@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Playfair+Display:wght@400;500;600;700&display=swap');

/* =========================================
   CSS 自定义属性
   ========================================= */
:root {
  --c-black: #000000;
  --c-white: #ffffff;
  --c-gray-100: #f5f5f5;
  --c-gray-200: #e8e8e8;
  --c-gray-400: #999999;
  --c-gray-600: #555555;
  --c-gray-800: #222222;
  --c-accent: #000000;

  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'Inter', Helvetica, Arial, sans-serif;

  --base: 8px;
  --sp-1: 8px;
  --sp-2: 16px;
  --sp-3: 24px;
  --sp-4: 32px;
  --sp-5: 40px;
  --sp-6: 48px;
  --sp-8: 64px;
  --sp-10: 80px;
  --sp-12: 96px;

  --grid-cols: 12;
  --grid-gap: 1rem;

  --radius: 0;
  --header-h: 56px;
  --announce-h: 36px;
  --sticky-h: 44px;
  --scroll-offset: calc(var(--header-h) + var(--announce-h) + var(--sticky-h) + 8px);

  --transition-fast: 180ms ease;
  --transition-std: 300ms ease;
  --transition-slow: 500ms ease;
}

/* =========================================
   Reset & Base
   ========================================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  color: var(--c-black);
  background: var(--c-white);
  overflow-x: hidden;
}

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

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

ul, menu {
  list-style: none;
}

dl, dt, dd {
  margin: 0;
  padding: 0;
}

hr {
  border: none;
  border-top: 1px solid var(--c-black);
  margin: var(--sp-2) 0;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* scroll-margin for anchored sections */
article[id] {
  scroll-margin-top: var(--scroll-offset);
}

/* =========================================
   公告条
   ========================================= */
.announce-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--announce-h);
  background: var(--c-black);
  color: var(--c-white);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  overflow: hidden;
}

.announce-text {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  padding: 0 var(--sp-3);
}

/* =========================================
   Header
   ========================================= */
.site-header {
  position: fixed;
  top: var(--announce-h);
  left: 0;
  width: 100%;
  height: var(--header-h);
  background: var(--c-white);
  border-bottom: 1px solid var(--c-black);
  z-index: 900;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 var(--sp-4);
  max-width: 1440px;
  margin: 0 auto;
}

.brand-mark {
  display: flex;
  align-items: center;
  z-index: 1100;
  position: relative;
}

.brand-monogram {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--c-black);
  color: var(--c-white);
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

/* =========================================
   Details/Summary 导航（汉堡全屏遮罩）
   ========================================= */
.nav-details {
  position: static;
}

.nav-toggle {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  cursor: pointer;
  list-style: none;
  padding: 0 var(--sp-2);
  min-height: 44px;
  height: 44px;
  border: 1px solid var(--c-black);
  user-select: none;
  position: relative;
  z-index: 1100;
  background: var(--c-white);
}

.nav-toggle::-webkit-details-marker { display: none; }
.nav-toggle::marker { display: none; }

.hamburger {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 22px;
}

.hamburger span {
  display: block;
  height: 2px;
  background: var(--c-black);
  transition: transform var(--transition-std), opacity var(--transition-std);
}

.toggle-label-open {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
}

.toggle-label-close {
  display: none;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
}

/* 打开状态 */
.nav-details[open] .toggle-label-open { display: none; }
.nav-details[open] .toggle-label-close { display: inline; }

.nav-details[open] .hamburger span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.nav-details[open] .hamburger span:nth-child(2) {
  opacity: 0;
}
.nav-details[open] .hamburger span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-overlay-bg {
  display: none;
}

.nav-details[open] .nav-overlay-bg {
  display: block;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.3);
  z-index: 950;
}

.nav-fullscreen {
  position: fixed;
  top: 0;
  right: 0;
  width: min(400px, 90vw);
  height: 100dvh;
  background: var(--c-black);
  color: var(--c-white);
  z-index: 1050;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--sp-12) var(--sp-8);
  overflow-y: auto;
  animation: slideInRight var(--transition-std) ease;
}

@keyframes slideInRight {
  from { transform: translateX(100%); opacity: 0; }
  to   { transform: translateX(0);    opacity: 1; }
}

.nav-menu {
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}

.nav-menu li {
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav-link {
  display: flex;
  align-items: center;
  padding: var(--sp-2) 0;
  font-size: clamp(18px, 3vw, 26px);
  font-family: var(--font-display);
  font-weight: 500;
  color: var(--c-white);
  letter-spacing: -0.01em;
  transition: padding-left var(--transition-fast), opacity var(--transition-fast);
  min-height: 52px;
  line-height: 1.2;
}

.nav-link:hover {
  padding-left: var(--sp-2);
  opacity: 0.7;
}

.nav-brand-large {
  margin-top: var(--sp-8);
  font-family: var(--font-display);
  font-size: clamp(28px, 5vw, 48px);
  font-weight: 700;
  color: rgba(255,255,255,0.08);
  letter-spacing: -0.03em;
  line-height: 1;
}

/* =========================================
   粘性锚点条
   ========================================= */
.sticky-anchors {
  position: sticky;
  top: calc(var(--announce-h) + var(--header-h));
  z-index: 800;
  background: var(--c-white);
  border-bottom: 2px solid var(--c-black);
  height: var(--sticky-h);
  overflow: hidden;
}

.anchors-inner {
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 var(--sp-4);
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
  max-width: 1440px;
  margin: 0 auto;
}

.anchors-inner::-webkit-scrollbar { display: none; }

.anchor-link {
  flex-shrink: 0;
  padding: 0 var(--sp-2);
  height: 100%;
  min-height: 44px;
  display: flex;
  align-items: center;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  border-right: 1px solid var(--c-gray-200);
  transition: background var(--transition-fast), color var(--transition-fast);
  white-space: nowrap;
  min-width: 44px;
  justify-content: center;
}

.anchor-link:first-child { border-left: 1px solid var(--c-gray-200); }

.anchor-link:hover {
  background: var(--c-black);
  color: var(--c-white);
}

/* =========================================
   Hero
   ========================================= */
.hero-section {
  position: relative;
  margin-top: calc(var(--announce-h) + var(--header-h));
  min-height: 70vh;
  background: var(--c-black);
  color: var(--c-white);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* 点阵底纹 */
.hero-grid-texture {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 0;
  pointer-events: none;
  z-index: 0;
  padding: var(--sp-4);
}

.dot {
  display: block;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: rgba(255,255,255,0.12);
  margin: auto;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  padding: var(--sp-10) var(--sp-4);
  width: 100%;
}

.hero-media {
  margin: 0 auto var(--sp-5);
  max-width: 600px;
}

.hero-img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.hero-eyebrow {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: rgba(255,255,255,0.5);
  margin-bottom: var(--sp-3);
}

.hero-h1 {
  font-family: var(--font-display);
  font-size: clamp(28px, 6vw, 72px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: var(--sp-3);
  color: var(--c-white);
}

.hero-desc {
  font-size: clamp(15px, 2vw, 18px);
  font-weight: 300;
  line-height: 1.7;
  color: rgba(255,255,255,0.72);
  max-width: 600px;
  margin: 0 auto var(--sp-5);
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  padding: var(--sp-2) var(--sp-5);
  background: var(--c-white);
  color: var(--c-black);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.08em;
  border: 2px solid var(--c-white);
  transition: background var(--transition-fast), color var(--transition-fast);
  min-height: 48px;
}

.hero-cta:hover {
  background: transparent;
  color: var(--c-white);
}

/* 斜切底边 */
.hero-clip {
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 80px;
  background: var(--c-white);
  clip-path: polygon(0 100%, 100% 100%, 100% 40%, 0 100%);
  z-index: 3;
}

/* =========================================
   主内容区
   ========================================= */
.site-main {
  max-width: 1440px;
  margin: 0 auto;
  padding: var(--sp-10) var(--sp-4);
}

/* main > div > article 三层直接嵌套 */
.content-article {
  width: 100%;
}

.article-section-wrap {
  width: 100%;
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--sp-8);
  align-items: start;
}

.article-body-col {
  min-width: 0;
}

/* =========================================
   正文排版
   ========================================= */
.content-prose {
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-gray-800);
}

.content-prose h1,
.content-prose h2,
.content-prose h3,
.content-prose h4 {
  font-family: var(--font-display);
  color: var(--c-black);
  line-height: 1.2;
  margin-top: var(--sp-8);
  margin-bottom: var(--sp-2);
  letter-spacing: -0.02em;
}

.content-prose h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  border-left: 4px solid var(--c-black);
  padding-left: var(--sp-2);
}

.content-prose h3 {
  font-size: clamp(18px, 2.5vw, 24px);
  font-weight: 600;
}

.content-prose h4 {
  font-size: 18px;
  font-weight: 600;
}

.content-prose p {
  margin-bottom: var(--sp-3);
  font-size: 16px;
  line-height: 1.75;
}

.content-prose ul,
.content-prose ol {
  margin: var(--sp-3) 0 var(--sp-3) var(--sp-4);
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}

.content-prose li {
  line-height: 1.65;
}

.content-prose ul li {
  list-style: disc;
}

.content-prose ol li {
  list-style: decimal;
}

.content-prose a {
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 500;
  transition: opacity var(--transition-fast);
}

.content-prose a:hover {
  opacity: 0.6;
}

.content-prose strong {
  font-weight: 700;
  color: var(--c-black);
}

.content-prose blockquote {
  border-left: 3px solid var(--c-black);
  padding: var(--sp-2) var(--sp-3);
  margin: var(--sp-4) 0;
  background: var(--c-gray-100);
  font-style: italic;
}

.content-prose hr {
  margin: var(--sp-6) 0;
  border-color: var(--c-gray-200);
}

.content-prose table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--sp-4) 0;
  font-size: 15px;
}

.content-prose th {
  background: var(--c-black);
  color: var(--c-white);
  padding: var(--sp-2) var(--sp-2);
  text-align: left;
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.05em;
}

.content-prose td {
  padding: var(--sp-2) var(--sp-2);
  border-bottom: 1px solid var(--c-gray-200);
  vertical-align: top;
}

.content-prose tr:hover td {
  background: var(--c-gray-100);
}

.content-prose article {
  padding-bottom: var(--sp-8);
  border-bottom: 1px solid var(--c-gray-200);
  margin-bottom: var(--sp-8);
}

.content-prose article:last-child {
  border-bottom: none;
}

/* =========================================
   侧边栏
   ========================================= */
.content-aside {
  position: sticky;
  top: var(--scroll-offset);
}

.aside-inner {
  border: 1px solid var(--c-black);
  padding: var(--sp-3);
}

.aside-title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-bottom: var(--sp-1);
}

.aside-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: var(--sp-2);
}

.aside-nav-list li {
  border-bottom: 1px solid var(--c-gray-200);
}

.aside-nav-list li:last-child {
  border-bottom: none;
}

.aside-nav-list a {
  display: flex;
  align-items: center;
  padding: 10px 0;
  font-size: 13px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--c-gray-600);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
  min-height: 44px;
}

.aside-nav-list a:hover {
  color: var(--c-black);
  padding-left: var(--sp-1);
}

.aside-note {
  margin-top: var(--sp-3);
  padding-top: var(--sp-2);
  border-top: 1px solid var(--c-gray-200);
}

.aside-note p {
  font-size: 11px;
  line-height: 1.6;
  color: var(--c-gray-400);
}

/* =========================================
   页脚
   ========================================= */
.site-footer {
  background: var(--c-black);
  color: var(--c-white);
  padding: var(--sp-10) var(--sp-4) var(--sp-4);
  margin-top: var(--sp-12);
}

.footer-top {
  max-width: 1440px;
  margin: 0 auto var(--sp-8);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--sp-6);
  align-items: start;
  padding-bottom: var(--sp-6);
  border-bottom: 1px solid rgba(255,255,255,0.15);
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--sp-2);
}

.footer-brand-desc {
  font-size: 14px;
  line-height: 1.6;
  color: rgba(255,255,255,0.55);
  max-width: 480px;
}

.footer-contact-block {
  text-align: right;
}

.footer-contact-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.4);
  margin-bottom: var(--sp-1);
}

.footer-contact-value {
  font-size: 14px;
  color: var(--c-white);
}

/* 三列 dl */
.footer-dl-row {
  max-width: 1440px;
  margin: 0 auto var(--sp-8);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-6);
}

.footer-dl dt {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: rgba(255,255,255,0.4);
  margin-bottom: var(--sp-3);
  padding-bottom: var(--sp-1);
  border-bottom: 1px solid rgba(255,255,255,0.15);
}

.footer-dl dd {
  font-size: 13px;
  line-height: 1.6;
  color: rgba(255,255,255,0.65);
  margin-bottom: var(--sp-1);
}

.footer-dl dd a {
  color: rgba(255,255,255,0.65);
  transition: color var(--transition-fast);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 4px 0;
}

.footer-dl dd a:hover {
  color: var(--c-white);
}

.footer-bottom {
  max-width: 1440px;
  margin: 0 auto;
  padding-top: var(--sp-4);
  border-top: 1px solid rgba(255,255,255,0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--sp-3);
  flex-wrap: wrap;
}

.footer-copy {
  font-size: 12px;
  color: rgba(255,255,255,0.4);
}

.footer-disclaimer {
  font-size: 12px;
  color: rgba(255,255,255,0.3);
  text-align: right;
}

/* =========================================
   Scroll Reveal 动效
   ========================================= */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  html {
    scroll-behavior: auto;
  }
  .nav-fullscreen {
    animation: none;
  }
}

/* =========================================
   响应式
   ========================================= */
@media (max-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr 240px;
    gap: var(--sp-6);
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 52px;
    --announce-h: 32px;
    --sticky-h: 44px;
  }

  .article-layout {
    grid-template-columns: 1fr;
  }

  .content-aside {
    position: static;
    order: -1;
  }

  .aside-inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-2);
  }

  .aside-title { grid-column: 1 / -1; }
  .aside-inner > hr { grid-column: 1 / -1; }
  .aside-nav-list { grid-column: 1; }
  .aside-note { grid-column: 2; }

  .footer-top {
    grid-template-columns: 1fr;
  }

  .footer-contact-block {
    text-align: left;
  }

  .footer-dl-row {
    grid-template-columns: 1fr;
    gap: var(--sp-4);
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

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

  .anchors-inner {
    padding: 0 var(--sp-2);
    gap: 0;
  }

  .anchor-link {
    font-size: 11px;
    padding: 0 var(--sp-1);
    min-height: 44px;
  }

  .hero-clip {
    height: 48px;
  }

  .site-main {
    padding: var(--sp-6) var(--sp-3);
  }
}

@media (max-width: 480px) {
  .announce-text {
    font-size: 10px;
    letter-spacing: 0.06em;
  }

  .header-inner {
    padding: 0 var(--sp-2);
  }

  .nav-fullscreen {
    width: 100vw;
    padding: var(--sp-10) var(--sp-4);
  }

  .hero-content {
    padding: var(--sp-8) var(--sp-3);
  }

  .content-prose h2 {
    font-size: 20px;
  }

  .aside-inner {
    grid-template-columns: 1fr;
  }

  .aside-note {
    grid-column: 1;
  }
}

/* =========================================
   印刷优化
   ========================================= */
@media print {
  .site-header,
  .announce-bar,
  .sticky-anchors,
  .nav-details,
  .content-aside {
    display: none !important;
  }

  .article-layout {
    grid-template-columns: 1fr;
  }

  body {
    color: #000;
    background: #fff;
  }
}