/* ==========================================================
   Aterl-DistSim 官网样式 · 南孚全球站式品牌语言
   黑白大色块对比 / 超大左对齐粗标题 / 品牌蓝点睛 / 大数字叙事
   ========================================================== */

:root {
  --black: #070809;
  --black-soft: #0E1012;
  --card-dark: #101214;
  --line-dark: #23262B;
  --white: #FFFFFF;
  --accent: #2E7CF6;
  --accent-hover: #1D6FE8;
  --accent-soft: rgba(46, 124, 246, .12);
  --t-dark-1: #FFFFFF;
  --t-dark-2: rgba(255, 255, 255, .64);
  --t-dark-3: rgba(255, 255, 255, .40);
  --t-light-1: #0A0A0A;
  --t-light-2: #52525B;
  --t-light-3: #9CA3AF;
  --line-light: #E5E7EB;
  --shadow-lg: 0 32px 80px -32px rgba(0, 0, 0, .55);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--black);
  color: var(--t-dark-1);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.container { max-width: 1240px; margin: 0 auto; padding: 0 28px; }

section { scroll-margin-top: 84px; }
img { max-width: 100%; }

/* ---------------- 顶部滚动进度条 ---------------- */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0;
  background: var(--accent);
  z-index: 200;
  transition: width .1s linear;
}

/* ---------------- Header ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(7, 8, 9, .82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease;
}
.site-header.scrolled { border-bottom-color: var(--line-dark); }
.header-inner { display: flex; align-items: center; gap: 44px; height: 68px; }
.brand { display: flex; align-items: center; flex-shrink: 0; }
.brand img { height: 24px; display: block; }
.nav { display: flex; gap: 34px; }
.nav a {
  color: var(--t-dark-2);
  text-decoration: none;
  font-size: 15px;
  transition: color .2s ease;
}
.nav a:hover { color: var(--t-dark-1); }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 14px; }

.lang-toggle {
  display: flex;
  align-items: center;
  background: var(--black-soft);
  border: 1px solid var(--line-dark);
  border-radius: 999px;
  padding: 3px;
  cursor: pointer;
  font-size: 13px;
  font-family: inherit;
}
.lang-toggle span {
  padding: 3px 11px;
  border-radius: 999px;
  color: var(--t-dark-2);
  transition: all .2s ease;
  line-height: 1.4;
}
.lang-toggle span.active {
  background: #fff;
  color: #0A0A0A;
  font-weight: 600;
}

/* ---------------- Buttons（胶囊）---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 15px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  cursor: pointer;
  border: none;
  font-family: inherit;
  transition: background .2s ease, border-color .2s ease,
    transform .2s ease, box-shadow .2s ease;
}
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 10px 26px -10px rgba(46, 124, 246, .65);
}
.btn-ghost { background: transparent; color: #fff; border: 1px solid rgba(255, 255, 255, .28); }
.btn-ghost:hover { border-color: rgba(255, 255, 255, .6); transform: translateY(-1px); }
.btn-outline-dark { background: transparent; color: var(--t-light-1); border: 1px solid #D4D4D8; }
.btn-sm { padding: 9px 20px; font-size: 14px; }
.btn-lg { padding: 15px 32px; font-size: 16px; }

/* ---------------- Hero（黑）---------------- */
.hero {
  position: relative;
  padding: 72px 0 96px;
  background: var(--black);
  overflow: hidden;
}
/* 视差装饰层（随鼠标线性位移） */
.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  pointer-events: none;
  z-index: 0;
  will-change: transform;
}
.hero-glow-a {
  width: 560px; height: 560px;
  right: -140px; top: -140px;
  background: radial-gradient(circle, rgba(46, 124, 246, .30), transparent 66%);
}
.hero-glow-b {
  width: 460px; height: 460px;
  left: -120px; bottom: -160px;
  background: radial-gradient(circle, rgba(46, 124, 246, .20), transparent 66%);
}
.hero-bg-grid {
  position: absolute;
  inset: -40px;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(46, 124, 246, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(46, 124, 246, .07) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 78%);
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 78%);
  will-change: transform;
}
.hero-grid { position: relative; z-index: 1; }
.scroll-hint { position: relative; z-index: 1; }
.shot-parallax { will-change: transform; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 56px;
  align-items: center;
}
.hero-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: .04em;
  padding-left: 16px;
  position: relative;
}
.hero-eyebrow::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}
.hero h1 {
  font-size: clamp(40px, 4.6vw, 62px);
  line-height: 1.18;
  letter-spacing: -.01em;
  font-weight: 800;
  margin: 20px 0 22px;
}
.hero-sub {
  font-size: 17px;
  line-height: 1.9;
  color: var(--t-dark-2);
  max-width: 520px;
  margin-bottom: 34px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 26px; }
.hero-trust { font-size: 13px; color: var(--t-dark-3); letter-spacing: .02em; }

/* 产品截图窗（深色融入黑底） */
.shot-window {
  border: 1px solid var(--line-dark);
  border-radius: 16px;
  background: var(--black-soft);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.shot-tabs {
  display: flex;
  gap: 6px;
  padding: 10px 12px;
  background: #0B0D0F;
  border-bottom: 1px solid var(--line-dark);
}
.shot-tab {
  border: 1px solid transparent;
  background: transparent;
  padding: 7px 16px;
  font-size: 13px;
  border-radius: 8px;
  color: var(--t-dark-2);
  cursor: pointer;
  font-family: inherit;
  transition: all .2s ease;
}
.shot-tab:hover { color: #fff; background: #16191C; }
.shot-tab.active {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}
.shot-body img { display: block; width: 100%; height: auto; transition: opacity .35s ease; }
.shot-body img.fading { opacity: 0; }

/* scroll 提示 */
.scroll-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  margin-top: 72px;
  color: var(--t-dark-3);
  font-size: 12px;
  letter-spacing: .18em;
  text-decoration: none;
}
.scroll-hint svg { width: 16px; height: 16px; animation: bounce 1.8s ease-in-out infinite; }
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(7px); }
}

/* ---------------- Sections ---------------- */
.section { padding: 104px 0; }
.section.light { background: var(--white); color: var(--t-light-1); }
.section.light.bordered-top { border-top: 1px solid var(--line-light); }
.section.dark { background: var(--black); }

.section-head { margin-bottom: 60px; max-width: 760px; }
.eyebrow {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .16em;
}
.section.light .eyebrow { color: var(--accent); }
.section-head h2 {
  font-size: clamp(32px, 3.6vw, 50px);
  font-weight: 800;
  letter-spacing: -.01em;
  line-height: 1.2;
  margin: 14px 0 16px;
}
.section.light .section-head h2 { color: var(--t-light-1); }
.section-head p {
  font-size: 16px;
  color: var(--t-light-2);
  max-width: 640px;
  line-height: 1.85;
}
.section.dark .section-head p { color: var(--t-dark-2); }

/* ---------------- 核心成果（白）---------------- */
.chart-card {
  background: #fff;
  border: 1px solid var(--line-light);
  border-radius: 16px;
  padding: 38px 42px 30px;
  margin-bottom: 56px;
}
.chart-card h3 { font-size: 20px; font-weight: 800; margin-bottom: 28px; }
.bar-row { display: flex; align-items: center; gap: 18px; margin-bottom: 18px; }
.bar-label { width: 170px; font-size: 14px; color: var(--t-light-2); flex-shrink: 0; }
.bar-row.lead .bar-label { color: var(--t-light-1); font-weight: 700; }
.bar-track { flex: 1; height: 14px; border-radius: 999px; background: #EEF0F3; overflow: hidden; }
.bar-fill {
  height: 100%;
  width: 0;
  border-radius: 999px;
  transition: width 1.5s cubic-bezier(.22, 1, .36, 1);
}
.bar-fill.gray { background: #B9BFC7; }
.bar-fill.accent { background: var(--accent); }
.bar-value {
  width: 64px;
  text-align: right;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
  font-size: 15px;
}
.chart-note { font-size: 13px; color: var(--t-light-3); margin-top: 4px; }

/* 大数字（南孚式） */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.stat { border-top: 3px solid var(--accent); padding-top: 22px; }
.stat-num {
  font-size: clamp(40px, 4vw, 56px);
  font-weight: 800;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}
.stat-label { font-size: 14px; color: var(--t-light-2); margin-top: 8px; }

/* ---------------- 卡片 ---------------- */
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }

.card {
  border: 1px solid var(--line-light);
  border-radius: 16px;
  padding: 30px;
  background: #fff;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.section.dark .card {
  background: var(--card-dark);
  border-color: var(--line-dark);
}
.card:hover {
  transform: translateY(-5px);
  border-color: var(--accent);
  box-shadow: 0 18px 44px -18px rgba(46, 124, 246, .28);
}
.section.dark .card:hover { box-shadow: 0 18px 44px -18px rgba(0, 0, 0, .8); }
.card h3 { font-size: 19px; font-weight: 800; margin-bottom: 10px; }
.card p { font-size: 15px; color: var(--t-light-2); line-height: 1.8; }
.section.dark .card p { color: var(--t-dark-2); }

.cap-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.cap-icon svg { width: 22px; height: 22px; }

.num-badge {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 800;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

/* ---------------- 系统架构 ---------------- */
.arch-stack { display: flex; flex-direction: column; gap: 14px; }
.arch-row {
  display: flex;
  align-items: center;
  gap: 24px;
  background: #fff;
  border: 1px solid var(--line-light);
  border-radius: 16px;
  padding: 24px 30px;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.arch-row:hover { transform: translateY(-3px); border-color: var(--accent); box-shadow: 0 14px 36px -16px rgba(46, 124, 246, .22); }
.layer-badge {
  flex-shrink: 0;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 14px;
  padding: 9px 20px;
  border-radius: 999px;
}
.arch-row p { flex: 1; font-size: 15px; color: var(--t-light-2); }
.arch-tech { flex-shrink: 0; font-size: 13px; color: var(--t-light-3); }

/* ---------------- 改进历程（时间轴）---------------- */
.timeline { position: relative; padding: 8px 0 4px; }
.timeline-rail {
  position: absolute;
  left: 50%; top: 0; bottom: 0;
  width: 1px;
  transform: translateX(-50%);
  background: var(--line-dark);
}
.timeline-fill {
  position: absolute;
  left: 50%; top: 0;
  width: 2px;
  transform: translateX(-50%);
  height: 0;
  background: var(--accent);
  box-shadow: 0 0 14px rgba(46, 124, 246, .8);
  transition: height .15s linear;
}
.tl-item { position: relative; width: 50%; padding-bottom: 56px; }
.tl-item.left { padding-right: 58px; text-align: right; }
.tl-item.right { margin-left: 50%; padding-left: 58px; }
.tl-dot {
  position: absolute;
  top: 2px;
  width: 42px; height: 42px;
  border-radius: 50%;
  background: var(--card-dark);
  border: 1px solid var(--line-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
  font-weight: 800;
  font-size: 13px;
  color: var(--accent);
}
.tl-item.left .tl-dot { right: -21px; }
.tl-item.right .tl-dot { left: -21px; }
.tl-item.left:last-child .tl-dot { box-shadow: 0 0 0 5px rgba(46,124,246,.15), 0 0 22px rgba(46,124,246,.55); }
.tl-card {
  display: inline-block;
  text-align: left;
  background: var(--card-dark);
  border: 1px solid var(--line-dark);
  border-radius: 16px;
  padding: 26px 30px;
  max-width: 460px;
  transition: border-color .25s ease, transform .25s ease;
}
.tl-card:hover { border-color: rgba(46, 124, 246, .55); transform: translateY(-3px); }
.tl-stage {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 10px;
}
.tl-card h3 { font-size: 20px; font-weight: 800; color: #fff; margin-bottom: 8px; }
.tl-card p { font-size: 14px; color: var(--t-dark-2); line-height: 1.8; }
.tl-acc {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--line-dark);
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.tl-acc-num {
  font-size: 26px;
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.tl-acc-label { font-size: 12px; color: var(--t-dark-3); }

/* ---------------- 全球部署图（黑）---------------- */
.section.dark.bordered-top { border-top: 1px solid var(--line-dark); }
.map-wrap { position: relative; }
.map-chips {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}
.map-chip {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--t-dark-2);
  border: 1px solid var(--line-dark);
  padding: 6px 14px;
  border-radius: 999px;
}
.map {
  max-width: 920px;
  margin: 0 auto;
}
.map svg { width: 100%; height: auto; }
.map-node .map-halo {
  animation: mapPulse 2.8s ease-in-out infinite;
  transform-box: fill-box;
  transform-origin: center;
}
@keyframes mapPulse {
  0%, 100% { opacity: .5; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.35); }
}
.map-note {
  text-align: center;
  font-size: 12px;
  color: var(--t-dark-3);
  margin-top: 18px;
}

/* ---------------- 开源下载（黑）---------------- */
.dl-card { padding: 38px; }
.dl-card h3 { font-size: 23px; margin-bottom: 10px; color: #fff; }
.dl-card p { font-size: 15px; color: var(--t-dark-2); margin-bottom: 28px; }
.dl-hint { font-size: 13px; color: var(--t-dark-3); margin-top: 14px; }

.tech-row {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 48px;
}
.tech-label { font-size: 13px; color: var(--t-dark-3); margin-right: 6px; }
.chip {
  background: transparent;
  border: 1px solid var(--line-dark);
  color: var(--t-dark-2);
  font-size: 13px;
  padding: 7px 16px;
  border-radius: 999px;
}

.contact-strip {
  margin-top: 48px;
  background: var(--card-dark);
  border: 1px solid var(--line-dark);
  border-radius: 16px;
  padding: 30px 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
.contact-strip h3 { font-size: 17px; margin-bottom: 4px; color: #fff; }
.contact-strip p { font-size: 14px; color: var(--t-dark-2); }
.contact-links a.email {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  font-size: 17px;
}
.contact-links a.email:hover { text-decoration: underline; }
.contact-links svg { width: 20px; height: 20px; }

/* ---------------- Footer（黑）---------------- */
.site-footer {
  background: var(--black);
  border-top: 1px solid var(--line-dark);
  padding: 56px 0 36px;
}
.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.footer-logo { height: 22px; }
.footer-nav { display: flex; gap: 28px; flex-wrap: wrap; }
.footer-nav a { color: var(--t-dark-2); font-size: 14px; text-decoration: none; }
.footer-nav a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid var(--line-dark); padding-top: 24px; }
.footer-meta {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--t-dark-2);
}
.footer-nonprofit {
  margin-top: 10px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--t-dark-3);
}

/* ---------------- 滚动入场动画 ---------------- */
/* 区块级入场：上浮 + 轻微放大 + 由虚到实，像画面"刷新"后重新对焦 */
.reveal {
  opacity: 0;
  transform: translate3d(0, 44px, 0) scale(.984);
  filter: blur(7px);
  transition:
    opacity .62s ease,
    transform 1s cubic-bezier(.16, 1, .3, 1),
    filter .62s ease;
  transition-delay: var(--d, 0ms);
  will-change: opacity, transform, filter;
}
.reveal.visible {
  opacity: 1;
  transform: none;
  filter: blur(0);
  will-change: auto;
}

/* 区块顶部的扫描线：进入视口时从左向右掠过一次 */
.section { position: relative; }
.section::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg,
    rgba(46, 124, 246, 0) 0%,
    rgba(46, 124, 246, .55) 22%,
    rgba(46, 124, 246, .95) 50%,
    rgba(46, 124, 246, .55) 78%,
    rgba(46, 124, 246, 0) 100%);
  transform: scaleX(0);
  transform-origin: left center;
  opacity: 0;
  pointer-events: none;
  z-index: 3;
}
.section.scan::after { animation: scanSweep 1.15s cubic-bezier(.4, 0, .2, 1) forwards; }
@keyframes scanSweep {
  0%   { transform: scaleX(0);   opacity: 0; }
  12%  { opacity: .95; }
  70%  { opacity: .75; }
  100% { transform: scaleX(1);   opacity: 0; }
}

/* 大屏时让整块内容整体上移得更多，强化"分区块推进"的节奏 */
@media (min-width: 1025px) {
  .section-head.reveal { transform: translate3d(0, 56px, 0) scale(.982); }
  .section-head.reveal.visible { transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .section-head.reveal {
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
    transition: none !important;
  }
  .section.scan::after { animation: none; }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; gap: 44px; }
  .hero-sub { max-width: 640px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  .nav { display: none; }
  .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .hero { padding: 56px 0 72px; }
  .hero-cta .btn-lg { width: 100%; }
  .section { padding: 72px 0; }
  .section-head { margin-bottom: 44px; }
  .chart-card { padding: 26px 22px 22px; }
  .bar-label { width: 112px; font-size: 13px; }
  .arch-row { flex-wrap: wrap; gap: 12px; }
  .arch-row p { flex-basis: 100%; order: 3; }
  .contact-strip { flex-direction: column; align-items: flex-start; }
  .footer-top { flex-direction: column; align-items: flex-start; }
  .footer-meta, .footer-nonprofit { flex-direction: column; }
  .scroll-hint { margin-top: 48px; }

  /* 时间轴：单列左轨 */
  .timeline-rail, .timeline-fill { left: 20px; }
  .tl-item, .tl-item.left, .tl-item.right {
    width: 100%;
    margin-left: 0;
    padding: 0 0 48px 58px;
    text-align: left;
  }
  .tl-item.left .tl-dot, .tl-item.right .tl-dot { left: 0; right: auto; }
  .tl-dot { width: 40px; height: 40px; }
  .tl-card { max-width: 100%; width: 100%; }
}

/* ---------------- 动效偏好 ---------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .bar-fill { transition: none; }
  .card:hover, .arch-row:hover { transform: none; }
  .scroll-hint svg { animation: none; }
}