/* ========== Reset & Base ========== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:#1a1a2e;background:#f8f9fd;line-height:1.6}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

/* ========== Header ========== */
.header{background:#fff;box-shadow:0 1px 4px rgba(0,0,0,.06);position:sticky;top:0;z-index:100}
.header-inner{max-width:1200px;margin:0 auto;padding:0 24px;height:64px;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;font-size:22px;font-weight:700;color:#1677ff}
.logo svg{width:32px;height:32px}
.header-nav{display:flex;gap:24px}
.header-nav a{font-size:15px;color:#555;transition:color .2s}
.header-nav a:hover{color:#1677ff}

/* ========== Hero ========== */
.hero{background:linear-gradient(135deg,#1677ff 0%,#4f46e5 100%);color:#fff;text-align:center;padding:80px 24px 72px}
.hero h1{font-size:clamp(28px,5vw,48px);font-weight:800;margin-bottom:16px}
.hero p{font-size:clamp(16px,2.5vw,20px);opacity:.9;max-width:640px;margin:0 auto}

/* ========== Tools Grid ========== */
.tools-section{max-width:1200px;margin:0 auto;padding:64px 24px 80px}
.section-title{text-align:center;font-size:28px;font-weight:700;margin-bottom:12px}
.section-desc{text-align:center;color:#666;margin-bottom:48px;font-size:16px}
.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:24px}
.tool-card{background:#fff;border-radius:16px;padding:32px 28px;box-shadow:0 2px 12px rgba(0,0,0,.06);transition:transform .25s,box-shadow .25s;display:flex;flex-direction:column;gap:16px;position:relative;overflow:hidden}
.tool-card:hover{transform:translateY(-4px);box-shadow:0 8px 32px rgba(22,119,255,.12)}
.tool-card::before{content:"";position:absolute;top:0;left:0;right:0;height:4px}
.tool-card.color-blue::before{background:#1677ff}
.tool-card.color-green::before{background:#52c41a}
.tool-card.color-orange::before{background:#fa8c16}
.tool-card.color-purple::before{background:#722ed1}
.tool-card.color-red::before{background:#f5222d}
.tool-card.color-cyan::before{background:#13c2c2}
.tool-icon{width:56px;height:56px;border-radius:14px;display:flex;align-items:center;justify-content:center;font-size:28px}
.tool-icon.bg-blue{background:#e6f4ff;color:#1677ff}
.tool-icon.bg-green{background:#f6ffed;color:#52c41a}
.tool-icon.bg-orange{background:#fff7e6;color:#fa8c16}
.tool-icon.bg-purple{background:#f9f0ff;color:#722ed1}
.tool-icon.bg-red{background:#fff1f0;color:#f5222d}
.tool-icon.bg-cyan{background:#e6fffb;color:#13c2c2}
.tool-name{font-size:20px;font-weight:700}
.tool-desc{color:#666;font-size:14px;line-height:1.7;flex:1}
.tool-tags{display:flex;flex-wrap:wrap;gap:6px}
.tool-tag{background:#f0f5ff;color:#1677ff;font-size:12px;padding:2px 10px;border-radius:20px}
.tool-link{display:inline-flex;align-items:center;gap:6px;color:#1677ff;font-weight:600;font-size:14px;margin-top:auto;transition:gap .2s}
.tool-link:hover{gap:10px}
.tool-link svg{width:16px;height:16px}

/* ========== Features ========== */
.features{background:#fff;padding:64px 24px}
.features-inner{max-width:1200px;margin:0 auto}
.features-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:32px;margin-top:48px}
.feature-item{text-align:center;padding:24px 16px}
.feature-icon{font-size:40px;margin-bottom:16px}
.feature-item h3{font-size:18px;font-weight:600;margin-bottom:8px}
.feature-item p{color:#666;font-size:14px}

/* ========== Footer ========== */
.footer{background:#1a1a2e;color:rgba(255,255,255,.7);padding:48px 24px 32px}
.footer-inner{max-width:1200px;margin:0 auto}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:32px;margin-bottom:32px}
.footer-col h4{color:#fff;font-size:16px;margin-bottom:16px}
.footer-col a{display:block;font-size:14px;margin-bottom:10px;transition:color .2s}
.footer-col a:hover{color:#fff}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:24px;text-align:center;font-size:13px}
.footer-bottom a{color:rgba(255,255,255,.6);transition:color .2s}
.footer-bottom a:hover{color:#fff}

/* ========== Responsive ========== */
@media(max-width:768px){
  .header-nav{display:none}
  .hero{padding:56px 20px 48px}
  .tools-grid{grid-template-columns:1fr}
  .features-grid{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:480px){
  .features-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
}