*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  color: #444;
  background: #fff;
  min-width: 320px;
}

h1,
h2,
h3,
h4,
h5,
h6,
p,
ul,
ol {
  margin: 0;
}

ul,
ol {
  padding: 0;
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
}

.container {
  width: min(1200px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.08);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 100px;
  gap: 24px;
}

.logo {
  font-size: 30px;
  font-weight: 700;
  color: #323250;
  white-space: nowrap;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 44px;
  font-size: 16px;
  font-weight: 600;
  color: #323250;
}

.desktop-nav a,
.mobile-nav a {
  transition: color 0.2s ease;
}

.desktop-nav a:hover,
.mobile-nav a:hover {
  color: #3a9bff;
}

.page-about .nav-about,
.page-contact .nav-contact {
  color: #3a9bff;
}

.desktop-nav .nav-about,
.desktop-nav .nav-contact {
  padding-bottom: 8px;
  border-bottom: 2px solid transparent;
}

.page-about .desktop-nav .nav-about,
.page-contact .desktop-nav .nav-contact {
  border-bottom-color: #3a9bff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin-left: auto;
  background: #323250;
  border-radius: 999px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-toggle.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.mobile-nav {
  display: none;
  padding: 0 20px 16px;
  border-top: 1px solid #efefef;
  background: #fff;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav a {
  display: block;
  padding: 12px 4px;
  font-size: 15px;
  color: #323250;
  border-bottom: 1px solid #f5f5f5;
}

.page-main {
  padding-top: 100px;
}

.hero {
  position: relative;
  height: 1200px;
  overflow: hidden;
  background:
    linear-gradient(rgba(18, 34, 68, 0.28), rgba(18, 34, 68, 0.28)),
    url("./img/banner.jpg") top center / cover no-repeat;
}

.hero-content {
  position: absolute;
  left: 50%;
  top: 37%;
  width: 722px;
  margin-left: -361px;
  text-align: center;
  color: #fff;
}

.hero-title {
  font-size: 60px;
  font-weight: 700;
  letter-spacing: 0.2em;
}

.hero-text {
  margin-top: 18px;
  font-size: 30px;
  letter-spacing: 0.18em;
}

.section {
  padding: 80px 0;
}

.section-muted {
  background: #f3f3f3;
}

.section-title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 56px;
  font-size: 28px;
  color: #333;
}

.section-title::before,
.section-title::after {
  content: "";
  width: 20px;
  height: 2px;
  background: #3a9bff;
}

.intro-text {
  font-size: 16px;
  line-height: 1.9;
  color: #737373;
  text-indent: 2em;
}

.intro-group {
  display: grid;
  gap: 16px;
}

.qualification-wrap {
  display: flex;
  justify-content: center;
}

.certificate-card {
  width: min(700px, 100%);
  min-height: 420px;
  padding: 40px 32px;
  border-radius: 16px;
  border: 1px solid #d8e8ff;
  background:
    linear-gradient(180deg, rgba(58, 155, 255, 0.08), rgba(255, 255, 255, 0.96)),
    #fff;
  box-shadow: 0 12px 36px rgba(58, 155, 255, 0.08);
  text-align: center;
}

.certificate-card--image {
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
}

.certificate-image {
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.12);
}

.certificate-badge {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 999px;
  background: #eaf4ff;
  color: #2878cf;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.certificate-title {
  margin-top: 28px;
  font-size: 28px;
  line-height: 1.5;
  color: #22304f;
}

.certificate-body {
  margin-top: 28px;
  font-size: 16px;
  line-height: 1.9;
  color: #5f6d85;
}

.certificate-note {
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px dashed #bfd6f8;
  font-size: 14px;
  color: #7e8ca2;
}

.contact-card {
  text-align: center;
}

.contact-card h2 {
  font-size: 28px;
  color: #333;
}

.contact-list {
  margin-top: 48px;
  display: grid;
  gap: 14px;
  font-size: 16px;
  line-height: 1.8;
  color: #666;
}

.article {
  padding: 82px 0 60px;
}

.article-title {
  font-size: 24px;
  color: #333;
  text-align: center;
  line-height: 1.5;
}

.article-date {
  margin-top: 20px;
  text-align: center;
  font-size: 16px;
  color: #666;
}

.article-body {
  width: min(1200px, calc(100% - 40px));
  margin: 40px auto 0;
  font-size: 15px;
  line-height: 1.9;
  color: #555;
}

.article-body p + p {
  margin-top: 12px;
}

.article-sign {
  margin-top: 24px;
  text-align: right;
}

.footer {
  background: #191919;
  color: #fff;
  padding: 40px 0 20px;
}

.footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
}

.footer-logo {
  font-size: 30px;
  font-weight: 700;
}

.footer-address {
  font-size: 14px;
  line-height: 1.7;
  text-align: right;
}

.footer-record {
  margin-top: 20px;
  text-align: center;
  font-size: 14px;
}

.footer-record a:hover {
  text-decoration: underline;
}

@media (max-width: 768px) {
  .header-inner {
    min-height: 64px;
  }

  .logo {
    font-size: 22px;
  }

  .desktop-nav {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }

  .page-main {
    padding-top: 64px;
  }

  .hero,
  .hero-content {
    min-height: 0;
  }

  .hero {
    height: 500px;
  }

  .hero-content {
    width: 90%;
    left: 5%;
    top: 30%;
    margin-left: 0;
  }

  .hero-title {
    font-size: 32px;
    letter-spacing: 0.1em;
  }

  .hero-text {
    font-size: 18px;
    letter-spacing: 0.08em;
  }

  .section {
    padding: 56px 0;
  }

  .section-title,
  .contact-card h2 {
    font-size: 22px;
  }

  .intro-text,
  .contact-list,
  .certificate-body,
  .article-body {
    font-size: 14px;
  }

  .certificate-card {
    min-height: 0;
    padding: 28px 20px;
  }

  .certificate-card--image {
    padding: 0;
  }

  .certificate-title {
    font-size: 22px;
  }

  .article {
    padding: 48px 0 56px;
  }

  .article-title {
    font-size: 18px;
    padding: 0 20px;
  }

  .footer-inner {
    flex-direction: column;
  }

  .footer-address {
    text-align: left;
  }
}