@import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

/* ============================================================
   CSS 变量 & 重置
   ============================================================ */
:root {
  --c-white: #ffffff;
  --c-light: #f5f5f5;
  --c-dark: #1f1f1f;
  --c-mid: #2e2e2e;
  --c-border: #333333;
  --c-accent: #e0e0e0;
  --c-dim: rgba(255,255,255,0.06);

  --shadow-sm: 0 2px 8px rgba(0,0,0,0.55);
  --shadow-md: 0 6px 20px rgba(0,0,0,0.6);
  --shadow-lg: 0 14px 40px rgba(0,0,0,0.65);
  --shadow-xl: 0 28px 64px rgba(0,0,0,0.75);

  --radius-card: 28px;
  --nav-height: 110px;
  --font-display: 'Bebas Neue', 'Arial Black', sans-serif;
  --font-body: 'Source Sans 3', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --ease-out: cubic-bezier(0.22,1,0.36,1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background: var(--c-dark);
  color: var(--c-white);
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  background: var(--c-dark);
  color: var(--c-white);
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font: inherit; }

/* scroll-margin for fixed header */
section[id] { scroll-margin-top: 120px; }

/* ============================================================
   页面根层
   ============================================================ */
.page-root {
  position: relative;
  z-index: 1;
}

/* ============================================================
   HEADER — 两行：品牌行 + 导航行
   ============================================================ */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(31,31,31,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  box-shadow: var(--shadow-md);
}

.header-brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 2rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-logo {
  height: 36px;
  width: auto;
}

.brand-text {
  font-family: var(--font-display);
  font-size: 2rem;
  letter-spacing: 0.05em;
  color: var(--c-white);
  line-height: 1;
}

/* 汉堡按钮 */
.menu-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 10px 8px;
  min-height: 44px;
  justify-content: center;
  z-index: 101;
}

.hamburger-line {
  display: block;
  width: 28px;
  height: 2px;
  background: var(--c-white);
  transition: transform 0.3s var(--ease-out), opacity 0.3s;
  transform-origin: center;
}

.menu-toggle.is-active .hamburger-line:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.is-active .hamburger-line:nth-child(2) { opacity: 0; }
.menu-toggle.is-active .hamburger-line:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 导航行 */
.header-nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
}

.header-aside {
  flex: 1;
}

.desktop-nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
}

.desktop-nav-list li a {
  display: block;
  padding: 0.55rem 0.9rem;
  font-size: 0.88rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: rgba(255,255,255,0.75);
  transition: color 0.2s;
  min-height: 44px;
  line-height: 44px;
  white-space: nowrap;
}

.desktop-nav-list li a:hover { color: var(--c-white); }

.contact-entry {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--c-border);
  border-radius: 4px;
  white-space: nowrap;
  min-height: 40px;
  display: flex;
  align-items: center;
}

/* ============================================================
   全屏遮罩菜单
   ============================================================ */
.fullscreen-menu {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: var(--c-dark);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  padding: 2rem 4rem;
  transform: translateX(-100%);
  transition: transform 0.5s var(--ease-out);
  overflow: hidden;
}

.fullscreen-menu.is-open {
  transform: translateX(0);
}

.menu-close {
  position: absolute;
  top: 1.5rem;
  right: 2rem;
  font-size: 2rem;
  color: var(--c-white);
  padding: 0.5rem;
  min-height: 44px;
  min-width: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.fs-menu-aside {
  width: 100%;
}

.fs-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.fs-nav-list li {
  overflow: hidden;
  opacity: 0;
  transform: translateX(-40px);
  transition:
    opacity 0.45s var(--ease-out) calc(var(--i, 0) * 0.06s),
    transform 0.45s var(--ease-out) calc(var(--i, 0) * 0.06s);
}

.fullscreen-menu.is-open .fs-nav-list li {
  opacity: 1;
  transform: translateX(0);
}

.fs-nav-list li a {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 6vw, 4.5rem);
  letter-spacing: 0.02em;
  color: var(--c-white);
  line-height: 1.15;
  padding: 0.25rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  transition: color 0.2s, padding-left 0.2s;
  min-height: 44px;
}

.fs-nav-list li a:hover {
  color: var(--c-accent);
  padding-left: 0.5rem;
}

.fs-brand-decor {
  position: absolute;
  right: -2rem;
  bottom: -3rem;
  font-family: var(--font-display);
  font-size: clamp(6rem, 22vw, 18rem);
  color: rgba(255,255,255,0.03);
  pointer-events: none;
  user-select: none;
  line-height: 1;
  z-index: 0;
}

/* ============================================================
   HERO — 满屏 100vh，双图错位，斜切色带
   ============================================================ */
.hero-section {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--c-dark);
  padding-top: var(--nav-height);
  overflow: hidden;
  z-index: 1;
}

/* 斜切色带装饰 */
.hero-slash {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.04) 0%, transparent 50%);
  clip-path: polygon(0 0, 58% 0, 42% 100%, 0 100%);
  z-index: 0;
  pointer-events: none;
}

.hero-slash::after {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 3px;
  height: 100%;
  background: rgba(255,255,255,0.15);
  transform: skewX(-8deg) translateX(30vw);
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 1300px;
  margin: 0 auto;
  padding: 4rem 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

/* 文案左对齐 */
.hero-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1.2rem;
}

.hero-eyebrow {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.5);
  border-left: 3px solid var(--c-white);
  padding-left: 0.7rem;
}

.hero-h1 {
  font-family: var(--font-display);
  font-size: clamp(3.5rem, 8vw, 7rem);
  line-height: 1.0;
  letter-spacing: 0.02em;
  color: var(--c-white);
  text-shadow: var(--shadow-lg);
}

.hero-sub {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.65);
  max-width: 38ch;
  line-height: 1.7;
}

.hero-cta {
  display: inline-block;
  padding: 0.85rem 2.2rem;
  background: var(--c-white);
  color: var(--c-dark);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.05em;
  border-radius: 4px;
  box-shadow: var(--shadow-lg);
  transition: transform 0.2s var(--ease-out), box-shadow 0.2s;
  min-height: 44px;
  line-height: 44px;
  padding-top: 0; padding-bottom: 0;
}

.hero-cta:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

/* 双图错位拼贴 */
.hero-media {
  position: relative;
  height: 480px;
}

.hero-card {
  position: absolute;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.08);
}

.hero-card-back {
  width: 72%;
  height: 75%;
  bottom: 0; right: 0;
  z-index: 2;
  box-shadow: var(--shadow-lg);
  transform: translateZ(0) rotate(2.5deg);
  background: var(--c-mid);
}

.hero-card-front {
  width: 68%;
  height: 70%;
  top: 0; left: 0;
  z-index: 4;
  box-shadow: var(--shadow-xl);
  transform: translateZ(20px) rotate(-2deg);
  background: #2a2a2a;
}

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

.hero-placeholder {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #2a2a2a 0%, #3a3a3a 100%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-placeholder-front {
  background: linear-gradient(135deg, #333 0%, #444 100%);
}

/* ============================================================
   MAIN 正文容器
   ============================================================ */
.site-main {
  position: relative;
  z-index: 2;
  background: var(--c-dark);
}

.wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

.content-section {
  padding: 4rem 0;
}

.content-article {
  width: 100%;
}

/* ============================================================
   正文内容样式（page.content 内部）
   ============================================================ */
.content-article h2,
.site-main h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  letter-spacing: 0.03em;
  color: var(--c-white);
  line-height: 1.1;
  margin-top: 3.5rem;
  margin-bottom: 1rem;
}

.content-article h3,
.site-main h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--c-white);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.content-article p,
.site-main p {
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(255,255,255,0.78);
  margin-bottom: 1rem;
}

.content-article ul,
.content-article ol,
.site-main ul,
.site-main ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
  color: rgba(255,255,255,0.78);
}

.content-article li,
.site-main li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.content-article a,
.site-main a {
  color: var(--c-white);
  border-bottom: 1px solid rgba(255,255,255,0.3);
  transition: border-color 0.2s;
}

.content-article a:hover,
.site-main a:hover {
  border-color: var(--c-white);
}

/* small 眉题（契约：h2 前的 <small>） */
.content-article small,
.site-main small {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  color: rgba(255,255,255,0.4);
  text-transform: uppercase;
  margin-top: 3rem;
  margin-bottom: 0.3rem;
}

/* section 区块分隔 */
.content-article section,
.site-main section:not(.hero-section):not(.content-section) {
  border-top: 1px solid rgba(255,255,255,0.07);
  padding-top: 1rem;
  position: relative;
}

/* 斜切色带区块分隔 */
.content-article section + section::before,
.site-main .content-section section + section::before {
  content: '';
  display: block;
  height: 3px;
  background: linear-gradient(90deg, rgba(255,255,255,0.2), transparent);
  margin-bottom: 2rem;
}

/* 卡片式块（正文内 Q&A 或列表块） */
.content-article .card-block,
.site-main .card-block {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-card);
  padding: 2rem 2.2rem;
  margin: 1.5rem 0;
  position: relative;
  z-index: 2;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, transform 0.3s;
}

.content-article .card-block:hover,
.site-main .card-block:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* ============================================================
   层次感浮动装饰层
   ============================================================ */
.layer-3 { z-index: 3; }
.layer-4 { z-index: 4; }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: #111111;
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 0;
  position: relative;
  z-index: 2;
}

/* 大 CTA 块 */
.footer-cta-block {
  background: var(--c-white);
  color: var(--c-dark);
  padding: 4rem 2rem 3.5rem;
  text-align: center;
  position: relative;
  clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
  margin-bottom: -1px;
}

.footer-eyebrow {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(31,31,31,0.5);
  margin-bottom: 0.5rem;
}

.footer-cta-h2 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 5rem);
  letter-spacing: 0.03em;
  color: var(--c-dark);
  line-height: 1.1;
  margin-bottom: 1.5rem;
}

.footer-cta-btn {
  display: inline-block;
  padding: 0.85rem 2.5rem;
  background: var(--c-dark);
  color: var(--c-white);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.05em;
  border-radius: 4px;
  box-shadow: var(--shadow-md);
  transition: transform 0.2s, box-shadow 0.2s;
  min-height: 44px;
  line-height: 44px;
  padding-top: 0; padding-bottom: 0;
}

.footer-cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* 三栏 dl */
.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 3rem 2rem 2rem;
}

.footer-dl dt {
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: 0.05em;
  color: var(--c-white);
  margin-bottom: 1rem;
  border-bottom: 2px solid rgba(255,255,255,0.12);
  padding-bottom: 0.5rem;
}

.footer-dl dd {
  font-size: 0.92rem;
  color: rgba(255,255,255,0.55);
  line-height: 1.7;
  margin-bottom: 0.5rem;
}

.footer-dl dd a {
  color: rgba(255,255,255,0.55);
  border-bottom: none;
  transition: color 0.2s;
  min-height: 40px;
  display: inline-flex;
  align-items: center;
}

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

/* 版权一行 */
.footer-bottom {
  text-align: center;
  padding: 1rem 2rem 1.5rem;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.25);
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.footer-sep {
  opacity: 0.4;
}

/* ============================================================
   滚动揭示动效（Scroll Reveal · Subtle）
   ============================================================ */
.sr {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.65s var(--ease-out), transform 0.65s var(--ease-out);
}

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

@media (prefers-reduced-motion: reduce) {
  .sr { opacity: 1; transform: none; transition: none; }
  .fs-nav-list li { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .hero-cta, .footer-cta-btn { transition: none; }
}

/* ============================================================
   移动端响应
   ============================================================ */
@media (max-width: 768px) {
  :root { --nav-height: 100px; }

  .header-nav-row { display: none; }

  .header-brand-row { padding: 0.6rem 1.2rem; }

  .hero-inner {
    grid-template-columns: 1fr;
    padding: 3rem 1.2rem 2rem;
    gap: 2rem;
  }

  .hero-media {
    height: 300px;
    order: -1;
  }

  .hero-h1 { font-size: clamp(2.8rem, 12vw, 4.5rem); }

  .hero-card-back { width: 75%; height: 70%; }
  .hero-card-front { width: 70%; height: 65%; }

  .wrap { padding: 0 1.2rem; }

  .content-section { padding: 2.5rem 0; }

  .footer-cols {
    grid-template-columns: 1fr;
    padding: 2rem 1.2rem;
    gap: 1.5rem;
  }

  .footer-cta-block {
    padding: 3rem 1.2rem 3rem;
    clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
  }

  .footer-bottom { gap: 0.3rem; }

  .fullscreen-menu { padding: 2rem 1.5rem; }

  .fs-nav-list li a { font-size: clamp(1.8rem, 10vw, 3rem); }

  section[id] { scroll-margin-top: 105px; }
}

@media (max-width: 480px) {
  .brand-text { font-size: 1.6rem; }
  .hero-media { height: 240px; }
  .footer-cta-h2 { font-size: 2.2rem; }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .hero-inner { gap: 2rem; padding: 3rem 1.5rem; }
  .footer-cols { padding: 2.5rem 1.5rem; }
  .wrap { padding: 0 1.5rem; }
}