/* ============================================================
   极夜群管 · 官网重构
   设计语言：极夜 / 极光 —— 深青夜色 + 极光青辉
   动效原则：拉长、分层、缓慢而确定
   ============================================================ */

:root {
  /* 白色模式（默认） */
  --bg: #f5f7fa;
  --bg-alt: #eef1f5;
  --card-bg: #ffffff;
  --card-bg-alt: #f8fafc;
  --text: #1a1a2e;
  --text-muted: #5c6b7a;
  --text-faint: #8a9aa8;
  --line: rgba(0, 0, 0, .08);
  --line-soft: rgba(0, 0, 0, .04);
  --teal: #0d9488;
  --teal-deep: #0f766e;
  --teal-bright: #14b8a6;
  --teal-dim: #5eead4;
  --ink: #1a1a2e;
  --muted: #5c6b7a;
  --faint: #8a9aa8;
  --night-0: #f5f7fa;
  --night-1: #eef1f5;
  --night-2: #e2e6ed;
  --night-3: #d1d7e0;
  /* 动效令牌 —— 拉长 */
  --ease-long: cubic-bezier(.16, 1, .3, 1);
  --ease-soft: cubic-bezier(.25, .8, .25, 1);
  --t-reveal: 1.6s;
  --t-hover: .55s;
  --serif: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --sans: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
}

.dark-mode {
  /* 夜色层级（深色族） */
  --night-0: #071316;
  --night-1: #0b1c20;
  --night-2: #11262a;
  --night-3: #16343a;
  /* 极光青 */
  --teal: #58beb4;
  --teal-deep: #087a76;
  --teal-bright: #8fe6da;
  --teal-dim: #4faaa2;
  /* 雾色文字 */
  --ink: #e9f4f1;
  --muted: #9eb2b5;
  --faint: #7d959b;
  /* 发丝线 */
  --line: rgba(88, 190, 180, .14);
  --line-soft: rgba(88, 190, 180, .08);
  --bg: var(--night-0);
  --bg-alt: var(--night-1);
  --card-bg: var(--night-1);
  --card-bg-alt: var(--night-2);
  --text: var(--ink);
  --text-muted: var(--muted);
  --text-faint: var(--faint);
}

.dark-mode .sky { display: block; }
.dark-mode .sky-light { display: none; }

.sky { display: none; }
.sky-light {
  display: block;
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
  background: linear-gradient(175deg, #f0f4f8 0%, #e2e8f0 40%, #dce3ec 100%);
}

.sky-light::after {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 70%;
  height: 70%;
  background: radial-gradient(circle at 50% 50%, rgba(20, 184, 166, .06) 0%, transparent 70%);
  filter: blur(30px);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.75;
  min-width: 320px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  transition: background .6s var(--ease-soft), color .6s var(--ease-soft);
}

::selection { background: rgba(20, 184, 166, .28); color: #fff; }

.dark-mode ::selection { background: rgba(88, 190, 180, .28); color: #fff; }

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
ol, ul { list-style: none; }

a:focus-visible, button:focus-visible {
  outline: 1.5px solid var(--teal);
  outline-offset: 4px;
}

/* ============ 背景：夜空分层（dark mode only） ============ */

.sky {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.sky-night {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(120% 90% at 78% -10%, rgba(18, 79, 82, .55) 0%, transparent 55%),
    radial-gradient(100% 80% at 8% 110%, rgba(8, 60, 63, .5) 0%, transparent 55%),
    linear-gradient(178deg, #081619 0%, var(--night-0) 42%, #060f12 100%);
}

/* 极光带：三条，各自以极慢速度漂移 */
.aurora {
  position: absolute;
  width: 130vmax;
  height: 42vmax;
  filter: blur(64px);
  opacity: .5;
  will-change: transform;
}

.aurora-a {
  top: -18vmax;
  left: -22vmax;
  background: conic-gradient(from 120deg at 50% 50%,
    transparent 0deg, rgba(8, 122, 118, .34) 60deg,
    rgba(88, 190, 180, .16) 110deg, transparent 170deg,
    rgba(18, 79, 82, .3) 250deg, transparent 320deg);
  animation: aurora-drift-a 46s var(--ease-soft) infinite alternate;
}

.aurora-b {
  top: 6vmax;
  right: -46vmax;
  background: conic-gradient(from 300deg at 50% 50%,
    transparent 0deg, rgba(79, 170, 162, .26) 70deg,
    rgba(8, 122, 118, .34) 140deg, transparent 210deg,
    rgba(88, 190, 180, .12) 300deg, transparent 360deg);
  animation: aurora-drift-b 62s var(--ease-soft) infinite alternate;
}

.aurora-c {
  bottom: -30vmax;
  left: -12vmax;
  opacity: .34;
  background: conic-gradient(from 200deg at 50% 50%,
    transparent 0deg, rgba(18, 79, 82, .4) 80deg,
    rgba(88, 190, 180, .14) 150deg, transparent 220deg,
    rgba(8, 60, 63, .4) 300deg, transparent 360deg);
  animation: aurora-drift-c 54s var(--ease-soft) infinite alternate;
}

@keyframes aurora-drift-a {
  0%   { transform: translate3d(0, var(--py, 0px), 0) rotate(-4deg) scale(1); }
  100% { transform: translate3d(9vmax, calc(4vmax + var(--py, 0px)), 0) rotate(7deg) scale(1.14); }
}
@keyframes aurora-drift-b {
  0%   { transform: translate3d(0, var(--py, 0px), 0) rotate(6deg) scale(1.08); }
  100% { transform: translate3d(-10vmax, calc(-3vmax + var(--py, 0px)), 0) rotate(-6deg) scale(1); }
}
@keyframes aurora-drift-c {
  0%   { transform: translate3d(0, var(--py, 0px), 0) rotate(0deg) scale(1); }
  100% { transform: translate3d(6vmax, calc(-5vmax + var(--py, 0px)), 0) rotate(9deg) scale(1.18); }
}

/* 星图：细网格 + 稀疏星点，缓慢呼吸 */
.sky-chart {
  position: absolute;
  inset: -2%;
  background-image:
    radial-gradient(circle at 18% 22%, rgba(143, 230, 218, .5) 0, 1px, transparent 1.6px),
    radial-gradient(circle at 66% 12%, rgba(143, 230, 218, .35) 0, 1px, transparent 1.6px),
    radial-gradient(circle at 84% 38%, rgba(143, 230, 218, .4) 0, 1px, transparent 1.6px),
    radial-gradient(circle at 34% 64%, rgba(143, 230, 218, .3) 0, 1px, transparent 1.6px),
    radial-gradient(circle at 8% 82%, rgba(143, 230, 218, .35) 0, 1px, transparent 1.6px),
    radial-gradient(circle at 52% 88%, rgba(143, 230, 218, .28) 0, 1px, transparent 1.6px),
    linear-gradient(rgba(88, 190, 180, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(88, 190, 180, .05) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 100% 100%, 100% 100%, 72px 72px, 72px 72px;
  mask-image: radial-gradient(90% 70% at 50% 30%, #000 30%, transparent 78%);
  -webkit-mask-image: radial-gradient(90% 70% at 50% 30%, #000 30%, transparent 78%);
  animation: chart-breathe 12s ease-in-out infinite alternate;
}

@keyframes chart-breathe {
  from { opacity: .55; }
  to   { opacity: 1; }
}

/* 颗粒质感 */
.sky-grain {
  position: absolute;
  inset: 0;
  opacity: .05;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ============ 主题切换按钮 ============ */

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--card-bg);
  color: var(--text-muted);
  cursor: pointer;
  transition: background .5s var(--ease-soft), color .5s var(--ease-soft), border-color .5s var(--ease-soft), transform .5s var(--ease-long);
  flex: none;
}

.theme-toggle:hover {
  color: var(--teal);
  border-color: var(--teal);
  transform: translateY(-1px);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
  position: absolute;
  transition: opacity .5s var(--ease-soft), transform .5s var(--ease-soft);
}

.theme-toggle .icon-sun { opacity: 1; transform: rotate(0deg) scale(1); }
.theme-toggle .icon-moon { opacity: 0; transform: rotate(90deg) scale(0); }

.dark-mode .theme-toggle .icon-sun { opacity: 0; transform: rotate(-90deg) scale(0); }
.dark-mode .theme-toggle .icon-moon { opacity: 1; transform: rotate(0deg) scale(1); }

/* ============ 滚动进度 ============ */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 60;
  background: transparent;
}

.scroll-progress i {
  display: block;
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--teal-deep), var(--teal-bright));
  transform-origin: 0 50%;
  transform: scaleX(0);
  transition: transform .18s linear;
}

/* ============ 页头 ============ */

.site-head {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: background var(--t-hover) var(--ease-soft),
              border-color var(--t-hover) var(--ease-soft),
              backdrop-filter var(--t-hover) var(--ease-soft);
  border-bottom: 1px solid transparent;
}

.site-head.scrolled {
  background: rgba(245, 247, 250, .8);
  -webkit-backdrop-filter: blur(18px) saturate(1.3);
  backdrop-filter: blur(18px) saturate(1.3);
  border-bottom-color: var(--line-soft);
}

.dark-mode .site-head.scrolled {
  background: rgba(7, 19, 22, .72);
}

.head-inner {
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 40px;
  height: 76px;
  display: flex;
  align-items: center;
  gap: 48px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
  color: var(--teal);
}

.brand-mark { width: 68px; height: 68px; display: block; object-fit: contain; border-radius: 12px; }

.brand-word b {
  display: block;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .14em;
  color: var(--text);
  line-height: 1.2;
  transition: color .5s var(--ease-soft);
}

.brand-word small {
  display: block;
  font-size: 9px;
  letter-spacing: .32em;
  color: var(--text-faint);
  margin-top: 2px;
  transition: color .5s var(--ease-soft);
}

.head-nav {
  flex: 1;
  display: flex;
  justify-content: center;
  gap: 40px;
}

.head-nav a {
  position: relative;
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: .08em;
  padding: 6px 2px;
  transition: color var(--t-hover) var(--ease-soft);
}

.head-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--teal);
  transform: scaleX(0);
  transform-origin: 100% 50%;
  transition: transform .7s var(--ease-long);
}

.head-nav a:hover { color: var(--text); }
.head-nav a:hover::after { transform: scaleX(1); transform-origin: 0 50%; }

.head-actions { position:relative; z-index:10;  display: flex; align-items: center; gap: 22px; flex: none; }

.head-group {
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: .06em;
  transition: color var(--t-hover) var(--ease-soft);
}
.head-group:hover { color: var(--teal-bright); }

/* ============ 按钮 ============ */

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-weight: 500;
  letter-spacing: .06em;
  white-space: nowrap;
  overflow: hidden;
  transition: transform var(--t-hover) var(--ease-long),
              box-shadow var(--t-hover) var(--ease-long),
              background var(--t-hover) var(--ease-soft),
              border-color var(--t-hover) var(--ease-soft),
              color var(--t-hover) var(--ease-soft);
}

.btn svg { width: 16px; height: 16px; flex: none; }

.btn-s { height: 40px; padding: 0 20px; font-size: 13px; border-radius: 3px; }
.btn-l { height: 56px; padding: 0 30px; font-size: 14px; border-radius: 3px; }
.btn-xl { height: 62px; padding: 0 40px; font-size: 15px; border-radius: 3px; }

.btn-solid {
  background: var(--teal-deep);
  color: #f2fbfa;
  box-shadow: 0 0 0 1px rgba(20, 184, 166, .18) inset, 0 14px 34px -12px rgba(15, 118, 110, .4);
}

.dark-mode .btn-solid {
  box-shadow: 0 0 0 1px rgba(143, 230, 218, .18) inset, 0 14px 34px -12px rgba(8, 122, 118, .55);
}

/* 扫光 */
.btn-solid::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 55%;
  height: 100%;
  background: linear-gradient(100deg, transparent, rgba(233, 244, 241, .22), transparent);
  transform: translate3d(-160%, 0, 0) skewX(-18deg);
  transition: transform 1.1s var(--ease-long);
  will-change: transform;
}

.btn-solid:hover {
  background: #076e6b;
  transform: translateY(-2px);
  box-shadow: 0 0 0 1px rgba(20, 184, 166, .3) inset, 0 22px 44px -14px rgba(15, 118, 110, .55);
}

.dark-mode .btn-solid:hover {
  box-shadow: 0 0 0 1px rgba(143, 230, 218, .3) inset, 0 22px 44px -14px rgba(8, 122, 118, .7);
}

.btn-solid:hover::before { transform: translate3d(260%, 0, 0) skewX(-18deg); }
.btn-solid:active { transform: translateY(0); }

.btn-ghost {
  border: 1px solid var(--line);
  color: var(--text);
  background: var(--card-bg);
}

.btn-ghost:hover {
  border-color: var(--teal);
  background: var(--card-bg-alt);
  transform: translateY(-2px);
}

.link-line {
  position: relative;
  font-size: 13.5px;
  color: var(--text-muted);
  letter-spacing: .05em;
  padding-bottom: 3px;
  transition: color var(--t-hover) var(--ease-soft);
}

.link-line::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 1px;
  width: 100%;
  background: currentColor;
  opacity: .35;
  transition: opacity var(--t-hover) var(--ease-soft);
}

.link-line .arr {
  display: inline-block;
  margin-left: 6px;
  transition: transform .7s var(--ease-long);
}

.link-line:hover { color: var(--teal-bright); }
.link-line:hover::after { opacity: 1; }
.link-line:hover .arr { transform: translateX(5px); }

/* ============ 通用排版 ============ */

.eyebrow {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 10.5px;
  letter-spacing: .38em;
  color: var(--teal-dim);
  font-weight: 500;
}

.eyebrow i {
  display: block;
  width: 34px;
  height: 1px;
  background: var(--teal-dim);
  opacity: .6;
}

.section { position: relative; padding: 150px 0 130px; }

.section-inner { max-width: 1360px; margin: 0 auto; padding: 0 40px; }

.section-heading { max-width: 640px; margin-bottom: 84px; }

.section-title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(30px, 3.6vw, 44px);
  line-height: 1.3;
  letter-spacing: .04em;
  color: var(--text);
  margin-top: 26px;
  transition: color .5s var(--ease-soft);
}

.section-sub {
  color: var(--text-muted);
  font-size: 14.5px;
  margin-top: 20px;
  max-width: 520px;
}

/* ============ 首屏 ============ */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 120px 0 76px;
  overflow: hidden;
}

.hero-inner {
  max-width: 1360px;
  width: 100%;
  margin: 0 auto;
  padding: 0 40px;
  display: grid;
  grid-template-columns: minmax(0, 46%) minmax(0, 54%);
  align-items: center;
  gap: 40px;
}

.hero-copy { max-width: 560px; }

.hero-title {
  font-family: var(--serif);
  font-weight: 900;
  font-size: clamp(40px, 4.6vw, 66px);
  line-height: 1.18;
  letter-spacing: .05em;
  color: var(--text);
  margin-top: 30px;
  transition: color .5s var(--ease-soft);
}

.hero-title em {
  font-style: normal;
  color: var(--teal-bright);
}

.hero-title .line { display: block; overflow: hidden; padding-bottom: .08em; margin-bottom: -.08em; white-space: nowrap; }

.js .hero-title .line-in {
  display: block;
  transform: translateY(112%);
  transition: transform 1.8s var(--ease-long);
  transition-delay: var(--d, 0s);
  will-change: transform;
}

.js body.loaded .hero-title .line-in { transform: translateY(0); }

.hero-lead {
  color: var(--text-muted);
  font-size: 15px;
  max-width: 460px;
  margin-top: 30px;
}

.hero-badges { display: flex; gap: 12px; margin-top: 30px; flex-wrap: wrap; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 34px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 100px;
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--teal);
  background: var(--card-bg-alt);
}

.pill svg { width: 14px; height: 14px; }

.pill-glow {
  border-color: var(--teal);
  background: rgba(20, 184, 166, .1);
  color: var(--teal-deep);
  box-shadow: 0 0 24px -6px rgba(20, 184, 166, .25);
}

.pill-count b {
  font-weight: 700;
  font-family: var(--serif);
  font-size: 13px;
  letter-spacing: .02em;
}

.dark-mode .pill-count {
  color: var(--teal-bright);
}

.dark-mode .pill-glow {
  border-color: rgba(88, 190, 180, .4);
  background: rgba(8, 122, 118, .18);
  color: var(--teal-bright);
  box-shadow: 0 0 24px -6px rgba(88, 190, 180, .35);
}

.hero-cta { position:relative; z-index:10;  display: flex; align-items: center; gap: 20px; margin-top: 44px; flex-wrap: wrap; }

.hero-meta {
  display: flex;
  gap: 0;
  margin-top: 34px;
  color: var(--text-faint);
  font-size: 12px;
  letter-spacing: .08em;
}

.hero-meta li { display: flex; align-items: center; }
.hero-meta li + li::before {
  content: "";
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--text-faint);
  opacity: .5;
  margin: 0 14px;
}

/* 首屏右侧：程序窗口舞台 */

.hero-stage {
  position: relative;
  perspective: 1400px;
}

.stage-ring {
  position: absolute;
  top: 50%;
  left: 52%;
  width: 720px;
  height: 720px;
  transform: translate(-50%, -50%);
  border: 1px solid var(--line);
  border-radius: 50%;
  mask-image: linear-gradient(200deg, #000 30%, transparent 72%);
  -webkit-mask-image: linear-gradient(200deg, #000 30%, transparent 72%);
}

.stage-ring::after {
  content: "";
  position: absolute;
  inset: 60px;
  border: 1px dashed var(--line);
  border-radius: 50%;
}

.stage-word {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-52%, -54%);
  font-family: var(--serif);
  font-weight: 900;
  font-size: 200px;
  letter-spacing: .1em;
  color: transparent;
  -webkit-text-stroke: 1px var(--line);
  user-select: none;
  white-space: nowrap;
}

.dark-mode .stage-word {
  -webkit-text-stroke: 1px rgba(88, 190, 180, .1);
}

.app-window {
  position: relative;
  width: 100%;
  max-width: 780px;
  margin-left: auto;
  border-radius: 10px;
  transform-style: preserve-3d;
  will-change: transform;
}

.js .app-window {
  opacity: 0;
  transform: translateY(60px) rotateX(8deg);
  transition: opacity 2s var(--ease-long) .5s,
              transform 2.2s var(--ease-long) .5s;
}

.js body.loaded .app-window { opacity: 1; transform: translateY(0) rotateX(0); }

/* 入场结束后由 main.js 加上 .tilt-live，解除 transform 过渡，让鼠标倾斜即时跟随 */
.app-window.tilt-live { transition: opacity 2s var(--ease-long) .5s; }

.app-window img {
  width: 100%;
  border-radius: 10px;
  border: 1px solid var(--line);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, .6) inset,
    0 30px 80px -20px rgba(0, 0, 0, .12),
    0 80px 160px -40px rgba(15, 118, 110, .08);
}

.dark-mode .app-window img {
  border: 1px solid rgba(88, 190, 180, .16);
  box-shadow:
    0 1px 0 rgba(233, 244, 241, .06) inset,
    0 30px 80px -20px rgba(0, 0, 0, .75),
    0 80px 160px -40px rgba(8, 122, 118, .25);
}

.window-glow {
  position: absolute;
  inset: -12%;
  z-index: -1;
  background: radial-gradient(50% 50% at 50% 55%, rgba(15, 118, 110, .15) 0%, transparent 70%);
  filter: blur(30px);
}

.dark-mode .window-glow {
  background: radial-gradient(50% 50% at 50% 55%, rgba(8, 122, 118, .4) 0%, transparent 70%);
}

.window-caption {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-top: 20px;
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--text-faint);
}

.window-caption .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 10px var(--teal);
  animation: dot-pulse 3.2s ease-in-out infinite;
}

@keyframes dot-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .35; }
}

/* 漂浮数据芯片 */
.stage-chip {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 14px 20px;
  background: var(--card-bg);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: 6px;
  box-shadow: 0 20px 50px -18px rgba(0, 0, 0, .1);
}

.dark-mode .stage-chip {
  background: rgba(11, 28, 32, .82);
  box-shadow: 0 20px 50px -18px rgba(0, 0, 0, .7);
}

.js .stage-chip {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 1.8s var(--ease-long), transform 1.8s var(--ease-long);
}

.stage-chip b {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 700;
  color: var(--teal-bright);
  line-height: 1.1;
}

.stage-chip span {
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--text-faint);
  margin-top: 3px;
}

.chip-a { top: 6%; left: -2%; transition-delay: 1s; }
.chip-b { bottom: 12%; right: -1%; transition-delay: 1.2s; }

.js body.loaded .stage-chip { opacity: 1; transform: translateY(0); }

body.loaded .chip-a { animation: chip-float-a 9s ease-in-out 3.2s infinite; }
body.loaded .chip-b { animation: chip-float-b 11s ease-in-out 3.4s infinite; }

@keyframes chip-float-a {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}
@keyframes chip-float-b {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(12px); }
}

/* 滚动提示 */

.scroll-cue {
  position: absolute;
  bottom: 34px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.js .scroll-cue {
  opacity: 0;
  transition: opacity 2s ease 1.6s;
}

.js body.loaded .scroll-cue { opacity: 1; }

.cue-line {
  position: relative;
  width: 1px;
  height: 52px;
  background: var(--line);
  overflow: hidden;
}

.cue-line i {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 40%;
  background: var(--teal-bright);
  transform: translateY(-100%);
  animation: cue-drop 2.8s var(--ease-soft) infinite;
  will-change: transform;
}

@keyframes cue-drop {
  0% { transform: translateY(-100%); }
  60%, 100% { transform: translateY(380%); }
}

.cue-text {
  font-size: 9px;
  letter-spacing: .42em;
  color: var(--text-faint);
}

/* ============ 整合包 ============ */

.bundle { border-top: 1px solid var(--line-soft); }

.bundle-head {
  display: grid;
  grid-template-columns: minmax(0, 38%) minmax(0, 62%);
  gap: 80px;
  align-items: start;
}

.sticky-col { position: sticky; top: 140px; }

.bundle-seal {
  margin-top: 54px;
  width: 96px;
  height: 96px;
  color: var(--teal-dim);
  opacity: .8;
  animation: seal-spin 40s linear infinite;
}

@keyframes seal-spin {
  to { transform: rotate(360deg); }
}

.bundle-list { border-top: 1px solid var(--line); }

.bundle-row {
  position: relative;
  display: flex;
  align-items: center;
  gap: 40px;
  padding: 44px 20px 44px 8px;
  border-bottom: 1px solid var(--line);
  transition: background .8s var(--ease-soft);
}

.bundle-row::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 2px;
  height: 100%;
  background: var(--teal);
  transform: scaleY(0);
  transform-origin: 50% 0;
  transition: transform .9s var(--ease-long);
}

.bundle-row:hover { background: var(--card-bg-alt); }
.dark-mode .bundle-row:hover { background: rgba(17, 38, 42, .35); }
.bundle-row:hover::before { transform: scaleY(1); }
.bundle-row:hover .row-main { transform: translateX(18px); }

.row-main { transition: transform .8s var(--ease-long); }

.row-no {
  font-family: var(--serif);
  font-size: 15px;
  color: var(--teal-dim);
  letter-spacing: .1em;
  flex: none;
  width: 34px;
}

.row-main { flex: 1; }

.row-main h3 {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--text);
  transition: color .5s var(--ease-soft);
}

.row-main p {
  color: var(--text-muted);
  font-size: 13.5px;
  margin-top: 8px;
}

.row-tag {
  flex: none;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--teal);
  border: 1px solid var(--line);
  border-radius: 100px;
  padding: 7px 15px;
  background: rgba(20, 184, 166, .08);
  white-space: nowrap;
}

.dark-mode .row-tag {
  background: rgba(8, 122, 118, .1);
}

/* ============ 产品亮点 ============ */

.advantages {
  border-top: 1px solid var(--line-soft);
  background: var(--bg-alt);
}

.dark-mode .advantages {
  background: linear-gradient(180deg, rgba(17, 38, 42, .28) 0%, transparent 40%);
}

.adv-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 26px;
}

.adv-card {
  position: relative;
  padding: 46px 40px 50px;
  background: var(--card-bg);
  border: 1px solid var(--line-soft);
  border-radius: 4px;
  transition: transform .9s var(--ease-long),
              border-color .9s var(--ease-soft),
              background .9s var(--ease-soft),
              box-shadow .9s var(--ease-long);
}

.dark-mode .adv-card {
  background: rgba(17, 38, 42, .45);
}

.adv-card:hover {
  transform: translateY(-8px);
  border-color: var(--teal);
  background: var(--card-bg);
  box-shadow: 0 30px 60px -24px rgba(0, 0, 0, .08), 0 0 40px -12px rgba(15, 118, 110, .1);
}

.dark-mode .adv-card:hover {
  border-color: rgba(88, 190, 180, .32);
  background: rgba(17, 38, 42, .7);
  box-shadow: 0 30px 60px -24px rgba(0, 0, 0, .6), 0 0 40px -12px rgba(8, 122, 118, .3);
}

/* 角标刻线：左上 + 右下 */
.card-corner {
  position: absolute;
  top: -1px;
  left: -1px;
  width: 14px;
  height: 14px;
  border-top: 1px solid var(--teal);
  border-left: 1px solid var(--teal);
  transition: width .8s var(--ease-long), height .8s var(--ease-long);
  pointer-events: none;
}

.adv-card::after {
  content: "";
  position: absolute;
  right: -1px;
  bottom: -1px;
  width: 14px;
  height: 14px;
  border-right: 1px solid var(--teal);
  border-bottom: 1px solid var(--teal);
  transition: width .8s var(--ease-long), height .8s var(--ease-long);
  pointer-events: none;
}

.adv-card:hover .card-corner,
.adv-card:hover::after { width: 26px; height: 26px; }

.adv-no {
  font-size: 10px;
  letter-spacing: .34em;
  color: var(--teal-dim);
  font-weight: 500;
}

.adv-icon {
  width: 40px;
  height: 40px;
  color: var(--teal);
  margin-top: 30px;
  transition: transform 1s var(--ease-long);
}

/* 字型图标：¥0 免费标记 / ›_ 控制台提示符 */
.adv-fee, .adv-cmd {
  display: flex;
  align-items: center;
  height: 40px;
  font-family: var(--serif);
  font-weight: 700;
  color: var(--teal-bright);
  letter-spacing: .02em;
}

.adv-fee span { font-size: 26px; }
.adv-cmd span { font-size: 30px; font-weight: 900; letter-spacing: .04em; }

.adv-card:hover .adv-icon,
.adv-card:hover .adv-fee,
.adv-card:hover .adv-cmd { transform: translateY(-4px); }

.adv-card h3 {
  font-family: var(--serif);
  font-size: 23px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--text);
  margin-top: 24px;
  transition: color .5s var(--ease-soft);
}

.adv-desc {
  color: var(--text-muted);
  font-size: 13.5px;
  margin-top: 14px;
}

.adv-free {
  background: linear-gradient(160deg, rgba(20, 184, 166, .08) 0%, var(--card-bg) 55%);
}

.dark-mode .adv-free {
  background: linear-gradient(160deg, rgba(8, 122, 118, .22) 0%, rgba(17, 38, 42, .5) 55%);
  border-color: rgba(88, 190, 180, .22);
}

.adv-free .adv-no { color: var(--teal-bright); }

/* ============ 使用流程 ============ */

.start { border-top: 1px solid var(--line-soft); }

.steps-wrap { position: relative; }

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 60px;
  counter-reset: step;
}

.steps-line {
  position: absolute;
  top: 27px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--line-soft);
}

.steps-line i {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--teal-deep), var(--teal));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 2.6s var(--ease-long) .3s;
}

.steps.in .steps-line i,
.in .steps-line i { transform: scaleX(1); }

.step { position: relative; padding-top: 74px; }

.step::before {
  content: "";
  position: absolute;
  top: 21px;
  left: 0;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1px solid var(--teal);
  background: var(--bg);
  box-shadow: 0 0 0 5px var(--bg);
  transition: background .8s var(--ease-soft), box-shadow .8s var(--ease-soft);
}

.dark-mode .step::before {
  background: var(--night-1);
  box-shadow: 0 0 0 5px var(--night-0);
}

.step:hover::before {
  background: var(--teal);
  box-shadow: 0 0 0 5px var(--bg), 0 0 18px var(--teal);
}

.dark-mode .step:hover::before {
  box-shadow: 0 0 0 5px var(--night-0), 0 0 18px rgba(88, 190, 180, .7);
}

.step-no {
  position: absolute;
  top: 0;
  right: 0;
  font-family: var(--serif);
  font-size: 64px;
  font-weight: 900;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px var(--line);
  transition: color 1s var(--ease-soft);
  user-select: none;
}

.dark-mode .step-no {
  -webkit-text-stroke: 1px rgba(88, 190, 180, .18);
}

.step:hover .step-no { color: var(--teal); }

.dark-mode .step:hover .step-no { color: rgba(88, 190, 180, .1); }

.step h3 {
  font-family: var(--serif);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--text);
  transition: color .5s var(--ease-soft);
}

.step p {
  color: var(--text-muted);
  font-size: 13.5px;
  margin-top: 12px;
  max-width: 300px;
}

/* ============ 下载 ============ */

.download { padding: 90px 0 150px; }

.dl-panel {
  position: relative;
  max-width: 1160px;
  margin: 0 auto;
  padding: 96px 80px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 280px);
  gap: 70px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--card-bg);
  overflow: hidden;
}

.dark-mode .dl-panel {
  background: rgba(11, 28, 32, .6);
}

@media (max-width: 1240px) {
  .dl-panel { margin-left: 28px; margin-right: 28px; }
}
@media (max-width: 860px) {
  .dl-panel { grid-template-columns: 1fr; gap: 48px; padding: 72px 40px; }
}
@media (max-width: 560px) {
  .dl-panel { margin-left: 20px; margin-right: 20px; padding: 64px 24px; }
}

/* 单边静态辉光（不旋转） */
.dl-glow {
  position: absolute;
  top: -40%;
  right: -16%;
  width: 60%;
  height: 180%;
  background: radial-gradient(50% 50% at 50% 50%, rgba(15, 118, 110, .12) 0%, transparent 70%);
  filter: blur(48px);
  pointer-events: none;
}

.dark-mode .dl-glow {
  background: radial-gradient(50% 50% at 50% 50%, rgba(8, 122, 118, .32) 0%, transparent 70%);
}

.dl-main { position: relative; }

.dl-title {
  position: relative;
  font-family: var(--serif);
  font-weight: 900;
  font-size: clamp(32px, 4vw, 50px);
  letter-spacing: .06em;
  line-height: 1.2;
  color: var(--text);
  margin-top: 24px;
  transition: color .5s var(--ease-soft);
}

.dl-sub {
  position: relative;
  color: var(--text-muted);
  font-size: 14px;
  letter-spacing: .06em;
  margin-top: 20px;
  max-width: 440px;
}

.dl-cta { position:relative; z-index:10; 
  position: relative;
  display: flex;
  gap: 16px;
  margin-top: 48px;
  flex-wrap: wrap;
}

.dl-meta {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 28px;
  padding-left: 40px;
  border-left: 1px solid var(--line);
}

.dl-meta li {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.dl-meta b {
  font-size: 10px;
  letter-spacing: .34em;
  color: var(--text-faint);
  font-weight: 500;
}

.dl-meta span {
  font-family: var(--serif);
  font-size: 17px;
  color: var(--text);
  letter-spacing: .04em;
  transition: color .5s var(--ease-soft);
}

@media (max-width: 860px) {
  .dl-meta { padding-left: 0; border-left: 0; border-top: 1px solid var(--line); padding-top: 36px; flex-direction: row; gap: 40px; flex-wrap: wrap; }
}

/* ============ 页脚 ============ */

.site-foot {
  border-top: 1px solid var(--line-soft);
  padding: 60px 0 46px;
  background: var(--bg-alt);
}

.foot-inner {
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 40px;
  display: flex;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
}

.foot-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--teal);
  flex: 1;
  min-width: 240px;
}

.foot-brand .brand-mark { width: 60px; height: 60px; display: block; object-fit: contain; border-radius: 10px; }

.foot-brand b {
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: .14em;
  color: var(--text);
  transition: color .5s var(--ease-soft);
}

.foot-brand p {
  font-size: 11.5px;
  color: var(--text-faint);
  letter-spacing: .05em;
  margin-top: 3px;
}

.foot-nav { display: flex; gap: 28px; }

.foot-nav a {
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: .1em;
  transition: color var(--t-hover) var(--ease-soft);
}

.foot-nav a:hover { color: var(--teal-bright); }

.foot-copy {
  font-size: 11px;
  color: var(--text-faint);
  letter-spacing: .12em;
}

/* ============ 进场与滚动显现（拉长） ============
   入场隐藏态仅在 .js 下生效；无 JS 时内容直接可见。 */

.js .reveal {
  opacity: 0;
  transform: translateY(44px);
  transition: opacity var(--t-reveal) var(--ease-long),
              transform var(--t-reveal) var(--ease-long);
  transition-delay: var(--d, 0s);
  will-change: opacity, transform;
}

.js .reveal.in,
.js body.loaded .hero .reveal {
  opacity: 1;
  transform: translateY(0);
}

/* ============ 跳转到下载（无障碍） ============ */

.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  z-index: 100;
  padding: 10px 18px;
  background: var(--teal-deep);
  color: #f2fbfa;
  font-size: 13px;
  letter-spacing: .06em;
  border-radius: 3px;
  transition: top .3s var(--ease-soft);
}

.skip-link:focus { top: 14px; }

/* ============ 响应式 ============ */

@media (max-width: 1120px) {
  .head-inner { padding: 0 28px; gap: 30px; }
  .section-inner { padding: 0 28px; }
  .hero-inner { padding: 0 28px; gap: 30px; }
  .stage-word { font-size: 150px; }
  .bundle-head { gap: 50px; }
}

@media (max-width: 940px) {
  .head-nav { display: none; }
  .hero { padding-top: 120px; }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-copy { max-width: 620px; }
  .hero-stage { margin-top: 60px; }
  .app-window { margin: 0 auto; }
  .stage-word { font-size: 130px; left: 50%; }
  .bundle-head { grid-template-columns: 1fr; }
  .sticky-col { position: static; }
  .bundle-seal { display: none; }
  .adv-grid { grid-template-columns: 1fr; gap: 18px; }
  .steps { grid-template-columns: 1fr; gap: 44px; }
  .steps-line { display: none; }
  .step { padding-top: 0; padding-left: 34px; }
  .step::before { top: 8px; }
  .step-no { font-size: 44px; }
  .section { padding: 100px 0 90px; }
  .foot-inner { justify-content: center; text-align: center; }
  .foot-brand { justify-content: center; }
}

@media (max-width: 560px) {
  body { font-size: 14px; }
  .head-inner { height: 66px; padding: 0 18px; gap: 12px; }
  .head-group { display: none; }
  .brand-word small { display: none; }
  .brand-mark { width: 54px; height: 54px; }
  .brand-word b { font-size: 15px; }
  .btn-s { height: 36px; padding: 0 12px; font-size: 12px; gap: 7px; }
  .section-inner, .hero-inner { padding: 0 20px; }
  .hero-title { font-size: clamp(34px, 9.6vw, 44px); }
  .hero-title .line { white-space: normal; }
  .hero-cta { position:relative; z-index:10;  gap: 14px; }
  .btn-l { height: 52px; padding: 0 22px; font-size: 13px; }
  .hero-meta { flex-wrap: wrap; row-gap: 8px; }
  .stage-word { font-size: 92px; }
  .stage-chip { display: none; }
  .scroll-cue { display: none; }
  .bundle-row { flex-wrap: wrap; gap: 14px; padding: 34px 12px; }
  .row-tag { order: 3; }
  .section-heading { margin-bottom: 56px; }
  .dl-meta { gap: 34px; }
}

/* ============ 减少动态偏好 ============ */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .aurora, .sky-chart, .bundle-seal,
  .stage-chip, .cue-line i, .window-caption .dot { animation: none !important; }
  .reveal, .hero-title .line-in, .app-window, .scroll-cue,
  .stage-chip, .steps-line i, .btn-solid::before, .bundle-row .row-main {
    transition-duration: .01s !important;
    transition-delay: 0s !important;
  }
  .reveal, .app-window, .stage-chip { transform: none !important; opacity: 1 !important; }
  .hero-title .line-in { transform: none !important; }
}