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

/* ===================== 重置与基础 ===================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --c-cream: #f5e6c8;
  --c-amber: #d4a574;
  --c-dark:  #262117;
  --c-dark2: #3a3020;
  --c-amber-light: #e8c99a;
  --c-amber-dim:   #b8895a;
  --c-cream-dim:   #e8d4a8;
  --c-shadow: rgba(38,33,23,0.18);
  --sidebar-w: 220px;
  --font-main: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --radius: 4px;
  --transition: 0.28s ease;
}

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

body {
  font-family: var(--font-main);
  font-weight: 400;
  line-height: 1.75;
  background: var(--c-cream);
  overflow-x: hidden;
  min-height: 100vh;
}

body.nav-open { overflow: hidden; }

/* ===================== Film Grain ===================== */
.grain-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23g)' opacity='0.06'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px 180px;
  opacity: 0.55;
  mix-blend-mode: multiply;
}

/* ===================== Light Leak ===================== */
.light-leak {
  position: fixed;
  top: -20%;
  right: -10%;
  width: 55vw;
  height: 65vh;
  pointer-events: none;
  z-index: 999;
  background: radial-gradient(ellipse at 60% 30%, rgba(212,165,116,0.18) 0%, rgba(245,230,200,0.08) 50%, transparent 75%);
  animation: leakMove 9s ease-in-out infinite alternate;
}

@keyframes leakMove {
  from { transform: translate(0,0) scale(1); opacity: 0.7; }
  to   { transform: translate(-4vw, 3vh) scale(1.08); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .light-leak { animation: none; }
  html { scroll-behavior: auto; }
}

/* ===================== 侧边导航 ===================== */
.sidebar-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--c-dark);
  color: var(--c-cream);
  display: flex;
  flex-direction: column;
  z-index: 200;
  overflow-y: auto;
  border-right: 2px solid var(--c-amber-dim);
  padding: 0;
  transition: transform var(--transition);
}

.nav-brand {
  padding: 28px 20px 20px;
  border-bottom: 1px solid rgba(212,165,116,0.25);
}

.brand-link {
  display: block;
  text-decoration: none;
  color: var(--c-amber);
}

.logo-text {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.6;
  display: block;
  padding: 4px 0;
}

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

/* nav > ol > li > a 结构 */
.nav-list {
  list-style: none;
  padding: 16px 0;
  flex: 1;
}

.nav-list li {
  border-bottom: 1px solid rgba(212,165,116,0.1);
}

.nav-list li a {
  display: flex;
  align-items: center;
  padding: 12px 20px;
  font-size: 0.82rem;
  font-weight: 400;
  color: var(--c-cream-dim);
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: background var(--transition), color var(--transition), padding-left var(--transition);
  min-height: 44px;
}

.nav-list li a:hover,
.nav-list li a:focus-visible {
  background: rgba(212,165,116,0.15);
  color: var(--c-amber);
  padding-left: 28px;
  outline: none;
}

.nav-cta {
  padding: 20px;
  border-top: 1px solid rgba(212,165,116,0.25);
}

.cta-btn {
  display: block;
  text-align: center;
  padding: 12px 16px;
  background: var(--c-amber);
  color: var(--c-dark);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  border-radius: var(--radius);
  text-decoration: none;
  transition: background var(--transition), transform var(--transition);
  min-height: 44px;
  line-height: 1.2;
}

.cta-btn:hover { background: var(--c-amber-light); transform: translateY(-1px); }

/* 汉堡按钮（仅移动端） */
.nav-toggle {
  display: none;
  position: fixed;
  top: 14px;
  left: 14px;
  z-index: 300;
  width: 44px;
  height: 44px;
  background: var(--c-dark);
  border: 1px solid var(--c-amber-dim);
  border-radius: var(--radius);
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  padding: 10px;
}

.toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--c-amber);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

/* ===================== 主内容区 ===================== */
.main-content {
  margin-left: var(--sidebar-w);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.page-article {
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* ===================== Hero ===================== */
.hero-section {
  position: relative;
  width: 100%;
  height: 70vh;
  min-height: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  scroll-margin-top: 0;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: sepia(0.45) contrast(1.05) saturate(0.75);
  display: block;
}

.hero-mask {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    160deg,
    rgba(38,33,23,0.72) 0%,
    rgba(38,33,23,0.45) 50%,
    rgba(38,33,23,0.65) 100%
  );
}

.vhs-track {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(38,33,23,0.04) 2px,
    rgba(38,33,23,0.04) 4px
  );
  animation: vhsShift 8s steps(1) infinite;
  z-index: 1;
}

@keyframes vhsShift {
  0%,100% { transform: skewX(0deg) translateY(0); opacity: 0.6; }
  10%      { transform: skewX(0.3deg) translateY(-1px); opacity: 0.8; }
  20%      { transform: skewX(0deg) translateY(0); opacity: 0.6; }
  85%      { transform: skewX(-0.2deg) translateY(1px); opacity: 0.7; }
  90%      { transform: skewX(0deg) translateY(0); opacity: 0.6; }
}

@media (prefers-reduced-motion: reduce) {
  .vhs-track { animation: none; }
}

.hero-inner {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 24px;
  max-width: 760px;
}

.hero-eyebrow {
  font-size: 0.72rem;
  font-weight: 300;
  letter-spacing: 0.35em;
  color: var(--c-amber);
  margin-bottom: 16px;
  opacity: 0.85;
}

.hero-h1 {
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  font-weight: 700;
  color: var(--c-cream);
  line-height: 1.25;
  letter-spacing: 0.04em;
  margin-bottom: 18px;
  text-shadow: 0 2px 12px rgba(38,33,23,0.5);
}

.hero-desc {
  font-size: 1rem;
  font-weight: 300;
  color: var(--c-cream-dim);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.7;
  opacity: 0.9;
}

.hero-bg-text {
  position: absolute;
  bottom: -0.15em;
  right: 0;
  font-size: clamp(6rem, 18vw, 14rem);
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1px rgba(212,165,116,0.12);
  letter-spacing: 0.05em;
  pointer-events: none;
  line-height: 1;
  z-index: 0;
  user-select: none;
}

/* ===================== 内容区（侧边栏 + 主文） ===================== */
.content-wrapper {
  display: flex;
  align-items: flex-start;
  gap: 0;
  flex: 1;
}

/* aside 在内容左侧 */
.content-aside {
  width: 220px;
  flex-shrink: 0;
  background: var(--c-dark2);
  border-right: 1px solid rgba(212,165,116,0.2);
  min-height: 100%;
  position: sticky;
  top: 0;
  max-height: 100vh;
  overflow-y: auto;
}

.aside-inner {
  padding: 32px 18px 24px;
}

.aside-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--c-amber-dim);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(212,165,116,0.2);
}

.aside-nav-list {
  list-style: none;
  padding: 0;
  margin-bottom: 32px;
}

.aside-nav-list li {
  border-bottom: 1px solid rgba(212,165,116,0.08);
}

.aside-nav-list li a {
  display: block;
  padding: 10px 4px;
  font-size: 0.78rem;
  color: var(--c-cream-dim);
  text-decoration: none;
  line-height: 1.45;
  transition: color var(--transition), padding-left var(--transition);
  min-height: 40px;
}

.aside-nav-list li a:hover,
.aside-nav-list li a:focus-visible {
  color: var(--c-amber);
  padding-left: 8px;
  outline: none;
}

.aside-stamp {
  display: flex;
  flex-direction: column;
  align-items: center;
  border: 2px solid var(--c-amber-dim);
  border-radius: var(--radius);
  padding: 12px 8px;
  opacity: 0.5;
  margin-top: 8px;
}

.stamp-text {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--c-amber);
  letter-spacing: 0.1em;
}

.stamp-sub {
  font-size: 0.6rem;
  letter-spacing: 0.15em;
  color: var(--c-amber-dim);
  margin-top: 2px;
}

/* ===================== 主文内容 ===================== */
.content-main {
  flex: 1;
  padding: 48px 48px 64px;
  max-width: 880px;
  min-width: 0;
}

.section-intro-title {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--c-amber-dim);
  margin-bottom: 8px;
}

.section-hr {
  border: none;
  border-top: 1px solid rgba(212,165,116,0.35);
  margin-bottom: 36px;
}

/* page.content 内的通用样式 */
.content-main section {
  margin-bottom: 56px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(212,165,116,0.18);
}

.content-main section:last-child {
  border-bottom: none;
}

.content-main h2 {
  font-size: clamp(1.25rem, 2.5vw, 1.75rem);
  font-weight: 700;
  color: var(--c-dark);
  margin-bottom: 10px;
  letter-spacing: 0.02em;
  line-height: 1.3;
}

.content-main h2 + hr {
  border: none;
  border-top: 2px solid var(--c-amber);
  margin-bottom: 24px;
  width: 48px;
}

.content-main h3 {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--c-dark2);
  margin: 28px 0 10px;
  letter-spacing: 0.02em;
}

.content-main h3 + hr {
  border: none;
  border-top: 1px solid var(--c-amber-dim);
  margin-bottom: 16px;
  width: 32px;
}

.content-main p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--c-dark);
  margin-bottom: 16px;
}

.content-main ul,
.content-main ol {
  padding-left: 1.5em;
  margin-bottom: 16px;
}

.content-main li {
  margin-bottom: 8px;
  line-height: 1.7;
  font-size: 0.97rem;
}

.content-main a {
  color: var(--c-amber-dim);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

.content-main a:hover { color: var(--c-dark); }

.content-main strong {
  font-weight: 700;
  color: var(--c-dark2);
}

.content-main blockquote {
  border-left: 3px solid var(--c-amber);
  padding: 12px 20px;
  background: rgba(212,165,116,0.08);
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 24px 0;
  font-style: italic;
  color: var(--c-dark2);
}

/* 玻璃拟态卡片 */
.content-main .card,
.card {
  background: rgba(245,230,200,0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(212,165,116,0.4);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 20px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.content-main .card:hover,
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px var(--c-shadow);
}

/* ===================== 滚动偏移 ===================== */
section[id] { scroll-margin-top: 24px; }

/* ===================== 页脚 ===================== */
.site-footer {
  margin-left: var(--sidebar-w);
  background: var(--c-dark);
  border-top: 2px solid var(--c-amber-dim);
  padding: 40px 48px 32px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.footer-brand {
  font-size: clamp(1.8rem, 5vw, 3.5rem);
  font-weight: 700;
  color: var(--c-amber);
  letter-spacing: 0.04em;
  line-height: 1.1;
  opacity: 0.85;
  filter: sepia(0.3);
}

.site-footer small {
  font-size: 0.78rem;
  color: rgba(245,230,200,0.45);
  letter-spacing: 0.04em;
  line-height: 1.6;
  display: block;
}

/* ===================== 响应式 ===================== */
@media (max-width: 1024px) {
  .content-aside { width: 180px; }
  .content-main  { padding: 36px 32px 48px; }
}

@media (max-width: 768px) {
  :root { --sidebar-w: 0px; }

  .sidebar-nav {
    transform: translateX(-100%);
    width: 260px;
    box-shadow: 4px 0 24px rgba(38,33,23,0.4);
  }

  .sidebar-nav.is-open { transform: translateX(0); }

  .nav-toggle { display: flex; }

  .main-content { margin-left: 0; }
  .site-footer  { margin-left: 0; padding: 32px 20px 24px; }

  .hero-section { height: 70vh; }
  .hero-h1 { font-size: 1.7rem; }

  .content-wrapper { flex-direction: column; }

  .content-aside {
    width: 100%;
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid rgba(212,165,116,0.2);
  }

  .aside-inner { padding: 20px 20px 16px; }

  .aside-nav-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0 16px;
  }

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

  .aside-stamp { display: none; }

  .content-main { padding: 28px 20px 40px; }

  .section-intro-title { font-size: 0.65rem; }
}

@media (max-width: 480px) {
  .hero-h1      { font-size: 1.45rem; }
  .hero-eyebrow { letter-spacing: 0.2em; }
  .hero-desc    { font-size: 0.9rem; }
  .footer-brand { font-size: 1.6rem; }
  .content-main h2 { font-size: 1.2rem; }
}

/* ===================== 品牌链接移动端 tap 区域 ===================== */
@media (max-width: 768px) {
  .brand-link {
    min-height: 44px;
    display: flex;
    align-items: center;
  }
}

/* ===================== Hover 微交互 ===================== */
@media (hover: hover) {
  .nav-list li a,
  .aside-nav-list li a,
  .cta-btn {
    position: relative;
  }
  .nav-list li a::after {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 2px;
    height: 0;
    background: var(--c-amber);
    transition: height var(--transition), top var(--transition);
    transform: translateY(-50%);
  }
  .nav-list li a:hover::after {
    height: 60%;
    top: 50%;
  }
}

/* ===================== 焦点可见样式 ===================== */
:focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 2px;
}

/* ===================== 图片基础 ===================== */
img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* ===================== 选中文字颜色 ===================== */
::selection {
  background: var(--c-amber);
  color: var(--c-dark);
}