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

/* ===== CSS 变量 ===== */
:root {
  --c-bg: #0D0D1A;
  --c-surface: #1A1A2E;
  --c-accent: #FF2D6B;
  --c-accent-dim: rgba(255,45,107,0.18);
  --c-text: #F0EFF8;
  --c-muted: #8A89A0;
  --c-border: rgba(255,45,107,0.22);
  --c-glass: rgba(26,26,46,0.72);
  --nav-w: 220px;
  --font-head: 'Rubik', 'Nunito Sans', system-ui, sans-serif;
  --font-body: 'Nunito Sans', 'Rubik', system-ui, sans-serif;
  --radius: 0;
  --transition: 0.28s cubic-bezier(0.4,0,0.2,1);
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  scroll-behavior: smooth;
  font-size: 16px;
  background: var(--c-bg);
  color: var(--c-text);
}
body, .body-dark {
  font-family: var(--font-body);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
ul { list-style: none; }

/* ===== 布局骨架 ===== */
.site-wrapper {
  display: flex;
  min-height: 100vh;
}

/* ===== 左侧固定竖排导航 ===== */
.side-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--nav-w);
  height: 100vh;
  background: var(--c-glass);
  backdrop-filter: blur(18px) saturate(1.4);
  -webkit-backdrop-filter: blur(18px) saturate(1.4);
  border-right: 1px solid var(--c-border);
  display: flex;
  flex-direction: column;
  padding: 2rem 1.2rem 1.5rem;
  z-index: 100;
  overflow-y: auto;
  transition: transform var(--transition);
}

.nav-brand {
  margin-bottom: 2.5rem;
}
.brand-link {
  display: block;
  text-decoration: none;
}
.logo-img {
  max-height: 44px;
  width: auto;
}
.logo-text {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--c-text);
  letter-spacing: 0.04em;
  line-height: 1.3;
  display: block;
  word-break: break-all;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  flex: 1;
}
.nav-list li {
  opacity: 0;
  transform: translateX(-14px);
  animation: navSlideIn 0.45s var(--transition) forwards;
  animation-delay: calc(var(--i) * 0.07s + 0.15s);
}
@keyframes navSlideIn {
  to { opacity: 1; transform: translateX(0); }
}

.nav-link {
  display: flex;
  align-items: center;
  font-family: var(--font-head);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--c-muted);
  padding: 0.65rem 0.75rem;
  border-left: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition), background var(--transition);
  letter-spacing: 0.02em;
  min-height: 44px;
  text-decoration: none;
}
.nav-link:hover {
  color: var(--c-accent);
  border-left-color: var(--c-accent);
  background: var(--c-accent-dim);
  text-decoration: none;
}

.nav-cta-wrap {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--c-border);
}
.btn-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--c-accent);
  color: #fff;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.9rem;
  padding: 0.75rem 1rem;
  min-height: 44px;
  letter-spacing: 0.04em;
  transition: opacity var(--transition), transform var(--transition);
  text-decoration: none;
}
.btn-cta:hover {
  opacity: 0.88;
  transform: translateY(-1px);
  text-decoration: none;
}

/* ===== 汉堡按钮（移动端） ===== */
.nav-toggle-wrap {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 200;
}
.nav-toggle {
  background: var(--c-glass);
  border: 1px solid var(--c-border);
  width: 44px;
  height: 44px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  padding: 0.5rem;
  backdrop-filter: blur(8px);
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--c-text);
  transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 主内容区 ===== */
.main-wrap {
  margin-left: var(--nav-w);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* ===== Hero ===== */
.hero-section {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--c-bg) 55%, var(--c-surface) 100%);
}
.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 80% at 80% 50%, rgba(255,45,107,0.12) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  padding: 4rem 3rem 4rem 3.5rem;
  position: relative;
  z-index: 2;
}
.hero-eyebrow {
  font-family: var(--font-head);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 1.2rem;
  opacity: 0;
  animation: fadeUp 0.6s ease forwards 0.2s;
}
.hero-h1 {
  font-family: var(--font-head);
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--c-text);
  margin-bottom: 1.2rem;
  opacity: 0;
  animation: fadeUp 0.6s ease forwards 0.4s;
  letter-spacing: -0.01em;
}
.hero-sub {
  font-size: 1rem;
  color: var(--c-muted);
  margin-bottom: 2rem;
  max-width: 420px;
  line-height: 1.7;
  opacity: 0;
  animation: fadeUp 0.6s ease forwards 0.6s;
}
.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.6s ease forwards 0.8s;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  background: var(--c-accent);
  color: #fff;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.8rem 2rem;
  min-height: 44px;
  letter-spacing: 0.05em;
  transition: transform var(--transition), box-shadow var(--transition);
  text-decoration: none;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(255,45,107,0.38);
  text-decoration: none;
}
.btn-ghost {
  display: inline-flex;
  align-items: center;
  background: transparent;
  color: var(--c-text);
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.8rem 1.8rem;
  min-height: 44px;
  border: 1px solid var(--c-border);
  letter-spacing: 0.04em;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
  text-decoration: none;
}
.btn-ghost:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
  background: var(--c-accent-dim);
  text-decoration: none;
}

/* Hero 右侧装饰 */
.hero-deco {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero-slash {
  position: absolute;
  left: -60px;
  top: 0;
  width: 90px;
  height: 100%;
  background: var(--c-accent);
  clip-path: polygon(40% 0, 100% 0, 60% 100%, 0 100%);
  opacity: 0.18;
}
.hero-kinetic {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  z-index: 2;
}
.kt-word {
  font-family: var(--font-head);
  font-size: clamp(3rem, 8vw, 6.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
  background: linear-gradient(135deg, var(--c-text) 30%, var(--c-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0;
  transform: translateY(30px) skewX(-6deg);
  display: block;
}
.kt-word:nth-child(1) { animation: ktRise 0.7s cubic-bezier(0.22,1,0.36,1) forwards 0.5s; }
.kt-word:nth-child(2) { animation: ktRise 0.7s cubic-bezier(0.22,1,0.36,1) forwards 0.72s; }
.kt-word:nth-child(3) { animation: ktRise 0.7s cubic-bezier(0.22,1,0.36,1) forwards 0.94s; }
@keyframes ktRise {
  to { opacity: 1; transform: translateY(0) skewX(0deg); }
}

/* ===== 正文主容器 ===== */
.content-main {
  background: var(--c-bg);
  position: relative;
  z-index: 1;
}
.content-article {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 2rem 4rem;
}
.page-content-section {
  padding-top: 1rem;
}

/* ===== page.content 内的 div 样式 ===== */
.content-article div,
.page-content-section div {
  padding: 4rem 0 2rem;
  border-top: 1px solid var(--c-border);
  scroll-margin-top: 80px;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.content-article div.is-visible,
.page-content-section div.is-visible {
  opacity: 1;
  transform: translateY(0);
}
.content-article div:first-child,
.page-content-section div:first-child {
  border-top: none;
}

/* div 内文字排版 */
.content-article h2,
.page-content-section h2 {
  font-family: var(--font-head);
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
  font-weight: 700;
  color: var(--c-text);
  margin-bottom: 0.5rem;
  line-height: 1.2;
  position: relative;
  padding-left: 1rem;
}
.content-article h2::before,
.page-content-section h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.15em;
  width: 3px;
  height: 0.85em;
  background: var(--c-accent);
}
.content-article p.subtitle,
.content-article p.subhead,
.content-article p.desc,
.content-article p.lead,
.page-content-section p.subtitle,
.page-content-section p.subhead,
.page-content-section p.desc,
.page-content-section p.lead {
  color: var(--c-accent);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 1.2rem;
  padding-left: 1rem;
}
.content-article h3 {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--c-text);
  margin: 1.6rem 0 0.6rem;
}
.content-article p,
.page-content-section p {
  color: var(--c-muted);
  font-size: 1rem;
  line-height: 1.75;
  margin-bottom: 1rem;
  max-width: 68ch;
}
.content-article ul,
.content-article ol,
.page-content-section ul,
.page-content-section ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
  color: var(--c-muted);
  font-size: 1rem;
  line-height: 1.75;
}
.content-article li,
.page-content-section li {
  margin-bottom: 0.4rem;
  list-style: disc;
}
.content-article a,
.page-content-section a {
  color: var(--c-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.content-article a:hover,
.page-content-section a:hover {
  opacity: 0.8;
}

/* 玻璃拟态卡片 */
.glass-card {
  background: var(--c-glass);
  border: 1px solid var(--c-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 1.5rem;
  margin: 1.5rem 0;
  transition: border-color var(--transition), transform var(--transition);
}
.glass-card:hover {
  border-color: var(--c-accent);
  transform: translateY(-2px);
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  position: relative;
  overflow: hidden;
}
.footer-brand-big {
  font-family: var(--font-head);
  font-size: clamp(3rem, 10vw, 7rem);
  font-weight: 700;
  color: rgba(255,255,255,0.03);
  letter-spacing: 0.05em;
  line-height: 1;
  padding: 2rem 2rem 0;
  pointer-events: none;
  user-select: none;
  white-space: nowrap;
  overflow: hidden;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  padding: 2rem 2rem 1.5rem;
  max-width: 960px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.footer-desc {
  color: var(--c-muted);
  font-size: 0.88rem;
  line-height: 1.7;
  max-width: 28ch;
}
.footer-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.footer-nav-list a {
  color: var(--c-muted);
  font-size: 0.85rem;
  padding: 0.5rem 0;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  transition: color var(--transition);
  text-decoration: none;
}
.footer-nav-list a:hover {
  color: var(--c-accent);
}
.footer-bar {
  border-top: 1px solid var(--c-border);
  padding: 1rem 2rem;
  text-align: center;
}
.footer-copy {
  color: var(--c-muted);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  margin: 0;
  max-width: none;
}

/* ===== scroll div 锚点偏移 ===== */
div[id] {
  scroll-margin-top: 80px;
}

/* ===== 动效关键帧 ===== */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ===== 减弱动效 ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .kt-word { opacity: 1; transform: none; }
  .nav-list li { opacity: 1; transform: none; }
  .hero-eyebrow, .hero-h1, .hero-sub, .hero-actions { opacity: 1; }
  .content-article div,
  .page-content-section div { opacity: 1; transform: none; }
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  :root { --nav-w: 0px; }
  .side-nav {
    width: 240px;
    transform: translateX(-100%);
  }
  .side-nav.is-open {
    transform: translateX(0);
    box-shadow: 4px 0 40px rgba(0,0,0,0.6);
  }
  .nav-toggle-wrap {
    display: block;
  }
  .main-wrap {
    margin-left: 0;
  }
  .hero-section {
    grid-template-columns: 1fr;
    min-height: 100vh;
    padding-top: 5rem;
  }
  .hero-content {
    padding: 3rem 1.5rem 2rem;
  }
  .hero-deco {
    display: none;
  }
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .footer-desc { max-width: none; }
}

@media (max-width: 600px) {
  .hero-h1 { font-size: 2rem; }
  .hero-content { padding: 2.5rem 1.2rem 2rem; }
  .content-article { padding: 0 1.2rem 3rem; }
  .hero-actions { gap: 0.75rem; }
  .btn-primary, .btn-ghost { font-size: 0.88rem; padding: 0.7rem 1.4rem; }
  .footer-inner { padding: 1.5rem 1.2rem 1rem; }
  .footer-bar { padding: 1rem 1.2rem; }
  .footer-brand-big { font-size: 2.5rem; }
}

@media (max-width: 375px) {
  html { font-size: 15px; }
  .hero-h1 { font-size: 1.75rem; }
}

/* ===== overlay for mobile nav ===== */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.55);
  z-index: 90;
  backdrop-filter: blur(2px);
}
.nav-overlay.is-active { display: block; }