/* === 导航栏优化 === */
.navbar {
  background-color: rgba(255, 255, 255, 0.95) !important;
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  padding: 1rem 0;
  transition: all 0.3s ease;
}

.navbar.scrolled {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.navbar-brand {
  display: flex;
  align-items: center;
  font-size: 1.5rem !important;
  font-weight: 700 !important;
  letter-spacing: 0.15em;
  color: #007bff !important;
  transition: all 0.3s ease;
}

.navbar-brand:hover {
  color: #0056b3 !important;
}

.navbar-brand i {
  margin-right: 0.5rem;
  font-size: 1.8rem;
}

.navbar-brand .brand-icon {
  margin-left: 0.5rem;
  margin-right: 0.55rem;
  width: 1.95rem;
  height: 1.95rem;
  display: inline-block;
  object-fit: contain;
  opacity: 0.95;
}

.navbar-nav {
  gap: 0.1rem;
}

.navbar-nav .nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #333 !important;
  padding: 0.5rem 1rem !important;
  position: relative;
  transition: all 0.3s ease;
}

.navbar-nav .nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background-color: #007bff;
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.navbar-nav .nav-link:hover {
  color: #007bff !important;
}

.navbar-nav .nav-link:hover::after,
.navbar-nav .nav-link.active::after {
  width: 80%;
}

.navbar-nav .nav-link.active {
  color: #007bff !important;
  font-weight: 700;
}

/* === 语言选择器优化 === */
.language-selector-wrapper {
  display: flex;
  align-items: center;
  margin-left: 1rem;
  padding: 0 0.5rem;
}

.language-selector-wrapper .language-icon {
  margin-left: -0.2rem;
  margin-right: 0.7rem;
  color: #6b7280;
  font-size: 0.95rem;
  transition: color 0.3s ease;
}

.language-selector-wrapper:hover .language-icon,
.language-selector-wrapper:focus-within .language-icon {
  color: #007bff;
}

.language-selector-custom {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-color: transparent;
  color: #333;
  border: none;
  border-bottom: 2px solid #e0e0e0;
  padding: 0.5rem 1.5rem 0.5rem 0;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: all 0.3s ease;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23007bff' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right center;
  background-size: 12px;
  text-transform: uppercase;
}

.language-selector-custom:hover {
  border-bottom-color: #007bff;
  color: #007bff;
}

.language-selector-custom:focus {
  outline: none;
  border-bottom-color: #007bff;
  color: #007bff;
  box-shadow: none;
}

.language-selector-custom option {
  color: #333;
  background-color: #fff;
  padding: 0.8rem;
  border: none;
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
}

.language-selector-custom option:hover {
  background: #f0f7ff;
  color: #007bff;
}

.language-selector-custom option:checked {
  background: linear-gradient(#e0f2ff, #e0f2ff);
  background-color: #e0f2ff;
  color: #007bff;
  font-weight: 700;
}

/* === 全局排版优化 === */
:root {
  --base-font-size: 16px;
  --line-height: 1.8;
  --letter-spacing: 0.3px;
}

body {
  font-size: var(--base-font-size);
  line-height: var(--line-height);
  letter-spacing: var(--letter-spacing);
  color: #333;
}

/* === Hero Section 优化 === */
.hero {
  padding: 80px 0 !important;
  height: 800px;
  min-height: 800%;
  max-height: 800px;
  display: flex;
  align-items: center;
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: scroll;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.3);
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero h2.h4 {
  font-size: 1.8rem;
  letter-spacing: 0.15em;
  margin-bottom: 0.5rem !important;
  font-weight: 400;
}

.hero h1.text-xl {
  font-size: 4rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  margin-bottom: 1.5rem !important;
  line-height: 1.2;
}

.hero h1.text-xl span {
  font-size: 1em;
}

.hero .h4.fw-normal {
  font-size: 2rem;
  margin-bottom: 2rem !important;
  letter-spacing: 0.08em;
  font-weight: 300;
}

.hero p.text-shadow {
  font-size: 1.1rem;
  line-height: 1.85;
  max-width: 800px;
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
  margin-top: 2rem;
  margin-bottom: 2rem;
  letter-spacing: 0.5px;
}

/* === 章节标题优化 === */
section header h2 {
  font-size: 2.5rem !important;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 2rem !important;
  line-height: 1.3;
  color: #333;
}

section header p {
  font-size: 0.95rem;
  letter-spacing: 0.15em;
  margin-bottom: 1.5rem !important;
  font-weight: 600;
}

.lined::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: #007bff;
  margin-top: 0.5rem;
}

/* === About Section 优化 === */
#about {
  padding: 80px 0 !important;
}

#about .lead {
  font-size: 1.25rem;
  line-height: 1.85;
  margin-bottom: 2rem;
  font-weight: 500;
}

#about p.text-muted {
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

#about p.text-muted a {
  color: #007bff;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}

#about p.text-muted a:hover {
  text-decoration: underline;
  color: #0056b3;
}

#about h4.h5 {
  color: #333 !important;
  font-weight: 700 !important;
  font-size: 1.15rem !important;
}

/* === Expertise Section 优化 === */
#expertise {
  padding: 80px 0 !important;
}

#expertise h3.h4 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 1.2rem;
  letter-spacing: 0.02em;
}

#expertise .h4 span {
  font-size: 1.8rem;
  font-weight: 800;
}

#expertise p.text-sm {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #666;
  margin: 0 !important;
}

#expertise .row > div {
  transition: all 0.3s ease;
}

#expertise .row > div:hover {
  transform: translateY(-8px);
}

/* === Education/Experience Section 优化 === */
#education,
#experience {
  padding: 80px 0 !important;
}

.timeline-item {
  margin-bottom: 3rem;
}

.timeline-item .col-lg-5 p {
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.timeline-item .col-lg-5 h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.5rem !important;
}

.timeline-item .col-lg-7 p {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #666;
  margin-top: 1.8rem;
}

/* === Contact Section 优化 === */
#contact {
  padding: 80px 0 !important;
}

.contact-item {
  transition: all 0.3s ease;
  border-radius: 8px;
  background: white;
  display: block;
  text-decoration: none;
  padding: 2rem 1.5rem !important;
}

.contact-item:hover {
  transform: translateY(-8px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15) !important;
}

.contact-item:hover i {
  transform: scale(1.1);
}

.contact-item i {
  transition: all 0.3s ease;
}

.contact-item h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem !important;
  color: #333;
}

.contact-item p {
  font-size: 1rem;
  line-height: 1.7;
  color: #666;
  word-break: break-word;
}

/* === Footer 优化 === */
footer {
  padding-top: 4rem !important;
}

footer h2 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  margin-bottom: 1rem !important;
}

footer h6 {
  font-size: 1rem;
  letter-spacing: 0.15em;
  margin-bottom: 1.5rem !important;
}

footer p {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #666;
}

.social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: #f0f0f0;
  color: #333;
  transition: all 0.3s ease;
  text-decoration: none;
  font-size: 1.2rem;
}

.social-link:hover {
  background: #007bff;
  color: white;
  transform: translateY(-3px);
}

/* === 语言选择器优化 === */
#language-selector {
  text-align: center;
  text-align-last: center;
  width: 170px;
  overflow: hidden;
  font-size: 15px;
  border: 1px solid #ccc;
  border-radius: 4px;
  background-color: #fff;
  color: #333;
  padding: 8px 10px;
  padding-left: 0px;
  transition: all 0.3s ease;
  cursor: pointer;
}

#language-selector:hover {
  border-color: #007bff;
  background-color: #f8f9fa;
}

#language-selector:focus {
  border-color: #007bff;
  outline: none;
  box-shadow: 0 0 5px rgba(0, 123, 255, 0.5);
}

#language-selector option {
  text-align: center;
  font-size: 15px;
  padding: 8px;
}

/* === 滚动优化 === */
html {
  scroll-behavior: smooth;
}

/* === 响应式设计优化 === */
@media (max-width: 768px) {
  .hero {
    min-height: 500px;
    padding: 60px 0 !important;
  }

  .hero h1.text-xl {
    font-size: 2.5rem;
  }

  .hero h2.h4 {
    font-size: 1.4rem;
  }

  .hero .h4.fw-normal {
    font-size: 1.4rem;
  }

  .hero p.text-shadow {
    font-size: 1rem;
  }

  section header h2 {
    font-size: 2rem !important;
  }

  #about .lead {
    font-size: 1.1rem;
  }

  #expertise h3.h4 {
    font-size: 1.2rem;
  }

  .contact-item {
    padding: 1.5rem 1rem !important;
  }

  .contact-item h4 {
    font-size: 1rem;
  }

  .contact-item p {
    font-size: 0.95rem;
  }

  footer h2 {
    font-size: 1.8rem;
  }
}