:root {
  --green-deep: #0b3d2e;
  --green-main: #1f7a4d;
  --green-mid: #2f9e62;
  --green-light: #8fd6a7;
  --green-soft: #eaf7ef;
  --green-bg: #f5fbf7;

  --text-dark: #172a22;
  --text-main: #2b4037;
  --text-soft: #64756d;

  --surface: #ffffff;
  --line: rgba(31, 122, 77, 0.12);

  --shadow-sm: 0 10px 24px rgba(12, 72, 46, 0.08);
  --shadow-md: 0 18px 42px rgba(12, 72, 46, 0.12);
  --shadow-lg: 0 24px 70px rgba(7, 55, 37, 0.18);

  --container: min(1200px, calc(100% - 48px));
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", "Microsoft YaHei", sans-serif;
  color: var(--text-dark);
  background:
    radial-gradient(circle at top left, rgba(47, 158, 98, 0.10), transparent 28%),
    radial-gradient(circle at bottom right, rgba(143, 214, 167, 0.14), transparent 24%),
    var(--green-bg);
  line-height: 1.75;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(31, 122, 77, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 122, 77, 0.03) 1px, transparent 1px);
  background-size: 34px 34px;
  opacity: 0.65;
}

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

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

.container {
  width: var(--container);
  margin: 0 auto;
}

/* ==================== 顶部导航 ==================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(11, 61, 46, 0.90);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.10);
  box-shadow: 0 8px 26px rgba(7, 55, 37, 0.15);
}

.navbar-inner {
  width: var(--container);
  margin: 0 auto;
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-width: 0;
}

.logo-img {
  width: 56px;
  height: 56px;
  object-fit: contain;
  padding: 8px;
  border-radius: 17px;
  background: rgba(255, 255, 255, 0.14);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.12),
    0 10px 24px rgba(0, 0, 0, 0.12);
}

.logo-text-wrap {
  min-width: 0;
}

.logo-text {
  color: #ffffff;
  font-family: "Noto Serif SC", serif;
  font-size: 1.32rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
  white-space: nowrap;
}

.logo-subtext {
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.58rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  margin-top: 4px;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.90);
  font-size: 0.96rem;
  font-weight: 700;
  padding: 0.72rem 1rem;
  border-radius: 999px;
  transition: 0.25s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.14);
}

/* ==================== 页头区域 ==================== */
.page-hero {
  position: relative;
  margin-top: 86px;
  padding: 5.8rem 0 4.8rem;
  background:
    linear-gradient(135deg, rgba(11, 61, 46, 0.96), rgba(31, 122, 77, 0.88)),
    url("../Figure/fig2.jpg");
  background-size: cover;
  background-position: center;
  color: #ffffff;
  overflow: hidden;
  border-bottom-left-radius: 34px;
  border-bottom-right-radius: 34px;
  box-shadow: var(--shadow-lg);
}

/* 右上角柔和圆形背景 */
.page-hero::before {
  content: "";
  position: absolute;
  right: -120px;
  top: -130px;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.075);
  pointer-events: none;
  z-index: 0;
}

/* 左下角柔和圆环背景 */
.page-hero::after {
  content: "";
  position: absolute;
  left: -140px;
  bottom: -150px;
  width: 390px;
  height: 390px;
  border-radius: 50%;
  border: 34px solid rgba(255, 255, 255, 0.055);
  pointer-events: none;
  z-index: 0;
}

.page-hero .container {
  position: relative;
  z-index: 2;
}

/* HTML 中写入的页头右侧 Logo */
.page-hero-logo-img {
  position: absolute;
  right: 8%;
  top: 50%;
  width: 260px;
  height: 260px;
  transform: translateY(-50%);
  opacity: 0.08;
  pointer-events: none;
  z-index: 1;
}

.page-hero-logo-img img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: brightness(0) invert(1);
}

/* HTML 中写入的页头中央淡 Logo */
.page-hero-watermark-img {
  position: absolute;
  left: 52%;
  top: 50%;
  width: 360px;
  height: 360px;
  transform: translate(-50%, -50%);
  opacity: 0.04;
  pointer-events: none;
  z-index: 1;
}

.page-hero-watermark-img img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: brightness(0) invert(1);
}

.page-label {
  display: inline-flex;
  align-items: center;
  padding: 0.42rem 0.95rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.16);
  backdrop-filter: blur(10px);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.page-hero h1 {
  font-family: "Noto Serif SC", serif;
  font-size: clamp(2.4rem, 5vw, 4rem);
  line-height: 1.2;
  letter-spacing: 0.04em;
  margin-bottom: 0.9rem;
  text-shadow: 0 12px 30px rgba(0, 0, 0, 0.22);
}

.page-desc {
  max-width: 760px;
  color: rgba(255, 255, 255, 0.84);
  font-size: 1.02rem;
  line-height: 1.9;
}

/* ==================== 主体区域 ==================== */
.research-page {
  position: relative;
  padding: 4.5rem 0 5.5rem;
  overflow: hidden;
}

.research-page::before {
  content: "";
  position: absolute;
  right: -120px;
  top: 120px;
  width: 330px;
  height: 330px;
  border-radius: 50%;
  background: rgba(143, 214, 167, 0.16);
  pointer-events: none;
  z-index: 0;
}

.research-page::after {
  content: "";
  position: absolute;
  left: -120px;
  bottom: 160px;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: rgba(31, 122, 77, 0.06);
  pointer-events: none;
  z-index: 0;
}

/* HTML 中写入的主体背景 Logo */
.research-page-logo-bg {
  position: absolute;
  top: 120px;
  right: 6%;
  width: 280px;
  height: 280px;
  opacity: 0.025;
  pointer-events: none;
  z-index: 0;
}

.research-page-logo-bg img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: grayscale(1);
}

/* 保持原来的纵向文章排版 */
.research-article {
  width: min(960px, calc(100% - 48px));
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

/* ==================== 研究方向段落 ==================== */
.research-section {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.97), rgba(250, 254, 251, 0.95));
  border: 1px solid var(--line);
  border-radius: 28px;
  padding: 2rem 2.2rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: 0.3s ease;
}

/* 右上角柔和绿色光晕 */
.research-section::before {
  content: "";
  position: absolute;
  top: -90px;
  right: -90px;
  width: 190px;
  height: 190px;
  border-radius: 50%;
  background:
    radial-gradient(
      circle,
      rgba(143, 214, 167, 0.26) 0%,
      rgba(31, 122, 77, 0.08) 58%,
      transparent 72%
    );
  pointer-events: none;
  z-index: 0;
}

.research-section:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: rgba(31, 122, 77, 0.22);
}

/* HTML 中写入的研究方向右上角 Logo */
.research-section-logo {
  position: absolute;
  top: 5px;
  right: 5px;
  width: 70px;
  height: 70px;
  padding: 9px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.36);
  border: 1px solid rgba(31, 122, 77, 0.08);
  opacity: 0.22;
  pointer-events: none;
  z-index: 1;
}

.research-section-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.research-section h2 {
  position: relative;
  z-index: 2;
  font-family: "Noto Serif SC", serif;
  color: var(--green-deep);
  font-size: 1.45rem;
  line-height: 1.45;
  margin-bottom: 0.9rem;
  padding-right: 5rem;
}

.research-section h2::after {
  content: "";
  display: block;
  width: 68px;
  height: 3px;
  border-radius: 999px;
  margin-top: 0.75rem;
  background: linear-gradient(90deg, var(--green-main), var(--green-light));
}

.research-section p {
  position: relative;
  z-index: 2;
  color: var(--text-soft);
  font-size: 1rem;
  line-height: 1.95;
  text-align: justify;
}

/* ==================== 页脚 ==================== */
footer {
  background: linear-gradient(180deg, #0b3d2e, #06261c);
  color: #ffffff;
  padding: 3.6rem 0 2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(143, 214, 167, 0.15), transparent 28%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  z-index: 2;
}

/* HTML 中写入的页脚 Logo */
.footer-logo-box {
  width: 150px;
  height: 150px;
  object-fit: contain;
  padding: 10px;
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 22px rgba(143, 214, 167, 0.22);
  margin: 0 auto;
}

.footer-logo-box img {
  width: 100%;
  height: 100%;
  border-radius: 30px;
  object-fit: contain;
}

.footer-inner h3 {
  font-family: "Noto Serif SC", serif;
  font-size: 1.45rem;
  margin-bottom: 0.6rem;
}

.footer-inner p {
  color: rgba(255, 255, 255, 0.68);
  line-height: 1.8;
}

.footer-inner .copyright {
  margin-top: 0.8rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.10);
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.56);
}

/* ==================== 响应式 ==================== */
@media (max-width: 900px) {
  .navbar-inner {
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem 0;
  }

  .nav-links {
    width: 100%;
    justify-content: flex-start;
  }

  .page-hero {
    margin-top: 146px;
  }

  .page-hero-logo-img {
    right: 4%;
    width: 200px;
    height: 200px;
    opacity: 0.06;
  }

  .page-hero-watermark-img {
    width: 260px;
    height: 260px;
    left: 75%;
    opacity: 0.035;
  }

  .research-page-logo-bg {
    width: 220px;
    height: 220px;
    right: -20px;
  }
}

@media (max-width: 768px) {
  :root {
    --container: min(100% - 28px, 1200px);
  }

  .page-hero {
    padding: 4.8rem 0 4rem;
  }

  .research-article {
    width: min(100% - 28px, 960px);
  }

  .research-section {
    padding: 1.45rem 1.35rem;
  }

  .research-section h2 {
    font-size: 1.25rem;
    padding-right: 4rem;
  }

  .research-section-logo {
    top: 22px;
    right: 22px;
    width: 56px;
    height: 56px;
    padding: 7px;
    opacity: 0.18;
  }

  .logo-text {
    font-size: 1.08rem;
  }

  .logo-subtext {
    font-size: 0.6rem;
  }

  .footer-logo-box {
    width: 68px;
    height: 68px;
  }
}

@media (max-width: 520px) {
  .navbar-inner {
    gap: 1rem;
  }

  .nav-links a {
    padding: 0.6rem 0.85rem;
    font-size: 0.88rem;
  }

  .page-hero h1 {
    font-size: 2.1rem;
  }

  .page-desc {
    font-size: 0.94rem;
  }

  .logo-img {
    width: 48px;
    height: 48px;
  }

  .logo-text {
    font-size: 1rem;
  }

  .logo-subtext {
    display: none;
  }

  .page-hero-logo-img,
  .page-hero-watermark-img,
  .research-page-logo-bg {
    display: none;
  }

  .research-section h2 {
    padding-right: 0;
  }

  .research-section-logo {
    opacity: 0.10;
  }
}