/* ============================================================
   SnowballX · 品牌主题
   主题色取自公司 PPT 设计系统（design-system.md）
   ============================================================ */
:root {
  --void: #050509;
  --ink: #0B0B10;
  --ink-2: #13131C;
  --paper: #FFFFFF;
  --muted: #8A91A0;
  --muted-2: #5B6472;
  --line: rgba(255, 255, 255, 0.10);
  --line-strong: rgba(255, 255, 255, 0.18);

  --violet: #7C5CFF;
  --azure: #3D8BFF;
  --cyan: #35D0E0;
  --lav: #F2EFFF;
  --ice: #ECF3FF;

  --grad: linear-gradient(100deg, var(--violet) 0%, var(--azure) 52%, var(--cyan) 100%);
  --grad-soft: linear-gradient(100deg, rgba(124, 92, 255, .22), rgba(61, 139, 255, .18) 55%, rgba(53, 208, 224, .14));

  --ease: cubic-bezier(.16, 1, .3, 1);
  --ease-io: cubic-bezier(.65, 0, .35, 1);
  --container: 1440px;
  --pad: clamp(20px, 5vw, 76px);
}

* { box-sizing: border-box; }
html { scroll-behavior: auto; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--void);
  color: var(--paper);
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
body.is-locked { overflow: hidden; }
::selection { background: var(--violet); color: #fff; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
h1, h2, h3, p, ul { margin: 0; }
ul { padding: 0; list-style: none; }

main, footer { position: relative; z-index: 1; }
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--pad);
  padding-right: var(--pad);
}

/* ---------- 背景 / 纹理 ---------- */
#gl {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  will-change: transform;
}
.grain {
  position: fixed;
  inset: -50%;
  z-index: 2;
  pointer-events: none;
  opacity: .055;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='3' stitchTiles='stitch'/></filter><rect width='200' height='200' filter='url(%23n)'/></svg>");
  animation: grain 8s steps(6) infinite;
}
@keyframes grain {
  0%, 100% { transform: translate(0, 0); }
  20% { transform: translate(-4%, 3%); }
  40% { transform: translate(3%, -2%); }
  60% { transform: translate(-2%, -3%); }
  80% { transform: translate(2%, 2%); }
}

/* ---------- 光标 ---------- */
.cursor, .cursor-ring {
  position: fixed;
  top: 0; left: 0;
  z-index: 9999;
  pointer-events: none;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  will-change: transform;
}
.cursor {
  width: 6px; height: 6px;
  background: var(--paper);
  mix-blend-mode: difference;
}
.cursor-ring {
  width: 38px; height: 38px;
  border: 1px solid rgba(255, 255, 255, .55);
  transition: width .35s var(--ease), height .35s var(--ease), border-color .35s var(--ease), background .35s var(--ease);
}
body.is-hovering .cursor-ring {
  width: 76px; height: 76px;
  border-color: rgba(124, 92, 255, .9);
  background: rgba(124, 92, 255, .10);
}
@media (hover: none) { .cursor, .cursor-ring { display: none; } }

/* ---------- 开场动画 ---------- */
#loader {
  position: fixed;
  inset: 0;
  z-index: 9998;
  background: var(--void);
  display: flex;
  align-items: flex-end;
  padding: var(--pad);
  transition: opacity .6s ease, visibility .6s;
}
#loader.is-done { opacity: 0; visibility: hidden; }
.loader__inner { width: 100%; }
.loader__meta {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  font-size: 11px;
  letter-spacing: .32em;
  color: var(--muted);
  margin-bottom: 18px;
}
.loader__count { font-variant-numeric: tabular-nums; color: var(--paper); letter-spacing: .1em; }
.loader__word {
  display: flex;
  gap: .04em;
  font-size: clamp(48px, 11vw, 160px);
  font-weight: 800;
  line-height: .92;
  letter-spacing: -.04em;
}
.loader__word span {
  display: inline-block;
  transform: translateY(110%);
  opacity: 0;
}
.loader__bar { height: 1px; background: rgba(255,255,255,.12); margin-top: 26px; overflow: hidden; }
.loader__bar i { display: block; height: 100%; width: 0%; background: var(--grad); }

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px var(--pad);
  transition: padding .5s var(--ease), background .5s var(--ease), backdrop-filter .5s;
}
.nav.is-stuck {
  padding-top: 12px;
  padding-bottom: 12px;
  background: rgba(5, 5, 9, .55);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}
.nav__brand { display: flex; align-items: center; gap: 12px; }
.nav__mark { width: 34px; height: auto; filter: drop-shadow(0 0 18px rgba(124, 92, 255, .55)); }
.nav__name { font-size: 14px; font-weight: 600; letter-spacing: .02em; white-space: nowrap; }
.nav__name em {
  font-style: normal;
  font-size: 10px;
  letter-spacing: .28em;
  color: var(--muted);
  margin-left: 8px;
}
.nav__links { display: flex; gap: clamp(18px, 3vw, 44px); font-size: 13px; color: rgba(255,255,255,.72); }
.nav__links a { position: relative; padding: 6px 0; }
.nav__links a::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  width: 100%; height: 1px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .5s var(--ease);
}
.nav__links a:hover { color: #fff; }
.nav__links a:hover::after { transform: scaleX(1); }
.nav__cta {
  position: relative;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 10px 20px;
  font-size: 12.5px;
  overflow: hidden;
  transition: border-color .4s, color .4s;
}
.nav__cta::before {
  content: "";
  position: absolute; inset: 0;
  background: var(--grad);
  transform: translateY(101%);
  transition: transform .55s var(--ease);
  z-index: -1;
}
.nav__cta:hover { border-color: transparent; }
.nav__cta:hover::before { transform: translateY(0); }
@media (max-width: 820px) { .nav__links { display: none; } }

/* ---------- 通用段落 ---------- */
.section-tag {
  font-size: 11px;
  letter-spacing: .30em;
  color: var(--muted);
  margin-bottom: 26px;
  text-transform: uppercase;
}
.section-title {
  font-size: clamp(34px, 4.4vw, 74px);
  line-height: 1.02;
  letter-spacing: -.03em;
  font-weight: 700;
}
.section-head { margin-bottom: clamp(40px, 7vw, 96px); }
.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- HERO ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 140px;
  padding-bottom: 90px;
}
.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 40px;
  align-items: end;
  width: 100%;
}
.eyebrow {
  font-size: 11px;
  letter-spacing: .38em;
  color: rgba(255,255,255,.55);
  margin-bottom: clamp(24px, 4vw, 48px);
}
.hero__title {
  font-size: clamp(52px, 9.6vw, 148px);
  line-height: .88;
  letter-spacing: -.045em;
  font-weight: 800;
  text-transform: none;
}
.hero__title .line { display: block; overflow: hidden; padding-bottom: .04em; }
.hero__title .line__inner { display: inline-block; }
.hero__sub {
  margin-top: clamp(26px, 4vw, 44px);
  font-size: clamp(15px, 1.5vw, 20px);
  color: rgba(255,255,255,.65);
  letter-spacing: .01em;
}
.hero__meta {
  display: flex;
  gap: clamp(28px, 5vw, 72px);
  margin-top: clamp(32px, 5vw, 64px);
}
.hero__meta b {
  display: block;
  font-size: clamp(26px, 2.6vw, 40px);
  font-weight: 700;
  letter-spacing: -.02em;
}
.hero__meta span { font-size: 11px; letter-spacing: .18em; color: var(--muted); }
.hero__right { padding-bottom: 8px; }
.hero__badge {
  display: flex; align-items: center; gap: 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 18px;
  font-size: 11.5px;
  color: rgba(255,255,255,.72);
  white-space: nowrap;
  backdrop-filter: blur(8px);
  background: rgba(255,255,255,.03);
}
.hero__badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 12px var(--cyan);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: .35; transform: scale(.7); } }
.hero__scroll {
  position: absolute;
  left: var(--pad);
  bottom: 34px;
  display: flex; align-items: center; gap: 12px;
  font-size: 10px; letter-spacing: .32em; color: var(--muted);
}
.hero__scroll i { display: block; width: 54px; height: 1px; background: var(--line-strong); position: relative; overflow: hidden; }
.hero__scroll i::after {
  content: ""; position: absolute; inset: 0;
  background: var(--grad);
  animation: scrollLine 2.2s var(--ease-io) infinite;
}
@keyframes scrollLine { 0% { transform: translateX(-100%); } 60%, 100% { transform: translateX(100%); } }

/* ---------- MARQUEE ---------- */
.marquee { padding: clamp(40px, 8vw, 110px) 0; overflow: hidden; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.marquee__row { display: flex; white-space: nowrap; }
.marquee__row--outline { color: transparent; -webkit-text-stroke: 1px rgba(255,255,255,.22); }
.marquee__row--fill { color: rgba(255,255,255,.92); }
.marquee__track { display: flex; gap: .28em; font-size: clamp(56px, 11vw, 190px); font-weight: 800; letter-spacing: -.04em; line-height: 1; animation: marquee 26s linear infinite; }
.marquee__track--rev { animation-direction: reverse; animation-duration: 22s; color: transparent; -webkit-text-stroke: 1px rgba(124,92,255,.55); }
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }

/* ---------- MANIFESTO ---------- */
.manifesto { padding: clamp(90px, 13vw, 190px) 0; }
.manifesto__text {
  font-size: clamp(26px, 3.6vw, 58px);
  line-height: 1.22;
  letter-spacing: -.02em;
  font-weight: 600;
  max-width: 20em;
}
.manifesto__text .w { display: inline-block; opacity: .12; }
.manifesto__text .w.is-on { opacity: 1; }

/* ---------- 业务线 ---------- */
.lines { padding: clamp(70px, 9vw, 130px) 0; }
.lines__grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(18px, 2.4vw, 34px); }
.line-card {
  position: relative;
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: clamp(26px, 3.4vw, 46px);
  background: linear-gradient(160deg, rgba(255,255,255,.045), rgba(255,255,255,.012));
  overflow: hidden;
  transform-style: preserve-3d;
  transition: border-color .5s var(--ease);
}
.line-card__glow {
  position: absolute;
  width: 480px; height: 480px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(124,92,255,.30), transparent 62%);
  left: var(--mx, 50%); top: var(--my, 0%);
  transform: translate(-50%, -50%);
  opacity: 0;
  transition: opacity .5s;
  pointer-events: none;
}
.line-card:hover { border-color: rgba(124,92,255,.5); }
.line-card:hover .line-card__glow { opacity: 1; }
.line-card__idx {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 50%;
  border: 1px solid var(--line-strong);
  font-size: 12px; color: var(--muted);
  margin-bottom: 26px;
}
.line-card h3 { font-size: clamp(24px, 2.6vw, 40px); letter-spacing: -.02em; line-height: 1.1; }
.line-card__desc { margin-top: 16px; color: rgba(255,255,255,.6); font-size: 14.5px; line-height: 1.7; max-width: 30em; }
.line-card__flow { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 34px; }
.line-card__flow li {
  font-size: 11px; letter-spacing: .1em;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 14px;
  color: rgba(255,255,255,.72);
}
.line-card__foot {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 40px; padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 11.5px; letter-spacing: .12em; color: var(--muted);
}
.line-card__foot i { font-style: normal; font-size: 18px; color: var(--paper); transition: transform .5s var(--ease); }
.line-card:hover .line-card__foot i { transform: translate(4px, -4px); }
@media (max-width: 860px) { .lines__grid { grid-template-columns: 1fr; } }

/* ---------- 数字 ---------- */
.numbers { padding: clamp(70px, 10vw, 140px) 0; border-top: 1px solid var(--line); }
.numbers__grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 24px; }
.num b {
  display: block;
  font-size: clamp(48px, 6vw, 104px);
  line-height: .95;
  font-weight: 700;
  letter-spacing: -.04em;
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.num span { display: block; margin-top: 12px; font-size: 12px; letter-spacing: .1em; color: var(--muted); }
@media (max-width: 760px) { .numbers__grid { grid-template-columns: repeat(2, 1fr); gap: 38px 20px; } }

/* ---------- 案例 ---------- */
.case { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: clamp(30px, 6vw, 100px); padding: clamp(80px, 11vw, 160px) 0; }
.case__sticky { align-self: start; position: sticky; top: 120px; }
.case__lede { margin-top: 28px; color: rgba(255,255,255,.6); font-size: 14.5px; line-height: 1.75; max-width: 24em; }
.case-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: start;
  padding: clamp(22px, 3vw, 36px) 0;
  border-top: 1px solid var(--line);
  transition: background .5s var(--ease), padding-left .5s var(--ease);
}
.case-row:last-child { border-bottom: 1px solid var(--line); }
.case-row:hover { background: linear-gradient(90deg, rgba(124,92,255,.10), transparent 70%); padding-left: 12px; }
.case-row__idx { font-size: 12px; color: var(--muted); letter-spacing: .1em; padding-top: 6px; }
.case-row h3 { font-size: clamp(20px, 2.1vw, 30px); letter-spacing: -.02em; }
.case-row p { margin-top: 10px; color: rgba(255,255,255,.62); font-size: 14.5px; line-height: 1.7; }
.case-row b { font-size: 10.5px; letter-spacing: .12em; color: var(--cyan); border: 1px solid rgba(53,208,224,.3); border-radius: 999px; padding: 6px 12px; white-space: nowrap; }
@media (max-width: 900px) { .case { grid-template-columns: 1fr; } .case__sticky { position: relative; top: 0; } }

/* ---------- 能力 ---------- */
.caps { padding: clamp(70px, 9vw, 130px) 0; }
.caps__grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid var(--line); }
.cap {
  position: relative;
  padding: clamp(26px, 3vw, 40px);
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  overflow: hidden;
  transition: color .4s;
}
.cap:nth-child(3n) { border-right: none; }
.cap::before {
  content: "";
  position: absolute; inset: 0;
  background: var(--grad-soft);
  opacity: 0;
  transition: opacity .5s var(--ease);
}
.cap:hover::before { opacity: 1; }
.cap span { position: relative; font-size: 11px; letter-spacing: .18em; color: var(--muted); }
.cap h3 { position: relative; margin-top: 34px; font-size: clamp(19px, 1.9vw, 26px); letter-spacing: -.01em; }
.cap p { position: relative; margin-top: 12px; font-size: 13.5px; line-height: 1.7; color: rgba(255,255,255,.55); }
@media (max-width: 860px) { .caps__grid { grid-template-columns: repeat(2, 1fr); } .cap:nth-child(3n) { border-right: 1px solid var(--line); } .cap:nth-child(2n) { border-right: none; } }

/* ---------- CTA ---------- */
.cta { padding: clamp(120px, 18vw, 260px) 0 clamp(90px, 12vw, 160px); }
.cta__title {
  font-size: clamp(72px, 14vw, 240px);
  line-height: .85;
  letter-spacing: -.05em;
  font-weight: 800;
}
.cta__text { margin-top: 30px; font-size: clamp(15px, 1.6vw, 21px); color: rgba(255,255,255,.65); max-width: 30em; }
.btn-magnet {
  display: inline-flex; align-items: center; gap: 18px;
  margin-top: clamp(36px, 5vw, 56px);
  padding: 18px 34px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.25);
  font-size: 14px;
  position: relative;
  overflow: hidden;
  transition: border-color .4s;
}
.btn-magnet span { position: relative; z-index: 1; }
.btn-magnet i { position: relative; z-index: 1; font-style: normal; transition: transform .5s var(--ease); }
.btn-magnet::before {
  content: ""; position: absolute; inset: 0;
  background: var(--grad);
  transform: scaleX(0); transform-origin: left;
  transition: transform .6s var(--ease);
}
.btn-magnet:hover { border-color: transparent; }
.btn-magnet:hover::before { transform: scaleX(1); }
.btn-magnet:hover i { transform: translateX(6px); }

/* ---------- FOOTER ---------- */
.footer { position: relative; border-top: 1px solid var(--line); padding-top: 60px; overflow: hidden; }
.footer__inner { display: flex; flex-wrap: wrap; gap: 30px; justify-content: space-between; align-items: flex-start; padding-bottom: 40px; }
.footer__brand { display: flex; gap: 14px; align-items: center; }
.footer__brand img { width: 40px; }
.footer__brand b { display: block; font-size: 14px; font-weight: 600; }
.footer__brand span { display: block; margin-top: 4px; font-size: 10px; letter-spacing: .22em; color: var(--muted); }
.footer__links { display: flex; flex-direction: column; gap: 10px; font-size: 12px; color: var(--muted); }
.footer__links a:hover { color: #fff; }
.footer__copy { width: 100%; font-size: 11px; color: rgba(255,255,255,.32); letter-spacing: .06em; }
.footer__word {
  font-size: clamp(70px, 17vw, 280px);
  line-height: .8;
  font-weight: 800;
  letter-spacing: -.05em;
  text-align: center;
  color: transparent;
  -webkit-text-stroke: 1px rgba(255,255,255,.10);
  transform: translateY(18%);
  user-select: none;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .hero__grid { grid-template-columns: 1fr; align-items: start; }
  .hero__right { display: none; }
}
@media (max-width: 640px) {
  .hero { padding-top: 120px; }
  .hero__meta { gap: 24px; flex-wrap: wrap; }
  .case-row { grid-template-columns: 34px minmax(0, 1fr); }
  .case-row b { grid-column: 2; justify-self: start; margin-top: 8px; }
  .footer__word { transform: translateY(10%); }
}

/* 降低动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001s !important; transition-duration: .001s !important; }
  .grain { display: none; }
}

/* 逐字拆分后的渐变文字：把渐变落到每个字符上，否则会被父级裁剪吃掉 */
.hero__title .grad .char,
.cta__title .grad .char {
  background-image: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* 右侧滚动进度 */
.scroll-progress {
  position: fixed;
  right: 14px; top: 50%;
  width: 1px; height: 30vh;
  transform: translateY(-50%);
  background: rgba(255,255,255,.10);
  z-index: 90;
}
.scroll-progress i {
  position: absolute; left: 0; top: 0;
  width: 100%; height: 0%;
  background: var(--grad);
  box-shadow: 0 0 12px rgba(124,92,255,.8);
}
@media (max-width: 860px) { .scroll-progress { display: none; } }

/* 极光背景 */
.aurora { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; }
.aurora i {
  position: absolute;
  width: 60vw; height: 60vw;
  border-radius: 50%;
  filter: blur(90px);
  opacity: .16;
  will-change: transform;
}
.aurora i:nth-child(1) { background: radial-gradient(circle, #7C5CFF, transparent 65%); left: -18vw; top: -20vw; animation: drift1 28s ease-in-out infinite alternate; }
.aurora i:nth-child(2) { background: radial-gradient(circle, #3D8BFF, transparent 65%); right: -22vw; top: 12vh; animation: drift2 34s ease-in-out infinite alternate; }
.aurora i:nth-child(3) { background: radial-gradient(circle, #35D0E0, transparent 68%); left: 26vw; bottom: -30vw; opacity: .10; animation: drift3 40s ease-in-out infinite alternate; }
@keyframes drift1 { to { transform: translate(14vw, 10vh) scale(1.15); } }
@keyframes drift2 { to { transform: translate(-12vw, -8vh) scale(1.1); } }
@keyframes drift3 { to { transform: translate(8vw, -12vh) scale(1.2); } }

/* 章节标题逐字 */
.section-title .char { display: inline-block; }
.caps__note {
  margin-top: 34px;
  font-size: 13.5px;
  color: var(--muted);
  letter-spacing: .02em;
}

.section-title, .cta__title { overflow: hidden; padding-bottom: .08em; }

/* 光标拖尾画布 */
#trail { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 9998; pointer-events: none; mix-blend-mode: screen; }
@media (hover: none) { #trail { display: none; } }