/* =========================================================
   LinkPal 营销站 · 样式表
   设计：Apple 风格，大量留白、超大字号、系统字体、克制配色
   配色：浅底 #fbfbfd / 深块 #000 #1d1d1f / 品牌蓝→青 #0066ff→#00c2ff
   ========================================================= */

:root {
  --bg: #fbfbfd;
  --bg-dark: #000000;
  --bg-dark-2: #1d1d1f;
  --ink: #1d1d1f;
  --ink-soft: #6e6e73;
  --line: rgba(0, 0, 0, 0.08);
  --brand-a: #0066ff;
  --brand-b: #00c2ff;
  --brand-grad: linear-gradient(120deg, #0066ff 0%, #00c2ff 100%);
  --radius: 18px;
  --maxw: 1080px;
  --nav-h: 56px;
  --scroll: 0; /* 由 JS 写入滚动进度 0–1 */
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; font-weight: 700; letter-spacing: -0.02em; }
p { margin: 0; }
code {
  font-family: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: rgba(0, 102, 255, 0.08);
  color: #0066ff;
  padding: 0.1em 0.4em;
  border-radius: 6px;
}

/* ---------------- 顶部毛玻璃导航 ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background 0.4s ease, border-color 0.4s ease, backdrop-filter 0.4s ease;
}
.site-header.is-solid {
  background: rgba(251, 251, 253, 0.72);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
.nav {
  max-width: var(--maxw);
  margin: 0 auto;
  height: 100%;
  padding: 0 22px;
  display: flex;
  align-items: center;
  gap: 18px;
}
.nav__brand { display: flex; align-items: center; gap: 8px; font-weight: 700; }
.nav__name { font-size: 18px; letter-spacing: -0.01em; }
.nav__links {
  display: flex;
  gap: 28px;
  list-style: none;
  margin: 0 auto 0 8px;
  padding: 0;
  font-size: 14px;
}
.nav__links a { color: var(--ink-soft); transition: color 0.25s ease; }
.nav__links a:hover { color: var(--ink); }
.nav__cta {
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  background: var(--brand-grad);
  padding: 7px 16px;
  border-radius: 980px;
  transition: transform 0.25s ease, box-shadow 0.25s ease, opacity 0.25s ease;
}
.nav__cta:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(0, 102, 255, 0.35); opacity: 0.95; }

/* ---------------- HERO ---------------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-h) + 40px) 22px 40px;
  overflow: hidden;
  background: radial-gradient(120% 80% at 50% 0%, #ffffff 0%, var(--bg) 60%);
}
.hero__orbs { position: absolute; inset: 0; z-index: 0; pointer-events: none; }
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.55;
  will-change: transform;
}
.orb--1 { width: 420px; height: 420px; left: 8%; top: 12%;
  background: radial-gradient(circle, rgba(0,102,255,0.55), transparent 70%); }
.orb--2 { width: 360px; height: 360px; right: 10%; top: 22%;
  background: radial-gradient(circle, rgba(0,194,255,0.5), transparent 70%); }
.orb--3 { width: 300px; height: 300px; left: 40%; bottom: 6%;
  background: radial-gradient(circle, rgba(120,90,255,0.4), transparent 70%); }

.hero__inner { position: relative; z-index: 2; max-width: 880px; }
.hero__eyebrow {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--brand-a);
  margin-bottom: 18px;
}
.hero__title {
  font-size: clamp(40px, 7vw, 80px);
  line-height: 1.05;
  margin-bottom: 22px;
}
.hero__subtitle {
  font-size: clamp(17px, 2.2vw, 22px);
  color: var(--ink-soft);
  max-width: 640px;
  margin: 0 auto 32px;
}
.hero__subtitle strong { color: var(--ink); font-weight: 600; }
.hero__cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 600;
  padding: 13px 28px;
  border-radius: 980px;
  transition: transform 0.25s ease, box-shadow 0.25s ease, opacity 0.25s ease;
}
.btn--primary { color: #fff; background: var(--brand-grad); box-shadow: 0 10px 30px rgba(0,102,255,0.3); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(0,102,255,0.45); }
.btn--ghost { color: var(--brand-a); background: rgba(0,102,255,0.08); }
.btn--ghost:hover { background: rgba(0,102,255,0.14); transform: translateY(-2px); }

.hero__devices {
  position: relative;
  z-index: 1;
  margin-top: 48px;
  width: min(920px, 92vw);
  will-change: transform;
}

/* ---------------- PINNED 隐私叙事 ---------------- */
.pinned {
  position: relative;
  background: var(--bg-dark);
  color: #f5f5f7;
  /* 外层高容器，制造滚动钉住的视差空间 */
  height: 200vh;
}
.pinned__sticky {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 22px;
  z-index: 2;
}
.pinned__eyebrow {
  font-size: 15px; font-weight: 600; letter-spacing: 0.05em;
  background: var(--brand-grad); -webkit-background-clip: text;
  background-clip: text; color: transparent; margin-bottom: 18px;
}
.pinned__title { font-size: clamp(38px, 6.5vw, 76px); line-height: 1.04; }
.pinned__text {
  margin-top: 26px;
  max-width: 560px;
  font-size: clamp(16px, 2vw, 20px);
  color: #a1a1a6;
}
.pinned__bg { position: absolute; inset: 0; z-index: 1; pointer-events: none; overflow: hidden; }
.pinned__glow { position: absolute; border-radius: 50%; filter: blur(90px); opacity: 0.4; will-change: transform; }
.pinned__glow--a { width: 500px; height: 500px; left: -10%; top: 10%;
  background: radial-gradient(circle, rgba(0,102,255,0.5), transparent 70%); }
.pinned__glow--b { width: 520px; height: 520px; right: -12%; bottom: 4%;
  background: radial-gradient(circle, rgba(0,194,255,0.45), transparent 70%); }

/* ---------------- 通用区块 ---------------- */
.section-head { max-width: var(--maxw); margin: 0 auto 48px; padding: 0 22px; text-align: center; }
.section-head h2 { font-size: clamp(30px, 4.5vw, 52px); }
.section-head__sub { margin-top: 14px; font-size: clamp(16px, 2vw, 20px); color: var(--ink-soft); }

.features, .characteristics, .how { padding: clamp(70px, 10vw, 130px) 0; }
.features { background: var(--bg); }
.characteristics { background: #ffffff; }
.how { background: var(--bg); }

/* 卡片 */
.cards {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(0,0,0,0.08); }
.card__icon {
  width: 64px; height: 64px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(0,102,255,0.1), rgba(0,194,255,0.1));
  margin-bottom: 18px;
}
.card h3 { font-size: 21px; margin-bottom: 10px; }
.card p { color: var(--ink-soft); font-size: 15px; }

/* 特点网格 */
.grid {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.feature {
  padding: 28px 26px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: #fff;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.feature:hover { transform: translateY(-3px); box-shadow: 0 14px 34px rgba(0,0,0,0.07); }
.feature h3 { font-size: 20px; margin-bottom: 8px;
  background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.feature p { color: var(--ink-soft); font-size: 15px; }

/* 步骤 */
.steps {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  counter-reset: step;
}
.step {
  position: relative;
  padding: 32px 26px 30px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, #ffffff, #fafafc);
  border: 1px solid var(--line);
}
.step__num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--brand-grad); color: #fff; font-weight: 700; font-size: 18px;
  margin-bottom: 16px;
}
.step h3 { font-size: 20px; margin-bottom: 8px; }
.step p { color: var(--ink-soft); font-size: 15px; }

/* ---------------- 下载 CTA ---------------- */
.download { background: var(--bg-dark-2); color: #f5f5f7; padding: clamp(80px, 11vw, 150px) 22px; }
.download__inner { max-width: 720px; margin: 0 auto; text-align: center; }
.download h2 { font-size: clamp(30px, 4.5vw, 56px); }
.download p { margin-top: 16px; color: #a1a1a6; font-size: clamp(16px, 2vw, 20px); }
.download__btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-top: 34px; }
.store-btn {
  display: flex; flex-direction: column; align-items: flex-start;
  background: #fff; color: #000;
  padding: 12px 26px; border-radius: 14px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.store-btn--mac { background: #d8d8da; }
.store-btn:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(0,0,0,0.3); }
.store-btn__small { font-size: 12px; opacity: 0.7; }
.store-btn__big { font-size: 20px; font-weight: 600; }
.download__note { margin-top: 26px; font-size: 13px; color: #86868b; }

/* ---------------- 页脚 ---------------- */
.footer { background: #f5f5f7; color: var(--ink-soft); padding: 40px 22px; }
.footer__inner { max-width: var(--maxw); margin: 0 auto; display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.footer__brand { display: flex; align-items: center; gap: 8px; font-weight: 700; color: var(--ink); }
.footer__nav { display: flex; gap: 22px; font-size: 14px; margin-left: auto; }
.footer__nav a:hover { color: var(--ink); }
.footer__copy { width: 100%; font-size: 13px; color: #86868b; border-top: 1px solid var(--line); padding-top: 18px; }
.footer__beian { width: 100%; font-size: 12.5px; color: #86868b; margin-top: 14px; display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.footer__beian a { color: #86868b; border-bottom: 1px solid rgba(0,0,0,0.15); padding-bottom: 1px; transition: color 0.2s ease; }
.footer__beian a:hover { color: var(--ink); }

/* ---------------- 滚动渐显 ----------------
   默认（无 JS 或不支持脚本）：直接显示，不做隐藏。
   仅当 <html> 含 .js 时才隐藏并绑定渐显动画，确保禁用 JS 时正文完全可见。 */
.reveal {
  opacity: 1;
  transform: none;
}
.js .reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
  transition-delay: calc(var(--i, 0) * 90ms);
}
.js .reveal.in-view { opacity: 1; transform: translateY(0); }

/* 兜底：浏览器声明禁用脚本时也强制显示（与 no-js 双保险） */
@media (scripting: none) {
  .reveal { opacity: 1 !important; transform: none !important; }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 900px) {
  .cards, .steps { grid-template-columns: 1fr; }
  .grid { grid-template-columns: 1fr; }
  .nav__links { display: none; }
  .pinned { height: 180vh; }
}
@media (max-width: 560px) {
  .nav__cta { padding: 6px 13px; font-size: 13px; }
  .hero__title { font-size: clamp(34px, 9vw, 48px); }
}

/* ---------------- 无障碍：关闭动画 ---------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .orb, .pinned__glow, .hero__devices { transform: none !important; }
}