.8;
}

.crc-param {
  margin-bottom: var(--spacing-xs);
}

.crc-param .label {
  color: var(--text-secondary);
  display: inline-block;
  width: 180px;
}

.crc-param .value {
  font-family: 'Monaco', 'Menlo', monospace;
  font-weight: 600;
}

.crc-param .value.bin {
  color: var(--accent-green);
}

.crc-param .value.hex {
  color: var(--accent-cyan);
}

.crc-param .desc {
  color: var(--text-muted);
  font-size: 0.75rem;
}

.crc-calc-line {
  margin-bottom: var(--spacing-xs);
}

.crc-calc-line .data {
  color: var(--accent-green);
  font-family: monospace;
  font-weight: 600;
}

.crc-calc-line .zeros {
  color: var(--text-muted);
  font-family: monospace;
}

.crc-calc-line .equals {
  color: var(--text-secondary);
}

.crc-calc-line .result {
  color: var(--accent-amber);
  font-family: monospace;
  font-weight: 700;
}

.crc-div-table {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.crc-div-row {
  background: rgba(0,0,0,0.2);
  border-radius: var(--radius-sm);
  padding: var(--spacing-sm);
}

.crc-div-step {
  font-size: 0.75rem;
  color: var(--accent-amber);
  font-weight: 600;
  margin-bottom: 4px;
}

.crc-div-content code {
  font-family: 'Monaco', 'Menlo', monospace;
  font-size: 0.8rem;
  color: var(--accent-cyan);
  background: rgba(255,255,255,0.05);
  padding: 1px 4px;
  border-radius: 2px;
}

.crc-div-content .operation {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.crc-div-content .remainder {
  font-size: 0.8rem;
  color: var(--accent-green);
  margin-top: 4px;
}

.crc-result-box {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.crc-result-item {
  font-size: 0.85rem;
}

.crc-result-item .label {
  color: var(--text-secondary);
  display: inline-block;
  width: 180px;
}

.crc-result-item .value {
  font-family: monospace;
  font-weight: 600;
  color: var(--text-primary);
}

.crc-result-item .value.fcs {
  color: var(--accent-amber);
}

.crc-result-item .value.data {
  color: var(--accent-green);
}

.crc-result-item .hex-value {
  color: var(--text-muted);
  font-size: 0.75rem;
}

.crc-result-item .plus {
  color: var(--text-secondary);
  margin: 0 4px;
}

.crc-result-item .equals {
  color: var(--accent-cyan);
  margin-left: 8px;
  font-family: monospace;
}

.crc-result-item.highlight {
  background: rgba(16,185,129,0.08);
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent-green);
}

.crc-verification {
  background: rgba(0,0,0,0.15);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  border-left: 3px solid var(--accent-purple);
}

.crc-verification h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.crc-verify-box {
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

.crc-verify-box.success {
  background: rgba(16,185,129,0.1);
  border: 1px solid rgba(16,185,129,0.2);
}

.crc-verify-box.error {
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.2);
}

.crc-verify-box div {
  margin-bottom: 4px;
}

.crc-verify-box code {
  font-family: monospace;
}

.verify-status {
  font-weight: 600;
  margin-top: var(--spacing-sm);
}

.verify-status .success-icon {
  color: var(--accent-green);
}

.verify-status .error-icon {
  color: var(--accent-red);
}

.error {
  color: var(--accent-red);
}

@media (max-width: 900px) {
  .crc-calculator {
    grid-template-columns: 1fr;
  }
}