/* =============================================
   WHERO — Travel Journal Landing Page
   Black & White Minimal Design
   ============================================= */

/* ===== RESET ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ===== CUSTOM PROPERTIES ===== */
:root {
  --bg:       #080808;
  --bg2:      #0e0e0e;
  --white:    #ffffff;
  --g1:       rgba(255,255,255,0.95);
  --g2:       rgba(255,255,255,0.72);
  --g3:       rgba(255,255,255,0.42);
  --g4:       rgba(255,255,255,0.10);
  --border:   rgba(255,255,255,0.12);
  --font:     'Inter', system-ui, sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

html {
  /* Lenis 接管滚动，禁用浏览器原生平滑以避免冲突 */
  scroll-behavior: auto;
  font-size: 16px;
}

body {
  background: var(--bg);
  color: var(--white);
  font-family: var(--font);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Hide default cursor on non-touch devices */
@media (pointer: fine) {
  body, a, button { cursor: none; }
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar          { width: 2px; }
::-webkit-scrollbar-track    { background: var(--bg); }
::-webkit-scrollbar-thumb    { background: var(--g3); border-radius: 2px; }

/* ===== SELECTION ===== */
::selection { background: var(--white); color: var(--bg); }

/* =============================================
   CUSTOM CURSOR
   ============================================= */
#cursor-dot,
#cursor-ring {
  position: fixed;
  top: 0;
  left: 0;
  pointer-events: none;
  z-index: 9999;
  transform: translate(-50%, -50%);
  border-radius: 50%;
}

/* 外圈：白色边框 + 白色填充 + difference → 内部区域反色 */
#cursor-ring {
  width: 48px;
  height: 48px;
  background: #ffffff;
  border: 2px solid #ffffff;
  mix-blend-mode: difference;
  transition: width 0.25s var(--ease-out),
              height 0.25s var(--ease-out);
}

/* 内圈：白色细边 + difference，分隔外圈与中心点 */
#cursor-ring-inner {
  position: fixed;
  top: 0;
  left: 0;
  pointer-events: none;
  z-index: 9999;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: transparent;
  border: 1px solid #ffffff;
  mix-blend-mode: difference;
  transition: width 0.25s var(--ease-out),
              height 0.25s var(--ease-out);
}

/* 中心点：叠在已反色的圈内部上面，二次 difference = 还原为背景色 */
#cursor-dot {
  width: 6px;
  height: 6px;
  background: #ffffff;
  mix-blend-mode: difference;
}

#cursor-ring.expanded {
  width: 80px;
  height: 80px;
}

#cursor-ring-inner.expanded {
  width: 76px;
  height: 76px;
}

/* =============================================
   PRELOADER
   ============================================= */
#preloader {
  position: fixed;
  inset: 0;
  z-index: 8000;
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
}

.pre-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  width: 220px;
}

.pre-logo {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -1px;
  color: var(--white);
}

.pre-bar-wrap {
  width: 100%;
  height: 1px;
  background: var(--g3);
  position: relative;
  overflow: hidden;
}

.pre-bar {
  height: 100%;
  background: var(--white);
  width: 0%;
  transition: width 0.1s linear;
}

.pre-count {
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--g2);
  align-self: flex-end;
}

/* =============================================
   NAVIGATION
   ============================================= */
#nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 28px 48px;
  transition: padding 0.4s var(--ease-out),
              background 0.4s,
              border-color 0.4s;
  border-bottom: 1px solid transparent;
}

#nav.scrolled {
  padding: 18px 48px;
  background: rgba(8,8,8,0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--border);
}

.nav-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.8px;
  color: var(--white);
  text-decoration: none;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 40px;
  align-items: center;
}

.nav-links a {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--g2);
  text-decoration: none;
  transition: color 0.25s;
}

.nav-links a:hover { color: var(--white); }

.nav-cta {
  padding: 9px 22px !important;
  border: 1px solid var(--g3) !important;
  border-radius: 2px !important;
  color: var(--white) !important;
  transition: background 0.25s, border-color 0.25s, color 0.25s !important;
}

.nav-cta:hover {
  background: var(--white) !important;
  color: var(--bg) !important;
  border-color: var(--white) !important;
}

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: none;
  border: none;
  padding: 4px;
}

.nav-hamburger span {
  display: block;
  width: 24px;
  height: 1px;
  background: var(--white);
  transition: transform 0.3s, opacity 0.3s;
}

/* =============================================
   BUTTONS
   ============================================= */
.btn {
  display: inline-block;
  padding: 13px 30px;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-decoration: none;
  border-radius: 2px;
  transition: all 0.3s var(--ease-out);
}

.btn-fill {
  background: var(--white);
  color: var(--bg);
  border: 1px solid var(--white);
}

.btn-fill:hover {
  background: transparent;
  color: var(--white);
}

.btn-ghost {
  background: transparent;
  color: var(--g2);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  border-color: var(--g3);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 1px solid var(--g3);
}

.btn-outline:hover {
  border-color: var(--white);
}

/* =============================================
   SHARED TEXT STYLES
   ============================================= */
.eyebrow {
  display: block;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--g2);
  margin-bottom: 18px;
}

.section-title {
  font-size: clamp(38px, 5.5vw, 76px);
  font-weight: 800;
  line-height: 1.0;
  letter-spacing: -2.5px;
  color: var(--white);
  margin-bottom: 28px;
}

/* Split-text structure */
.section-title .line {
  display: block;
  overflow: hidden;
}
.section-title .line-inner {
  display: block;
}

/* =============================================
   HERO
   ============================================= */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 130px 48px 0;
  overflow: hidden;
}

/* Subtle dot grid background */
.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255,255,255,0.12) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  opacity: 0.5;
}

.hero-inner {
  max-width: 1520px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  align-items: flex-end;
  justify-content: flex-start;
  gap: clamp(32px, 5vw, 88px);
  overflow: visible;
}

.hero-left {
  flex: 0 1 auto;
  max-width: 620px;
  align-self: center;
  margin-bottom: clamp(24px, 6vh, 72px);
}

.hero-eyebrow {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--g2);
  margin-bottom: 28px;
}

/* Hero title is big */
.hero-title {
  font-size: clamp(72px, 10vw, 148px);
  font-weight: 900;
  line-height: 0.92;
  letter-spacing: -5px;
  color: var(--white);
  margin-bottom: 36px;
  overflow: hidden;
}

.hero-title-motion {
  display: block;
  transform-origin: 50% 55%;
  will-change: transform;
}

.hero-title .line {
  display: block;
  overflow: hidden;
}

.hero-title .line-inner {
  display: block;
}

.hero-sub {
  font-size: 17px;
  line-height: 1.75;
  color: var(--g2);
  max-width: 400px;
  margin-bottom: 44px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-right {
  flex: 0 0 auto;
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  width: clamp(700px, 54vw, 900px);
  max-width: 900px;
  min-width: 0;
  align-self: flex-end;
  margin-right: clamp(-20px, -2vw, 0);
  margin-bottom: clamp(-32px, -4vh, 8px);
  opacity: 0;
}

.hero-nanoflow-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 600 / 400;
  flex-shrink: 0;
}

.hero-nanoflow-wrap canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
}

@keyframes ringPulse {
  0%, 100% { opacity: 0.2; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(1.03); }
}

/* Scroll indicator */
.hero-scroll {
  position: absolute;
  bottom: 72px;
  left: 50%;
  transform: translateX(-50%) translateY(-20%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.hero-scroll-lottie lottie-player {
  filter: invert(1) grayscale(1);
  opacity: 0.5;
}

.hero-scroll span {
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--g2);
}

/* Ticker / Marquee */
.hero-ticker {
  position: absolute;
  bottom: 32px;
  left: 0;
  right: 0;
  overflow: hidden;
  background: #ffffff;
  padding: 13px 0;
  white-space: nowrap;
  user-select: none;
}

.ticker-track {
  display: inline-flex;
  align-items: center;
  gap: 0;
}

.ticker-track span {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #080808;
  padding: 0 20px;
  flex-shrink: 0;
}

.ticker-arrow {
  display: inline-flex;
  align-items: center;
  padding: 0 18px !important;
  flex-shrink: 0;
}

.ticker-arrow svg {
  width: 36px;
  height: 22px;
  display: block;
  transform-origin: center;
  transition: transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* =============================================
   ABOUT → FEATURES 横向衔接舞台
   ============================================= */
.about-features-stage {
  position: relative;
}

.about-features-pin {
  height: 100vh;
  width: 100%;
  overflow: hidden;
  background: var(--bg);
}

@media (min-width: 901px) {
  /* 额外滚动行程驱动横向位移，sticky 替代 pin，避免滚轮顿住 */
  .about-features-stage {
    height: 200vh;
  }

  .about-features-pin {
    position: sticky;
    top: 0;
  }
}

.about-features-track {
  display: flex;
  flex-wrap: nowrap;
  height: 100%;
  width: max-content;
}

.stage-panel {
  flex: 0 0 100vw;
  width: 100vw;
  max-width: 100vw;
  height: 100vh;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
}

.stage-panel--about {
  background: var(--bg);
}

.stage-panel--features {
  background: var(--bg);
}

@media (min-width: 901px) {
  #about.stage-panel,
  #features.stage-panel {
    padding: 48px clamp(24px, 4vw, 48px);
    border: none;
  }

  #features.stage-panel {
    border-top: none;
    border-bottom: none;
  }

  .stage-panel .about-inner,
  .stage-panel .features-inner {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
  }

  .stage-panel--features .features-header {
    margin-bottom: 40px;
  }

  .stage-panel--features .features-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
    --feat-pad-block: 36px;
    --feat-pad-inline: 28px;
  }
}

@media (max-width: 900px) {
  .about-features-pin {
    height: auto;
    overflow: visible;
  }

  .about-features-track {
    display: block;
    width: 100%;
    height: auto;
  }

  .stage-panel {
    width: 100%;
    max-width: none;
    flex: none;
    height: auto;
    min-height: 0;
    overflow: visible;
    display: block;
  }

  #about.stage-panel,
  #features.stage-panel {
    padding: 160px 48px;
  }

  #features.stage-panel {
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
  }
}

/* =============================================
   ABOUT / VIDEO
   ============================================= */
#about {
  padding: 160px 48px;
}

.about-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 120px;
}

/* VIDEO COLUMN */
.about-video-col {
  flex: 0 0 auto;
  position: relative;
}

@media (min-width: 901px) {
  .about-video-col {
    z-index: 2;
  }
}

/* 手机外壳（About 视频预览） */
.video-frame,
.phone-shell:not(.faq-phone) {
  position: relative;
  width: 300px;
  max-width: 100%;
  border-radius: 28px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #111;
  aspect-ratio: 9 / 19.5;
  user-select: none;
  -webkit-user-select: none;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.06) inset,
    0 28px 72px rgba(0, 0, 0, 0.55);
  flex-shrink: 0;
}

.phone-shell-island {
  position: absolute;
  top: 11px;
  left: 50%;
  transform: translateX(-50%);
  width: 32%;
  max-width: 108px;
  height: 24px;
  border-radius: 20px;
  background: #000;
  z-index: 4;
  pointer-events: none;
}

.phone-shell-screen {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: #ededed;
}

.phone-shell-screen img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  object-position: center top;
  pointer-events: none;
  -webkit-user-drag: none;
}

.video-frame video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  pointer-events: none;
  -webkit-touch-callout: none;
}

/* 拦截悬停/点击，避免浏览器弹出翻译、画中画、原生控件等 */
.video-shield {
  position: absolute;
  inset: 0;
  z-index: 2;
  cursor: default;
  background: transparent;
}

/* 隐藏 WebKit / 部分浏览器在 video 上的原生控件层 */
.video-frame video::-webkit-media-controls,
.video-frame video::-webkit-media-controls-enclosure,
.video-frame video::-webkit-media-controls-panel,
.video-frame video::-webkit-media-controls-overlay-play-button,
.video-frame video::-webkit-media-controls-start-playback-button,
.video-frame video::-webkit-media-controls-toggle-closed-captions-button,
.video-frame video::-webkit-media-controls-fullscreen-button,
.video-frame video::-webkit-media-controls-picture-in-picture-button {
  display: none !important;
  -webkit-appearance: none;
  opacity: 0;
  pointer-events: none;
}

.video-noise {
  z-index: 3;
}

.video-badge {
  z-index: 4;
}

/* Grain noise overlay for texture */
.video-noise {
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  opacity: 0.3;
}

.video-badge {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  pointer-events: none;
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--g2);
  background: rgba(8,8,8,0.7);
  padding: 5px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
  white-space: nowrap;
}

/* Decorative Lottie next to video */
.about-deco-lottie {
  position: absolute;
  right: -40px;
  top: -30px;
  filter: invert(1) grayscale(1);
  opacity: 0.6;
  pointer-events: none;
}

/* TEXT COLUMN */
.about-text-col {
  flex: 1;
}

.about-desc {
  font-size: 17px;
  line-height: 1.8;
  color: var(--g2);
  margin-bottom: 40px;
  max-width: 480px;
}

.about-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.about-list li {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 15px;
  color: var(--g1);
}

.dot {
  flex-shrink: 0;
  width: 5px;
  height: 5px;
  background: var(--white);
  border-radius: 50%;
}

/* =============================================
   FEATURES
   ============================================= */
#features {
  padding: 160px 48px;
  background: var(--bg);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.features-inner {
  max-width: 1400px;
  margin: 0 auto;
}

.features-header {
  margin-bottom: 72px;
  max-width: 600px;
}

/* 标题行：逐字 GSAP 动画 */
.features-title-loop .line {
  overflow: hidden;
}

.features-title-loop .line-inner {
  display: inline-block;
}

.feat-title-char {
  display: inline-block;
  white-space: pre;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--feat-gap, 24px);
  border: none;
  position: relative;
  isolation: isolate;
  --feat-radius: 88px;
  --feat-border-outer: 3px;
  --feat-border-inner: 2px;
  --feat-pad-block: 50px;
  --feat-pad-inline: 38px;
  --feat-gap: 24px;
}

.feat-card {
  padding: var(--feat-pad-block) var(--feat-pad-inline);
  background: #ffffff;
  border-radius: var(--feat-radius);
  position: relative;
  z-index: 1;
  overflow: hidden;
  border: var(--feat-border-outer) solid #ffffff;
  transform-origin: center center;
  /* transform 由 GSAP 统一控制（y 浮动 + hover scale） */
  transition:
    box-shadow 0.4s var(--ease-out),
    opacity 0.4s var(--ease-out),
    z-index 0s;
  box-shadow:
    inset 0 0 0 var(--feat-border-inner) #0a0a0a,
    0 6px 28px rgba(0, 0, 0, 0.14);
  -webkit-font-smoothing: antialiased;
}

.features-grid:has(.feat-card:hover) .feat-card:not(:hover) {
  z-index: 0;
}

.feat-card:hover {
  z-index: 20;
  box-shadow:
    inset 0 0 0 var(--feat-border-inner) #0a0a0a,
    0 20px 48px rgba(0, 0, 0, 0.26);
}

.feat-icon {
  margin-bottom: 28px;
  filter: none;
  opacity: 1;
}

.feat-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 12px;
  color: #080808;
  letter-spacing: -0.3px;
}

.feat-card p {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(8, 8, 8, 0.58);
}

/* =============================================
   STATS
   ============================================= */
#stats {
  padding: 120px 48px;
}

.stats-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-around;
}

.stat-item {
  text-align: center;
  flex: 1;
}

.stat-num-wrap {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
}

.stat-num {
  font-size: clamp(52px, 7vw, 96px);
  font-weight: 900;
  letter-spacing: -3px;
  line-height: 1;
  color: var(--white);
}

.stat-num--text {
  font-size: clamp(36px, 5vw, 64px);
  letter-spacing: -1px;
}

.stat-sfx {
  font-size: clamp(24px, 3vw, 44px);
  font-weight: 700;
  color: var(--g2);
}

.stat-label {
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--g2);
  margin-top: 14px;
}

.stat-divider {
  width: 1px;
  height: 72px;
  background: var(--border);
  flex-shrink: 0;
}

/* =============================================
   FAQ — 左固定介绍 + 右滚动切换对话图
   ============================================= */
.faq-stage {
  position: relative;
  z-index: 2;
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

@media (min-width: 901px) {
  .faq-stage {
    height: var(--faq-scroll-height, 260vh);
  }

  .faq-pin {
    position: sticky;
    top: 0;
    height: 100vh;
    width: 100%;
    overflow: hidden;
  }
}

.faq-inner {
  max-width: 1400px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  gap: clamp(40px, 6vw, 88px);
  padding: clamp(48px, 5vh, 72px) clamp(24px, 4vw, 48px);
  box-sizing: border-box;
}

.faq-left {
  flex: 0 0 min(420px, 38%);
  max-width: 460px;
}

@media (min-width: 901px) {
  .faq-inner {
    --faq-phone-w: min(320px, 26vw, 1216px, calc((100vh - 260px) * 1216 / 2020));
    /* 右列总宽 = 手机宽 + 仅右侧动画留白（×1.6）；左侧无占位，贴齐列左缘 */
    --faq-col-gap: clamp(8px, 1vw, 14px);
    --faq-col-w: calc((var(--faq-phone-w) + var(--faq-col-gap)) * 1.6);

    max-width: none;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    gap: clamp(28px, 3vw, 48px);
    align-items: center;
  }

  .faq-left {
    flex: 1 1 auto;
    min-width: 0;
    max-width: none;
    align-self: center;
    padding: clamp(48px, 5vh, 72px) clamp(24px, 3vw, 40px)
      clamp(48px, 5vh, 72px)
      max(24px, calc((100vw - 1400px) / 2 + clamp(24px, 4vw, 48px)));
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .faq-right {
    flex: 0 0 var(--faq-col-w);
    width: var(--faq-col-w);
    max-width: var(--faq-col-w);
    min-width: var(--faq-col-w);
    height: auto;
    max-height: 100vh;
    align-self: center;
    margin-right: 0;
    padding: clamp(12px, 2vh, 24px) 0;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: stretch;
    overflow-x: hidden;
    overflow-y: visible;
  }
}

#faq .section-title .line {
  overflow: visible;
}

.faq-word {
  display: inline-block;
  transform-origin: 50% 85%;
  will-change: transform, opacity;
}

.faq-ch {
  display: inline-block;
}

.faq-intro,
.faq-contact {
  font-size: 15px;
  line-height: 1.75;
  color: var(--g2);
  max-width: 36em;
}

.faq-intro {
  margin-top: 28px;
}

.faq-contact {
  margin-top: 16px;
}

.faq-contact a {
  color: var(--g1);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.25s var(--ease-out);
}

.faq-contact a:hover {
  color: var(--white);
}

.faq-right {
  min-width: 0;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
}

.faq-slides {
  --faq-phone-w: min(320px, 26vw, 1216px, calc((100vh - 260px) * 1216 / 2020));
  --faq-track-h: calc(var(--faq-phone-w) * 2020 / 1216 + 52px);

  position: relative;
  width: 100%;
  height: auto;
  min-height: var(--faq-track-h);
  flex: 0 0 auto;
  overflow-x: hidden;
  overflow-y: visible;
  box-sizing: border-box;
}

@media (min-width: 901px) {
  .faq-slides {
    width: 100%;
    max-width: 100%;
    align-self: stretch;
  }
}

/* 在文档流中撑开高度，供绝对 定位的 .faq-slide 填满 */
.faq-slides-sizer {
  display: block;
  width: 1px;
  height: var(--faq-track-h);
  max-height: calc(100vh - 180px);
  margin-left: 0;
  visibility: hidden;
  pointer-events: none;
}

.faq-slide {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  height: 100%;
  min-height: 100%;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  z-index: 1;
  pointer-events: none;
  box-sizing: border-box;
}

@media (min-width: 901px) {
  .faq-slides {
    padding: clamp(16px, 2.5vh, 32px) 0;
    padding-left: 0;
    padding-right: 0;
    min-height: min(var(--faq-track-h), calc(100vh - 180px));
  }

  .faq-slides-sizer {
    height: min(var(--faq-track-h), calc(100vh - 180px));
    max-height: calc(100vh - 180px);
    margin-left: 0;
  }

  .faq-slide {
    padding: 0;
    align-items: center;
    justify-content: flex-start;
  }

  .faq-slide,
  .faq-slide.is-active {
    min-height: 100%;
    height: 100%;
  }

  .faq-phone.phone-shell {
    flex-shrink: 0;
    max-height: 100%;
  }

  .faq-phone .phone-shell-screen {
    max-height: calc(100% - 36px);
  }

}

.faq-slide.is-active {
  z-index: 3;
  pointer-events: auto;
}

@media (min-width: 901px) {
  .faq-slide {
    visibility: visible;
  }
}

@media (max-width: 900px) {
  .faq-slide {
    visibility: hidden;
    pointer-events: none;
  }

  .faq-slide.is-active {
    visibility: visible;
    pointer-events: auto;
  }
}

/* FAQ 手机框：外框比例贴合截图 1216×2020，听筒区在边框内不压画面 */
.faq-phone.phone-shell {
  --faq-img-ar: 1216 / 2020;
  width: var(--faq-phone-w, min(440px, 36vw, 1216px));

  display: flex;
  flex-direction: column;
  align-items: stretch;
  max-width: 100%;
  height: auto;
  aspect-ratio: unset;
  padding: 12px 11px 14px;
  border-radius: 42px;
  background: linear-gradient(165deg, #353535 0%, #181818 42%, #0a0a0a 100%);
  border: 1px solid rgba(255, 255, 255, 0.16);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.06) inset,
    0 32px 80px rgba(0, 0, 0, 0.55),
    0 6px 20px rgba(0, 0, 0, 0.4);
  box-sizing: border-box;
  overflow: hidden;
  will-change: transform;
  opacity: 1;
  visibility: visible;
}

.faq-phone-bezel {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 18px;
  margin-bottom: 6px;
}

.faq-phone-speaker {
  display: block;
  width: 26%;
  max-width: 88px;
  height: 10px;
  border-radius: 6px;
  background: #0a0a0a;
  box-shadow: inset 0 1px 2px rgba(255, 255, 255, 0.1);
}

.faq-phone .phone-shell-screen {
  position: relative;
  flex: 0 0 auto;
  width: 100%;
  height: auto;
  aspect-ratio: var(--faq-img-ar);
  border-radius: 30px;
  overflow: hidden;
  background: #ededed;
  line-height: 0;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.06);
}

.faq-phone .phone-shell-screen img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: top center;
}

@media (max-width: 900px) {
  .faq-slides-sizer {
    display: none;
  }

  .faq-slides {
    --faq-phone-w: min(300px, 88vw, 1216px, calc((100vh - 180px) * 1216 / 2020));
    --faq-track-h: auto;
    height: auto;
    min-height: 0;
    padding: clamp(20px, 4vh, 32px) 0;
    overflow: visible;
  }

  .faq-slide,
  .faq-slide.is-active {
    position: relative;
    top: auto;
    left: auto;
    right: auto;
    bottom: auto;
    width: 100%;
    height: auto;
    min-height: 0;
    padding: 0;
    margin-bottom: 20px;
  }

  .faq-slide:last-child {
    margin-bottom: 0;
  }

  .faq-phone.phone-shell {
    width: var(--faq-phone-w);
    margin: 0 auto;
    max-height: calc(100vh - 180px);
  }
}

@media (min-width: 901px) {
  .faq-pin {
    overflow-x: hidden;
    overflow-y: visible;
  }
}

@media (max-width: 900px) {
  .faq-stage {
    padding: 80px 24px 100px;
  }

  .faq-pin {
    height: auto;
    overflow: visible;
  }

  .faq-inner {
    flex-direction: column;
    align-items: flex-start;
    height: auto;
    padding: 0;
    gap: 48px;
  }

  .faq-left {
    flex: none;
    width: 100%;
    max-width: none;
  }

  .faq-right {
    flex: 1;
    width: 100%;
    height: auto;
    max-height: none;
  }

  .faq-slides {
    display: flex;
    flex-direction: column;
    gap: 20px;
    min-height: 0;
    border: none;
    background: transparent;
    overflow: visible;
  }

  .faq-slide {
    position: relative;
    inset: auto;
    visibility: visible;
    pointer-events: auto;
    padding: 0;
    overflow: hidden;
  }

  .faq-phone {
    width: min(280px, 78vw);
    margin: 0 auto;
  }

}

/* =============================================
   DOWNLOAD / CTA
   ============================================= */
#download {
  padding: 160px 48px 0;
  position: relative;
  z-index: 1;
}

.download-inner {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  min-height: clamp(520px, 62vh, 760px);
  /* 不使用 display:grid / z-index，靠 DOM 顺序和 absolute 定位控制层次 */
}

/* ── 图片层：绝对定位，贴左贴底，先绘制 = 在下方 ── */
.dl-visual {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 1000px;
  max-width: min(1000px, 82vw);
  pointer-events: none;
  line-height: 0;
  /* 不设 z-index，不形成 stacking context，让 mix-blend-mode 可穿透 */
}

.dl-icon-img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: contain;
  object-position: bottom left;
}

/* ── 文字层：相对定位，DOM 靠后 = 绘制在图片上面 ── */
.download-text-col {
  position: relative;
  /* 同样不设 z-index，保持和 .dl-visual 在同一 stacking context */
  /* 左边距 ≈ 图片宽度的 45%，让右侧文字与图片右半部分重叠 */
  margin-left: clamp(320px, 42%, 520px);
  padding: 0 0 48px 48px;
}

/* ── mix-blend-mode 直接加在各文字/按钮上（勿用 z-index）── */
#download .dl-text-blend .eyebrow,
#download .dl-text-blend .section-title,
#download .dl-text-blend .dl-desc,
#download .dl-btns .btn {
  mix-blend-mode: difference;
}

#download .dl-text-blend .eyebrow,
#download .dl-text-blend .section-title,
#download .dl-text-blend .dl-desc {
  color: #ffffff;
}

#download .dl-btns .btn-fill {
  background: #ffffff;
  color: #080808;
  border-color: #ffffff;
}

#download .dl-btns .btn-fill:hover {
  background: #ffffff;
  color: #080808;
  border-color: #ffffff;
}

#download .dl-btns .btn-outline {
  background: transparent;
  color: #ffffff;
  border-color: #ffffff;
}

#download .dl-btns .btn-outline:hover {
  background: transparent;
  color: #ffffff;
  border-color: #ffffff;
}

/* section-title .line 有 overflow:hidden，会裁掉文字与图片
   的混合区域，必须设为 visible                            */
#download .section-title .line {
  overflow: visible;
}

.dl-desc {
  font-size: 17px;
  line-height: 1.8;
  color: var(--g2);
  margin-bottom: 40px;
}

.dl-btns {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 4px;
}

/* =============================================
   FOOTER
   ============================================= */
#footer {
  padding: 56px 48px 40px;
  background: #ffffff;
  color: #080808;
}

.footer-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 32px;
}

.footer-logo {
  display: block;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.8px;
  margin-bottom: 8px;
  color: #080808;
}

.footer-brand p {
  font-size: 13px;
  color: rgba(8, 8, 8, 0.55);
}

.footer-links {
  display: flex;
  gap: 32px;
}

.footer-links a {
  font-size: 13px;
  color: rgba(8, 8, 8, 0.72);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(8, 8, 8, 0.28);
  transition: color 0.2s, text-decoration-color 0.2s;
}

.footer-links a:hover {
  color: #080808;
  text-decoration-color: #080808;
}

.footer-copy {
  max-width: 1400px;
  margin: 0 auto;
  font-size: 12px;
  color: rgba(8, 8, 8, 0.45);
  text-align: center;
}

.footer-copy p {
  margin: 0;
}

.footer-legal-en {
  margin-top: 6px;
  font-size: 11px;
  color: rgba(8, 8, 8, 0.4);
  letter-spacing: 0.02em;
}

.footer-beian {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
}

.footer-beian a {
  color: #080808;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  text-decoration-color: rgba(8, 8, 8, 0.45);
  cursor: pointer;
  transition: color 0.2s, text-decoration-color 0.2s;
}

.footer-beian a:hover {
  color: #000000;
  text-decoration-color: #080808;
}

.footer-beian a:focus-visible {
  outline: 2px solid #080808;
  outline-offset: 3px;
  border-radius: 2px;
}

.footer-beian-sep {
  color: rgba(8, 8, 8, 0.35);
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 1400px) {
  .hero-right {
    width: clamp(620px, 50vw, 780px);
    max-width: 780px;
  }
}

@media (max-width: 1200px) {
  .hero-inner { gap: 40px; }
  .hero-left { margin-bottom: 40px; }
  .hero-right {
    width: clamp(560px, 48vw, 680px);
    max-width: 680px;
    margin-right: 0;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
    --feat-gap: 20px;
    --feat-pad-block: 46px;
    --feat-pad-inline: 34px;
  }
}

@media (max-width: 1024px) {
  .about-inner   { gap: 60px; }
}

@media (max-width: 768px) {
  #nav { padding: 20px 24px; }
  #nav.scrolled { padding: 14px 24px; }
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }

  #hero { padding: 110px 24px 0; }
  .hero-right { display: none; }
  .hero-title { letter-spacing: -3px; }
  .hero-sub   { font-size: 15px; }

  #about { padding: 80px 24px; }
  .about-inner {
    flex-direction: column;
    gap: 60px;
    align-items: flex-start;
  }
  .video-frame { width: 260px; }
  .about-deco-lottie { display: none; }

  #features { padding: 80px 24px; }
  .features-grid {
    grid-template-columns: 1fr;
    --feat-gap: 18px;
    --feat-pad-block: 44px;
    --feat-pad-inline: clamp(32px, 9vw, 44px);
  }
  #stats { padding: 80px 24px; }
  .stats-inner { flex-wrap: wrap; gap: 48px; justify-content: center; }
  .stat-divider { display: none; }
  .stat-item { min-width: 140px; }

  .faq-stage { padding: 80px 24px 100px; }

  #download { padding: 80px 24px 0; }

  .download-inner {
    min-height: clamp(440px, 75vh, 620px);
  }

  .dl-visual {
    width: min(94vw, 640px);
    max-width: none;
    left: 50%;
    transform: translateX(-50%);
  }

  .download-text-col {
    margin-left: 0;
    padding: 0 8px 48px;
    /* 文字在上，图片贴底，用负 margin-bottom 制造重叠 */
    margin-bottom: calc(-1 * clamp(220px, 42vh, 380px));
  }

  .dl-btns {
    margin-top: 12px;
  }

  #footer { padding: 40px 24px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-links { flex-wrap: wrap; gap: 20px; }

  .section-title { letter-spacing: -1.5px; }
}

@media (max-width: 480px) {
  .hero-title { font-size: clamp(56px, 15vw, 72px); letter-spacing: -2px; }
  .hero-actions { flex-direction: column; }
  .btn { text-align: center; }
  .dl-visual { width: min(96vw, 480px); }
  .download-inner { min-height: 380px; }
  .download-text-col { margin-bottom: calc(-1 * clamp(160px, 30vh, 260px)); }
  .dl-btns { flex-direction: column; }
}

/* =============================================
   ANIMATION INITIAL STATES (for GSAP)
   在 JS 执行之前用 CSS 隐藏所有将被 GSAP 驱动入场的元素，
   避免预加载器期间内容闪现。
   ============================================= */

/* 导航 */
#nav {
  opacity: 0;
}

/* Hero 左侧 */
.hero-eyebrow,
.hero-sub,
.hero-actions,
.hero-scroll {
  opacity: 0;
}

/* hero-right 初始隐藏已合并到原 .hero-right 定义 */

/* Ticker */
.hero-ticker {
  opacity: 0;
}

/* 标题行位移由 GSAP yPercent 控制（勿在此写 transform，会与 GSAP 冲突） */