:root {
  --sidebar-width: 240px;
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --bg: #f8fafc;
  --card-bg: #fff;
  --text: #1e293b;
  --text-light: #64748b;
  --border: #e2e8f0;
  --hot: #2563eb;
  --hot-bg: #dbeafe;
  --radius: 12px;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --gradient: linear-gradient(135deg, #4f46e5 0%, #818cf8 100%);
  --gradient-hover: linear-gradient(135deg, #3730a3 0%, #6366f1 100%);
  --card-shadow: 0 2px 4px rgba(0,0,0,0.05);
  --card-shadow-hover: 0 12px 24px -8px rgba(79,70,229,0.2);
}

body {
  margin: 0;
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  line-height: 1.5;
}

.sidebar {
  width: var(--sidebar-width);
  background: var(--card-bg);
  border-right: 1px solid var(--border);
  padding: 32px 0 0 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  box-shadow: var(--shadow);
  position: relative;
  z-index: 10;
  transition: all 0.3s ease;
}

.sidebar::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100%;
  background: var(--gradient);
  opacity: 0.03;
  z-index: -1;
  transition: opacity 0.3s ease;
}

.sidebar:hover::before {
  opacity: 0.05;
}

.sidebar .logo {
  font-size: 1.8rem;
  font-weight: bold;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 40px;
  letter-spacing: 2px;
  padding: 0 20px;
  position: relative;
}

.sidebar .logo::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 3px;
  background: var(--gradient);
  border-radius: 3px;
  opacity: 0.5;
}

.menu {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 0 12px;
}

.menu-item {
  display: flex;
  align-items: center;
  padding: 14px 20px;
  color: var(--text);
  font-size: 1.08rem;
  cursor: pointer;
  border-left: 4px solid transparent;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: 12px;
  text-decoration: none;
  position: relative;
  overflow: hidden;
  margin: 0 4px;
}

.menu-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}

.menu-item:hover {
  color: var(--primary);
  transform: translateX(4px);
  background: var(--bg);
}

.menu-item:hover::before {
  opacity: 0.05;
}

.menu-item.active {
  color: white;
  border-left: 4px solid var(--primary-dark);
  background: var(--gradient);
  box-shadow: 0 4px 12px rgba(79,70,229,0.2);
}

.menu-item.active::before {
  opacity: 1;
}

.menu-item i {
  font-size: 1.3rem;
  margin-right: 16px;
  transition: transform 0.3s ease;
  opacity: 0.8;
}

.menu-item:hover i {
  transform: scale(1.1);
  opacity: 1;
}

.menu-item.active i {
  opacity: 1;
}

.menu-item span {
  font-weight: 500;
  transition: all 0.3s ease;
}

.menu-item:hover span {
  transform: translateX(2px);
}

.menu-item.active span {
  font-weight: 600;
}

.main {
  flex: 1;
  padding: 40px 48px 32px 48px;
  min-width: 0;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  position: relative;
  justify-content: flex-start;
  align-items: center;
}

.main::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 300px;
  background: var(--gradient);
  opacity: 0.03;
  z-index: 0;
  transition: opacity 0.3s ease;
}

.main:hover::before {
  opacity: 0.05;
}

.logo-link {
  display: block;
  text-align: center;
  text-decoration: none;
  margin-bottom: 18px;
}

.logo-text {
  font-size: 2.2rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 2px;
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
  transition: all 0.3s ease;
}

.search-bar {
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.search-bar {
  display: flex;
  align-items: center;
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 0 20px;
  height: 48px;
  margin-bottom: 18px;
  border: 1px solid var(--border);
  width: 100%;
  max-width: 700px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.search-bar:focus-within {
  box-shadow: 0 0 0 3px var(--primary-light);
  border-color: var(--primary);
  transform: translateY(-1px);
}

.search-bar input {
  border: none;
  outline: none;
  flex: 1;
  font-size: 1.1rem;
  background: transparent;
  color: var(--text);
  padding: 0 12px;
}

.search-bar input::placeholder {
  color: var(--text-light);
  opacity: 0.7;
}

.search-bar i {
  color: var(--text-light);
  font-size: 1.3rem;
  transition: color 0.3s ease;
}

.search-bar:focus-within i {
  color: var(--primary);
}

.section {
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}

.section-title {
  display: flex;
  align-items: center;
  font-size: 1.18rem;
  font-weight: 600;
  margin-bottom: 18px;
  color: var(--text);
  padding: 8px 0;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--gradient);
  border-radius: 3px;
  opacity: 0.5;
}

.section-title .hot-icon {
  color: var(--hot);
  margin-right: 8px;
  font-size: 1.3rem;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  width: 100%;
  max-width: 1600px;
  margin: 0 auto;
  padding: 0 12px;
}

.tool-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 16px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
  border: 1px solid var(--border);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  text-decoration: none;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
  border-color: var(--primary-light);
}

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

.tool-logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 2px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: all 0.3s ease;
  position: relative;
}

.tool-logo::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient);
  opacity: 0.1;
  z-index: 0;
}

.tool-logo i {
  color: var(--primary);
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  position: relative;
  z-index: 1;
}

.tool-logo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 10px;
  transition: transform 0.3s ease;
  position: relative;
  z-index: 1;
}

.tool-card:hover .tool-logo {
  transform: scale(1.05) rotate(2deg);
  box-shadow: 0 4px 12px rgba(79,70,229,0.15);
}

.tool-card:hover .tool-logo::before {
  opacity: 0.15;
}

.tool-card:hover .tool-logo i {
  transform: scale(1.1);
  color: var(--primary-dark);
}

.tool-card:hover .tool-logo img {
  transform: scale(1.1);
}

.tool-name {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  transition: color 0.3s ease;
  margin-top: 2px;
  line-height: 1.4;
  text-decoration: none;
}

.tool-card:hover .tool-name {
  color: var(--primary);
}

.tool-desc {
  color: var(--text-light);
  font-size: 0.9rem;
  line-height: 1.5;
  min-height: 42px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-decoration: none;
}

.tool-category {
  font-size: 0.8rem;
  color: var(--text-light);
  margin-top: 4px;
  padding: 4px 8px;
  background: var(--bg);
  border-radius: 6px;
  display: inline-block;
  transition: all 0.3s ease;
}

.tool-card:hover .tool-category {
  background: var(--primary-light);
  color: white;
}

@media (max-width: 1400px) {
  .tools-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (max-width: 1200px) {
  .tools-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 900px) {
  .main { padding: 24px 16px; }
  .sidebar {
    width: 60px;
    padding: 20px 0 0 0;
  }
  .sidebar .logo {
    font-size: 1.1rem;
    margin-bottom: 20px;
  }
  .menu-item {
    padding: 12px 0;
    justify-content: center;
    margin: 0 8px;
  }
  .menu-item span {
    display: none;
  }
  .menu-item i {
    margin-right: 0;
    font-size: 1.4rem;
  }
  .menu-item.active {
    border-left: none;
    border-radius: 8px;
  }
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 0 8px;
  }
  .tool-card {
    padding: 14px;
    gap: 10px;
  }
  .tool-logo {
    width: 36px;
    height: 36px;
  }
  .tool-name {
    font-size: 1rem;
  }
  .tool-desc {
    font-size: 0.85rem;
    min-height: 38px;
  }
}

@media (max-width: 480px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }
}