/* =========================================================
   平行岛 ai — 官网落地页样式
   移动优先 / 断点 768px、1024px / 无外部依赖
   ========================================================= */

:root {
  /* 底色 */
  --c-bg: #06051a;
  --c-bg-soft: #0c0a26;

  /* 边框 / 分割 */
  --c-border: rgba(158, 136, 255, 0.16);
  --c-border-strong: rgba(178, 152, 255, 0.38);

  /* 文字 */
  --c-text: #f3efff;
  --c-text-soft: #c2badf;
  --c-text-mute: #8f88ae;

  /* 渐变 */
  --grad-brand: linear-gradient(118deg, #a99bff 0%, #c77bff 46%, #ff9ad9 100%);
  --grad-btn: linear-gradient(102deg, #6d47ff 0%, #a855f7 52%, #f472b6 100%);
  --grad-btn-alt: linear-gradient(102deg, #2f2a6e 0%, #5636a8 55%, #8b5cd6 100%);
  --grad-line: linear-gradient(90deg, rgba(167, 140, 255, 0), rgba(167, 140, 255, 0.55), rgba(167, 140, 255, 0));

  /* 形状 / 阴影 */
  --radius-sm: 12px;
  --radius: 18px;
  --radius-lg: 26px;
  --shadow-card: 0 18px 40px -26px rgba(0, 0, 0, 0.9);
  --shadow-glow: 0 18px 46px -18px rgba(123, 92, 255, 0.55);

  /* 版式 */
  --nav-h: 58px;
  --maxw: 1120px;
  --gap: 14px;
  --font: "PingFang SC", "HarmonyOS Sans SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-text);
  background-color: var(--c-bg);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* 星空底：多层径向渐变，固定铺满视口 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background-color: var(--c-bg);
  background-image:
    radial-gradient(circle at 82% 6%, rgba(150, 96, 255, 0.28), transparent 46%),
    radial-gradient(circle at 8% 24%, rgba(70, 60, 190, 0.26), transparent 48%),
    radial-gradient(circle at 50% 62%, rgba(123, 62, 168, 0.22), transparent 52%),
    radial-gradient(circle at 92% 86%, rgba(214, 92, 170, 0.16), transparent 46%),
    linear-gradient(180deg, #08061f 0%, #06051a 42%, #04030f 100%);
}

/* 星点 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.75;
  background-image:
    radial-gradient(1.2px 1.2px at 12% 18%, rgba(255, 255, 255, 0.9), transparent),
    radial-gradient(1px 1px at 28% 42%, rgba(214, 200, 255, 0.8), transparent),
    radial-gradient(1.4px 1.4px at 44% 12%, rgba(255, 255, 255, 0.7), transparent),
    radial-gradient(1px 1px at 62% 34%, rgba(200, 190, 255, 0.75), transparent),
    radial-gradient(1.3px 1.3px at 78% 20%, rgba(255, 255, 255, 0.8), transparent),
    radial-gradient(1px 1px at 88% 52%, rgba(220, 205, 255, 0.6), transparent),
    radial-gradient(1.2px 1.2px at 18% 72%, rgba(255, 255, 255, 0.65), transparent),
    radial-gradient(1px 1px at 36% 88%, rgba(210, 195, 255, 0.55), transparent),
    radial-gradient(1.4px 1.4px at 58% 76%, rgba(255, 255, 255, 0.6), transparent),
    radial-gradient(1px 1px at 74% 92%, rgba(200, 190, 255, 0.5), transparent),
    radial-gradient(1.1px 1.1px at 94% 68%, rgba(255, 255, 255, 0.55), transparent);
  background-size: 100% 100%;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

h1,
h2,
h3,
p,
ul,
ol {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

button {
  font-family: inherit;
  color: inherit;
}

::selection {
  background: rgba(199, 123, 255, 0.35);
  color: #fff;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 999;
  padding: 10px 16px;
  background: var(--c-bg-soft);
  border-radius: 0 0 var(--radius-sm) 0;
}

.skip-link:focus {
  left: 0;
}

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 18px;
}

.grad-text {
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

/* ===================== 顶部导航 ===================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6, 5, 26, 0.72);
  border-bottom: 1px solid rgba(158, 136, 255, 0.12);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

.nav-inner {
  position: relative;
  height: var(--nav-h);
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--c-text);
  flex: 0 0 auto;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 9px;
  color: #fff;
  background: linear-gradient(140deg, rgba(155, 139, 255, 0.95), rgba(199, 123, 255, 0.85) 55%, rgba(255, 154, 217, 0.9));
  box-shadow: 0 6px 16px -8px rgba(199, 123, 255, 0.9);
}

.logo-text {
  font-size: 1.14rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.2;
  white-space: nowrap;
}

.logo-text em {
  font-style: normal;
  font-weight: 600;
  letter-spacing: 0.04em;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 4px;
  flex: 1 1 auto;
  justify-content: center;
}

.nav-links a {
  padding: 6px 10px;
  font-size: 0.88rem;
  color: var(--c-text-soft);
  border-radius: 999px;
  transition: color 0.22s ease, background-color 0.22s ease;
}

.nav-links a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.07);
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
  color: #fff;
  font-weight: 600;
  background: var(--grad-btn);
  border-radius: 999px;
  box-shadow: var(--shadow-glow);
  transition: transform 0.22s ease, box-shadow 0.22s ease, filter 0.22s ease;
}

.btn-cta--nav {
  flex: 0 0 auto;
  height: 26px;
  padding: 0 11px;
  font-size: 0.72rem;
  letter-spacing: 0.02em;
}

.btn-cta:hover {
  transform: translateY(-1px);
  filter: brightness(1.06);
  box-shadow: 0 20px 40px -16px rgba(168, 85, 247, 0.7);
}

/* ===================== 封面海报 ===================== */
.hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

/* 用海报本身做柔焦背景，让宽屏两侧的星河自然延续 */
.hero::before {
  content: "";
  position: absolute;
  inset: -6% -4%;
  z-index: 0;
  background-image: url("../images/pingxingdaoaiapp1.jpg");
  background-size: cover;
  background-position: center top;
  filter: blur(52px) saturate(125%) brightness(0.62);
  opacity: 0.85;
  transform: scale(1.06);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(180deg, rgba(6, 5, 26, 0.55) 0%, rgba(6, 5, 26, 0) 22%, rgba(6, 5, 26, 0) 82%, rgba(6, 5, 26, 0.75) 100%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 750px;
  margin: 0 auto;
}

.hero-poster {
  display: block;
  width: 100%;
  height: auto;
}

/* ===================== 平台数据 ===================== */
.stats {
  padding: 22px 0 10px;
  margin-top: -6px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  padding: 18px 14px;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, rgba(123, 92, 255, 0.14), rgba(255, 143, 214, 0.05));
  box-shadow: var(--shadow-card);
}

.stat {
  text-align: center;
  padding: 6px 4px;
}

.stat-num {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
  font-weight: 800;
  font-size: 1.72rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
}

.stat-unit {
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--c-text-soft);
}

.stat-label {
  margin-top: 4px;
  font-size: 0.76rem;
  color: var(--c-text-mute);
  letter-spacing: 0.02em;
}

/* ===================== 通用区块 ===================== */
.section {
  padding: 52px 0;
  scroll-margin-top: calc(var(--nav-h) + 12px);
}

.eyebrow {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: rgba(204, 186, 255, 0.85);
  padding: 4px 12px;
  border: 1px solid var(--c-border-strong);
  border-radius: 999px;
  background: rgba(123, 92, 255, 0.1);
  margin-bottom: 16px;
}

.section-title {
  font-size: 1.6rem;
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: 0.01em;
  background: linear-gradient(96deg, #ffffff 8%, #e6dcff 46%, #ffc6ea 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.lead {
  margin-top: 14px;
  font-size: 0.94rem;
  color: var(--c-text-soft);
  line-height: 1.9;
  max-width: 46em;
}

.lead--center {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.section--intro .section-title,
.section--faq .section-title {
  max-width: 18em;
}

.br-mobile {
  display: block;
}

/* 卡片通用 */
.card {
  position: relative;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: linear-gradient(165deg, rgba(255, 255, 255, 0.075), rgba(255, 255, 255, 0.02) 60%);
  box-shadow: var(--shadow-card);
  padding: 20px 18px;
  transition: transform 0.28s ease, border-color 0.28s ease, box-shadow 0.28s ease;
  overflow: hidden;
}

.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(120% 80% at 50% -20%, rgba(199, 123, 255, 0.16), transparent 62%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--c-border-strong);
  box-shadow: 0 22px 48px -26px rgba(123, 92, 255, 0.75);
}

.card:hover::after {
  opacity: 1;
}

.icon-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  color: #dcd1ff;
  background: linear-gradient(150deg, rgba(123, 92, 255, 0.34), rgba(255, 143, 214, 0.16));
  border: 1px solid rgba(178, 152, 255, 0.3);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.16);
}

/* 3 卡布局 */
.cards-3 {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  margin-top: 26px;
}

.card--point h3 {
  margin-top: 14px;
  font-size: 1.06rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.card--point p {
  margin-top: 8px;
  font-size: 0.88rem;
  color: var(--c-text-soft);
  line-height: 1.85;
}

/* 6 卡布局（统一居中） */
.cards-6 {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
  margin-top: 26px;
}

.card--feature {
  text-align: center;
}

.card--feature h3 {
  margin-top: 14px;
  font-size: 1.02rem;
  font-weight: 700;
}

.card--feature p {
  margin: 8px auto 0;
  max-width: 30em;
  font-size: 0.86rem;
  color: var(--c-text-soft);
  line-height: 1.85;
}

/* ===================== 角色预览 ===================== */
.cards-4 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 26px;
}

.char-card {
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.04);
  box-shadow: var(--shadow-card);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.char-card:hover {
  transform: translateY(-5px);
  border-color: var(--c-border-strong);
  box-shadow: 0 26px 52px -28px rgba(160, 100, 255, 0.85);
}

.char-media {
  width: 100%;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background: var(--c-bg-soft);
}

.char-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 22%;
  transition: transform 0.6s ease;
}

.char-card:hover .char-media img {
  transform: scale(1.04);
}

.char-body {
  padding: 12px 12px 16px;
  background: linear-gradient(180deg, rgba(6, 5, 26, 0.15), rgba(6, 5, 26, 0.86) 42%);
}

.char-name {
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.char-tag {
  display: inline-block;
  margin-top: 6px;
  padding: 2px 9px;
  font-size: 0.68rem;
  color: #e7dcff;
  border: 1px solid rgba(178, 152, 255, 0.4);
  border-radius: 999px;
  background: rgba(123, 92, 255, 0.18);
}

.char-line {
  margin-top: 9px;
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* ===================== 用户评价 ===================== */
.cards-3--reviews {
  margin-top: 26px;
}

.card--review {
  padding: 18px 16px;
}

.review-head {
  display: flex;
  align-items: center;
  gap: 11px;
}

.avatar {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.02em;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.avatar--1 { background: #6b4bd6; }
.avatar--2 { background: #c2559b; }
.avatar--3 { background: #3f6ed6; }
.avatar--4 { background: #8b4bd6; }
.avatar--5 { background: #2f8f9e; }
.avatar--6 { background: #b45c4b; }

.review-name {
  font-size: 0.88rem;
  font-weight: 600;
}

.stars {
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  line-height: 1.4;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.review-text {
  margin-top: 12px;
  font-size: 0.86rem;
  line-height: 1.9;
  color: var(--c-text-soft);
}

/* ===================== 版本更新 ===================== */
.timeline {
  position: relative;
  margin-top: 26px;
  padding-left: 22px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--grad-line);
}

.timeline-item {
  position: relative;
  padding-bottom: 16px;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -22px;
  top: 20px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--grad-brand);
  box-shadow: 0 0 0 4px rgba(123, 92, 255, 0.16);
}

.timeline-card {
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: linear-gradient(165deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.02));
  padding: 16px;
  box-shadow: var(--shadow-card);
}

.timeline-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.version-badge {
  display: inline-flex;
  align-items: center;
  height: 24px;
  padding: 0 10px;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #fff;
  border-radius: 999px;
  background: linear-gradient(102deg, rgba(109, 71, 255, 0.9), rgba(244, 114, 182, 0.9));
  box-shadow: 0 8px 18px -12px rgba(244, 114, 182, 0.9);
}

.version-badge--lg {
  height: 28px;
  padding: 0 13px;
  font-size: 0.8rem;
  vertical-align: middle;
}

.timeline-head time {
  font-size: 0.76rem;
  color: var(--c-text-mute);
}

.badge-new {
  font-size: 0.68rem;
  padding: 1px 8px;
  border-radius: 999px;
  color: #ffd9f2;
  border: 1px solid rgba(255, 143, 214, 0.5);
  background: rgba(255, 143, 214, 0.14);
}

.timeline-list {
  margin-top: 12px;
  display: grid;
  gap: 7px;
}

.timeline-list li {
  position: relative;
  padding-left: 15px;
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--c-text-soft);
}

.timeline-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: rgba(199, 123, 255, 0.85);
}

/* ===================== FAQ ===================== */
.faq-list {
  margin-top: 24px;
  display: grid;
  gap: 10px;
}

.faq-item {
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  background: linear-gradient(165deg, rgba(255, 255, 255, 0.065), rgba(255, 255, 255, 0.018));
  overflow: hidden;
  transition: border-color 0.25s ease;
}

.faq-item.is-open {
  border-color: var(--c-border-strong);
}

.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 16px;
  background: none;
  border: 0;
  text-align: left;
  font-size: 0.9rem;
  font-weight: 600;
  line-height: 1.6;
  color: var(--c-text);
  cursor: pointer;
}

.faq-icon {
  position: relative;
  flex: 0 0 auto;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1px solid var(--c-border-strong);
}

.faq-icon::before,
.faq-icon::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: #d7caff;
  border-radius: 2px;
  transform: translate(-50%, -50%);
  transition: transform 0.28s ease, opacity 0.28s ease;
}

.faq-icon::before {
  width: 8px;
  height: 1.5px;
}

.faq-icon::after {
  width: 1.5px;
  height: 8px;
}

.faq-item.is-open .faq-icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
  opacity: 0;
}

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.34s ease;
}

.faq-a-inner {
  padding: 12px 16px 16px;
  font-size: 0.85rem;
  line-height: 1.9;
  color: var(--c-text-soft);
  border-top: 1px solid rgba(158, 136, 255, 0.14);
}

/* ===================== 下载区 ===================== */
.section--download {
  padding-top: 56px;
  padding-bottom: 58px;
}

.download-wrap {
  position: relative;
  text-align: center;
  padding: 30px 18px 34px;
  border: 1px solid var(--c-border-strong);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 90% at 50% 0%, rgba(150, 96, 255, 0.28), transparent 60%),
    linear-gradient(180deg, rgba(20, 15, 56, 0.85), rgba(8, 6, 28, 0.92));
  box-shadow: 0 30px 80px -40px rgba(123, 92, 255, 0.9);
  overflow: hidden;
}

.download-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1.4px 1.4px at 18% 22%, rgba(255, 255, 255, 0.8), transparent),
    radial-gradient(1px 1px at 72% 16%, rgba(220, 205, 255, 0.7), transparent),
    radial-gradient(1.2px 1.2px at 38% 72%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1px 1px at 86% 64%, rgba(210, 195, 255, 0.55), transparent),
    radial-gradient(1.3px 1.3px at 56% 34%, rgba(255, 255, 255, 0.45), transparent);
  pointer-events: none;
}

.download-wrap > * {
  position: relative;
}

.download-title {
  font-size: 1.6rem;
  line-height: 1.4;
  font-weight: 800;
  letter-spacing: 0.01em;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  background: linear-gradient(96deg, #ffffff 10%, #e8ddff 50%, #ffc9ec 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.download-title .version-badge {
  -webkit-text-fill-color: #fff;
  color: #fff;
}

.download-meta {
  margin-top: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: nowrap;
  gap: 8px;
  white-space: nowrap;
  font-size: 0.72rem;
  color: var(--c-text-mute);
}

.download-meta li {
  white-space: nowrap;
}

.download-meta li + li::before {
  content: "·";
  margin-right: 8px;
  color: rgba(178, 152, 255, 0.7);
}

.download-actions {
  margin-top: 22px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.btn-dl {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 50px;
  padding: 12px 18px;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: #ffffff;
  border-radius: 999px;
  background: var(--grad-btn);
  box-shadow: 0 18px 40px -20px rgba(168, 85, 247, 0.95);
  transition: transform 0.22s ease, box-shadow 0.22s ease, filter 0.22s ease;
}

.btn-dl--alt {
  background: var(--grad-btn-alt);
  box-shadow: 0 16px 36px -22px rgba(123, 92, 255, 0.95);
  border: 1px solid rgba(178, 152, 255, 0.4);
}

.btn-dl:hover {
  transform: translateY(-2px);
  filter: brightness(1.07);
}

.btn-dl svg {
  flex: 0 0 auto;
  opacity: 0.95;
}

.download-tip {
  margin: 18px auto 0;
  max-width: 30em;
  font-size: 0.8rem;
  line-height: 1.8;
  color: rgba(214, 202, 255, 0.9);
}

/* ===================== 页脚 ===================== */
.site-footer {
  padding: 26px 0 34px;
  border-top: 1px solid rgba(158, 136, 255, 0.12);
  background: rgba(3, 2, 14, 0.6);
}

.footer-inner {
  text-align: center;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--c-text-mute);
}

.footer-link {
  color: #d9cbff;
  text-decoration: none;
  border-bottom: 0;
  transition: color 0.22s ease;
}

.footer-link:hover {
  color: #ffd0ee;
  text-decoration: none;
}

.footer-sub {
  margin-top: 6px;
  font-size: 0.72rem;
  color: rgba(143, 136, 174, 0.75);
  letter-spacing: 0.04em;
}

/* ===================== 返回顶部浮球 ===================== */
.back-top {
  position: fixed;
  right: 14px;
  bottom: 18px;
  z-index: 90;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  border: 1px solid rgba(198, 176, 255, 0.45);
  border-radius: 50%;
  background: linear-gradient(150deg, rgba(109, 71, 255, 0.95), rgba(199, 123, 255, 0.85) 60%, rgba(244, 114, 182, 0.85));
  box-shadow: 0 14px 32px -14px rgba(168, 85, 247, 0.95);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px) scale(0.9);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.back-top:hover {
  filter: brightness(1.08);
}

.back-top:focus-visible,
.faq-q:focus-visible,
.btn-cta:focus-visible,
.btn-dl:focus-visible,
.logo:focus-visible,
.nav-links a:focus-visible {
  outline: 2px solid rgba(199, 123, 255, 0.9);
  outline-offset: 3px;
}

/* ===================== 平板 ≥ 768px ===================== */
@media (min-width: 768px) {
  :root {
    --nav-h: 66px;
    --gap: 16px;
    --radius: 20px;
  }

  .wrap {
    padding: 0 28px;
  }

  .nav-inner {
    padding: 0 28px;
    gap: 18px;
  }

  .nav-links {
    display: flex;
  }

  .logo-text {
    font-size: 1.26rem;
  }

  .logo-mark {
    width: 30px;
    height: 30px;
  }

  .btn-cta--nav {
    height: 30px;
    padding: 0 15px;
    font-size: 0.8rem;
  }

  .section {
    padding: 68px 0;
  }

  .section-title {
    font-size: 2.05rem;
  }

  .lead {
    font-size: 1rem;
  }

  .br-mobile {
    display: none;
  }

  .stats {
    padding-top: 28px;
  }

  .stats-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding: 24px 18px;
  }

  .stat-num {
    font-size: 2.1rem;
  }

  .stat-unit {
    font-size: 0.95rem;
  }

  .stat-label {
    font-size: 0.8rem;
  }

  .cards-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
    margin-top: 30px;
  }

  .cards-6 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
    margin-top: 30px;
  }

  .cards-4 {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
    margin-top: 30px;
  }

  .card {
    padding: 24px 20px;
  }

  .char-body {
    padding: 14px 14px 18px;
  }

  .char-name {
    font-size: 1.12rem;
  }

  .char-line {
    font-size: 0.84rem;
  }

  .timeline {
    padding-left: 28px;
    margin-top: 30px;
  }

  .timeline::before {
    left: 6px;
  }

  .timeline-dot {
    left: -28px;
    width: 13px;
    height: 13px;
  }

  .timeline-card {
    padding: 20px 22px;
  }

  .faq-q {
    padding: 18px 22px;
    font-size: 0.98rem;
  }

  .faq-a-inner {
    padding: 14px 22px 20px;
    font-size: 0.9rem;
  }

  .download-wrap {
    padding: 44px 40px 48px;
  }

  .download-title {
    font-size: 2.1rem;
  }

  .download-meta {
    font-size: 0.84rem;
    gap: 12px;
  }

  .download-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    max-width: 620px;
    margin: 26px auto 0;
  }

  .download-tip {
    font-size: 0.86rem;
  }

  .back-top {
    right: 24px;
    bottom: 26px;
    width: 50px;
    height: 50px;
  }

  .footer-copy {
    font-size: 0.84rem;
  }
}

/* ===================== 桌面 ≥ 1024px ===================== */
@media (min-width: 1024px) {
  :root {
    --nav-h: 74px;
    --gap: 20px;
    --maxw: 1160px;
  }

  /* 桌面端：中部菜单相对导航栏真正居中 */
  .nav-links {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    flex: 0 0 auto;
    gap: 8px;
  }

  .nav-links a {
    font-size: 0.92rem;
    padding: 8px 14px;
  }

  .logo-text {
    font-size: 1.38rem;
  }

  .logo-mark {
    width: 32px;
    height: 32px;
  }

  .btn-cta--nav {
    height: 32px;
    padding: 0 17px;
    font-size: 0.84rem;
  }

  .section {
    padding: 84px 0;
  }

  .section-title {
    font-size: 2.5rem;
    line-height: 1.3;
  }

  .lead {
    font-size: 1.04rem;
    margin-top: 16px;
  }

  .stats {
    padding-top: 34px;
  }

  .stats-grid {
    padding: 30px 24px;
  }

  .stat-num {
    font-size: 2.6rem;
  }

  .card {
    padding: 28px 24px;
  }

  .cards-3 {
    gap: 22px;
    margin-top: 34px;
  }

  .cards-6 {
    gap: 20px;
    margin-top: 34px;
  }

  .cards-4 {
    gap: 20px;
    margin-top: 34px;
  }

  .download-title {
    font-size: 2.6rem;
  }

  .download-wrap {
    padding: 56px 56px 58px;
  }

  .btn-dl {
    min-height: 54px;
    font-size: 1rem;
  }
}

/* 动效克制：尊重系统偏好 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms;
    animation-duration: 0.01ms;
  }
}