*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--primary:#2563eb;--primary-light:#3b82f6;--primary-dark:#1d4ed8;--secondary:#0d9488;--tertiary:#f59e0b;--bg:#f8fafc;--bg-alt:#f1f5f9;--card:#fff;--text:#1e293b;--text-light:#64748b;--text-muted:#94a3b8;--border:#e2e8f0;--border-dark:#cbd5e1;--shadow-sm:0 1px 3px rgba(0,0,0,.05);--shadow:0 4px 12px rgba(0,0,0,.07);--shadow-lg:0 8px 24px rgba(0,0,0,.1);--radius:14px;--radius-sm:10px;--font-main:'Noto Sans SC','Inter',sans-serif;--transition:all .15s ease}
html{-webkit-text-size-adjust:100%}
body{font-family:var(--font-main);background:var(--bg);color:var(--text);line-height:1.6;overflow-x:hidden;-webkit-font-smoothing:antialiased}
a{text-decoration:none;color:inherit}
img{max-width:100%}
.container{max-width:1120px;margin:0 auto;padding:0 18px}

/* Header */
header{background:#fff;border-bottom:1px solid var(--border);position:relative;z-index:100}
@media(min-width:768px){header{position:sticky;top:0}}
.nav{display:flex;align-items:center;justify-content:space-between;height:58px}
.logo{display:flex;align-items:center;gap:8px;font-size:18px;font-weight:800;color:var(--primary)}
.logo svg{width:28px;height:28px;flex-shrink:0}
.logo span{color:var(--text)}
.desktop-nav{display:none;align-items:center;gap:2px}
.desktop-nav a{padding:7px 14px;font-size:13px;font-weight:600;color:var(--text-light);border-radius:99px;white-space:nowrap}
.desktop-nav a:hover,.desktop-nav a.active{background:#eff6ff;color:var(--primary)}
.mobile-menu-btn{display:block;background:0;border:1.5px solid var(--border);padding:8px 13px;border-radius:var(--radius-sm);font-size:18px;cursor:pointer;min-width:44px;min-height:44px}
.mobile-menu{display:none;background:#fff;border-bottom:1px solid var(--border);padding:6px 18px 14px;flex-direction:column;gap:2px}
.mobile-menu.open{display:flex}
.mobile-menu a{display:block;padding:12px 14px;font-size:14px;font-weight:600;color:var(--text-light);border-radius:var(--radius-sm)}
.mobile-menu a:hover{background:#eff6ff;color:var(--primary)}
@media(min-width:768px){.desktop-nav{display:flex}.mobile-menu-btn{display:none}}

/* Hero */
.hero{background:linear-gradient(135deg,#eff6ff 0%,#f8fafc 50%,#f0fdf4 100%);padding:36px 0 24px;text-align:center}
.hero-title{font-size:32px;font-weight:900;margin-bottom:8px;line-height:1.3}
.hero-title .hl{color:var(--primary)}
.hero-sub{font-size:15px;color:var(--text-light);max-width:480px;margin:0 auto}
@media(min-width:768px){.hero{padding:48px 0 32px}.hero-title{font-size:40px}.hero-sub{font-size:16px}}

/* Tool Tabs */
.tool-tabs{display:flex;gap:6px;overflow-x:auto;padding:16px 0;margin-bottom:8px;-webkit-overflow-scrolling:touch;scrollbar-width:none}
.tool-tabs::-webkit-scrollbar{display:none}
.tool-tab{display:flex;align-items:center;gap:6px;padding:9px 16px;border:1.5px solid var(--border);border-radius:99px;font-size:13px;font-weight:600;white-space:nowrap;flex-shrink:0;cursor:pointer;background:var(--card);color:var(--text-light);transition:var(--transition)}
.tool-tab:hover{border-color:var(--primary-light);color:var(--primary)}
.tool-tab.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.tab-icon{width:18px;height:18px}
@media(min-width:768px){.tool-tabs{justify-content:center;gap:8px}.tool-tab{padding:10px 18px;font-size:14px}}

/* Tool Panels */
.tool-panel-container{min-height:250px}
.tool-panel{display:none;background:var(--card);border-radius:var(--radius);border:1px solid var(--border);padding:28px;box-shadow:var(--shadow-sm)}
.tool-panel.active{display:block}
.tool-title{font-size:22px;font-weight:800;margin-bottom:6px}
.tool-desc{font-size:14px;color:var(--text-light);margin-bottom:20px;line-height:1.6}
.tool-grid{display:grid;grid-template-columns:1fr;gap:24px}
@media(min-width:768px){.tool-grid{grid-template-columns:1fr 1fr}}
.tool-inputs{display:flex;flex-direction:column;gap:14px}
.input-group{display:flex;flex-direction:column;gap:5px}
.input-label{font-size:13px;font-weight:600;color:var(--text)}
.tool-input{padding:11px 14px;border:2px solid var(--border);border-radius:var(--radius-sm);font-size:15px;font-family:var(--font-main);color:var(--text);background:#fff;outline:0;transition:var(--transition)}
.tool-input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.1)}
select.tool-input{cursor:pointer}
.tool-slider{accent-color:var(--primary);width:100%}
.tool-btn{padding:12px 28px;background:var(--primary);color:#fff;border:0;border-radius:99px;font-size:15px;font-weight:700;cursor:pointer;font-family:var(--font-main);transition:var(--transition);align-self:flex-start}
.tool-btn:hover{background:var(--primary-dark);transform:translateY(-1px)}
.tool-btn:active{transform:translateY(0)}
.tool-btn.sm{padding:8px 18px;font-size:13px}
.tool-result{margin-top:10px;animation:fadeIn .3s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}
.result-value{font-size:36px;font-weight:900;color:var(--primary);line-height:1.2}
.result-label{font-size:14px;color:var(--text-light);margin-top:4px}
.result-bar{height:6px;background:var(--border);border-radius:3px;margin-top:10px;overflow:hidden}
.result-bar-fill{height:100%;border-radius:3px;transition:width .5s ease}
.input-row{display:flex;align-items:flex-end;gap:10px}
.swap-icon{font-size:20px;cursor:pointer;padding:8px;border-radius:50%;background:var(--bg-alt);flex-shrink:0;transition:var(--transition);min-width:40px;text-align:center;margin-bottom:4px}
.swap-icon:hover{background:var(--primary);color:#fff}
.checkbox-row{display:flex;flex-wrap:wrap;gap:12px}
.checkbox-label{display:flex;align-items:center;gap:6px;font-size:14px;color:var(--text);cursor:pointer}
.password-display{font-family:monospace;font-size:18px;padding:12px 16px;background:var(--bg-alt);border-radius:var(--radius-sm);word-break:break-all;margin-bottom:10px;letter-spacing:1px}

/* BMI Chart */
.bmi-chart{background:var(--bg-alt);border-radius:var(--radius-sm);padding:20px}
.bmi-chart-title{font-size:14px;font-weight:700;margin-bottom:14px}
.bmi-bar-wrap{display:flex;align-items:center;gap:8px;margin-bottom:10px;font-size:13px}
.bmi-bar-label{width:36px;font-weight:600;flex-shrink:0}
.bmi-bar{height:16px;border-radius:8px;flex:1}
.bmi-bar-wrap span{color:var(--text-muted);font-size:12px;white-space:nowrap}
.bmi-under{background:linear-gradient(90deg,#93c5fd,#60a5fa)}
.bmi-normal{background:linear-gradient(90deg,#6ee7b7,#34d399)}
.bmi-over{background:linear-gradient(90deg,#fcd34d,#fbbf24)}
.bmi-obese{background:linear-gradient(90deg,#fca5a5,#f87171)}

/* Ad */
.ad-container {max-width: 1070px;margin: 15px auto;background:var(--bg);border:1px dashed #4cc9f0;border-radius:8px;padding:5px;text-align:center;display:flex;align-items:center;justify-content:center;flex-direction:column;box-shadow:0 3px 8px rgba(0,0,0,0.15);}
.ad-label { text-transform: uppercase;color:#4cc9f0;font-size:0.7rem;margin-bottom:5px;display:flex;align-items:center;justify-content:center;gap:6px;}
.ad-content {color:#888;padding:5px;font-style:italic;display:flex;align-items:center;justify-content:center;background:rgba(255,255,255,0.05);border-radius:6px;width:100%;font-size:0.9rem;}

/* Features */
.features-section{padding:48px 0 32px}
.section-title{text-align:center;font-size:24px;font-weight:800;margin-bottom:24px}
.features-grid{display:grid;grid-template-columns:1fr;gap:14px}
.feature-card{background:var(--card);border-radius:var(--radius-sm);padding:22px 18px;border:1px solid var(--border);text-align:center;transition:var(--transition)}
.feature-card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}
.feature-icon{margin-bottom:12px}
.feature-card h3{font-size:16px;font-weight:700;margin-bottom:6px}
.feature-card p{font-size:13px;color:var(--text-light)}
@media(min-width:640px){.features-grid{grid-template-columns:repeat(3,1fr)}}

/* Footer */
footer{background:#1e293b;padding:36px 0 24px;color:#94a3b8;margin-top:32px}
.footer-grid{display:grid;grid-template-columns:1fr;gap:28px;text-align:center}
.footer-brand{font-size:17px;font-weight:800;color:#fff;margin-bottom:8px}
.footer-desc{font-size:12px;color:#94a3b8;max-width:280px;margin:0 auto}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:14px}
.footer-links a{font-size:13px;color:#94a3b8}
.footer-links a:hover{color:#fff}
.footer-disclaimer{font-size:10px;color:#64748b;text-transform:uppercase;margin-bottom:12px}
.footer-copy{font-size:12px}
@media(min-width:768px){.footer-grid{grid-template-columns:1.5fr 1fr 1fr;text-align:left;gap:36px}.footer-desc{margin:0}.footer-links{flex-direction:column;align-items:flex-start;gap:8px}.footer-right{text-align:right}}

/* Content Pages */
.content-page{max-width:1120px;margin:0 auto;padding:32px 20px 48px}
.content-page h1{font-size:28px;font-weight:800;margin-bottom:10px}
.content-page .update-date{font-size:13px;color:var(--text-muted);margin-bottom:28px}
.content-page h2{font-size:19px;font-weight:700;margin:28px 0 10px}
.content-page p{font-size:15px;line-height:1.8;color:var(--text-light);margin-bottom:14px}
.content-page ul{margin:10px 0 18px 20px}
.content-page ul li{font-size:15px;line-height:1.8;color:var(--text-light);margin-bottom:5px}
.content-page a{color:var(--primary);text-decoration:underline}

/* Blog */
.blog-hero{background:linear-gradient(135deg,#eff6ff 0%,#f8fafc 50%,#f0fdf4 100%);padding:32px 0 20px;text-align:center;border-bottom:1px solid var(--border)}
.blog-hero h1{font-size:30px;font-weight:900}
.blog-hero p{color:var(--text-light);font-size:15px;margin-top:6px}
.blog-list{max-width:1120px;margin:0 auto;padding:28px 20px 40px}
.blog-item{display:flex;flex-direction:column;gap:6px;padding:18px 0;border-bottom:1px solid var(--border);transition:var(--transition)}
.blog-item:hover .blog-item-title{color:var(--primary)}
.blog-item-title{font-size:19px;font-weight:700;color:var(--text);line-height:1.4}
.blog-item-meta{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--text-muted);flex-wrap:wrap}
.blog-item-tag{background:#eff6ff;color:var(--primary);padding:2px 9px;border-radius:99px;font-size:11px;font-weight:600}
.blog-item-excerpt{font-size:14px;color:var(--text-light);line-height:1.6}
.blog-item-link{font-size:13px;font-weight:600;color:var(--primary)}

/* Article */
.article-page{max-width:1120px;margin:0 auto;padding:28px 20px 40px}
.article-page h1{font-size:26px;font-weight:900;line-height:1.4;margin-bottom:10px}
.article-meta{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--text-muted);margin-bottom:24px}
.article-tag{background:#eff6ff;color:var(--primary);padding:2px 9px;border-radius:99px;font-size:11px;font-weight:600}
.article-body{font-size:15px;line-height:1.9;color:var(--text)}
.article-body p{margin-bottom:16px}
.article-back{display:inline-flex;align-items:center;gap:6px;color:var(--primary);font-weight:600;font-size:14px;margin-bottom:20px}
.article-nav{display:flex;gap:14px;margin-top:36px;padding-top:20px;border-top:1px solid var(--border);justify-content:space-between}
.article-nav a,.article-nav>div{flex:1;padding:14px 18px;background:var(--bg-alt);border:1px solid var(--border);border-radius:var(--radius-sm);min-width:0}
.article-nav a:hover{border-color:var(--primary)}
.article-nav .nav-label{font-size:11px;color:var(--text-muted);margin-bottom:4px}
.article-nav .nav-title{font-size:14px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.article-nav .nav-empty{opacity:.3}

/* Contact */
.contact-info{background:var(--bg-alt);border-radius:var(--radius-sm);padding:24px;margin:16px 0;border:1px solid var(--border)}
.contact-item{display:flex;align-items:flex-start;gap:12px;padding:12px 0;border-bottom:1px solid var(--border)}
.contact-item:last-child{border-bottom:0}
.contact-icon-svg{font-size:22px;flex-shrink:0;width:40px;height:40px;display:flex;align-items:center;justify-content:center;background:#eff6ff;border-radius:10px}
.form-group{margin-bottom:16px}
.form-label2{display:block;font-size:14px;font-weight:600;margin-bottom:5px}
.form-input2{width:100%;padding:11px 14px;border:2px solid var(--border);border-radius:var(--radius-sm);font-size:15px;font-family:var(--font-main);outline:0;transition:var(--transition)}
.form-input2:focus{border-color:var(--primary)}
.form-textarea2{width:100%;padding:11px 14px;border:2px solid var(--border);border-radius:var(--radius-sm);font-size:15px;font-family:var(--font-main);outline:0;resize:vertical;min-height:130px;transition:var(--transition)}
.form-textarea2:focus{border-color:var(--primary)}
.form-submit2{padding:12px 32px;background:var(--primary);color:#fff;border:0;border-radius:99px;font-size:15px;font-weight:700;cursor:pointer;font-family:var(--font-main);transition:var(--transition)}
.form-submit2:hover{background:var(--primary-dark)}
.form-submit2:disabled{background:#94a3b8;cursor:not-allowed}
.form-success{margin-bottom:12px;padding:10px 14px;background:#f0fdf4;border:1px solid #bbf7d0;border-radius:var(--radius-sm);font-size:14px;color:#166534;font-weight:600;display:none}

/* Mobile */
@media(max-width:640px){
  .tool-panel{padding:20px}
  .tool-title{font-size:19px}
  .content-page h1{font-size:24px}
  .article-page h1{font-size:22px}
  .hero-title{font-size:26px}
}