:root {
  --color-primary: #0F5F7A;
  --color-accent: #D4A837;
  --color-white: #F7F9FA;
  --color-night: #1D2A35;
  --color-sand: #9B7653;
  --color-lake: #E3F0F5;
  --color-gold-soft: #F6E7C5;
  --color-ink: #1A1A1A;
  --color-gray: #4A6372;
  --gradient-hero: linear-gradient(135deg, #0F5F7A 0%, #1D6E8C 35%, #8A9B6E 70%, #D4A837 100%);
  --gradient-line: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  --gradient-fade: linear-gradient(180deg, rgba(247,249,250,0) 0%, var(--color-white) 100%);
  --shadow-card: 0 4px 24px rgba(15, 95, 122, 0.12);
  --shadow-header: 0 2px 16px rgba(29, 42, 53, 0.06);
  --font-head: "Source Han Sans Heavy", "Noto Sans CJK SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Source Han Serif SC", "Noto Serif CJK SC", "Songti SC", "STSong", "SimSun", serif;
  --font-sans: "Source Han Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --radius: 14px;
  --radius-clip: 18px 8px 18px 8px;
  --container-max: 1440px;
  --header-h: 72px;
  --transition: 0.28s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --space: clamp(1rem, 3vw, 4rem);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-ink);
  background-color: var(--color-white);
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 900;
  line-height: 1.25;
  color: var(--color-primary);
  margin-bottom: 0.6em;
  letter-spacing: 0.01em;
}

p {
  margin-bottom: 1em;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition), background-color var(--transition);
}

a:hover {
  color: var(--color-accent);
}

ul, ol {
  list-style: none;
}

button {
  font-family: var(--font-sans);
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 4px;
}

::selection {
  background: var(--color-gold-soft);
  color: var(--color-night);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 2000;
  padding: 10px 20px;
  background: var(--color-night);
  color: var(--color-white);
  border-radius: 0 0 8px 8px;
  font-family: var(--font-sans);
  font-weight: 600;
  transition: top 0.3s ease;
}

.skip-link:focus {
  top: 0;
  color: var(--color-gold-soft);
}

/* ========== 头部 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(247, 249, 250, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 3px solid transparent;
  border-image: var(--gradient-line) 1;
  box-shadow: var(--shadow-header);
  width: 100%;
}

.site-header__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 48px);
  position: relative;
}

.site-header__brand {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 14px;
  gap: 20px;
}

.site-header__logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.site-header__logo-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  font-family: var(--font-head);
  font-size: 24px;
  font-weight: 900;
  color: var(--color-white);
  background: var(--gradient-hero);
  border-radius: 12px 4px 12px 4px;
  transform: rotate(-3deg);
  box-shadow: 0 4px 12px rgba(15, 95, 122, 0.3);
}

.site-header__logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.site-header__logo-cn {
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 900;
  color: var(--color-night);
  letter-spacing: 0.06em;
}

.site-header__logo-en {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.28em;
  color: var(--color-gray);
  text-transform: uppercase;
  margin-top: 2px;
}

.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  gap: 5px;
  background: var(--color-lake);
  border-radius: 10px;
  border: 1px solid rgba(15, 95, 122, 0.2);
  transition: background-color var(--transition);
}

.site-header__toggle:hover {
  background: var(--color-gold-soft);
}

.site-header__toggle-bar {
  width: 22px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-header__nav {
  border-top: 1px solid rgba(15, 95, 122, 0.14);
  border-bottom: 1px solid rgba(15, 95, 122, 0.14);
  background: transparent;
}

.site-header__menu {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(0px, 2vw, 36px);
  flex-wrap: wrap;
}

.site-header__link {
  display: block;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-night);
  padding: 14px 8px;
  letter-spacing: 0.04em;
  border-bottom: 3px solid transparent;
  margin-bottom: -1px;
  position: relative;
}

.site-header__link::after {
  content: "";
  position: absolute;
  left: 8px;
  right: 8px;
  bottom: 0;
  height: 3px;
  background: var(--gradient-line);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.site-header__link:hover::after,
.site-header__link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-header__link[aria-current="page"] {
  color: var(--color-primary);
}

.site-header__contact {
  position: absolute;
  right: clamp(16px, 4vw, 48px);
  top: 50%;
  transform: translateY(-50%);
  margin-top: 12px;
}

.site-header__contact-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  color: var(--color-white);
  background: var(--color-primary);
  padding: 10px 16px;
  border-radius: 24px 6px 24px 6px;
  box-shadow: 0 4px 12px rgba(15, 95, 122, 0.25);
  transition: background-color var(--transition), transform var(--transition);
}

.site-header__contact-btn:hover {
  background: var(--color-accent);
  transform: translateY(-2px);
}

.site-header__contact-arrow {
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 6px solid currentColor;
  transition: transform var(--transition);
}

.site-header__contact[data-open] .site-header__contact-arrow {
  transform: rotate(180deg);
}

.site-header__contact-panel {
  display: none;
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  min-width: 220px;
  background: var(--color-white);
  border-radius: 10px;
  box-shadow: 0 12px 32px rgba(29, 42, 53, 0.16);
  border-left: 4px solid var(--color-accent);
  padding: 8px 0;
}

.site-header__contact[data-open] .site-header__contact-panel {
  display: block;
  animation: panel-in 0.25s ease both;
}

@keyframes panel-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.site-header__contact-item {
  display: block;
  padding: 10px 16px;
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--color-night);
}

.site-header__contact-item:hover {
  background: var(--color-lake);
  color: var(--color-primary);
}

/* ========== 页脚 ========== */
.site-footer {
  background: var(--color-night);
  color: rgba(247, 249, 250, 0.82);
  position: relative;
  margin-top: 100px;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-line);
}

.site-footer a {
  color: rgba(247, 249, 250, 0.85);
}

.site-footer a:hover {
  color: var(--color-accent);
}

.site-footer__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: clamp(40px, 7vw, 88px) clamp(16px, 4vw, 48px) 48px;
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: clamp(32px, 6vw, 72px);
}

.site-footer__logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.site-footer__logo-mark {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 900;
  color: var(--color-night);
  background: linear-gradient(135deg, var(--color-accent), #F6E7C5);
  border-radius: 8px 2px 8px 2px;
}

.site-footer__logo-text {
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 900;
  color: var(--color-white);
  letter-spacing: 0.08em;
}

.site-footer__slogan {
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--color-gold-soft);
  border-left: 3px solid var(--color-accent);
  padding-left: 14px;
  margin-bottom: 16px;
}

.site-footer__note {
  font-size: 14px;
  line-height: 1.9;
  color: rgba(247, 249, 250, 0.6);
  max-width: 32em;
}

.site-footer__cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.site-footer__heading {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(212, 168, 55, 0.25);
}

.site-footer__list li {
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.7;
}

.site-footer__contact li::before {
  content: "·";
  color: var(--color-accent);
  margin-right: 8px;
}

.site-footer__legal {
  background: rgba(0, 0, 0, 0.25);
  border-top: 1px solid rgba(247, 249, 250, 0.08);
}

.site-footer__legal-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 18px clamp(16px, 4vw, 48px);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  font-family: var(--font-sans);
  font-size: 12px;
  color: rgba(247, 249, 250, 0.45);
  letter-spacing: 0.04em;
}

/* ========== 布局基础 ========== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: clamp(16px, 4vw, 48px);
  padding-right: clamp(16px, 4vw, 48px);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(16px, 3vw, 32px);
}

.col-7 {
  grid-column: span 7;
}

.col-5 {
  grid-column: span 5;
}

.col-6 {
  grid-column: span 6;
}

.col-4 {
  grid-column: span 4;
}

.col-3 {
  grid-column: span 3;
}

.card {
  background: var(--color-white);
  border: 1px solid rgba(15, 95, 122, 0.10);
  border-radius: var(--radius-clip);
  box-shadow: var(--shadow-card);
  padding: clamp(20px, 4vw, 40px);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(15, 95, 122, 0.16);
}

.card--flush {
  padding: 0;
  overflow: hidden;
}

.card--invert {
  background: var(--color-night);
  color: var(--color-white);
  border-color: var(--color-night);
}

.card--lake {
  background: var(--color-lake);
}

.card--sand {
  background: var(--color-gold-soft);
}

.tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-lake);
  padding: 4px 12px;
  border-radius: 999px;
  letter-spacing: 0.06em;
}

.tag--gold {
  color: var(--color-night);
  background: var(--color-gold-soft);
}

.tag--outline {
  background: transparent;
  border: 1px solid rgba(15, 95, 122, 0.3);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  padding: 12px 28px;
  border-radius: 8px 2px 8px 2px;
  transition: background-color var(--transition), color var(--transition), transform var(--transition), border-color var(--transition);
  cursor: pointer;
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: 0 4px 16px rgba(15, 95, 122, 0.24);
}

.btn--primary:hover {
  background: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid rgba(15, 95, 122, 0.35);
}

.btn--ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn--light {
  background: var(--color-white);
  color: var(--color-primary);
}

.btn--light:hover {
  background: var(--color-gold-soft);
  color: var(--color-night);
}

.breadcrumb {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--color-gray);
  padding: 16px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.breadcrumb a {
  color: var(--color-primary);
  font-weight: 600;
}

.breadcrumb a:hover {
  color: var(--color-accent);
}

.divider {
  height: 3px;
  background: var(--gradient-line);
  border-radius: 2px;
  margin: 24px 0;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-label::before {
  content: "";
  width: 28px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* ========== 图片容器基础 ========== */
.figure {
  position: relative;
  overflow: hidden;
  background: var(--color-lake);
  border-radius: var(--radius-clip);
  border: 1px solid rgba(15, 95, 122, 0.12);
}

.figure--wide {
  aspect-ratio: 16 / 9;
}

.figure--portrait {
  aspect-ratio: 4 / 5;
}

.figure--landscape {
  aspect-ratio: 21 / 9;
}

.figure svg, .figure img, .figure > * {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.figure__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  background: rgba(29, 42, 53, 0.78);
  color: var(--color-white);
  font-family: var(--font-sans);
  font-size: 12px;
  padding: 6px 14px;
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

/* ========== 进度条 ========== */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 100%;
  background: transparent;
  z-index: 2001;
  pointer-events: none;
  transform-origin: 0 50%;
  transform: scaleX(0);
  background: var(--gradient-line);
}

/* ========== 返回顶部 ========== */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  background: var(--color-night);
  color: var(--color-white);
  border-radius: 12px 3px 12px 3px;
  box-shadow: 0 6px 20px rgba(29, 42, 53, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition), background-color var(--transition);
  z-index: 900;
}

.back-to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-accent);
}

/* ========== 滚动渐显 ========== */
.fade-in, [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: opacity, transform;
}

.fade-in.is-visible, [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========== 标签页 ========== */
.tabs {
  width: 100%;
}

.tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: 3px solid rgba(15, 95, 122, 0.12);
  margin-bottom: 24px;
}

.tablist__item {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  color: var(--color-gray);
  padding: 12px 22px;
  background: transparent;
  border-radius: 8px 8px 0 0;
  border: 2px solid transparent;
  border-bottom: none;
  position: relative;
  transition: color var(--transition), background-color var(--transition);
}

.tablist__item:hover {
  color: var(--color-primary);
  background: rgba(227, 240, 245, 0.5);
}

.tablist__item[aria-selected="true"] {
  color: var(--color-white);
  background: var(--color-primary);
}

.tablist__item[aria-selected="true"]::after {
  content: "";
  position: absolute;
  bottom: -3px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-accent);
}

.tabpanel {
  padding: 2px 0;
  animation: panel-in 0.25s ease both;
}

.tabpanel--hidden {
  display: none;
}

/* ========== 折叠面板 ========== */
.accordion {
  border: 1px solid rgba(15, 95, 122, 0.12);
  border-radius: var(--radius-clip);
  background: var(--color-white);
}

.accordion__header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-night);
  padding: 18px 22px;
  background: transparent;
  border-bottom: 1px solid rgba(15, 95, 122, 0.06);
  transition: background-color var(--transition);
}

.accordion__header:hover {
  background: var(--color-lake);
}

.accordion__icon {
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: rotate(45deg);
  transition: transform var(--transition);
  flex-shrink: 0;
  margin-top: -5px;
}

.accordion__panel {
  padding: 0 22px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.accordion__panel-inner {
  padding: 18px 0;
  border-bottom: 1px solid transparent;
}

.accordion__item[data-open] .accordion__icon {
  transform: rotate(-135deg);
  margin-top: 5px;
}

.accordion__item[data-open] .accordion__panel {
  padding-bottom: 8px;
}

/* ========== 模态框 ========== */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1500;
  background: rgba(29, 42, 53, 0.55);
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.modal[data-open] {
  display: flex;
}

.modal__panel {
  background: var(--color-white);
  max-width: 600px;
  width: 100%;
  border-radius: var(--radius-clip);
  box-shadow: 0 20px 60px rgba(29, 42, 53, 0.35);
  padding: 32px;
  position: relative;
  animation: panel-in 0.3s ease both;
}

.modal__close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  font-family: var(--font-sans);
  font-size: 18px;
  color: var(--color-gray);
  border-radius: 8px;
  background: rgba(15, 95, 122, 0.06);
  transition: background-color var(--transition), color var(--transition);
}

.modal__close:hover {
  background: var(--color-gold-soft);
  color: var(--color-night);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .site-footer__note {
    max-width: none;
  }

  .col-7, .col-5, .col-6, .col-4, .col-3 {
    grid-column: span 12;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 60px;
  }

  .site-header__brand {
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .site-header__logo-mark {
    width: 38px;
    height: 38px;
    font-size: 18px;
  }

  .site-header__logo-cn {
    font-size: 18px;
  }

  .site-header__logo-en {
    font-size: 8px;
    letter-spacing: 0.18em;
  }

  .site-header__toggle {
    display: flex;
  }

  .site-header__nav {
    display: none;
    border-top: none;
  }

  .site-header__nav[data-open] {
    display: block;
    animation: panel-in 0.3s ease both;
  }

  .site-header__menu {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding-bottom: 14px;
  }

  .site-header__link {
    padding: 12px 4px;
    font-size: 16px;
    border-bottom: 1px solid rgba(15, 95, 122, 0.08);
  }

  .site-header__link::after {
    display: none;
  }

  .site-header__link[aria-current="page"] {
    color: var(--color-primary);
    background: linear-gradient(to right, var(--color-lake), transparent);
    border-radius: 6px;
    padding-left: 12px;
  }

  .site-header__contact {
    display: none;
  }

  .site-header__inner {
    padding-left: 16px;
    padding-right: 16px;
  }

  .site-footer__cols {
    grid-template-columns: 1fr;
  }

  .site-footer__legal-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 42px;
    height: 42px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  [data-reveal], .fade-in {
    opacity: 1;
    transform: none;
  }

  .progress-bar {
    display: none;
  }
}