/* ==========================================================================
   SOPAC / SPC GEM (Geoscience, Energy & Maritime) Division Theme
   严格对齐 sopac.org / gem.spc.int 真实设计
   2026-10-12 v1

   真实设计系统 (从 sopac.org 提取):
   - 主色: ocean blue   #1B6FB0 (海洋蓝)
   - 深蓝:  #0F4D7F (深海)
   - 强调: 浅蓝 / 绿色 / 橙色 (4 圆形 key work 图标)
   - 文字:  #1a1a1a on white
   - 字体:  sans-serif
   - 风格: 大图 hero (海洋/海浪) + 4 圆形 key work + 新闻 3-col + 事件
   ========================================================================== */

:root {
  --spc-blue:        #1B6FB0;
  --spc-blue-dark:   #0F4D7F;
  --spc-blue-light:   #4A92D2;
  --spc-blue-pale:    #D8E9F5;
  --spc-green:        #2E8B57;
  --spc-orange:       #E67E22;
  --spc-navy:         #2C3E50;
  --spc-ink:          #1a1a1a;
  --spc-grey-50:      #f5f7f9;
  --spc-grey-100:     #e5e8eb;
  --spc-grey-700:     #5a6373;
  --spc-white:        #ffffff;

  --spc-font-body:    "Source Sans Pro", "Inter", "Helvetica Neue", -apple-system, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --spc-font-heading: var(--spc-font-body);

  --spc-s-xxs: .25rem; --spc-s-xs: .5rem;  --spc-s-s:  1rem;
  --spc-s-m:  1.5rem; --spc-s-l:  2rem;   --spc-s-xl: 2.5rem;
  --spc-s-xxl: 3rem;  --spc-s-xxxl: 4rem;  --spc-s-xxxxl: 5rem;

  --spc-radius:       9999px;
  --spc-radius-md:    8px;
  --spc-t:            200ms ease;
  --spc-container:    1280px;
}

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

body {
  margin: 0;
  font-family: var(--spc-font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--spc-ink);
  background: var(--spc-white);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--spc-blue); text-decoration: none; transition: color var(--spc-t); }
a:hover { color: var(--spc-blue-dark); text-decoration: underline; }

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--spc-s-s);
  font-family: var(--spc-font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--spc-navy);
}
h1 { font-size: clamp(2rem, 4.5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: 1.25rem; }
p { margin: 0 0 var(--spc-s-s); }


/* ===== Site Header (SOPAC 真实: 白底 + 蓝色链接) ===== */
.site-header {
  background: var(--spc-white);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
.site-header__top {
  background: var(--spc-blue);
  color: var(--spc-white);
  font-size: 0.875rem;
}
.site-header__top-inner {
  max-width: var(--spc-container);
  margin: 0 auto;
  padding: 0.5rem var(--spc-s-s);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spc-s-s);
  flex-wrap: wrap;
}
.site-header__top-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.site-header__brand {
  display: flex;
  align-items: center;
  text-decoration: none;
}
.site-header__brand img { height: 32px; width: auto; background: var(--spc-white); padding: 4px 8px; border-radius: 4px; }
.site-header__top-right {
  display: flex;
  align-items: center;
  gap: var(--spc-s-m);
}
.site-header__top a {
  color: var(--spc-white);
  text-decoration: none;
}
.site-header__top a:hover { color: var(--spc-white); opacity: 0.8; }
.site-header__main {
  background: var(--spc-white);
  border-bottom: 1px solid var(--spc-grey-100);
}
.site-header__main-inner {
  max-width: var(--spc-container);
  margin: 0 auto;
  padding: var(--spc-s-s);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spc-s-s);
  flex-wrap: wrap;
}
.site-brand {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}
.site-brand__img { height: 48px; width: auto; }
.site-brand__text {
  font-family: var(--spc-font-heading);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--spc-navy);
  margin-left: 0.75rem;
}
.site-header__nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex-wrap: wrap;
}
.site-header__nav-item {
  padding: 0.5rem 0.875rem;
  color: var(--spc-navy) !important;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--spc-radius);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.site-header__nav-item:hover {
  color: var(--spc-blue) !important;
  background: var(--spc-blue-pale);
  text-decoration: none;
}
.site-header__search {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  background: var(--spc-blue);
  color: var(--spc-white);
  border-radius: 50%;
  text-decoration: none;
  font-size: 1rem;
}
.site-header__search:hover { background: var(--spc-blue-dark); color: var(--spc-white); }


/* ===== Hero (SOPAC 真实: 海浪/海洋照片 + 暗 navy 蒙版 + 居中大字) ===== */
.home-hero {
  position: relative;
  min-height: 520px;
  background: var(--spc-blue-dark);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.home-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse at 20% 30%, rgba(74, 146, 210, 0.3) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 70%, rgba(46, 139, 87, 0.2) 0%, transparent 50%),
    linear-gradient(180deg, var(--spc-blue-dark) 0%, var(--spc-navy) 100%);
}
.home-hero__bg::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='40' viewBox='0 0 100 40'%3E%3Cpath fill='none' stroke='rgba(255,255,255,0.08)' stroke-width='1' d='M0 20 Q 25 5, 50 20 T 100 20'/%3E%3C/svg%3E");
  background-size: 200px 80px;
  opacity: 0.4;
}
.home-hero__overlay {
  position: relative;
  z-index: 2;
  color: var(--spc-white);
  padding: var(--spc-s-xxxxl) var(--spc-s-s);
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}
.home-hero__eyebrow {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--spc-blue-light);
  margin: 0 0 var(--spc-s-s);
  padding: 0.4rem 1rem;
  background: rgba(255,255,255,0.1);
  border-radius: var(--spc-radius);
}
.home-hero__title {
  font-family: var(--spc-font-heading);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--spc-white);
  margin: 0 0 var(--spc-s-m);
  text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}
.home-hero__sub {
  font-size: 1.0625rem;
  color: rgba(255,255,255,0.92);
  margin: 0 0 var(--spc-s-l);
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.5;
}
.home-hero__actions { display: flex; gap: var(--spc-s-s); flex-wrap: wrap; justify-content: center; }


/* ===== Buttons (SOPAC 真实: 圆角小, 蓝色实心) ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--spc-font-body);
  font-size: 0.9375rem;
  font-weight: 700;
  border-radius: var(--spc-radius);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all var(--spc-t);
  text-decoration: none;
  line-height: 1.2;
}
.btn--primary {
  background: var(--spc-blue);
  color: var(--spc-white);
  border-color: var(--spc-blue);
}
.btn--primary:hover { background: var(--spc-blue-dark); border-color: var(--spc-blue-dark); color: var(--spc-white); text-decoration: none; }
.btn--outline {
  background: transparent;
  color: var(--spc-blue);
  border-color: var(--spc-blue);
}
.btn--outline:hover { background: var(--spc-blue); color: var(--spc-white); text-decoration: none; }
.btn--white {
  background: var(--spc-white);
  color: var(--spc-blue);
  border-color: var(--spc-white);
}
.btn--white:hover { background: var(--spc-blue-pale); color: var(--spc-blue); text-decoration: none; }


/* ===== Sections ===== */
.section {
  width: 100%;
  padding: var(--spc-s-xxxxl) var(--spc-s-s);
}
.section--white { background: var(--spc-white); }
.section--grey { background: var(--spc-grey-50); }
.section--blue { background: var(--spc-blue); color: var(--spc-white); }
.section--blue h1, .section--blue h2, .section--blue h3 { color: var(--spc-white); }
.section__container { max-width: var(--spc-container); margin: 0 auto; }
.section__head { margin-bottom: var(--spc-s-xl); text-align: center; }
.section__title {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--spc-navy);
  margin: 0 0 var(--spc-s-s);
}
.section--blue .section__title { color: var(--spc-white); }
.section__sub {
  font-size: 1.0625rem;
  color: var(--spc-grey-700);
  max-width: 48rem;
  margin: 0 auto;
}
.section--blue .section__sub { color: rgba(255,255,255,0.9); }


/* ===== 4 圆形 key work (SOPAC 真实: 4 主题色) ===== */
.keywork-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spc-s-l);
  max-width: var(--spc-container);
  margin: -3rem auto 0;
  padding: 0 var(--spc-s-s);
  position: relative;
  z-index: 5;
}
.keywork-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  background: var(--spc-white);
  border: 1px solid var(--spc-grey-100);
  border-radius: var(--spc-radius-md);
  padding: var(--spc-s-l) var(--spc-s-m);
  text-decoration: none;
  color: var(--spc-ink);
  transition: all var(--spc-t);
  box-shadow: 0 4px 12px rgba(0,0,0,0.06);
}
.keywork-card:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(0,0,0,0.1); color: var(--spc-ink); text-decoration: none; }
.keywork-card__icon {
  width: 80px; height: 80px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--spc-white);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--spc-s-s);
}
.keywork-card--green .keywork-card__icon { background: var(--spc-green); }
.keywork-card--orange .keywork-card__icon { background: var(--spc-orange); }
.keywork-card--blue .keywork-card__icon { background: var(--spc-blue); }
.keywork-card--navy .keywork-card__icon { background: var(--spc-navy); }
.keywork-card__title {
  font-family: var(--spc-font-heading);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--spc-navy);
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  line-height: 1.3;
}


/* ===== 描述段 (浅蓝条) ===== */
.desc-section {
  background: var(--spc-blue-pale);
  padding: var(--spc-s-xxl) var(--spc-s-s);
  text-align: center;
}
.desc-section__inner {
  max-width: 56rem;
  margin: 0 auto;
}
.desc-section p {
  font-size: 1rem;
  color: var(--spc-navy);
  margin: 0 0 var(--spc-s-s);
  line-height: 1.6;
}
.desc-section p:last-of-type { margin-bottom: var(--spc-s-m); }


/* ===== News 3-col (SOPAC 真实: 图片+日期+标题) ===== */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spc-s-m);
  max-width: var(--spc-container);
  margin: 0 auto;
  padding: 0 var(--spc-s-s);
}
.news-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--spc-ink);
  background: var(--spc-white);
  border: 1px solid var(--spc-grey-100);
  border-radius: var(--spc-radius-md);
  overflow: hidden;
  transition: all var(--spc-t);
}
.news-card:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.08); color: var(--spc-ink); text-decoration: none; }
.news-card__media {
  width: 100%;
  aspect-ratio: 16/10;
  background: linear-gradient(135deg, var(--spc-blue) 0%, var(--spc-blue-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.4);
  font-size: 3rem;
  font-weight: 700;
}
.news-card__body { padding: var(--spc-s-m); }
.news-card__date {
  font-size: 0.75rem;
  color: var(--spc-blue);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 0.5rem;
}
.news-card__title {
  font-family: var(--spc-font-heading);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--spc-navy);
  line-height: 1.3;
  margin: 0 0 var(--spc-s-s);
}
.news-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--spc-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
  margin-top: auto;
}


/* ===== Events 列表 (SOPAC 真实: 横条带日期) ===== */
.event-list {
  max-width: var(--spc-container);
  margin: 0 auto;
  padding: 0 var(--spc-s-s);
}
.event-row {
  display: grid;
  grid-template-columns: 140px 1fr 200px;
  gap: var(--spc-s-m);
  align-items: center;
  background: var(--spc-white);
  border: 1px solid var(--spc-grey-100);
  border-left: 4px solid var(--spc-blue);
  padding: var(--spc-s-m);
  margin-bottom: var(--spc-s-s);
  text-decoration: none;
  color: var(--spc-ink);
  transition: all var(--spc-t);
}
.event-row:hover { transform: translateX(2px); box-shadow: 0 2px 8px rgba(0,0,0,0.06); color: var(--spc-ink); text-decoration: none; }
.event-row__date {
  text-align: center;
  font-weight: 700;
  color: var(--spc-blue);
  font-size: 0.9375rem;
}
.event-row__date-day { font-size: 1.25rem; display: block; }
.event-row__title {
  font-family: var(--spc-font-heading);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--spc-navy);
  margin: 0;
  line-height: 1.3;
}
.event-row__meta {
  font-size: 0.8125rem;
  color: var(--spc-grey-700);
  text-align: right;
}


/* ===== Page Hero (内页) ===== */
.page-hero {
  background: var(--spc-blue);
  color: var(--spc-white);
  padding: var(--spc-s-xl) var(--spc-s-s);
}
.page-hero__container { max-width: var(--spc-container); margin: 0 auto; }
.page-hero__breadcrumb {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.85);
  margin: 0 0 var(--spc-s-s);
}
.page-hero__breadcrumb a { color: var(--spc-white); }
.page-hero__title {
  font-family: var(--spc-font-heading);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  color: var(--spc-white);
  margin: 0 0 var(--spc-s-s);
}
.page-hero__sub {
  font-size: 1.0625rem;
  color: rgba(255,255,255,0.9);
  max-width: 48rem;
  margin: 0;
}


/* ===== Content (prose) ===== */
.page-content {
  max-width: var(--spc-container);
  margin: 0 auto;
  padding: var(--spc-s-xxxxl) var(--spc-s-s);
}
.prose {
  max-width: 56rem;
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--spc-ink);
}
.prose h2 {
  font-size: 1.625rem;
  color: var(--spc-navy);
  margin: var(--spc-s-xl) 0 var(--spc-s-s);
  border-bottom: 3px solid var(--spc-blue);
  padding-bottom: 0.5rem;
  display: inline-block;
}
.prose h3 { font-size: 1.25rem; color: var(--spc-navy); margin: var(--spc-s-l) 0 var(--spc-s-xs); }
.prose a { color: var(--spc-blue); text-decoration: underline; }
.prose blockquote {
  border-left: 4px solid var(--spc-blue);
  padding: 0.5rem var(--spc-s-m);
  margin: var(--spc-s-m) 0;
  background: var(--spc-blue-pale);
  font-style: italic;
}


/* ===== Footer (SOPAC 真实: 深蓝 + 4 列) ===== */
.site-footer {
  background: var(--spc-navy);
  color: var(--spc-white);
  padding: var(--spc-s-xxxxl) var(--spc-s-s) var(--spc-s-l);
}
.site-footer__grid {
  max-width: var(--spc-container);
  margin: 0 auto var(--spc-s-xl);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spc-s-l);
}
.site-footer__col h4 {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--spc-blue-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 var(--spc-s-s);
}
.site-footer__col p {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.85);
  margin: 0 0 var(--spc-s-xs);
  line-height: 1.5;
}
.site-footer__col ul { list-style: none; padding: 0; margin: 0; }
.site-footer__col li { margin: 0 0 var(--spc-s-xs); }
.site-footer__col a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 0.875rem;
}
.site-footer__col a:hover { color: var(--spc-blue-light); text-decoration: underline; }
.site-footer__network {
  max-width: var(--spc-container);
  margin: 0 auto var(--spc-s-l);
  padding: var(--spc-s-m) 0;
  border-top: 1px solid rgba(255,255,255,0.15);
  border-bottom: 1px solid rgba(255,255,255,0.15);
}
.site-footer__network-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: rgba(255,255,255,0.6);
  letter-spacing: 0.1em;
  margin: 0 0 var(--spc-s-xs);
}
.site-footer__network ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--spc-s-xs) var(--spc-s-m);
}
.site-footer__network a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 0.8125rem;
}
.site-footer__network a:hover { color: var(--spc-blue-light); text-decoration: underline; }
.site-footer__bottom {
  max-width: var(--spc-container);
  margin: 0 auto;
  padding-top: var(--spc-s-l);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--spc-s-s);
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.7);
}
.site-footer__bottom a { color: rgba(255,255,255,0.85); text-decoration: underline; }


/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .keywork-grid { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .site-footer__grid { grid-template-columns: repeat(2, 1fr); }
  .event-row { grid-template-columns: 100px 1fr; }
  .event-row__meta { display: none; }
}
@media (max-width: 640px) {
  .site-header__top-inner { flex-direction: column; align-items: flex-start; gap: 0.4rem; }
  .site-header__main-inner { padding: 0.5rem var(--spc-s-s); }
  .keywork-grid, .news-grid, .site-footer__grid { grid-template-columns: 1fr; }
  .section { padding: var(--spc-s-xl) var(--spc-s-s); }
  .home-hero__title { font-size: 1.875rem; }
}