<style>
    *{margin:0;padding:0;box-sizing:border-box;}
    body{font-family:'Inter',sans-serif;background:#f5f9ff;color:#112b4f;line-height:1.5;}
    .container{max-width:1280px;margin:0 auto;padding:0 24px;}
    /* 柔和蓝白质感 */
    :root{--primary:#1565c0;--primary-light:#e3f2fd;--accent:#42a5f5;--blue-bg:#eef6ff;--card-white:#ffffff;--border-soft:#bbdefb;--shadow-sm:0 8px 20px rgba(21,101,192,0.08);--shadow-hover:0 16px 30px rgba(21,101,192,0.12);--text-dark:#0b2b4a;}
    h1,h2,h3{font-weight:600;letter-spacing:-0.01em;}
    a{text-decoration:none;color:inherit;}
    /* header */
    header{background:rgba(255,255,255,0.9);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--border-soft);position:sticky;top:0;z-index:50;box-shadow:var(--shadow-sm);}
    .header-flex{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;padding:12px 0;}
    .logo-area{display:flex;align-items:center;gap:8px;}
    .logo-icon{background:linear-gradient(145deg,#1565c0,#42a5f5);width:42px;height:42px;border-radius:14px;display:flex;align-items:center;justify-content:center;box-shadow:0 6px 12px rgba(21,101,192,0.2);}
    .logo-icon svg{width:28px;height:28px;fill:white;}
    .logo-text{font-weight:700;font-size:1.7rem;color:var(--primary);letter-spacing:-0.02em;}
    nav{display:flex;align-items:center;gap:4px;flex-wrap:wrap;}
    .nav-item{padding:8px 16px;font-weight:500;color:#1e4a76;border-radius:40px;transition:all 0.2s;position:relative;}
    .nav-item:hover{background:var(--primary-light);color:var(--primary);}
    .dropdown{position:relative;}
    .dropdown-content{display:none;position:absolute;top:40px;left:0;background:white;border-radius:20px;box-shadow:var(--shadow-hover);min-width:160px;padding:8px;z-index:30;border:1px solid var(--border-soft);}
    .dropdown:hover .dropdown-content{display:block;}
    .dropdown-content a{display:block;padding:10px 16px;border-radius:16px;}
    .btn-download-header{background:var(--primary);color:white;padding:10px 24px;border-radius:40px;font-weight:600;box-shadow:0 8px 14px rgba(21,101,192,0.25);transition:0.2s;border:none;cursor:pointer;margin-left:8px;}
    .btn-download-header:hover{background:#0d47a1;transform:scale(1.02);}
    /* 公用按钮 */
    .btn{display:inline-block;padding:14px 32px;border-radius:60px;font-weight:600;transition:0.2s;text-align:center;}
    .btn-primary{background:var(--primary);color:white;box-shadow:0 10px 18px rgba(21,101,192,0.25);}
    .btn-primary:hover{background:#0d47a1;}
    .btn-outline{border:1.5px solid var(--primary);color:var(--primary);background:transparent;}
    .btn-outline:hover{background:var(--primary-light);}
    /* 卡片 */
    .card{background:var(--card-white);border-radius:32px;padding:28px;box-shadow:var(--shadow-sm);border:1px solid rgba(187,222,251,0.5);transition:0.2s;}
    .card:hover{box-shadow:var(--shadow-hover);}
    /* 底部 */
    footer{background:#0b2b4a;color:#d6e9ff;padding:48px 0 24px;margin-top:60px;border-radius:48px 48px 0 0;}
    .footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.2fr;gap:32px;}
    .footer-copyright{border-top:1px solid #1e4970;margin-top:32px;padding-top:24px;text-align:center;font-size:0.9rem;}
    /* 轮播简易 */
    .carousel{display:flex;gap:24px;overflow-x:auto;scroll-snap-type:x mandatory;padding:8px 0 20px;scrollbar-width:thin;}
    .carousel-item{flex:0 0 300px;scroll-snap-align:start;}
    /* 评分星星 */
    .stars{color:#fbbf24;letter-spacing:2px;}
    /* 问答折叠 */
    details{margin-bottom:16px;background:white;border-radius:20px;padding:16px 20px;box-shadow:0 4px 8px rgba(0,0,0,0.02);border:1px solid #e3f2fd;}
    summary{font-weight:600;cursor:pointer;list-style:none;display:flex;align-items:center;gap:8px;}
    summary::-webkit-details-marker{display:none;}
    /* 响应式 */
    @media(max-width:900px){.header-flex{flex-direction:column;gap:12px;}.footer-grid{grid-template-columns:1fr;}}
    @media(max-width:640px){nav{justify-content:center;}.btn-download-header{margin-left:0;}}
    /* 步骤序号 */
    .step-number{background:var(--primary);color:white;width:36px;height:36px;border-radius:36px;display:inline-flex;align-items:center;justify-content:center;font-weight:700;margin-right:12px;}
    /* 图标卡 */
    .icon-badge{background:var(--primary-light);width:56px;height:56px;border-radius:20px;display:flex;align-items:center;justify-content:center;font-size:28px;margin-bottom:16px;}
</style>