* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --menu-default-bgc: #f9f9f9;
  --item-active-color: #3498db;
  --menu-font-color: #394246;
  --hamburger-icon-item-height: 3px;
}

a,
a:hover,
a:active,
a:visited,
a:link,
a:focus {
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
  outline: none;
  background: none;
  text-decoration: none;
}

nav {
  background: var(--menu-default-bgc);
  /* padding: 1rem; */
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 999;
  padding: 10px;
}

.logo-icon {
  max-width: 120px;
  font-size: 0;
}

.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.nav-container {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* 汉堡菜单样式 */
.hamburger {
  display: none;
  cursor: pointer;
  padding: 10px;
  background: none;
  border: none;
  position: relative;
  z-index: 100;
}

.hamburger__box {
  width: 2rem;
  height: 24px;
  display: inline-block;
  position: relative;
}

.hamburger__inner {
  width: 100%;
  height: var(--hamburger-icon-item-height);
  background: var(--menu-font-color);
  position: absolute;
  left: 0;
  top: 10px;
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger__inner::before,
.hamburger__inner::after {
  content: '';
  width: 100%;
  height: var(--hamburger-icon-item-height);
  background: var(--menu-font-color);
  position: absolute;
  left: 0;
  transition: transform 0.3s;
}

.hamburger__inner::before {
  top: -10px;
}

.hamburger__inner::after {
  top: 10px;
}

/* 激活状态的汉堡菜单动画 */
.hamburger.active .hamburger__inner {
  transform: rotate(45deg);
}

.hamburger.active .hamburger__inner::before {
  transform: translateY(10px) rotate(-90deg);
  opacity: 0;
}

.hamburger.active .hamburger__inner::after {
  transform: translateY(-10px) rotate(90deg);
}

/* 菜单项样式 */
.menu {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin-left: auto;
  margin-right: 1em;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.menu>li.active {
  font-weight: bold;
}

/* .menu>li.active a:after {
  height: 3px;
} */

.menu a {
  /* font-weight: bold; */
  color: var(--menu-font-color);
  text-decoration: none;
  padding: 1rem 0;
  /* padding: 0.8rem 1.2rem; */
  border-radius: 4px;
  transition:
    background 0.3s,
    transform 0.2s;
  display: block;
  position: relative;
}

/* .menu a:after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 16px;
  width: 100%;
  height: 2px;
  background: #000;
} */

/* 响应式设计 */
@media (max-width: 1024px) {
  /* nav {
    padding: 0.8rem;
  } */

  /* .logo-icon {
    padding: 0 1.2rem;
  } */

  .hamburger {
    display: block;
    margin-left: auto;
  }

  .menu {
    margin-right: 0;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    gap: 0;
    background: var(--menu-default-bgc);
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    padding: 0 2rem;
    transform: translateY(-10px);
  }

  .menu a {
    padding: 12px 0;
  }
  .menu a:after {
    height: 0;
  }

  .menu>li.active a:after {
    height: 0;
  }

  .menu.active {
    max-height: 500px;
    opacity: 1;
    transform: translateY(0);
    padding: 1rem 1.5rem;
    padding-top: 0.4rem;
    box-shadow: 0 2px 3px rgba(0, 0, 0, 0.1);
  }


  .menu li {
    opacity: 0;
    transform: translateX(-20px);
    transition:
      opacity 0.3s,
      transform 0.3s;
  }

  .menu.active li {
    opacity: 1;
    transform: translateX(0);
    transition-delay: 0.2s;
  }

}

.section-box {
  margin: 2.5rem auto 6rem;
  padding: 2rem;
  max-width: 1200px;
}

@media (max-width: 769px) {
  .section-box {
    padding: .5rem 1.2rem;
  }
}