:root{
    --primary:#6C4CF1;
    --primary-dark:#5338d4;
    --text:#222;
    --muted:#666;
    --border:#e9e9ef;
    --bg:#f7f8fc;
    --white:#fff;
    --radius:18px;
    --shadow:0 10px 35px rgba(0,0,0,.08);
}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:Inter,Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
.container{width:min(1150px,92%);margin:auto}

/* HEADER */
.header{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1000}
.header .container{display:flex;justify-content:space-between;align-items:center;min-height:168px;gap:24px}
.logo img{height:144px;width:auto;display:block}
nav{display:flex;gap:30px;align-items:center;flex-wrap:wrap}
nav a{color:#333;text-decoration:none;font-weight:600;transition:.25s}
nav a:hover{color:var(--primary)}

/* SEARCH */
.search-section{padding:30px 0 10px}
.search-box{position:relative}
.search-box input{width:100%;padding:18px 22px;font-size:17px;border-radius:16px;border:1px solid var(--border);outline:none;background:#fff;box-shadow:var(--shadow)}
#searchResults{position:absolute;width:100%;background:#fff;margin-top:8px;border-radius:14px;overflow:hidden;box-shadow:var(--shadow);display:none;z-index:10}

/* HERO */
.hero{text-align:center;padding:34px 0 36px;min-height:auto;display:block}
.hero h1{font-size:48px;margin-bottom:16px}
.hero p{max-width:760px;margin:auto;color:var(--muted);font-size:18px}

/* CALCULATOR */
.calculator{padding:10px 0 35px}
.calculation-type{max-width:1150px;margin:0 auto 24px}
.calculation-type label{display:block;margin-bottom:10px;font-size:16px;font-weight:700}
.calculator-select{width:100%;padding:15px 16px;font-size:16px;border:1px solid #dfe3ea;border-radius:12px;background:#fff;cursor:pointer}
.calculator-card,.result-card{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:35px;margin-bottom:30px}
.inputs{display:flex;gap:15px;align-items:center;margin:25px 0}
.inputs input{flex:1;padding:16px;font-size:18px;border:1px solid var(--border);border-radius:12px}
.inputs span{font-size:20px;font-weight:700}
button{cursor:pointer}
#calculateBtn{background:var(--primary);color:#fff;border:none;padding:16px 30px;border-radius:12px;font-size:17px;font-weight:700;transition:.25s}
#calculateBtn:hover{background:var(--primary-dark)}
.result-card h3{margin-bottom:15px}
#result{font-size:40px;font-weight:800;color:var(--primary);margin-bottom:12px}
#formula{color:var(--muted);margin-bottom:25px}
.buttons{display:flex;gap:15px}
.buttons button{flex:1;padding:14px;border:none;border-radius:10px;background:#efeff6;font-weight:600}

/* CONTENT */
.examples,.faq,.related-tools{padding:55px 0}
.examples h2,.faq h2,.related-tools h2{margin-bottom:25px}
.examples li{margin:0 0 12px 20px}
details{background:#fff;margin-bottom:14px;border-radius:12px;padding:18px;box-shadow:var(--shadow)}
summary{cursor:pointer;font-weight:700}
details p{margin-top:12px;color:var(--muted)}
.tool-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px}
.tool-grid a{background:#fff;border-radius:12px;text-decoration:none;color:#333;padding:22px;text-align:center;font-weight:600;box-shadow:var(--shadow);transition:.25s}
.tool-grid a:hover{transform:translateY(-3px);color:var(--primary)}

footer{background:#fff;border-top:1px solid var(--border);padding:30px;text-align:center;color:var(--muted)}
footer a{color:inherit}

@media(max-width:768px){
    .header .container{min-height:auto;flex-direction:column;padding:18px 0}
    .logo img{height:136px}
    nav{gap:16px;justify-content:center}
    .search-section{padding-top:22px}
    .hero{padding:28px 0 30px}
    .hero h1{font-size:34px}
    .inputs{flex-direction:column;align-items:stretch}
    .inputs span{display:none}
    .buttons{flex-direction:column}
}