/* ============================================================
   知跃 CogniLeap 官网 · 深空极光版
   底色 #0A0E2A · 主色 #3B5BFF · 电光紫 #A855F7
   极光青 #22D3EE · 霓虹粉 #F472B6（点缀） · 星光金 #FFC861
   ============================================================ */

:root {
  --bg: #0A0E2A;
  --bg-deep: #050722;
  --primary: #3B5BFF;
  --violet: #A855F7;
  --cyan: #22D3EE;
  --pink: #F472B6;
  --gold: #FFC861;
  --text: #FFFFFF;
  --text-soft: #B8C1DC;
  --text-dim: #7E88A8;
  --line: rgba(184, 193, 220, .16);
  --grad-main: linear-gradient(120deg, #3B5BFF 0%, #A855F7 55%, #22D3EE 100%);
  --grad-gold: linear-gradient(120deg, #FFC861, #F472B6);
  --glass: rgba(23, 30, 62, .72);
  --radius: 16px;
  --radius-lg: 22px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

img, svg, video { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

/* ---------- 整屏滚动 ---------- */
html { scroll-snap-type: y mandatory; scroll-behavior: smooth; overscroll-behavior-y: none; }
.screen {
  min-height: 100vh;
  scroll-snap-align: start;
  position: relative;
  display: flex;
  align-items: center;
  padding: 96px 0 72px;
  overflow: hidden;
}

/* ---------- 星空与极光背景 ---------- */
.stars {
  position: absolute; inset: 0; pointer-events: none; z-index: 0;
  background-image:
    radial-gradient(1.5px 1.5px at 12% 22%, rgba(255,255,255,.8) 50%, transparent 51%),
    radial-gradient(1px 1px at 28% 68%, rgba(255,255,255,.55) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 42% 34%, rgba(255,255,255,.7) 50%, transparent 51%),
    radial-gradient(1px 1px at 58% 78%, rgba(255,255,255,.5) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 71% 18%, rgba(255,200,97,.85) 50%, transparent 51%),
    radial-gradient(1px 1px at 84% 58%, rgba(255,255,255,.6) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 92% 30%, rgba(168,85,247,.8) 50%, transparent 51%),
    radial-gradient(1px 1px at 6% 84%, rgba(34,211,238,.7) 50%, transparent 51%),
    radial-gradient(1px 1px at 63% 92%, rgba(255,255,255,.45) 50%, transparent 51%);
}

.aurora {
  position: absolute; inset: 0; pointer-events: none; z-index: 0;
  background:
    radial-gradient(720px 420px at 82% 8%, rgba(79,107,255,.22), transparent 62%),
    radial-gradient(640px 380px at 12% 92%, rgba(168,85,247,.16), transparent 62%),
    radial-gradient(520px 300px at 60% 78%, rgba(34,211,238,.10), transparent 60%);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 50px; padding: 0 28px; border-radius: 14px;
  font-size: 17px; font-weight: 600; border: none; cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, filter .18s ease;
  white-space: nowrap;
  position: relative; z-index: 2;
}
.btn-lg { min-height: 58px; padding: 0 36px; font-size: 18px; border-radius: 16px; }
.btn-xl { min-height: 64px; padding: 0 44px; font-size: 19px; border-radius: 18px; }

.btn-primary {
  background: var(--grad-main); color: #fff;
  box-shadow: 0 10px 34px rgba(79, 107, 255, .38);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 44px rgba(168, 85, 247, .45); filter: brightness(1.06); }

.btn-ghost {
  background: rgba(255, 255, 255, .06); color: var(--text);
  border: 1.5px solid rgba(184, 193, 220, .4);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); transform: translateY(-2px); }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  background: rgba(10, 14, 42, .55);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease, background .2s ease;
}
.nav.scrolled { border-bottom-color: var(--line); background: rgba(10, 14, 42, .82); }

.nav-inner { display: flex; align-items: center; gap: 30px; height: 76px; }

.brand { display: inline-flex; align-items: center; }
.brand-logo { width: 46px; height: 46px; object-fit: contain; border-radius: 14px; }

.nav-links { display: flex; gap: 28px; margin-left: 10px; }
.nav-links a { font-size: 16px; font-weight: 500; color: var(--text-soft); transition: color .15s; }
.nav-links a:hover { color: var(--gold); }

.nav-cta { margin-left: auto; min-height: 44px; padding: 0 20px; font-size: 15.5px; }

.nav-burger {
  display: none; flex-direction: column; gap: 5px; width: 44px; height: 44px;
  margin-left: auto; background: none; border: none; cursor: pointer;
  align-items: center; justify-content: center;
}
.nav-burger span { width: 22px; height: 2.5px; border-radius: 2px; background: var(--text); transition: transform .2s, opacity .2s; }

/* ---------- 屏 1 Hero ---------- */
.hero { background: linear-gradient(180deg, #0B1030 0%, var(--bg) 55%); }
.hero-inner { position: relative; z-index: 2; display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 32px; width: 100%; padding: 0 56px; box-sizing: border-box; }

.hero-copy { position: relative; z-index: 2; }

.hero-badge {
  display: inline-flex; padding: 8px 18px; border-radius: 999px;
  font-size: 14px; font-weight: 600; color: var(--gold);
  background: rgba(255, 200, 97, .1); border: 1px solid rgba(255, 200, 97, .35);
  margin-bottom: 26px;
}

.hero h1 { font-size: clamp(40px, 5.4vw, 62px); line-height: 1.22; font-weight: 800; letter-spacing: 1px; }
.grad-text {
  background: var(--grad-gold);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.hero-lead { margin-top: 22px; font-size: 19px; color: var(--text-soft); line-height: 1.8; }

.hero-actions { display: flex; gap: 16px; margin-top: 34px; flex-wrap: wrap; }

.hero-points { list-style: none; display: flex; gap: 24px; margin-top: 30px; flex-wrap: wrap; }
.hero-points li { display: flex; align-items: center; gap: 9px; font-size: 15px; color: var(--text-soft); }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 12px rgba(34, 211, 238, .8); }

.hero-art { position: relative; z-index: 2; display: flex; justify-content: center; align-items: center; }

.hero-spirit {
  position: absolute; top: -30px; right: 2%; width: 150px; height: 150px;
  object-fit: contain; filter: drop-shadow(0 0 26px rgba(34, 211, 238, .45));
  animation: float 5s ease-in-out infinite;
}

.island-cutout {
  width: min(430px, 88%); border-radius: 28px; overflow: hidden;
  border: 1px solid rgba(184, 193, 220, .28);
  box-shadow: 0 0 0 6px rgba(168, 85, 247, .18), 0 24px 70px rgba(0, 0, 0, .5), 0 0 60px rgba(34, 211, 238, .18);
  animation: float 6s ease-in-out infinite;
  transform: rotate(1.5deg);
}
.island-cutout img { width: 100%; }

.glow-star {
  position: absolute; border-radius: 50%; animation: twinkle 3s ease-in-out infinite;
}
.glow-star.s1 { width: 10px; height: 10px; background: var(--gold); top: 12%; left: 6%; box-shadow: 0 0 18px var(--gold); }
.glow-star.s2 { width: 7px; height: 7px; background: var(--pink); bottom: 16%; left: 14%; box-shadow: 0 0 14px var(--pink); animation-delay: .8s; }
.glow-star.s3 { width: 8px; height: 8px; background: var(--cyan); top: 22%; right: 8%; box-shadow: 0 0 16px var(--cyan); animation-delay: 1.4s; }

@keyframes float { 0%, 100% { transform: translateY(0) rotate(1.5deg); } 50% { transform: translateY(-14px) rotate(1.5deg); } }
@keyframes twinkle { 0%, 100% { opacity: 1; } 50% { opacity: .35; } }

.scroll-hint {
  position: absolute; left: 50%; bottom: 26px; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  font-size: 13px; color: var(--text-dim); z-index: 2;
}
.scroll-hint span {
  width: 26px; height: 42px; border-radius: 14px;
  border: 1.5px solid var(--text-dim); position: relative;
}
.scroll-hint span::after {
  content: ""; position: absolute; left: 50%; top: 8px; width: 4px; height: 8px;
  margin-left: -2px; border-radius: 4px; background: var(--gold);
  animation: scrollDot 1.8s ease-in-out infinite;
}
@keyframes scrollDot { 0% { opacity: 1; transform: translateY(0); } 70% { opacity: 0; transform: translateY(16px); } 100% { opacity: 0; } }

/* ---------- 区块标题 ---------- */
.sec-head { text-align: center; max-width: 680px; margin: 0 auto 50px; position: relative; z-index: 2; }
.sec-tag {
  display: inline-block; color: var(--cyan); background: rgba(34, 211, 238, .1);
  border: 1px solid rgba(34, 211, 238, .35);
  padding: 6px 18px; border-radius: 999px; font-size: 13.5px; font-weight: 600;
  letter-spacing: 1px; margin-bottom: 18px;
}
.sec-head h2 { font-size: clamp(28px, 3.8vw, 42px); font-weight: 800; line-height: 1.3; }
.sec-head p { margin-top: 14px; font-size: 17px; color: var(--text-soft); }

/* ---------- 屏 2 知跃是什么 ---------- */
.about-inner { position: relative; z-index: 2; display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }

.shot-card {
  position: relative; border-radius: 26px; overflow: hidden;
  border: 1px solid rgba(184, 193, 220, .26);
  box-shadow: 0 24px 70px rgba(0, 0, 0, .45);
}
.shot-card img { width: 100%; }
.shot-glow {
  position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(120% 90% at 50% 100%, rgba(255, 200, 97, .20), transparent 55%),
              radial-gradient(90% 70% at 100% 0%, rgba(34, 211, 238, .16), transparent 55%);
}

.about-copy { position: relative; z-index: 2; }
.about-copy h2 { font-size: clamp(30px, 3.8vw, 42px); font-weight: 800; line-height: 1.3; margin-bottom: 20px; }
.about-lead { font-size: 18px; color: var(--text-soft); line-height: 1.9; }
.about-lead b { color: var(--gold); font-weight: 600; }

.about-list { list-style: none; margin-top: 26px; display: flex; flex-direction: column; gap: 14px; }
.about-list li { font-size: 16.5px; color: var(--text); background: var(--glass); border: 1px solid var(--line); border-radius: 14px; padding: 12px 18px; backdrop-filter: blur(6px); }

/* ---------- 屏 3 玩法亮点 ---------- */
.features { background: linear-gradient(180deg, var(--bg) 0%, #0D1034 100%); }
.features-grid { position: relative; z-index: 2; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

.card {
  background: var(--glass); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 34px 28px; backdrop-filter: blur(10px);
  transition: transform .22s ease, border-color .22s ease, box-shadow .22s ease;
}
.card:hover { transform: translateY(-6px); border-color: rgba(168, 85, 247, .55); box-shadow: 0 18px 50px rgba(168, 85, 247, .2); }

.card-ico {
  width: 58px; height: 58px; border-radius: 18px; display: flex; align-items: center; justify-content: center;
  font-size: 27px; margin-bottom: 20px;
  background: color-mix(in srgb, var(--c, var(--primary)) 18%, transparent);
  border: 1px solid color-mix(in srgb, var(--c, var(--primary)) 45%, transparent);
  box-shadow: 0 0 24px color-mix(in srgb, var(--c, var(--primary)) 28%, transparent);
}
.card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.card p { font-size: 15.5px; color: var(--text-soft); }

/* ---------- 屏 4 家长视角 ---------- */
.parents-inner { position: relative; z-index: 2; display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.parents-copy h2 { font-size: clamp(30px, 3.8vw, 42px); font-weight: 800; line-height: 1.3; margin-bottom: 20px; }
.parents-lead { font-size: 18px; color: var(--text-soft); line-height: 1.9; }
.parents-list { list-style: none; margin-top: 26px; display: flex; flex-direction: column; gap: 12px; }
.parents-list li { font-size: 16.5px; color: var(--text-soft); }
.parents-list b { color: var(--cyan); font-weight: 700; margin-right: 8px; }

.parents-visual { position: relative; display: flex; flex-direction: column; gap: 16px; }
.report {
  background: var(--glass); border: 1px solid var(--line); border-radius: 18px;
  padding: 18px 22px; backdrop-filter: blur(8px);
}
.rp-tag { font-size: 14px; font-weight: 700; color: var(--gold); }
.rp-row { display: flex; align-items: center; gap: 14px; margin-top: 12px; font-size: 13.5px; color: var(--text-soft); }
.rp-row span { width: 110px; flex: none; }
.rp-row i { display: block; height: 9px; border-radius: 999px; background: rgba(184, 193, 220, .18); flex: 1; overflow: hidden; position: relative; }
.rp-row i::after { content: ""; position: absolute; inset: 0; border-radius: 999px; background: var(--grad-main); transform-origin: left; }
.p80::after { transform: scaleX(.8); }
.p90::after { transform: scaleX(.9); }
.p60::after { transform: scaleX(.6); }

.rp-pills { display: flex; gap: 12px; margin-top: 14px; }
.rp-pills i {
  font-style: normal; font-size: 13.5px; color: var(--text-soft);
  background: rgba(184, 193, 220, .1); border: 1px solid var(--line);
  border-radius: 12px; padding: 10px 14px; flex: 1; text-align: center;
}
.rp-pills b { font-size: 17px; font-weight: 800; margin-left: 6px; }
.b90 { color: var(--cyan); } .b78 { color: var(--pink); } .b85 { color: var(--gold); }

/* ---------- 屏 5 宣传片 ---------- */
.video-sec { background: linear-gradient(180deg, #0D1034 0%, var(--bg) 100%); }
.video-wrap {
  position: relative; max-width: 920px; margin: 0 auto;
  border-radius: var(--radius-lg); overflow: hidden;
  border: 1px solid rgba(184, 193, 220, .24);
  box-shadow: 0 30px 80px rgba(0, 0, 0, .5), 0 0 50px rgba(168, 85, 247, .14);
  aspect-ratio: 16 / 9; background: #000;
}
.video-wrap video { width: 100%; height: 100%; object-fit: cover; }

.video-play {
  position: absolute; inset: 0; margin: auto; width: 92px; height: 92px;
  border-radius: 50%; border: 2px solid rgba(255, 255, 255, .7);
  background: rgba(10, 14, 42, .45); backdrop-filter: blur(6px);
  cursor: pointer; color: #fff; font-size: 34px; padding-left: 6px;
  display: flex; align-items: center; justify-content: center;
  transition: transform .18s ease, background .18s ease;
}
.video-play:hover { transform: scale(1.08); background: var(--grad-main); border-color: transparent; }

/* ---------- 屏 6 下载 ---------- */
.download { background: linear-gradient(180deg, var(--bg) 0%, #0B1030 70%, #050722 100%); }
.download-inner { position: relative; z-index: 2; display: grid; grid-template-columns: 1.3fr .7fr; gap: 32px; align-items: center; width: 100%; padding: 0 72px; box-sizing: border-box; }

.download-copy h2 { font-size: clamp(32px, 4.4vw, 48px); font-weight: 800; line-height: 1.28; margin-bottom: 18px; }
.download-lead { font-size: 18px; color: var(--text-soft); margin-bottom: 30px; }
.btn-ico { font-size: 22px; }
.download-note { margin-top: 16px; font-size: 13.5px; color: var(--text-dim); }

.download-side { display: flex; flex-direction: column; align-items: center; gap: 26px; }

.thanks {
  display: inline-flex; align-items: center; gap: 12px;
  background: var(--glass); border: 1px solid var(--line); border-radius: 999px;
  padding: 14px 26px; backdrop-filter: blur(8px);
}
.thanks-title { font-size: 14.5px; color: var(--text-soft); }
.thanks-dot { font-size: 16px; color: var(--gold); }
.thanks-name { font-size: 15px; font-weight: 700; color: var(--text); }

.thanks-spirit {
  width: 150px; height: 150px; object-fit: contain;
  filter: drop-shadow(0 0 30px rgba(34, 211, 238, .4));
  animation: float 5s ease-in-out infinite;
}

.footer { position: relative; z-index: 2; margin-top: 40px; border-top: 1px solid var(--line); padding-top: 24px; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer p { font-size: 13.5px; color: var(--text-dim); }
.footer a { font-size: 13.5px; color: var(--cyan); }
.footer a:hover { color: var(--gold); }

/* ---------- 渐入动画 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; gap: 50px; }
  .hero-copy { display: flex; flex-direction: column; align-items: center; }
  .hero-actions { justify-content: center; }
  .hero-points { justify-content: center; }
  .hero-spirit { top: -12px; right: 4%; width: 110px; height: 110px; }
  .about-inner, .parents-inner { grid-template-columns: 1fr; gap: 44px; }
  .about-copy, .parents-copy { text-align: center; }
  .about-list, .parents-list { align-items: center; }
  .about-list li { max-width: 440px; }
  .parents-visual { max-width: 460px; margin: 0 auto; width: 100%; }
  .download-inner { grid-template-columns: 1fr; text-align: center; justify-items: center; }
  .download-side { flex-direction: row; justify-content: center; flex-wrap: wrap; }
}

@media (max-width: 760px) {
  html { scroll-snap-type: none; }
  .screen { min-height: auto; padding: 88px 0 60px; }

  .nav-links {
    position: fixed; top: 76px; left: 0; right: 0; flex-direction: column;
    background: rgba(10, 14, 42, .96); padding: 14px 24px; gap: 4px;
    border-bottom: 1px solid var(--line); display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; font-size: 17px; }
  .nav-cta { display: none; }
  .nav-burger { display: flex; }

  .features-grid { grid-template-columns: 1fr; }
  .hero-actions .btn { width: 100%; }
  .island-cutout { width: 92%; }
  .scroll-hint { display: none; }
  .footer-inner { flex-direction: column; text-align: center; }
}