/* ==========================================================================
   祉安 zhian · 官网样式表
   设计语言:青玉 · 米白 · 鹿小安
   无外部依赖,纯手写 CSS
   ========================================================================== */

/* ---------- Design Tokens ---------- */
:root {
  /* 墨色文字 */
  --ink:        #16211F;
  --ink-2:      #465855;
  --ink-3:      #7E918D;
  --ink-4:      #A9B8B4;

  /* 纸面 */
  --paper:      #FBFAF7;
  --paper-2:    #F3F1EA;
  --paper-3:    #EDEAE1;
  --card:       #FFFFFF;

  /* 主色 · 青玉 */
  --jade:       #0F766E;
  --jade-deep:  #0A5751;
  --jade-mid:   #14A594;
  --jade-light: #5EEAD4;
  --jade-veil:  #E6F4F1;
  --jade-veil-2:#C9E7E2;

  /* 强调 · 暖珊瑚 */
  --coral:      #F5A78A;
  --coral-deep: #DE7F5C;
  --coral-veil: #FDEEE7;

  /* 辅助 */
  --gold:       #C77D2B;
  --gold-veil:  #FBF0DF;
  --danger:     #C2410C;

  /* 线 / 影 */
  --line:       #E7E4DB;
  --line-soft:  #F0EDE6;
  --shadow-xs:  0 1px 2px rgba(22,33,31,.05);
  --shadow-sm:  0 2px 10px rgba(22,33,31,.06);
  --shadow-md:  0 10px 34px rgba(22,33,31,.09);
  --shadow-lg:  0 30px 70px rgba(22,33,31,.13);
  --shadow-jade:0 14px 40px rgba(15,118,110,.22);

  /* 几何 */
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 24px;
  --r-xl: 32px;
  --r-pill: 999px;

  --maxw: 1160px;
  --gutter: 24px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
               -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--jade); text-decoration: none; transition: color .18s ease; }
a:hover { color: var(--jade-deep); }
h1, h2, h3, h4 { margin: 0; line-height: 1.28; letter-spacing: -.015em; font-weight: 800; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
::selection { background: var(--jade-veil-2); color: var(--jade-deep); }

/* ---------- 无障碍:键盘跳转 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: var(--r-pill);
  background: var(--jade);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  box-shadow: var(--shadow-md);
  transition: top .18s ease;
}
.skip-link:focus { top: 12px; color: #fff; }
:focus-visible { outline: 2.5px solid var(--jade-mid); outline-offset: 3px; border-radius: 4px; }

/* ---------- Layout ---------- */
.shell {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: clamp(64px, 9vw, 112px); position: relative; }
.section--tight { padding-block: clamp(48px, 6vw, 76px); }

/* ---------- Type scale ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--jade);
  background: var(--jade-veil);
  border: 1px solid var(--jade-veil-2);
  border-radius: var(--r-pill);
  padding: 6px 14px;
  margin-bottom: 20px;
}
.eyebrow--coral {
  color: var(--coral-deep);
  background: var(--coral-veil);
  border-color: #FAD9CB;
}
.display {
  font-size: clamp(2.5rem, 6.2vw, 4.35rem);
  letter-spacing: -.03em;
  line-height: 1.1;
  font-weight: 900;
}
.h2 {
  font-size: clamp(1.85rem, 3.6vw, 2.75rem);
  letter-spacing: -.025em;
}
.h3 { font-size: clamp(1.15rem, 1.8vw, 1.4rem); font-weight: 800; }
.lede {
  font-size: clamp(1.02rem, 1.5vw, 1.19rem);
  color: var(--ink-2);
  line-height: 1.75;
}
.muted { color: var(--ink-3); }
.section-head { max-width: 660px; margin-bottom: clamp(38px, 5vw, 58px); }
.section-head--center { margin-inline: auto; text-align: center; }
.section-head .h2 { margin-bottom: 16px; }

/* ---------- Buttons ---------- */
.btn {
  --btn-bg: var(--jade);
  --btn-fg: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 14px 26px;
  border-radius: var(--r-pill);
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: .01em;
  background: var(--btn-bg);
  color: var(--btn-fg);
  box-shadow: var(--shadow-jade);
  transition: transform .2s cubic-bezier(.2,.8,.3,1), box-shadow .2s ease, background .2s ease;
  white-space: nowrap;
}
.btn:hover {
  transform: translateY(-2px);
  background: var(--jade-deep);
  box-shadow: 0 20px 46px rgba(15,118,110,.3);
  color: #fff;
}
.btn:active { transform: translateY(0); }
.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  box-shadow: none;
  border: 1.5px solid var(--line);
  background: rgba(255,255,255,.7);
  backdrop-filter: blur(6px);
}
.btn--ghost:hover {
  background: #fff;
  border-color: var(--jade-veil-2);
  color: var(--jade-deep);
  box-shadow: var(--shadow-sm);
}
.btn--sm { padding: 10px 18px; font-size: 14px; }
.btn--block { width: 100%; }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(251,250,247,.82);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, background .25s ease, box-shadow .25s ease;
}
.nav.is-stuck {
  border-bottom-color: var(--line-soft);
  box-shadow: 0 1px 20px rgba(22,33,31,.05);
}
.nav__inner {
  display: flex;
  align-items: center;
  gap: 18px;
  height: 72px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 900;
  font-size: 19px;
  letter-spacing: .04em;
  color: var(--ink);
  flex-shrink: 0;
}
.brand:hover { color: var(--ink); }
.brand__mark {
  width: 38px; height: 38px;
  border-radius: 12px;
  background: linear-gradient(145deg, var(--jade-mid), var(--jade-deep));
  display: grid;
  place-items: center;
  box-shadow: 0 6px 16px rgba(15,118,110,.28);
  overflow: hidden;
}
.brand__mark svg { width: 26px; height: 26px; }
.brand__sub {
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: .22em;
  color: var(--ink-4);
  margin-left: 2px;
}
.nav__menu {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav__link {
  padding: 9px 14px;
  border-radius: var(--r-pill);
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink-2);
  transition: background .18s ease, color .18s ease;
}
.nav__link:hover { background: var(--jade-veil); color: var(--jade-deep); }
.nav__cta { margin-left: 4px; }
.nav__toggle {
  display: none;
  width: 42px; height: 42px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.8);
  margin-left: auto;
  place-items: center;
}
.nav__toggle span {
  display: block;
  width: 18px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  position: relative;
}
.nav__toggle span::before,
.nav__toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
}
.nav__toggle span::before { top: -6px; }
.nav__toggle span::after  { top: 6px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding-block: clamp(52px, 7vw, 96px) clamp(64px, 8vw, 120px);
  overflow: hidden;
}
.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  pointer-events: none;
  z-index: 0;
}
.hero__glow--jade {
  width: 760px; height: 760px;
  background: radial-gradient(circle, rgba(94,234,212,.34), rgba(94,234,212,0) 68%);
  top: -320px; right: -220px;
}
.hero__glow--coral {
  width: 560px; height: 560px;
  background: radial-gradient(circle, rgba(245,167,138,.32), rgba(245,167,138,0) 68%);
  bottom: -260px; left: -200px;
}
.hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.06fr .94fr;
  gap: clamp(28px, 4vw, 60px);
  align-items: center;
}
.hero__title .accent {
  background: linear-gradient(100deg, var(--jade) 10%, var(--jade-mid) 55%, var(--coral) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__lede {
  margin-top: 22px;
  max-width: 30em;
  font-size: clamp(1.02rem, 1.55vw, 1.17rem);
  line-height: 1.8;
  color: var(--ink-2);
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}
.hero__trust {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: 34px;
  padding-top: 24px;
  border-top: 1px solid var(--line-soft);
  font-size: 13px;
  color: var(--ink-3);
}
.hero__trust li {
  display: flex;
  align-items: center;
  gap: 7px;
  font-weight: 600;
}
.hero__trust .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--jade-mid);
  box-shadow: 0 0 0 3px var(--jade-veil);
}

/* Hero 视觉:鹿小安舞台 */
.stage {
  position: relative;
  aspect-ratio: 1 / 1;
  max-width: 480px;
  margin-inline: auto;
  display: grid;
  place-items: center;
}
.stage__plate {
  position: absolute;
  inset: 8%;
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 34%, #FFFFFF 0%, #F1FBF9 42%, #DCF1ED 72%, #CBE8E3 100%);
  box-shadow:
    inset 0 2px 0 rgba(255,255,255,.9),
    0 34px 80px rgba(15,118,110,.16),
    0 4px 14px rgba(15,118,110,.08);
}
.stage__ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1.5px dashed rgba(15,118,110,.16);
  animation: spin 48s linear infinite;
}
.stage__ring--2 {
  inset: 12%;
  border-style: solid;
  border-color: rgba(245,167,138,.18);
  animation-direction: reverse;
  animation-duration: 64s;
}
@keyframes spin { to { transform: rotate(360deg); } }

.stage__deer {
  position: relative;
  z-index: 2;
  width: 62%;
  filter: drop-shadow(0 18px 30px rgba(139,111,78,.22));
  animation: deerBreath 4.2s ease-in-out infinite;
  transform-origin: 50% 72%;
}
@keyframes deerBreath {
  0%, 100% { transform: scale(1) translateY(0); }
  50%      { transform: scale(1.035) translateY(-6px); }
}
.stage__deer .eye { animation: blink 5.4s infinite; transform-origin: center; }
@keyframes blink {
  0%, 92%, 100% { transform: scaleY(1); }
  95%, 97%      { transform: scaleY(.08); }
}
.stage__deer .ear-l { animation: earL 5.6s ease-in-out infinite; transform-origin: 50% 100%; }
.stage__deer .ear-r { animation: earR 5.6s ease-in-out infinite; transform-origin: 50% 100%; }
@keyframes earL {
  0%, 100% { transform: rotate(-3deg); }
  50%      { transform: rotate(4deg); }
}
@keyframes earR {
  0%, 100% { transform: rotate(3deg); }
  50%      { transform: rotate(-4deg); }
}
.stage__deer .spark { animation: hornPulse 3s ease-in-out infinite; }
@keyframes hornPulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: .45; }
}

/* 浮动小卡 */
.float-card {
  position: absolute;
  z-index: 3;
  background: rgba(255,255,255,.94);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,.9);
  border-radius: 16px;
  padding: 11px 15px;
  box-shadow: var(--shadow-md);
  font-size: 13px;
  font-weight: 700;
  color: var(--ink-2);
  display: flex;
  align-items: center;
  gap: 9px;
  white-space: nowrap;
}
.float-card__ico {
  width: 28px; height: 28px;
  border-radius: 9px;
  display: grid;
  place-items: center;
  font-size: 14px;
  flex-shrink: 0;
}
.float-card--1 {
  top: 8%; left: -2%;
  animation: floatY 6.5s ease-in-out infinite;
}
.float-card--1 .float-card__ico { background: var(--jade-veil); color: var(--jade); }
.float-card--2 {
  bottom: 16%; right: -3%;
  animation: floatY 7.5s ease-in-out infinite .8s;
}
.float-card--2 .float-card__ico { background: var(--coral-veil); color: var(--coral-deep); }
.float-card--3 {
  bottom: 2%; left: 12%;
  animation: floatY 8.2s ease-in-out infinite 1.6s;
}
.float-card--3 .float-card__ico { background: var(--gold-veil); color: var(--gold); }
@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-13px); }
}

/* ---------- Trust strip ---------- */
.strip {
  border-block: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(255,255,255,.6), rgba(251,250,247,0));
}
.strip__inner {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  padding-block: 26px;
}
.strip__item {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 13.5px;
  font-weight: 650;
  color: var(--ink-2);
}
.strip__item svg { width: 20px; height: 20px; color: var(--jade); flex-shrink: 0; }

/* ---------- Feature grid ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature {
  position: relative;
  padding: 30px 26px 28px;
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-xs);
  transition: transform .28s cubic-bezier(.2,.8,.3,1), box-shadow .28s ease, border-color .28s ease;
  overflow: hidden;
}
.feature::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(420px 200px at 50% -10%, rgba(94,234,212,.16), transparent 70%);
  opacity: 0;
  transition: opacity .3s ease;
  pointer-events: none;
}
.feature:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--jade-veil-2);
}
.feature:hover::after { opacity: 1; }
.feature__ico {
  width: 50px; height: 50px;
  border-radius: 15px;
  display: grid;
  place-items: center;
  margin-bottom: 20px;
  background: linear-gradient(150deg, var(--jade-veil), #fff);
  border: 1px solid var(--jade-veil-2);
  box-shadow: 0 4px 12px rgba(15,118,110,.09);
}
.feature__ico svg { width: 24px; height: 24px; color: var(--jade); }
.feature h3 { font-size: 1.16rem; margin-bottom: 9px; letter-spacing: -.01em; }
.feature p { font-size: 14.5px; line-height: 1.72; color: var(--ink-2); }
.feature__tag {
  position: absolute;
  top: 18px; right: 18px;
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: .1em;
  color: var(--jade);
  background: var(--jade-veil);
  border-radius: var(--r-pill);
  padding: 3px 9px;
}

/* ---------- 鹿小安 人格区 ---------- */
.personas {
  background:
    radial-gradient(800px 420px at 88% 0%, rgba(94,234,212,.14), transparent 62%),
    radial-gradient(680px 380px at 4% 100%, rgba(245,167,138,.14), transparent 62%),
    var(--paper-2);
  border-block: 1px solid var(--line-soft);
}
.personas__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 8px;
}
.persona {
  position: relative;
  background: var(--card);
  border: 1.5px solid var(--line-soft);
  border-radius: var(--r-lg);
  padding: 28px 24px 26px;
  transition: transform .3s cubic-bezier(.2,.8,.3,1), box-shadow .3s ease, border-color .3s ease;
  overflow: hidden;
}
.persona:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--coral);
}
.persona__top {
  display: flex;
  align-items: center;
  gap: 13px;
  margin-bottom: 16px;
}
.persona__avatar {
  width: 54px; height: 54px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  font-size: 25px;
  flex-shrink: 0;
  border: 1px solid rgba(22,33,31,.06);
}
.persona--cotton .persona__avatar { background: linear-gradient(145deg,#FDE2E4,#FFD1DA); }
.persona--alarm  .persona__avatar { background: linear-gradient(145deg,#E0F2F1,#C7E8E4); }
.persona--monkey .persona__avatar { background: linear-gradient(145deg,#FEF3C7,#FDE3A7); }
.persona__name { font-size: 1.08rem; font-weight: 800; letter-spacing: -.01em; }
.persona__kind { font-size: 12px; font-weight: 650; color: var(--ink-3); letter-spacing: .04em; }
.persona__quote {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: 4px 16px 16px 16px;
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-2);
  margin-bottom: 14px;
}
.persona__quote::before {
  content: "";
  position: absolute;
  left: -1px; top: -1px;
  width: 14px; height: 14px;
  border-left: 1px solid var(--line-soft);
  border-top: 1px solid var(--line-soft);
  border-radius: 4px 0 0 0;
  background: var(--paper);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}
.persona__meta {
  font-size: 12.5px;
  color: var(--ink-3);
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
}

/* ---------- 对话演示 ---------- */
.chat-demo {
  display: grid;
  grid-template-columns: .92fr 1.08fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: center;
}
.phone {
  position: relative;
  width: 100%;
  max-width: 322px;
  margin-inline: auto;
  border-radius: 40px;
  background: #0C1514;
  padding: 9px;
  box-shadow: 0 34px 80px rgba(22,33,31,.28), 0 0 0 1px rgba(255,255,255,.07);
}
.phone__screen {
  border-radius: 32px;
  overflow: hidden;
  background: var(--paper);
  display: flex;
  flex-direction: column;
  height: 552px;
}
.phone__bar {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 14px 16px 12px;
  border-bottom: 1px solid var(--line-soft);
  background: rgba(255,255,255,.8);
}
.phone__back { font-size: 19px; color: var(--ink-4); line-height: 1; }
.phone__who { font-size: 14px; font-weight: 800; }
.phone__who small { display: block; font-size: 10.5px; font-weight: 600; color: var(--ink-4); margin-top: 1px; }
.phone__body {
  flex: 1;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 9px;
  overflow: hidden;
  background: linear-gradient(180deg, #FFFDF9, var(--paper));
}
.msg {
  max-width: 84%;
  padding: 10px 13px;
  border-radius: 16px;
  font-size: 13px;
  line-height: 1.6;
}
.msg--bot {
  align-self: flex-start;
  background: #fff;
  border: 1px solid var(--line-soft);
  border-top-left-radius: 4px;
  color: var(--ink);
  box-shadow: var(--shadow-xs);
}
.msg--me {
  align-self: flex-end;
  background: linear-gradient(150deg, var(--jade-mid), var(--jade));
  border-top-right-radius: 4px;
  color: #fff;
  box-shadow: 0 6px 16px rgba(15,118,110,.24);
}
.msg__chips { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 8px; }
.msg__chip {
  font-size: 11px;
  font-weight: 700;
  padding: 4px 9px;
  border-radius: var(--r-pill);
  background: var(--jade-veil);
  border: 1px solid var(--jade-veil-2);
  color: var(--jade-deep);
}
.phone__input {
  padding: 10px 12px 14px;
  border-top: 1px solid var(--line-soft);
  background: rgba(255,255,255,.9);
  display: flex;
  align-items: center;
  gap: 8px;
}
.phone__field {
  flex: 1;
  background: var(--paper-2);
  border-radius: var(--r-pill);
  padding: 8px 14px;
  font-size: 12.5px;
  color: var(--ink-4);
}
.phone__send {
  width: 34px; height: 34px;
  border-radius: 50%;
  background: var(--jade);
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 13px;
  flex-shrink: 0;
  box-shadow: 0 5px 14px rgba(15,118,110,.28);
}
.chat-demo__list { display: grid; gap: 18px; }
.chat-demo__item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.chat-demo__num {
  width: 30px; height: 30px;
  border-radius: 9px;
  flex-shrink: 0;
  display: grid;
  place-items: center;
  font-size: 12.5px;
  font-weight: 800;
  color: var(--jade);
  background: var(--jade-veil);
  border: 1px solid var(--jade-veil-2);
}
.chat-demo__item h4 { font-size: 15px; margin-bottom: 3px; font-weight: 800; }
.chat-demo__item p { font-size: 14px; color: var(--ink-2); line-height: 1.68; }

/* ---------- Privacy ---------- */
.privacy {
  background: linear-gradient(165deg, #0C3B37 0%, #0F5C55 48%, #0B4A45 100%);
  color: #EAF6F3;
  position: relative;
  overflow: hidden;
}
.privacy::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(700px 380px at 82% 8%, rgba(94,234,212,.2), transparent 60%),
    radial-gradient(560px 320px at 6% 96%, rgba(245,167,138,.14), transparent 62%);
  pointer-events: none;
}
.privacy .shell { position: relative; z-index: 1; }
.privacy .h2 { color: #fff; }
.privacy .lede { color: rgba(234,246,243,.78); }
.privacy .eyebrow {
  color: var(--jade-light);
  background: rgba(94,234,212,.1);
  border-color: rgba(94,234,212,.22);
}
.privacy__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 40px;
}
.privacy__item {
  display: flex;
  gap: 15px;
  padding: 24px 22px;
  border-radius: var(--r-md);
  background: rgba(255,255,255,.055);
  border: 1px solid rgba(94,234,212,.14);
  backdrop-filter: blur(6px);
  transition: background .25s ease, border-color .25s ease, transform .25s ease;
}
.privacy__item:hover {
  background: rgba(255,255,255,.085);
  border-color: rgba(94,234,212,.3);
  transform: translateY(-3px);
}
.privacy__ico {
  width: 40px; height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  background: rgba(94,234,212,.13);
  border: 1px solid rgba(94,234,212,.24);
}
.privacy__ico svg { width: 20px; height: 20px; color: var(--jade-light); }
.privacy__item h4 { font-size: 15px; color: #fff; margin-bottom: 5px; font-weight: 800; }
.privacy__item p { font-size: 13.5px; line-height: 1.72; color: rgba(234,246,243,.72); }

/* ---------- Download ---------- */
.download__card {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: clamp(28px, 4vw, 56px);
  align-items: center;
  padding: clamp(30px, 4.4vw, 56px);
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}
.download__card::before {
  content: "";
  position: absolute;
  width: 460px; height: 460px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(94,234,212,.2), transparent 68%);
  top: -220px; right: -160px;
  pointer-events: none;
}
.download__platforms { display: grid; gap: 12px; position: relative; z-index: 1; }
.plat {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-radius: var(--r-md);
  border: 1.5px solid var(--line-soft);
  background: var(--paper);
  transition: border-color .22s ease, background .22s ease, transform .22s ease;
}
.plat:hover { border-color: var(--jade-veil-2); background: #fff; transform: translateX(3px); }
.plat--active { border-color: var(--jade-veil-2); background: linear-gradient(120deg, #fff, var(--jade-veil)); }
.plat__ico {
  width: 42px; height: 42px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  background: #fff;
  border: 1px solid var(--line-soft);
}
.plat__ico svg { width: 22px; height: 22px; }
.plat__txt { flex: 1; }
.plat__name { font-size: 14.5px; font-weight: 800; }
.plat__note { font-size: 12.5px; color: var(--ink-3); font-weight: 600; }
.plat__badge {
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: .06em;
  padding: 3px 9px;
  border-radius: var(--r-pill);
  background: var(--paper-3);
  color: var(--ink-3);
  flex-shrink: 0;
}
.plat--active .plat__badge { background: var(--jade); color: #fff; }

/* ---------- FAQ ---------- */
.faq { display: grid; gap: 12px; max-width: 820px; margin-inline: auto; }
.faq details {
  background: var(--card);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  padding: 4px 22px;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.faq details[open] { border-color: var(--jade-veil-2); box-shadow: var(--shadow-sm); }
.faq summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px 0;
  font-size: 15.5px;
  font-weight: 750;
  cursor: pointer;
  list-style: none;
  color: var(--ink);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  margin-left: auto;
  font-size: 21px;
  font-weight: 400;
  color: var(--ink-4);
  line-height: 1;
  transition: transform .25s ease, color .25s ease;
}
.faq details[open] summary::after { transform: rotate(45deg); color: var(--jade); }
.faq p {
  padding-bottom: 20px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ink-2);
}

/* ---------- CTA banner ---------- */
.cta {
  text-align: center;
  padding: clamp(48px, 7vw, 84px) clamp(24px, 5vw, 64px);
  border-radius: var(--r-xl);
  background:
    radial-gradient(600px 300px at 50% -20%, rgba(94,234,212,.26), transparent 62%),
    linear-gradient(160deg, #0D5F58, #0A4A45);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.cta::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(420px 220px at 88% 110%, rgba(245,167,138,.22), transparent 66%);
  pointer-events: none;
}
.cta .h2 { color: #fff; margin-bottom: 14px; position: relative; z-index: 1; }
.cta p { color: rgba(255,255,255,.76); max-width: 560px; margin: 0 auto 30px; position: relative; z-index: 1; font-size: 15.5px; }
.cta .btn { position: relative; z-index: 1; background: #fff; color: var(--jade-deep); box-shadow: 0 16px 40px rgba(0,0,0,.24); }
.cta .btn:hover { background: var(--coral-veil); color: var(--coral-deep); }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--line-soft);
  background: var(--paper-2);
  padding-block: 52px 34px;
  font-size: 13.5px;
  color: var(--ink-3);
}
.footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 36px;
}
.footer__brand p { margin-top: 14px; max-width: 30em; line-height: 1.72; }
.footer h5 {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 0 0 14px;
}
.footer__links { display: grid; gap: 9px; }
.footer__links a { color: var(--ink-2); font-size: 13.5px; font-weight: 600; }
.footer__links a:hover { color: var(--jade); }
.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--ink-4);
}
.footer__bottom a { color: var(--ink-3); }

/* ---------- 滚动动效 ----------
   渐进增强:默认完全可见(无 JS / 老浏览器也能读内容);
   只有 <html class="js"> 存在时才启用"先隐藏再渐入"。
   JS 由页面 <head> 内联脚本注入,不依赖任何外部库。            */
.reveal { opacity: 1; transform: none; }
html.js .reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .7s cubic-bezier(.2,.8,.3,1), transform .7s cubic-bezier(.2,.8,.3,1);
  will-change: opacity, transform;
}
html.js .reveal.is-in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .07s; }
.reveal[data-delay="2"] { transition-delay: .14s; }
.reveal[data-delay="3"] { transition-delay: .21s; }
.reveal[data-delay="4"] { transition-delay: .28s; }
.reveal[data-delay="5"] { transition-delay: .35s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__visual { order: -1; max-width: 420px; margin-inline: auto; }
  .hero__lede { margin-inline: auto; }
  .hero__actions, .hero__trust { justify-content: center; }
  .hero__copy { text-align: center; }
  .stage { max-width: 400px; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .personas__grid { grid-template-columns: 1fr; max-width: 520px; margin-inline: auto; }
  .chat-demo { grid-template-columns: 1fr; }
  .download__card { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .strip__inner { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 760px) {
  :root { --gutter: 18px; }
  .nav__menu { display: none; }
  .nav__toggle { display: grid; }
  .nav.is-open .nav__menu {
    display: flex;
    position: absolute;
    top: 72px; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-left: 0;
    padding: 16px var(--gutter) 22px;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
  }
  .nav.is-open .nav__links {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }
  .nav.is-open .nav__link { padding: 12px 14px; font-size: 15.5px; }
  .nav.is-open .nav__cta { width: 100%; }
  .features { grid-template-columns: 1fr; }
  .privacy__grid { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr; gap: 26px; }
  .float-card { font-size: 12px; padding: 9px 12px; }
  .float-card--1 { left: -4%; }
  .float-card--2 { right: -4%; }
  .phone { max-width: 300px; }
  .phone__screen { height: 520px; }
  .display { letter-spacing: -.02em; }
}

@media (max-width: 420px) {
  .float-card--3 { display: none; }
  .strip__inner { grid-template-columns: 1fr; gap: 12px; }
}

/* ---------- 深色模式 ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --ink:        #ECF3F1;
    --ink-2:      #B6C6C3;
    --ink-3:      #8B9E9A;
    --ink-4:      #64767373;
    --paper:      #0E1614;
    --paper-2:    #121C1A;
    --paper-3:    #172321;
    --card:       #14201E;
    --line:       #24332F;
    --line-soft:  #1C2A27;
    --jade-veil:  rgba(94,234,212,.09);
    --jade-veil-2:rgba(94,234,212,.2);
    --coral-veil: rgba(245,167,138,.1);
    --gold-veil:  rgba(199,125,43,.14);
    --shadow-xs:  0 1px 2px rgba(0,0,0,.4);
    --shadow-sm:  0 2px 10px rgba(0,0,0,.36);
    --shadow-md:  0 10px 34px rgba(0,0,0,.46);
    --shadow-lg:  0 30px 70px rgba(0,0,0,.55);
  }
  body { background: var(--paper); }
  .nav { background: rgba(14,22,20,.82); }
  .stage__plate {
    background: radial-gradient(circle at 50% 34%, #1B2B28 0%, #16241F 45%, #12201D 75%, #0F1B18 100%);
    box-shadow: inset 0 2px 0 rgba(255,255,255,.06), 0 34px 80px rgba(0,0,0,.5);
  }
  .float-card { background: rgba(20,32,30,.94); border-color: rgba(255,255,255,.08); }
  .feature__ico { background: linear-gradient(150deg, rgba(94,234,212,.12), rgba(20,32,30,.6)); }
  .phone__screen { background: var(--paper); }
  .phone__body { background: linear-gradient(180deg, #101918, var(--paper)); }
  .msg--bot { background: var(--card); border-color: var(--line-soft); }
  .persona__avatar { border-color: rgba(255,255,255,.08); }
  .persona__quote::before { border-color: var(--line-soft); background: var(--paper); }
  .plat { background: var(--paper-2); }
  .plat--active { background: linear-gradient(120deg, var(--card), rgba(94,234,212,.07)); }
  .plat__ico { background: var(--paper-3); border-color: var(--line); }
  .btn--ghost { background: rgba(255,255,255,.05); border-color: var(--line); color: var(--ink); }
  .btn--ghost:hover { background: rgba(255,255,255,.09); }
  .privacy { background: linear-gradient(165deg, #08211F 0%, #0A302C 48%, #072421 100%); }
  .footer { background: var(--paper-2); }
}