/* ===== 老唐陪你读 · tangnotes.com · 蓝金温和调 v3 ===== */
:root{
  --bg:#13293F;          /* 柔和藏蓝主背景（降饱和提舒适度） */
  --bg-deep:#0E2133;     /* 更深的蓝（页脚/对比区块） */
  --panel:#1B334C;       /* 卡片面板 */
  --panel-soft:rgba(255,255,255,.05);
  --ink:#F0F4F9;         /* 主文字 */
  --ink-soft:rgba(226,235,244,.72);  /* 次文字 */
  --ink-faint:rgba(226,235,244,.46); /* 弱文字 */
  --gold:#CDA968;        /* 柔金强调 */
  --gold-bright:#E3C88E;
  --gold-dim:rgba(205,169,104,.14);
  --line:rgba(255,255,255,.09);
  --line-strong:rgba(205,169,104,.30);
  --radius:18px;
  --shadow:0 10px 32px rgba(5,12,24,.32);
  --serif:Georgia,"Songti SC","STSong","SimSun","Noto Serif SC",serif;
  --sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:var(--sans);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
.container{max-width:1120px;margin:0 auto;padding:0 24px}
a{color:var(--gold);text-decoration:none}
img,svg{max-width:100%}

/* 标题用衬线，书卷气 */
h1,h2,h3,.brand-name,.product-price,.hero-sub{
  font-family:var(--serif);
}

/* ===== 导航 ===== */
.nav{
  position:sticky;top:0;z-index:100;
  background:rgba(19,41,63,.85);
  backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid transparent;
  transition:border-color .3s,box-shadow .3s;
}
.nav.scrolled{border-bottom-color:var(--line);box-shadow:0 4px 20px rgba(5,12,24,.30)}
.nav-inner{display:flex;align-items:center;gap:26px;height:58px}
.brand{display:flex;align-items:center;gap:9px;color:var(--ink);font-weight:700}
.brand-mark{width:24px;height:24px;color:var(--gold);flex:none}
.brand-name{font-size:18px;letter-spacing:.5px}
.nav-links{display:flex;gap:24px;margin-left:auto}
.nav-links a{color:var(--ink-soft);font-size:14.5px;transition:color .2s}
.nav-links a:hover{color:var(--gold-bright)}
.nav-cta{margin-left:8px}
.nav-toggle{display:none;background:none;border:0;cursor:pointer;padding:6px;margin-left:auto}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0;border-radius:2px;transition:.3s}

/* ===== 按钮 ===== */
.btn{
  display:inline-block;padding:11px 26px;border-radius:999px;
  font-size:15px;font-weight:600;cursor:pointer;
  transition:transform .2s,box-shadow .2s,background .2s,border-color .2s,color .2s;
  border:1.5px solid transparent;text-align:center;letter-spacing:.5px;
}
.btn:active{transform:translateY(1px)}
.btn-primary{background:linear-gradient(135deg,var(--gold-bright),var(--gold));color:#14263C}
.btn-primary:hover{box-shadow:0 8px 22px rgba(205,169,104,.28);transform:translateY(-1px)}
.btn-ghost{border-color:rgba(240,244,249,.38);color:var(--ink);background:transparent}
.btn-ghost:hover{border-color:var(--gold);color:var(--gold-bright)}
.btn-sm{padding:8px 18px;font-size:13.5px}

/* ===== Hero ===== */
.hero{
  position:relative;padding:88px 0 68px;text-align:center;overflow:hidden;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(205,169,104,.09), transparent 60%),
    linear-gradient(180deg,#17304A 0%,var(--bg) 100%);
}
.hero-glow{
  position:absolute;left:50%;bottom:-320px;width:900px;height:520px;transform:translateX(-50%);
  background:radial-gradient(ellipse at center, rgba(90,140,200,.16), transparent 65%);
  pointer-events:none;
}
.eyebrow{
  display:inline-block;font-size:12.5px;letter-spacing:4px;font-weight:600;
  color:var(--gold-bright);
  border:1px solid var(--line-strong);border-radius:999px;
  padding:5px 18px;margin-bottom:22px;background:var(--gold-dim);
}
.hero h1{
  font-size:clamp(34px,8vw,58px);letter-spacing:3px;line-height:1.24;font-weight:700;
  text-shadow:0 2px 28px rgba(5,12,24,.45);
}
.hero-sub{
  font-size:clamp(15.5px,2.2vw,19px);color:var(--gold-bright);
  margin-top:14px;font-weight:600;letter-spacing:1.5px;
}
.hero-desc{max-width:600px;margin:14px auto 0;color:var(--ink-soft);font-size:15.5px}
.hero-actions{display:flex;gap:14px;justify-content:center;margin-top:30px;flex-wrap:wrap}

/* Hero 数据条 */
.hero-stats{
  display:flex;justify-content:center;align-items:center;gap:30px;flex-wrap:wrap;
  margin-top:42px;padding-top:26px;border-top:1px solid var(--line);
}
.stat{display:flex;flex-direction:column;gap:3px;min-width:140px}
.stat b{
  font-family:var(--serif);font-size:29px;font-weight:700;color:var(--gold-bright);letter-spacing:1px;
}
.stat span{font-size:12.5px;color:var(--ink-faint);letter-spacing:.5px}
.stat-sep{width:1px;height:34px;background:var(--line)}

/* ===== 区块 ===== */
.section{padding:62px 0;position:relative}
.section-alt{background:var(--bg-deep);border-block:1px solid var(--line)}
.section-eyebrow{
  text-align:center;font-size:12px;letter-spacing:5px;font-weight:600;
  color:var(--gold);opacity:.85;margin-bottom:10px;
}
.section-title{font-size:clamp(25px,3.4vw,32px);letter-spacing:2.5px;text-align:center;font-weight:700}
.section-desc{text-align:center;color:var(--ink-soft);max-width:620px;margin:12px auto 0;font-size:15.5px}

/* ===== 卡片 ===== */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:38px}
.card{
  position:relative;
  background:linear-gradient(160deg,var(--panel-soft),rgba(255,255,255,.015));
  border:1px solid var(--line);border-radius:var(--radius);
  padding:28px 26px 26px;overflow:hidden;
  transition:transform .3s,border-color .3s,box-shadow .3s;
}
.card:hover{transform:translateY(-5px);border-color:var(--line-strong);box-shadow:var(--shadow)}
.card-no{
  position:absolute;top:14px;right:20px;
  font-family:var(--serif);font-size:36px;font-weight:700;
  color:rgba(255,255,255,.055);letter-spacing:1px;line-height:1;
}
.card-icon{
  width:44px;height:44px;border-radius:12px;
  background:var(--gold-dim);border:1px solid var(--line-strong);
  display:flex;align-items:center;justify-content:center;color:var(--gold-bright);margin-bottom:14px;
}
.card-icon svg{width:22px;height:22px}
.card h3{font-size:19px;margin-bottom:8px;letter-spacing:1.2px}
.card p{color:var(--ink-soft);font-size:14.5px}

/* ===== 免费资源大卡 ===== */
.feature{display:grid;grid-template-columns:1.15fr .85fr;gap:38px;align-items:center;margin-top:36px}
.feature-tag{
  display:inline-block;font-size:12.5px;letter-spacing:2px;font-weight:600;color:var(--gold-bright);
  border:1px solid var(--line-strong);border-radius:999px;padding:3px 14px;margin-bottom:14px;
  background:var(--gold-dim);
}
.feature-body h3{font-size:23px;letter-spacing:1.2px;margin-bottom:12px}
.feature-body p{color:var(--ink-soft);margin-bottom:10px;font-size:15px}
.feature-body .btn{margin-top:8px}
.feature-note{font-size:12.5px;color:var(--ink-faint);margin-top:14px}
.mock-window{
  background:#10233A;border:1px solid var(--line);border-radius:14px;overflow:hidden;
  box-shadow:var(--shadow);
}
.mock-bar{display:flex;gap:7px;padding:10px 14px;background:rgba(255,255,255,.05);border-bottom:1px solid var(--line);align-items:center}
.mock-bar span{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.18)}
.mock-bar span:first-child{background:var(--gold)}
.mock-bar em{
  margin-left:10px;font-style:normal;font-size:11px;letter-spacing:.5px;
  color:var(--ink-faint);font-family:var(--sans);
}
.mock-body{padding:18px}
.mock-kpis{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-bottom:14px}
.mock-kpis i{height:38px;border-radius:8px;background:rgba(205,169,104,.13);border:1px solid var(--line)}
.mock-chart{display:flex;align-items:flex-end;gap:8px;height:96px;padding:0 4px;margin-bottom:16px}
.mock-chart i{flex:1;border-radius:6px 6px 3px 3px;background:linear-gradient(180deg,var(--gold),rgba(205,169,104,.24))}
.mock-rows i{display:block;height:12px;border-radius:6px;background:rgba(255,255,255,.08);margin-bottom:9px}
.mock-rows i:nth-child(2){width:78%}
.mock-rows i:nth-child(3){width:56%}

/* ===== 产品 ===== */
.card-product{position:relative}
.product-tag{
  position:absolute;top:16px;right:18px;font-size:12px;letter-spacing:2px;
  color:var(--gold-bright);background:var(--gold-dim);border:1px solid var(--line-strong);
  border-radius:999px;padding:3px 12px;
}
.product-price{
  font-size:24px;color:var(--gold-bright);margin:6px 0 10px;letter-spacing:1px;font-weight:700;
}
.product-note{text-align:center;color:var(--ink-faint);font-size:13px;max-width:640px;margin:30px auto 0}

/* ===== 关注引导 ===== */
.follow{display:grid;grid-template-columns:1.2fr .8fr;gap:38px;align-items:center}
.follow .section-eyebrow{text-align:left}
.follow h2{font-size:clamp(23px,3.2vw,28px);letter-spacing:2px;margin-bottom:10px;font-weight:700}
.follow-text>p{color:var(--ink-soft);font-size:15px}
.follow-list{list-style:none;margin-top:16px}
.follow-list li{
  position:relative;padding-left:24px;margin-bottom:10px;color:var(--ink);font-size:14.5px;
}
.follow-list li::before{
  content:"";position:absolute;left:2px;top:.6em;width:7px;height:7px;
  border-radius:50%;background:var(--gold);
}
.follow-list li b{color:var(--gold-bright);font-weight:600}
.qr-box{
  background:var(--panel-soft);border:1.5px dashed var(--line-strong);border-radius:var(--radius);
  padding:24px;text-align:center;color:var(--gold);
}
.qr-real{
  border-style:solid;padding:22px;
  background:linear-gradient(160deg,rgba(205,169,104,.09),rgba(255,255,255,.02));
}
.qr-real img{
  width:200px;height:200px;border-radius:14px;display:block;margin:0 auto;
  box-shadow:0 6px 18px rgba(5,12,24,.35);background:#fff;
}
.qr-pattern{width:134px;height:134px;opacity:.9}
.qr-tip{font-size:14px;color:var(--ink);margin-top:12px;line-height:1.55;font-weight:600;letter-spacing:1px}
.qr-tip span{font-size:12px;color:var(--ink-faint);font-weight:400}

/* ===== 关于 ===== */
.about{max-width:680px;margin:26px auto 0;text-align:center}
.about p{color:var(--ink-soft);margin-bottom:10px;font-size:15px}
.about strong{color:var(--gold-bright);font-weight:600}
.about-note{font-size:13.5px;color:var(--ink-faint)}

/* ===== 页脚 ===== */
.footer{border-top:1px solid var(--line);padding:28px 0;background:var(--bg-deep)}
.footer-inner{text-align:center}
.footer p{font-size:13.5px;color:var(--ink-soft)}
.footer-note{font-size:12px;color:var(--ink-faint);margin-top:5px}

/* ===== 滚动显现 ===== */
.reveal{opacity:0;transform:translateY(18px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}

/* ===== 移动端 ===== */
@media (max-width:860px){
  .grid-3{grid-template-columns:1fr;gap:14px}
  .feature,.follow{grid-template-columns:1fr;gap:28px}
  .feature-visual{order:-1}
  .follow-qr{max-width:300px;margin:0 auto}
  .section{padding:50px 0}
  .hero{padding:60px 0 50px}
  .hero-stats{gap:20px;margin-top:32px;padding-top:22px}
  .stat-sep{display:none}
  .nav-links,.nav-cta{
    display:none;position:absolute;top:58px;left:0;right:0;
    background:rgba(19,41,63,.97);backdrop-filter:blur(14px);
    border-bottom:1px solid var(--line);
    flex-direction:column;gap:0;padding:8px 24px 16px;
  }
  .nav-links.open,.nav-cta.open{display:flex}
  .nav-links a{padding:12px 0;border-bottom:1px solid var(--line)}
  .nav-cta{margin:12px 0 0}
  .nav-toggle{display:block}
  .nav-toggle.open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  .nav-toggle.open span:nth-child(2){opacity:0}
  .nav-toggle.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
}