:root{--bg:#f3f5f8;--card:#fff;--text:#1f2d3d;--primary:#0a5bd7;--border:#dce3ec}
*{box-sizing:border-box}body{margin:0;font-family:Arial,"Hiragino Kaku Gothic ProN",sans-serif;background:var(--bg);color:var(--text)}
.header{background:#17324d;color:#fff;padding:12px 20px;display:flex;justify-content:space-between;align-items:center}
.container{max-width:1200px;margin:20px auto;padding:0 16px}.card{background:var(--card);border:1px solid var(--border);border-radius:8px;padding:16px;margin-bottom:16px}
.nav a{margin-right:10px;color:#fff;text-decoration:none}.btn{display:inline-block;background:var(--primary);color:#fff;border:none;padding:8px 12px;border-radius:6px;text-decoration:none;cursor:pointer}
.btn-secondary{background:#6b7788}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px}.status{padding:3px 8px;border-radius:999px;font-size:12px;color:#fff}
.status-受付{background:#177ddc}.status-調査中{background:#fa8c16}.status-回答済み{background:#722ed1}.status-お客様確認中{background:#13a8a8}.status-解決{background:#389e0d}.status-保留{background:#595959}.status-クローズ{background:#262626}
.severity{font-weight:700}.sev-高{color:#cf1322}.sev-中{color:#d48806}.sev-低{color:#389e0d}
table{width:100%;border-collapse:collapse}th,td{border-bottom:1px solid var(--border);padding:8px;text-align:left;vertical-align:top}
input,select,textarea{width:100%;padding:8px;border:1px solid #c9d2dd;border-radius:6px}label{font-weight:700;font-size:13px}.row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.flash{padding:10px;border-radius:6px;margin-bottom:12px}.flash-success{background:#f6ffed;border:1px solid #b7eb8f}.flash-error{background:#fff2f0;border:1px solid #ffccc7}
.thread{border-left:3px solid #d9d9d9;padding-left:12px;margin-bottom:12px}.thread.support{border-left-color:#1677ff}.thread.customer{border-left-color:#52c41a}
@media (max-width:768px){.row{grid-template-columns:1fr}}