*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;font-size:14px;line-height:1.5;color:#333;background:#f5f5f5}
a{color:inherit;text-decoration:none}
#app{width:100%;height:100vh}
#landing{min-height:auto;height:auto}

.nav{display:flex;align-items:center;justify-content:flex-end;padding:12px 24px;background:#e8f0fe;position:sticky;top:0;z-index:10}
.lang-select{padding:8px 32px 8px 12px;border:2px solid #e0e0e0;border-radius:8px;background:#fff;font-size:14px;color:#666;cursor:pointer;appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%236b7280'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 10px center;background-size:16px;transition:border-color .2s}
.lang-select:hover{border-color:#2196f3}

.hero{padding:80px 24px 60px;text-align:center;background:linear-gradient(180deg,#e8f0fe 0%,#f5f5f5 100%)}
.hero-inner{max-width:640px;margin:0 auto}
.hero h1{font-size:40px;font-weight:700;line-height:1.2;margin-bottom:16px;color:#1a1a2e}
.hero-sub{font-size:17px;line-height:1.6;color:#666;margin-bottom:32px}
.hero-actions{display:flex;gap:12px;justify-content:center;align-items:center}
.btn-primary{display:inline-block;padding:12px 28px;background:#2196f3;color:#fff;border-radius:8px;font-size:15px;font-weight:500;transition:background .2s,transform .1s}
.btn-primary:hover{background:#1976d2;transform:translateY(-1px)}

.features{padding:60px 24px;max-width:960px;margin:0 auto}
.features h2{text-align:center;font-size:28px;font-weight:600;margin-bottom:40px;color:#1a1a2e}
.features-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.feature-card{padding:28px;background:#fff;border-radius:12px;border:1px solid #e0e0e0}
.feature-icon{width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:10px;background:rgba(33,150,243,.08);color:#2196f3;margin-bottom:16px}
.feature-card h3{font-size:16px;font-weight:600;margin-bottom:8px}
.feature-card p{font-size:14px;line-height:1.6;color:#666}

.steps{padding:60px 24px;background:#fafafa}
.steps h2{text-align:center;font-size:28px;font-weight:600;margin-bottom:40px;color:#1a1a2e}
.steps-list{max-width:600px;margin:0 auto;display:flex;flex-direction:column;gap:24px}
.step-item{display:flex;gap:16px;align-items:flex-start}
.step-num{flex-shrink:0;width:36px;height:36px;display:flex;align-items:center;justify-content:center;border-radius:50%;background:#2196f3;color:#fff;font-size:15px;font-weight:600}
.step-content h3{font-size:16px;font-weight:600;margin:4px 0}
.step-content p{font-size:14px;line-height:1.6;color:#666}
.steps-cta{text-align:center;margin-top:40px}

.footer{padding:24px;text-align:center;font-size:13px;color:#999;border-top:1px solid #e0e0e0}

/* Language switching via CSS attribute selectors */
html[lang="zh-CN"] [data-lang="en"] { display: none; }
html[lang="en"] [data-lang="zh-CN"] { display: none; }

@media(max-width:640px){
  .hero h1{font-size:28px}
  .features-grid{grid-template-columns:1fr}
  .hero-actions{flex-direction:column}
}