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

:root {
  --ink: #000000;
  --paper: #ffffff;
  --grau: #666666;
  --wash: #f0f0f0;
  --line: #000000;
  --gut: clamp(16px, 4vw, 40px);
  --maxw: 1200px;
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Noto Sans Arabic", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  font-kerning: normal;
}

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

a {
  color: var(--ink);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

a:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
}

/* 顶部细条 */
.band {
  display: flex;
  align-items: center;
  height: 32px;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
  font-size: 13px;
  letter-spacing: 0.3em;
}

.band-run {
  display: flex;
  align-items: center;
  gap: 16px;
  white-space: nowrap;
  padding-left: 16px;
  animation: slide 30s linear infinite;
}

.band-run i {
  font-style: normal;
  opacity: 0.55;
}

@keyframes slide {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* 顶栏 */
.top {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: var(--gut);
  padding: 8px var(--gut);
  background: var(--paper);
  border-bottom: 2px solid var(--line);
}

.mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0 10px;
  background: var(--ink);
  color: var(--paper);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.06em;
  transition: background 0.2s, color 0.2s;
}

.mark:hover {
  background: var(--paper);
  color: var(--ink);
  outline: 2px solid var(--ink);
  outline-offset: -2px;
  text-decoration: none;
}

.nav {
  flex: 1;
  min-width: 0;
}

.nav ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav li {
  display: flex;
}

.nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 2px;
  font-size: 16px;
  letter-spacing: 0.02em;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s;
}

.nav a:hover {
  border-bottom-color: var(--ink);
  text-decoration: none;
}

/* 主栅格 */
.frame {
  display: grid;
  grid-template-columns: minmax(160px, 220px) minmax(0, 1fr);
  gap: clamp(20px, 4vw, 56px);
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(20px, 4vw, 48px) var(--gut);
}

/* 侧栏 */
.rail {
  position: sticky;
  top: 84px;
  align-self: start;
  padding: 18px 16px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.rail small {
  display: block;
  font-size: 13px;
  letter-spacing: 0.34em;
  color: var(--grau);
  margin-bottom: 4px;
}

.rail-t {
  margin: 0 0 12px;
  padding-bottom: 10px;
  font-size: 17px;
  letter-spacing: 0.22em;
  border-bottom: 1px solid var(--line);
}

.rail-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: rl;
}

.rail-list li {
  counter-increment: rl;
  animation: rise 0.5s ease both;
}

.rail-list li:nth-child(2) { animation-delay: 0.05s; }
.rail-list li:nth-child(3) { animation-delay: 0.1s; }
.rail-list li:nth-child(4) { animation-delay: 0.15s; }
.rail-list li:nth-child(5) { animation-delay: 0.2s; }
.rail-list li:nth-child(6) { animation-delay: 0.25s; }
.rail-list li:nth-child(7) { animation-delay: 0.3s; }

.rail-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  min-height: 40px;
  padding: 8px 0;
  font-size: 16px;
  line-height: 1.4;
}

.rail-list a::before {
  content: counter(rl, decimal-leading-zero);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--grau);
}

@keyframes rise {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* 正文 */
main {
  min-width: 0;
}

section {
  counter-reset: sec;
}

section > article {
  position: relative;
  scroll-margin-top: 96px;
  padding: clamp(36px, 6vw, 80px) 0;
}

section > article:not(.hero) {
  border-top: 2px solid var(--line);
  counter-increment: sec;
}

section > article:not(.hero)::before {
  content: counter(sec, decimal-leading-zero);
  position: absolute;
  top: 6px;
  right: 0;
  font-size: clamp(56px, 11vw, 132px);
  font-weight: 700;
  line-height: 0.8;
  letter-spacing: -0.05em;
  color: #e6e6e6;
  pointer-events: none;
}

/* 首屏 */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: clamp(20px, 4vw, 56px);
  min-height: 100vh;
  padding: clamp(24px, 6vw, 64px) 0;
}

.hero-num {
  position: absolute;
  left: 0;
  top: clamp(8px, 3vw, 26px);
  z-index: 0;
  font-size: clamp(64px, 14vw, 168px);
  font-weight: 700;
  line-height: 0.78;
  letter-spacing: -0.06em;
  color: var(--wash);
  pointer-events: none;
}

.hero-copy {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero h1 {
  margin: 0 auto 20px;
  max-width: 20em;
  font-size: clamp(2rem, 4.6vw, 3.6rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  font-weight: 700;
}

.hero-lead {
  margin: 0 auto;
  max-width: 34em;
  color: #333333;
  font-size: 17px;
}

.hero-media {
  position: relative;
  z-index: 1;
  aspect-ratio: 4 / 5;
  overflow: hidden;
  background: var(--ink);
}

.hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(1) contrast(1.06);
}

.hero-fill {
  width: 100%;
  height: 100%;
  background:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.55) 0 1px, transparent 1px 26px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.55) 0 1px, transparent 1px 26px),
    #000000;
}

section h2 {
  margin: 0 0 18px;
  max-width: 26em;
  font-size: clamp(1.5rem, 2.6vw, 2.1rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
}

section h3 {
  margin: 32px 0 10px;
  font-size: 1.15rem;
  line-height: 1.4;
}

section p {
  margin: 0 0 16px;
  max-width: 40em;
}

section ul,
section ol {
  margin: 0 0 18px;
  padding-left: 1.4em;
  max-width: 40em;
}

section li {
  margin: 0 0 8px;
}

section blockquote {
  margin: 24px 0;
  padding: 12px 0 12px 20px;
  border-left: 3px solid var(--line);
  font-size: 1.05rem;
}

section img {
  margin: 24px 0;
  filter: grayscale(1);
}

section a {
  border-bottom: 1px solid var(--line);
}

/* 页脚 */
.foot {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: clamp(20px, 4vw, 56px);
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(28px, 5vw, 56px) var(--gut);
  border-top: 2px solid var(--line);
}

.foot article {
  min-width: 0;
}

.f-mark {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.f-brand {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.16em;
}

.foot small {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  letter-spacing: 0.34em;
  color: var(--grau);
}

.foot h2 {
  margin: 0 0 12px;
  padding-bottom: 8px;
  font-size: 15px;
  letter-spacing: 0.18em;
  border-bottom: 1px solid var(--line);
}

.f-list ol {
  margin: 0;
  padding: 0;
  list-style: none;
  columns: 2;
  column-gap: 20px;
}

.f-list a {
  display: inline-block;
  min-height: 40px;
  padding: 8px 0;
  font-size: 16px;
}

.f-copy p {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: #333333;
}

@media (max-width: 900px) {
  .frame {
    grid-template-columns: minmax(0, 1fr);
  }

  main {
    order: 1;
  }

  .rail {
    order: 2;
    position: static;
  }

  .rail-list {
    columns: 2;
    column-gap: 20px;
  }

  .hero {
    grid-template-columns: minmax(0, 1fr);
    min-height: auto;
    gap: 24px;
    padding-top: 36px;
  }

  .hero-media {
    aspect-ratio: 16 / 10;
  }

  .foot {
    grid-template-columns: 1fr 1fr;
  }

  .f-copy {
    grid-column: 1 / -1;
    padding-top: 16px;
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 700px) {
  .nav ol {
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
  }

  .nav ol::-webkit-scrollbar {
    display: none;
  }

  .nav a {
    white-space: nowrap;
  }

  .rail-list {
    columns: 1;
  }

  .f-list ol {
    columns: 1;
  }

  section > article:not(.hero)::before {
    top: 4px;
    font-size: 52px;
  }
}

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

  .band-run {
    animation: none;
  }

  .rail-list li {
    animation: none;
  }

  .mark,
  .nav a {
    transition: none;
  }
}

button[aria-expanded]{min-width:44px;min-height:44px}