/* 高校化学補助サイト - Complete Styles */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#0D47A1;
  --primary-dark:#0A3578;
  --secondary:#1565C0;
  --accent:#29B6F6;
  --bg:#f8fafc;
  --bg-white:#ffffff;
  --text:#1e293b;
  --text-light:#64748b;
  --border:#e2e8f0;
  --tag-bg:#EFF6FF;
  --shadow:0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover:0 8px 24px rgba(13,71,161,0.15);
}
body{font-family:'Noto Sans JP','Hiragino Sans','Meiryo',sans-serif;background:var(--bg);color:var(--text);line-height:1.8;min-height:100vh;display:flex;flex-direction:column}
.header{background:linear-gradient(135deg,#0D47A1 0%,#1565C0 100%);padding:0;position:sticky;top:0;z-index:100;box-shadow:0 2px 12px rgba(0,0,0,0.2)}
.header-inner{max-width:1200px;margin:0 auto;padding:0.75rem 2rem;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-size:1.3rem;font-weight:700}
.nav{display:flex;align-items:center;gap:1.75rem}
.nav a{color:#bfdbfe;text-decoration:none;font-weight:500;font-size:0.9rem;transition:color 0.2s}
.nav a:hover{color:#fff}
.hamburger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:4px}
.hamburger span{display:block;width:24px;height:2px;background:#fff;border-radius:2px}
.hero{background:linear-gradient(135deg,#0D47A1 0%,#29B6F6 100%);color:#fff;text-align:center;padding:80px 2rem;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");opacity:0.5}
.hero-content{position:relative;max-width:800px;margin:0 auto}
.hero h1{font-size:2.8rem;font-weight:800;margin-bottom:1rem;line-height:1.3}
.hero p{font-size:1.1rem;opacity:0.9;max-width:600px;margin:0 auto 2rem}
.hero-stats{display:flex;justify-content:center;gap:3rem;margin-top:3rem}
.hero-stat{text-align:center}
.hero-stat strong{display:block;font-size:2rem;font-weight:800}
.hero-stat span{font-size:0.85rem;opacity:0.8}
.btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 28px;border-radius:8px;font-weight:600;font-size:0.95rem;text-decoration:none;transition:all 0.25s;cursor:pointer;border:none}
.btn-primary{background:#fff;color:#0D47A1}
.btn-primary:hover{background:#EFF6FF;transform:translateY(-1px)}
.btn-outline{background:transparent;color:#0D47A1;border:2px solid #0D47A1;padding:10px 24px}
.btn-outline:hover{background:#0D47A1;color:#fff}
.container{max-width:1200px;margin:0 auto;padding:0 2rem}
.section{padding:60px 0}
.section:nth-child(even){background:var(--bg-white)}
.section-header{text-align:center;margin-bottom:40px}
.section-header h2{font-size:2rem;font-weight:700;color:var(--primary);margin-bottom:8px}
.section-header p{color:var(--text-light);font-size:1.05rem}
.cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:24px}
.tool-card,.article-card{background:var(--bg-white);border-radius:12px;padding:24px;box-shadow:var(--shadow);transition:all 0.3s;border:1px solid var(--border);text-decoration:none;color:inherit;display:flex;flex-direction:column}
.tool-card:hover,.article-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-hover);border-color:var(--accent)}
.tag{display:inline-block;background:var(--tag-bg);color:var(--primary);padding:3px 12px;border-radius:20px;font-size:0.75rem;font-weight:600;align-self:flex-start}
.tool-container{display:grid;grid-template-columns:1fr 1fr;gap:32px;margin:32px 0}
.tool-form{background:#fff;border-radius:12px;padding:28px;box-shadow:var(--shadow);border:1px solid var(--border)}
.tool-result{background:linear-gradient(135deg,#EFF6FF 0%,#dbeafe 100%);border-radius:12px;padding:28px;border:1px solid #bfdbfe;display:flex;flex-direction:column;justify-content:center}
.form-group{margin-bottom:16px}
.form-group label{display:block;font-weight:600;margin-bottom:6px;color:var(--text)}
.result-value{font-size:2rem;font-weight:700;color:var(--primary)}
.breadcrumb{padding:12px 0;font-size:0.85rem;color:var(--text-light)}
.article-content h2{font-size:1.5rem;color:var(--primary);margin:1.5em 0 0.5em;border-bottom:2px solid var(--accent);padding-bottom:0.3em}
.article-content p{color:#374151;margin-bottom:16px;font-size:1.02rem;line-height:2}
.article-content img{border-radius:8px;max-width:100%;height:auto;margin:16px 0}
.explanation-box{background:#EFF6FF;border-left:4px solid var(--primary);padding:20px;border-radius:8px;margin:24px 0}
.related-links{background:#f1f5f9;padding:20px;border-radius:8px;margin:24px 0}
.related-links h4{margin-bottom:12px}
details{background:#fff;border-radius:8px;margin:8px 0;overflow:hidden;box-shadow:0 1px 3px rgba(0,0,0,0.1)}
summary{padding:16px;cursor:pointer;font-weight:600;list-style:none}
summary::-webkit-details-marker{display:none}
.faq-list details[open] summary{border-bottom:1px solid var(--border)}
.footer{background:var(--primary);color:#bfdbfe;padding:3rem 0 1rem;margin-top:auto}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:2rem;max-width:1200px;margin:0 auto}
.footer-col h4{color:#fff;font-size:1rem;margin-bottom:12px}
.footer-col a{color:#93c5fd;text-decoration:none;font-size:0.9rem;display:block;margin-bottom:8px}
.footer-col a:hover{color:#fff;text-decoration:underline}
.footer-bottom{text-align:center;padding:1.5rem 2rem 0;margin-top:2rem;border-top:1px solid rgba(255,255,255,0.1);max-width:1200px;margin-left:auto;margin-right:auto}
.footer-bottom p{font-size:0.85rem;opacity:0.6}
.filter-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px;justify-content:center}
.filter-tab{padding:8px 20px;border-radius:20px;background:var(--bg-white);border:1px solid var(--border);cursor:pointer;font-weight:500;transition:all 0.2s}
.filter-tab.active,.filter-tab:hover{background:var(--primary);color:#fff;border-color:var(--primary)}
@media(max-width:768px){
  .hero h1{font-size:2rem}
  .nav{display:none;flex-direction:column;position:absolute;top:100%;left:0;right:0;background:var(--primary);padding:1rem;gap:0.5rem}
  .nav.active{display:flex}
  .hamburger{display:flex}
  .tool-container{grid-template-columns:1fr}
  .hero-stats{flex-direction:column;gap:1.5rem}
}