/* ============================================================
   NEXTX 官网
   深色 —— 品牌 logo 是白色字形，必须深底才立得住。
   ============================================================ */

:root {
  --bg:          #04060B;
  --bg-alt:      #070A11;
  --surface:     #0C1017;
  --surface-2:   #10151E;
  --line:        rgba(255,255,255,.07);
  --line-mid:    rgba(255,255,255,.13);
  --line-strong: rgba(255,255,255,.22);

  --text:        #EAEEF5;
  --text-dim:    #929CB0;
  --text-faint:  #5C6579;

  --accent:      #2E9BFF;
  --accent-lit:  #7CC4FF;
  --accent-soft: rgba(46,155,255,.13);
  --accent-line: rgba(46,155,255,.34);

  --wrap: 1160px;
  --nav-h: 66px;
  --ease: cubic-bezier(.22,.61,.36,1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
               "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
::selection { background: var(--accent); color: #fff; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.wrap--narrow { max-width: 760px; }
.center { text-align: center; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100; height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between; padding: 0 30px;
  border-bottom: 1px solid transparent;
  transition: background .35s var(--ease), border-color .35s var(--ease);
}
.nav.is-solid {
  background: rgba(4,6,11,.84);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom-color: var(--line);
}
/* logo-tight.png 已裁掉透明边距，宽高比约 4.6:1 */
.nav__logo { height: 16px; width: auto; opacity: .95; }
.nav__links { display: flex; gap: 30px; }
.nav__links a {
  font-size: 13.5px; color: var(--text-dim); letter-spacing: .05em;
  position: relative; padding: 4px 0; transition: color .25s var(--ease);
}
.nav__links a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 1px;
  background: var(--accent); transform: scaleX(0); transform-origin: left;
  transition: transform .3s var(--ease);
}
.nav__links a:hover { color: var(--text); }
.nav__links a:hover::after { transform: scaleX(1); }

/* ---------- 首屏 ---------- */
.hero {
  position: relative; min-height: 100svh; overflow: hidden; isolation: isolate;
  display: flex; align-items: center; justify-content: center; text-align: center;
  padding: calc(var(--nav-h) + 48px) 24px 104px;
}
/* WebGL 画布容器。
   底图是峡谷夜景（翼装飞行的叙事场景），上面压深色渐变保证文字可读。
   WebGL 不可用 / 上下文丢失时，这层自己就是一幅完整的首屏背景。 */
.hero__canvas {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(78% 58% at 50% 46%, rgba(4,6,11,.62) 0%, rgba(4,6,11,.30) 52%, transparent 76%),
    linear-gradient(180deg, rgba(4,6,11,.55) 0%, transparent 30%, rgba(4,6,11,.85) 82%, var(--bg) 100%),
    radial-gradient(100% 70% at 50% 30%, rgba(46,155,255,.10) 0%, transparent 62%),
    url("/images/hero-bg.jpg") center / cover no-repeat,
    #06090F;
}
/* WebGL 起来后把底图再压暗一档，避免和丝线叠得过亮、抢掉字形 */
.hero__canvas.is-live {
  background:
    radial-gradient(78% 58% at 50% 46%, rgba(4,6,11,.80) 0%, rgba(4,6,11,.52) 52%, rgba(4,6,11,.25) 78%),
    linear-gradient(180deg, rgba(4,6,11,.7) 0%, rgba(4,6,11,.35) 30%, rgba(4,6,11,.9) 82%, var(--bg) 100%),
    url("/images/hero-bg.jpg") center / cover no-repeat,
    #05080E;
}

/* 四周压暗，保证中间文字始终可读 */
.hero__vignette {
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background:
    radial-gradient(58% 46% at 50% 50%, rgba(4,6,11,.82) 0%, rgba(4,6,11,.35) 55%, transparent 78%),
    linear-gradient(180deg, rgba(4,6,11,.55) 0%, transparent 26%, transparent 70%, var(--bg) 100%);
}

.hero__inner { position: relative; z-index: 2; max-width: 900px; }

/* 文字可读性：不用遮罩层压丝线（试过 ::before + z-index:-1，会盖在文字上面），
   改为给文字本身加深色外发光 —— 只影响字，不会误伤任何东西。 */
.hero__kicker,
.hero__title,
.hero__sub,
.hero__desc {
  text-shadow:
    0 0 18px rgba(4,6,11,.95),
    0 0 44px rgba(4,6,11,.85),
    0 2px 10px rgba(4,6,11,.9);
}

.hero__kicker {
  margin: 0 0 20px; font-size: 11.5px; letter-spacing: .34em; text-indent: .34em;
  color: var(--accent); text-transform: uppercase;
  animation: rise .9s var(--ease) both;
}
.hero__title {
  margin: 0 0 20px;
  font-size: clamp(40px, 8.2vw, 92px); line-height: 1.04; font-weight: 800;
  letter-spacing: .005em;
  animation: rise .9s .08s var(--ease) both;
}
.hero__title .accent {
  color: var(--accent);
  /* 深色外发光保底可读，再叠品牌蓝辉光 */
  text-shadow:
    0 0 18px rgba(4,6,11,.95),
    0 0 44px rgba(4,6,11,.8),
    0 0 68px rgba(46,155,255,.5);
}
.hero__sub {
  margin: 0 0 26px; font-size: clamp(14px, 1.9vw, 18px);
  letter-spacing: .22em; text-indent: .22em; color: var(--text);
  animation: rise .9s .16s var(--ease) both;
}
.hero__desc {
  margin: 0 auto 40px; max-width: 640px;
  font-size: clamp(14.5px, 1.6vw, 16.5px); color: var(--text-dim); line-height: 2.05;
  animation: rise .9s .24s var(--ease) both;
}

.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 32px; border-radius: 999px; font-size: 14.5px; letter-spacing: .05em;
  transition: background .3s var(--ease), border-color .3s var(--ease), transform .3s var(--ease);
}
.btn--ghost {
  border: 1px solid var(--accent-line); background: var(--accent-soft); color: var(--text);
  animation: rise .9s .32s var(--ease) both;
}
.btn--ghost:hover { background: rgba(46,155,255,.24); border-color: var(--accent); transform: translateY(-2px); }

.hero__scroll {
  position: absolute; left: 50%; bottom: 26px; transform: translateX(-50%);
  width: 1px; height: 50px; background: linear-gradient(var(--line-strong), transparent);
  overflow: hidden; z-index: 2;
}
.hero__scroll span {
  position: absolute; top: -50px; left: 0; width: 1px; height: 50px;
  background: linear-gradient(transparent, var(--accent));
  animation: scrollLine 2.1s ease-in-out infinite;
}
@keyframes rise { from { opacity: 0; transform: translateY(24px); } to { opacity: 1; transform: none; } }
@keyframes scrollLine { 0% { top: -50px; } 60%,100% { top: 100px; } }

/* ---------- 通用段落 ---------- */
.section { padding: clamp(78px, 11vw, 138px) 0; position: relative; }
.section--alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

.eyebrow {
  margin: 0 0 14px; font-size: 11.5px; letter-spacing: .3em; text-indent: .3em;
  color: var(--accent); text-transform: uppercase;
}
.h2 {
  margin: 0 0 24px;
  font-size: clamp(27px, 4.2vw, 46px); line-height: 1.28; font-weight: 700;
}
.lead { margin: 0 0 52px; color: var(--text-dim); font-size: 16px; max-width: 680px; line-height: 1.95; }
.center .lead { margin-inline: auto; }
.lead strong { color: var(--text); font-weight: 600; }

/* ---------- 三个时代 ---------- */
.era {
  list-style: none; margin: 0 0 64px; padding: 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
.era__item {
  position: relative; padding: 30px 26px; border-radius: 6px;
  background: var(--surface); border: 1px solid var(--line);
}
.era__item--now { border-color: var(--accent-line); background: var(--surface-2); }
.era__idx { font-size: 11px; letter-spacing: .2em; color: var(--text-faint); }
.era__name { margin: 8px 0 4px; font-size: 26px; font-weight: 700; }
.era__item--now .era__name { color: var(--accent); }
.era__desc { margin: 0; color: var(--text-dim); font-size: 14px; }
.era__tag {
  position: absolute; top: 16px; right: 16px;
  padding: 3px 10px; border-radius: 999px; font-size: 11px;
  background: var(--accent); color: #fff; letter-spacing: .04em;
}

/* ---------- 断层 ---------- */
.gap { display: grid; grid-template-columns: 1.15fr 1fr; gap: clamp(32px, 6vw, 72px); }
.gap__title { margin: 0 0 20px; font-size: 15px; font-weight: 600; color: var(--text); letter-spacing: .04em; }
.gap__list { list-style: none; margin: 0; padding: 0; }
.gap__list li {
  padding: 15px 0; border-bottom: 1px solid var(--line);
  display: flex; justify-content: space-between; gap: 18px; align-items: baseline;
}
.gap__list li:first-child { border-top: 1px solid var(--line); }
.gap__list strong { font-weight: 600; font-size: 15px; white-space: nowrap; }
.gap__list span { color: var(--text-faint); font-size: 13.5px; text-align: right; }
.gap__lead { margin: 0 0 16px; font-size: 19px; line-height: 1.8; }
.gap__lead em {
  font-style: normal; color: var(--accent);
  border-bottom: 1px solid var(--accent-line); padding-bottom: 2px;
}
.gap__note { margin: 0; color: var(--text-dim); font-size: 14.5px; }

/* ---------- 引擎四层 ---------- */
.layers { display: grid; grid-template-columns: repeat(auto-fit, minmax(258px, 1fr)); gap: 18px; }
.layer {
  padding: 30px 26px; background: var(--surface); border: 1px solid var(--line);
  border-radius: 6px; position: relative; overflow: hidden;
  transition: border-color .3s var(--ease), transform .3s var(--ease), background .3s var(--ease);
}
.layer::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 2px;
  background: linear-gradient(var(--accent), transparent);
  opacity: .55; transition: opacity .3s var(--ease);
}
.layer:hover { border-color: var(--accent-line); transform: translateY(-4px); background: var(--surface-2); }
.layer:hover::before { opacity: 1; }
.layer__head { display: flex; gap: 14px; align-items: flex-start; margin-bottom: 14px; }
.layer__no { font-size: 12px; color: var(--accent); letter-spacing: .12em; padding-top: 4px; }
.layer__cn { margin: 0; font-size: 18px; font-weight: 600; }
.layer__en { margin: 2px 0 0; font-size: 11px; letter-spacing: .17em; color: var(--text-faint); text-transform: uppercase; }
.layer__desc { margin: 0; color: var(--text-dim); font-size: 14.5px; line-height: 1.9; }

/* ---------- ZERO ---------- */
.zero-mark {
  color: var(--accent); letter-spacing: .02em;
  text-shadow: 0 0 40px rgba(46,155,255,.35);
}
.shot {
  margin: 0 0 44px; border: 1px solid var(--line); border-radius: 8px;
  overflow: hidden; background: var(--surface); position: relative;
}
.shot img { width: 100%; aspect-ratio: 21/9; object-fit: cover; }
.shot.is-empty::before {
  content: ""; display: block; aspect-ratio: 21/9;
  background:
    radial-gradient(80% 90% at 50% 15%, rgba(46,155,255,.18), transparent 62%),
    linear-gradient(160deg, #101A2A, #06090F);
}
.shot.is-empty::after {
  content: "体验场景图"; position: absolute; inset: 0;
  display: grid; place-items: center; color: var(--text-faint);
  font-size: 12.5px; letter-spacing: .22em;
}
.shot figcaption {
  padding: 12px 18px; font-size: 12px; color: var(--text-faint);
  border-top: 1px solid var(--line); letter-spacing: .07em;
}

/* 体验流程 */
.flow {
  list-style: none; margin: 0 0 48px; padding: 0;
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px;
}
.flow__step {
  position: relative; padding: 22px 14px; text-align: center;
  background: var(--surface); border: 1px solid var(--line); border-radius: 6px;
}
.flow__step::after {
  content: ""; position: absolute; right: -6px; top: 50%; width: 6px; height: 1px;
  background: var(--line-mid);
}
.flow__step:last-child::after { display: none; }
.flow__no {
  display: inline-grid; place-items: center; width: 26px; height: 26px; margin-bottom: 10px;
  border-radius: 50%; border: 1px solid var(--accent-line);
  color: var(--accent); font-size: 12px; font-weight: 700;
}
.flow__step p { margin: 0; font-size: 13.5px; color: var(--text-dim); }
.flow__step--climax { border-color: var(--accent-line); background: var(--surface-2); }
.flow__step--climax p { color: var(--text); font-weight: 600; }
.flow__step--climax .flow__no { background: var(--accent); border-color: var(--accent); color: #fff; }

.traits { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 16px; margin-bottom: 46px; }
.trait { padding: 24px 22px; background: var(--surface); border: 1px solid var(--line); border-radius: 6px; }
.trait h3 { margin: 0 0 7px; font-size: 15.5px; font-weight: 600; }
.trait p { margin: 0; color: var(--text-dim); font-size: 13.5px; }

.punch {
  margin: 0; text-align: center;
  font-size: clamp(19px, 2.9vw, 28px); font-weight: 600; letter-spacing: .02em;
}
.punch em {
  font-style: normal; color: var(--accent);
  text-shadow: 0 0 34px rgba(46,155,255,.4);
}

/* ---------- 路线图 ---------- */
.roadmap { list-style: none; margin: 0; padding: 0; }
.road {
  display: grid; grid-template-columns: 130px 1fr; gap: 26px; align-items: start;
  padding: 26px 0; border-top: 1px solid var(--line);
  transition: background .3s var(--ease);
}
.road:last-child { border-bottom: 1px solid var(--line); }
.road__year {
  font-size: 13px; letter-spacing: .12em; color: var(--text-faint); padding-top: 5px;
}
.road--live .road__year { color: var(--accent); }
.road__name { margin: 0 0 4px; font-size: 21px; font-weight: 700; letter-spacing: .04em; }
.road__name span { color: var(--accent); }
.road--live .road__name::after {
  content: "即将上线"; margin-left: 12px; padding: 3px 10px; border-radius: 999px;
  background: var(--accent); color: #fff; font-size: 11px; font-weight: 500; letter-spacing: .04em;
  vertical-align: middle;
}
.road__kind { margin: 0 0 3px; font-size: 13.5px; color: var(--text-dim); }
.road__items { margin: 0; font-size: 13px; color: var(--text-faint); letter-spacing: .03em; }

/* ---------- 技术 ---------- */
.techs { display: grid; grid-template-columns: repeat(auto-fit, minmax(232px, 1fr)); gap: 16px; }
.tech {
  padding: 26px 24px; background: var(--surface); border: 1px solid var(--line); border-radius: 6px;
  transition: border-color .3s var(--ease), transform .3s var(--ease);
}
.tech:hover { border-color: var(--accent-line); transform: translateY(-3px); }
.tech h3 { margin: 0 0 9px; font-size: 16px; font-weight: 600; }
.tech p { margin: 0; color: var(--text-dim); font-size: 13.5px; line-height: 1.85; }

/* ---------- 收束宣言 ---------- */
.section--statement {
  background:
    radial-gradient(70% 100% at 50% 50%, rgba(46,155,255,.09), transparent 70%),
    var(--bg-alt);
  border-block: 1px solid var(--line);
  padding-block: clamp(96px, 14vw, 168px);
}
.statement__en {
  margin: 0 0 18px; font-size: clamp(15px, 2.1vw, 20px);
  letter-spacing: .14em; color: var(--text-dim); text-transform: uppercase;
}
.statement__en--dim { margin: 18px 0 0; color: var(--text-faint); font-size: clamp(12px, 1.5vw, 14px); }
.statement__cn {
  margin: 0; font-size: clamp(28px, 5.4vw, 58px); font-weight: 800; line-height: 1.3;
}
.statement__cn em {
  font-style: normal; color: var(--accent); text-shadow: 0 0 56px rgba(46,155,255,.5);
}

/* ---------- 联系 ---------- */
.mail {
  display: inline-block; margin-top: 4px;
  font-size: clamp(19px, 2.8vw, 27px); font-weight: 600; color: var(--accent);
  border-bottom: 1px solid var(--accent-line); padding-bottom: 6px;
  transition: color .3s var(--ease), border-color .3s var(--ease);
}
.mail:hover { color: var(--accent-lit); border-bottom-color: var(--accent-lit); }

/* ---------- 页脚 ---------- */
.footer { padding: 52px 0 44px; background: #020408; border-top: 1px solid var(--line); }
.footer__inner { display: flex; align-items: flex-start; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.footer__logo { height: 15px; width: auto; opacity: .5; margin-bottom: 10px; }
.footer__slogan { margin: 0; font-size: 11.5px; letter-spacing: .2em; color: var(--text-faint); text-transform: uppercase; }
.footer__legal { text-align: right; font-size: 13px; color: var(--text-faint); }
.footer__company { margin: 0 0 3px; color: var(--text-dim); }
.footer__company--en { color: var(--text-faint); font-size: 12px; margin-bottom: 9px; }
.footer__beian { margin: 0 0 8px; display: flex; gap: 10px; justify-content: flex-end; flex-wrap: wrap; }
.footer__beian a { color: var(--text-faint); transition: color .25s var(--ease); }
.footer__beian a:hover { color: var(--accent); }
.footer__sep { color: var(--line-strong); }
.footer__police { display: inline-flex; align-items: center; gap: 5px; }
.footer__police-icon { width: 14px; height: 14px; }
.footer__copy { margin: 0; }

/* ---------- 入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(20px); }
.reveal.in { opacity: 1; transform: none; transition: opacity .7s var(--ease), transform .7s var(--ease); }
.layers .layer:nth-child(2), .techs .tech:nth-child(2), .traits .trait:nth-child(2),
.era .era__item:nth-child(2), .flow .flow__step:nth-child(2) { transition-delay: .06s; }
.layers .layer:nth-child(3), .techs .tech:nth-child(3), .traits .trait:nth-child(3),
.era .era__item:nth-child(3), .flow .flow__step:nth-child(3) { transition-delay: .12s; }
.layers .layer:nth-child(4), .techs .tech:nth-child(4), .traits .trait:nth-child(4),
.flow .flow__step:nth-child(4) { transition-delay: .18s; }
.techs .tech:nth-child(5), .flow .flow__step:nth-child(5) { transition-delay: .24s; }

/* ---------- 响应式 ---------- */
@media (max-width: 940px) {
  .gap { grid-template-columns: 1fr; }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .flow__step::after { display: none; }
  .flow__step--climax { grid-column: 1 / -1; }
}
@media (max-width: 680px) {
  .nav { padding: 0 16px; }
  .nav__links { gap: 15px; }
  .nav__links a { font-size: 12.5px; }
  .nav__links a:nth-child(1), .nav__links a:nth-child(4), .nav__links a:nth-child(5) { display: none; }
  .hero { min-height: 92svh; }
  .era { grid-template-columns: 1fr; }
  .road { grid-template-columns: 1fr; gap: 8px; }
  .road__year { padding-top: 0; }
  .footer__inner { flex-direction: column; align-items: center; text-align: center; }
  .footer__legal { text-align: center; }
  .footer__beian { justify-content: center; }
  .footer__brand { display: flex; flex-direction: column; align-items: center; }
}
@media (max-width: 400px) {
  .nav__links a:nth-child(2) { display: none; }
}

/* ---------- 无障碍 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important; animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

@media print {
  .nav, .hero__scroll, .hero__canvas, .hero__vignette { display: none; }
  body { background: #fff; color: #000; }
}