.brand-method {
  --method-scale: 1;
  --method-word-scale: 1;
  --method-mask-opacity: 0;
  --method-cover-opacity: 1;
  --method-intro-opacity: 1;
  --method-label-opacity: 1;
  --method-large-opacity: 0;
  --method-phone-progress: 0;
  --method-scene-opacity: 1;
  --method-final-phone-opacity: 0;
  --method-detail-opacity: 0;
  position: relative;
  min-height: 0;
  background: #000;
  color: #f5f5f7;
}

.brand-method__motion {
  position: relative;
  height: 200vh;
  min-height: 1440px;
}

.brand-method__sticky {
  position: sticky;
  z-index: 1;
  top: 0;
  height: 100vh;
  overflow: hidden;
  background: #000;
}

.brand-method__canvas-shell {
  position: absolute;
  top: 0;
  left: 50%;
  width: 1920px;
  height: 1080px;
  transform: translateX(-50%) scale(var(--method-scale));
  transform-origin: top center;
}

.brand-method__canvas {
  position: relative;
  width: 1920px;
  height: 1080px;
}

.brand-method__detail-shell {
  position: relative;
  z-index: 2;
  height: calc(1025px * var(--method-scale));
  /* detail-canvas 顶部与 final-phone 底部在画布坐标系恒定重叠 75px（Figma 基准）。
     final-phone 底部在画布坐标 970px（top:134 + height:836）。
     detail-shell 顶部相对于 sticky 顶部 = 100vh + margin-top。
     令 100vh + margin-top = (970 - 75) × scale = 895 × scale，
     得 margin-top = 895×scale - 100vh。
     这样重叠量不再随窗口宽高比变化，跨浏览器一致。 */
  margin-top: calc(895px * var(--method-scale) - 100vh + 50px);
  overflow: hidden;
  background: transparent;
  opacity: var(--method-detail-opacity);
}

.brand-method__detail-canvas {
  position: absolute;
  top: 0;
  left: 50%;
  width: 1920px;
  height: 1025px;
  transform: translateX(-50%) scale(var(--method-scale));
  transform-origin: top center;
}

.brand-method__scene {
  position: absolute;
  z-index: 0;
  inset: 0 auto auto 0;
  display: block;
  width: 1920px;
  height: 1080px;
  object-fit: fill;
  opacity: var(--method-scene-opacity);
  will-change: opacity;
}

.brand-method__intro-cover {
  position: absolute;
  z-index: 1;
  inset: 0 auto auto 0;
  width: 1920px;
  height: 1080px;
  background: #000;
  opacity: var(--method-cover-opacity);
  will-change: opacity;
}

.brand-method__reveal-mask {
  position: absolute;
  z-index: 2;
  top: 0;
  left: 0;
  display: block;
  width: 1920px;
  height: 1080px;
  overflow: hidden;
}

.brand-method__mask-word,
.brand-method__mask-label {
  font-family: "Montserrat", "Arial Black", sans-serif;
  font-weight: 700;
  letter-spacing: 0;
  text-anchor: middle;
  dominant-baseline: central;
}

.brand-method__mask-word {
  font-size: 80px;
  transform: scale(var(--method-word-scale));
  transform-box: view-box;
  transform-origin: 1040.5px 539px;
  will-change: transform;
}

.brand-method__mask-media {
  opacity: var(--method-mask-opacity);
  will-change: opacity;
}

.brand-method__mask-label {
  fill: #f5f5f7;
  font-size: 80px;
  opacity: var(--method-label-opacity);
  will-change: opacity;
}

.brand-method__intro {
  position: absolute;
  z-index: 4;
  top: 381px;
  left: 477px;
  width: 967px;
  height: 318px;
  margin: 0;
  color: #f5f5f7;
  font-family: "MiSans", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 80px;
  font-weight: 330;
  line-height: 106px;
  letter-spacing: 0;
  text-align: center;
}

.brand-method__intro > span {
  display: block;
  white-space: nowrap;
}

.brand-method__intro-line--first,
.brand-method__intro-line--third,
.brand-method__intro-copy {
  opacity: var(--method-intro-opacity);
  will-change: opacity;
}

.brand-method__intro-copy {
  display: inline;
}

.brand-method__intro strong {
  display: inline;
  font-family: "Montserrat", "Arial Black", sans-serif;
  font-size: inherit;
  font-weight: 700;
  opacity: 0;
}

/* 大显示器（883_66）：外框 2268×1935，内容 2167×1086 */
.brand-method__large-phone {
  position: absolute;
  z-index: 3;
  top: -111px;
  left: -195px;
  width: 2268px;
  height: 1935px;
  opacity: var(--method-large-opacity);
  transform: translate3d(calc(var(--method-phone-progress) * 21px), calc(var(--method-phone-progress) * -304.5px), 0)
    scale(calc(1 - var(--method-phone-progress) * .5679));
  transform-origin: 50% 50%;
  will-change: transform, opacity;
}

.brand-method__large-phone-image,
.brand-method__large-phone-frame,
.brand-method__final-phone-image,
.brand-method__final-phone-frame {
  position: absolute;
  display: block;
  object-fit: fill;
}

.brand-method__large-phone-image {
  z-index: 2;
  top: 107px;
  left: 51px;
  width: 2167px;
  height: 1086px;
}

.brand-method__large-phone-frame {
  z-index: 1;
  inset: 0;
  width: 2268px;
  height: 1935px;
}

/* 小显示器（449_162）：外框 980×836，内容 936×469 */
.brand-method__final-phone {
  position: absolute;
  z-index: 4;
  top: 134px;
  left: 470px;
  width: 980px;
  height: 836px;
  opacity: var(--method-final-phone-opacity);
  will-change: opacity;
}

.brand-method__final-phone-image {
  z-index: 2;
  top: 46px;
  left: 22px;
  width: 936px;
  height: 469px;
}

.brand-method__final-phone-frame {
  z-index: 1;
  inset: 0;
  width: 980px;
  height: 836px;
}

.brand-method__detail-copy,
.brand-method__principle,
.brand-method__cta { z-index: 5; }

.brand-method [data-method-reveal] {
  opacity: 0;
  transform: translate3d(0, 30px, 0);
  transition: opacity 900ms ease, transform 700ms cubic-bezier(.16,1,.3,1);
  will-change: transform, opacity;
}

.brand-method [data-method-reveal].is-visible {
  opacity: 1;
  transform: none;
}

.brand-method__principle--center[data-method-reveal] { transition-delay: 150ms; }
.brand-method__principle--right[data-method-reveal] { transition-delay: 300ms; }

.brand-method__detail-copy {
  position: absolute;
  top: 95px;
  left: 680px;
  width: 560px;
  text-align: center;
}

.brand-method__eyebrow,
.brand-method__title,
.brand-method__description,
.brand-method__principle p {
  margin: 0;
  font-family: "MiSans", "PingFang SC", "Microsoft YaHei", sans-serif;
}

.brand-method__eyebrow {
  height: 32px;
  color: transparent;
  font-size: 24px;
  font-weight: 450;
  line-height: 32px;
  background: linear-gradient(180deg, #fec28a 0%, #ca4b09 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-method__title {
  height: 70px;
  margin-top: 28px;
  color: #f5f5f7;
  font-size: 80px;
  font-weight: 630;
  line-height: 70px;
  white-space: nowrap;
}

.brand-method__description {
  width: 450px;
  margin: 28px auto 0;
  color: #86868b;
  font-size: 18px;
  font-weight: 330;
  line-height: 28.8px;
}

.brand-method__principles {
  position: absolute;
  top: 420px;
  left: 371px;
  width: 1188px;
  height: 270px;
}

.brand-method__principle {
  position: absolute;
  width: 267px;
  text-align: center;
}

.brand-method__principle--left {
  top: 1px;
  left: 0;
}

.brand-method__principle--center {
  top: 8px;
  left: 456px;
}

.brand-method__principle--right {
  top: -1px;
  left: 921px;
}

.brand-method__principle-icon {
  position: relative;
  display: block;
}

.brand-method__principle-icon img {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
}

.brand-method__principle-icon--left {
  left: 69px;
  width: 129.64px;
  height: 107px;
  margin-bottom: 55px;
}

.brand-method__principle-icon--center {
  left: 87px;
  width: 93px;
  height: 91px;
  margin-bottom: 63px;
}

.brand-method__principle-icon--right {
  left: 80px;
  width: 107.31px;
  height: 107.43px;
  margin-bottom: 55px;
}

.brand-method__principle p {
  width: 267px;
  color: #b5b5b5;
  font-size: 20px;
  font-weight: 330;
  line-height: 35.5px;
}

.brand-method__principle-title {
  margin-right: .55em;
  color: #f5f5f7;
  font-weight: 630;
}

.brand-method__principle-copy {
  color: #b5b5b5;
}

.brand-method__cta {
  position: absolute;
  top: 815px;
  left: 788px;
  width: 344px;
  height: 60px;
  padding: 0;
  border: 0;
  border-radius: 29px;
  background: #222224;
  color: #f5f5f7;
  font-family: "MiSans", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 18px;
  font-weight: 630;
  cursor: pointer;
}

.brand-method__cta > span {
  position: absolute;
  top: 0;
  left: 37px;
  line-height: 56px;
}

.brand-method__cta > img {
  position: absolute;
  top: 11px;
  left: 297px;
  width: 37px;
  height: 37px;
}

.brand-method__cta:focus-visible {
  outline: 3px solid rgba(0, 113, 227, .75);
  outline-offset: 4px;
}

@media (hover: hover) {
  .brand-method__cta:hover {
    filter: brightness(1.1);
  }
}

@media (max-width: 900px) {
  .brand-method {
    padding: 88px 20px 96px;
    overflow: hidden;
  }

  .brand-method__motion {
    height: auto;
    min-height: 0;
  }

  .brand-method__sticky {
    position: relative;
    height: auto;
    overflow: visible;
  }

  .brand-method__canvas-shell,
  .brand-method__canvas,
  .brand-method__detail-shell,
  .brand-method__detail-canvas {
    position: relative;
    top: auto;
    left: auto;
    width: 100%;
    height: auto;
    transform: none;
  }

  .brand-method__detail-shell { margin-top: 0; overflow: visible; }

  .brand-method__scene,
  .brand-method__intro-cover,
  .brand-method__reveal-mask {
    display: none;
  }

  .brand-method__large-phone {
    position: relative;
    top: auto;
    left: 50%;
    width: min(112vw, 620px);
    height: auto;
    aspect-ratio: 2552 / 1236.13;
    margin-top: 58px;
    opacity: 1;
    transform: translateX(-50%);
  }

  .brand-method__large-phone-image {
    top: 4.435%;
    left: 1.953%;
    width: 96.093%;
    height: 91.129%;
  }

  .brand-method__large-phone-frame {
    width: 100%;
    height: 100%;
  }

  .brand-method__intro {
    position: relative;
    top: auto;
    left: auto;
    width: 100%;
    height: auto;
    font-size: clamp(36px, 10.8vw, 54px);
    line-height: 1.22;
    opacity: 1;
  }

  .brand-method__intro > span {
    white-space: normal;
  }

  .brand-method__intro strong {
    opacity: 1;
    color: transparent;
    background: linear-gradient(180deg, #fec28a, #ca4b09);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

  .brand-method__final-phone-image,
  .brand-method__final-phone-frame {
    display: none;
  }

  .brand-method__detail-copy,
  .brand-method__principles,
  .brand-method__principle,
  .brand-method__cta {
    position: relative;
    inset: auto;
    width: 100%;
    opacity: 1;
    transform: none;
  }

  .brand-method__detail-copy {
    margin-top: 82px;
  }

  .brand-method__eyebrow {
    font-size: 20px;
  }

  .brand-method__title {
    height: auto;
    margin-top: 20px;
    font-size: clamp(40px, 12vw, 58px);
    line-height: 1.12;
    white-space: normal;
  }

  .brand-method__description {
    width: 100%;
    margin-top: 24px;
    font-size: 16px;
    line-height: 1.75;
  }

  .brand-method__description br {
    display: none;
  }

  .brand-method__principles {
    display: grid;
    gap: 58px;
    margin-top: 74px;
  }

  .brand-method__principle-icon--left,
  .brand-method__principle-icon--center,
  .brand-method__principle-icon--right {
    left: auto;
    margin-right: auto;
    margin-bottom: 26px;
    margin-left: auto;
  }

  .brand-method__principle p {
    width: min(100%, 320px);
    margin: 0 auto;
    font-size: 17px;
    line-height: 1.8;
  }

  .brand-method__cta {
    width: min(100%, 344px);
    margin: 74px auto 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .brand-method__canvas,
  .brand-method__scene,
  .brand-method__intro-cover,
  .brand-method__mask-word,
  .brand-method__mask-media,
  .brand-method__large-phone,
  .brand-method__detail-copy,
  .brand-method__principles,
  .brand-method__cta {
    will-change: auto;
  }
}