* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Segoe UI', system-ui, sans-serif; line-height: 1.6; color: #1e293b; background: #f8fafc; min-height: 100vh; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
header { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,0.08); position: sticky; top: 0; z-index: 100; }
header .container { display: flex; justify-content: space-between; align-items: center; padding: 15px 20px; }
.logo { font-size: 26px; font-weight: 700; color: #0ea5e9; text-decoration: none; }
nav a { color: #64748b; text-decoration: none; margin-left: 25px; font-weight: 500; }
nav a:hover { color: #0ea5e9; }
.hero { background: linear-gradient(135deg, #0ea5e9, #0284c7); color: #fff; padding: 60px 0; text-align: center; }
.hero h1 { font-size: 38px; margin-bottom: 12px; }
.hero p { font-size: 18px; opacity: 0.95; }
main { padding: 50px 0; }
.tools-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 20px; margin-top: 30px; }
.tool-card { background: #fff; border-radius: 12px; padding: 24px; box-shadow: 0 2px 8px rgba(0,0,0,0.06); transition: all 0.25s ease; border: 1px solid #e2e8f0; }
.tool-card:hover { transform: translateY(-4px); box-shadow: 0 8px 25px rgba(14,165,233,0.15); border-color: #0ea5e9; }
.tool-card .icon { width: 50px; height: 50px; background: linear-gradient(135deg, #0ea5e9, #0284c7); border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 15px; }
.tool-card h3 { font-size: 17px; margin-bottom: 8px; color: #1e293b; }
.tool-card h3 a { color: inherit; text-decoration: none; }
.tool-card p { color: #64748b; font-size: 14px; }
.tool-card .btn { display: inline-block; margin-top: 12px; padding: 8px 16px; background: #0ea5e9; color: #fff; text-decoration: none; border-radius: 6px; font-size: 14px; }
.tool-card .btn:hover { background: #0284c7; }
footer { background: #1e293b; color: #94a3b8; padding: 30px 0; text-align: center; }
footer a { color: #0ea5e9; text-decoration: none; }
.category-title { color: #1e293b; margin: 40px 0 20px; font-size: 24px; border-bottom: 3px solid #0ea5e5; padding-bottom: 10px; display: inline-block; }
.tool-page { background: #fff; border-radius: 16px; padding: 40px; margin: 30px auto; max-width: 800px; box-shadow: 0 4px 20px rgba(0,0,0,0.08); }
.tool-page h1 { color: #0ea5e9; margin-bottom: 8px; }
.tool-page .desc { color: #64748b; margin-bottom: 25px; }
.tool-page input { width: 100%; padding: 14px 18px; border: 2px solid #e2e8f0; border-radius: 10px; font-size: 16px; margin-bottom: 15px; transition: border-color 0.2s; }
.tool-page input:focus { outline: none; border-color: #0ea5e9; }
.tool-page button { padding: 14px 28px; background: #0ea5e9; color: #fff; border: none; border-radius: 10px; font-size: 16px; font-weight: 600; cursor: pointer; transition: background 0.2s; }
.tool-page button:hover { background: #0284c7; }
.tool-page .result { background: #f1f5f9; padding: 20px; border-radius: 10px; margin-top: 20px; min-height: 100px; white-space: pre-wrap; }
.tool-page .result.error { background: #fef2f2; color: #dc2626; }
.tool-page .result.success { background: #f0fdf4; color: #16a34a; }
.tool-page .info-box { background: #eff6ff; border-left: 4px solid #0ea5e9; padding: 15px 20px; border-radius: 0 8px 8px 0; margin: 20px 0; }
.tool-page .info-box h4 { color: #1e293b; margin-bottom: 8px; }
.tool-page .info-box p { color: #64748b; font-size: 14px; }
.tool-page .result-content { font-size: 15px; line-height: 1.8; }
.tool-page .result-content table { width: 100%; border-collapse: collapse; margin: 10px 0; }
.tool-page .result-content td { padding: 8px; border-bottom: 1px solid #e2e8f0; }
.tool-page .result-content td:first-child { font-weight: 600; color: #64748b; width: 40%; }
.back-link { display: inline-block; margin-bottom: 20px; color: #0ea5e9; text-decoration: none; font-weight: 500; }
.back-link:hover { color: #0284c7; }