/* ปุ่ม "กลับสู่หน้าหลัก" — ใช้แบบเดียวกันทุกหน้า: อยู่มุมขวาบนสุดของแถบบนเสมอ (หน้าที่ไม่มีแถบบน ใช้ .fixed ลอยมุมขวาบน)
   markup:  <a class="homebtn" href="https://utmwork.com" title="กลับสู่หน้าหลัก utmwork.com" aria-label="กลับสู่หน้าหลัก"><svg viewBox="0 0 24 24" aria-hidden="true"><path d="M3.5 11.2 12 4l8.5 7.2"/><path d="M6 10v9.5h12V10"/><path d="M10 19.5v-5h4v5"/></svg><span>หน้าหลัก</span></a>
   ตัวแปรเสริม: .on-blue = วางบนแถบสีน้ำเงิน (หน้าตัวแทน/ศูนย์รวมหลังบ้าน) · .fixed = ลอยมุมขวาบน */
.homebtn{display:inline-flex;align-items:center;justify-content:center;gap:7px;height:36px;padding:0 15px 0 12px;box-sizing:border-box;border-radius:999px;
  font-family:inherit;font-size:13.5px;font-weight:600;line-height:1;text-decoration:none;white-space:nowrap;flex:none;cursor:pointer;opacity:1;
  color:#1b49c8;background:linear-gradient(180deg,#fff 0%,#eaf1ff 100%);border:1px solid rgba(27,73,200,.22);
  box-shadow:0 1px 2px rgba(15,40,90,.10),0 4px 10px rgba(27,73,200,.10);-webkit-tap-highlight-color:transparent;
  transition:transform .15s,box-shadow .15s,background .15s,color .15s,border-color .15s}
.homebtn svg{width:17px;height:17px;flex:none;fill:none;stroke:currentColor;stroke-width:1.9;stroke-linecap:round;stroke-linejoin:round}
.homebtn:hover{transform:translateY(-1px);color:#fff;background:linear-gradient(135deg,#4a8bff,#1b49c8);border-color:transparent;box-shadow:0 6px 16px rgba(27,73,200,.30)}
.homebtn:active{transform:none}
.homebtn:focus-visible{outline:3px solid rgba(74,139,255,.55);outline-offset:2px}
.homebtn.fixed{position:fixed;top:max(12px,env(safe-area-inset-top,0px));right:max(14px,env(safe-area-inset-right,0px));z-index:40}
.homebtn.on-blue,.homebtn.on-blue:link,.homebtn.on-blue:visited{color:#1b49c8;background:#fff;border-color:transparent;opacity:1;font-size:13.5px;box-shadow:0 2px 8px rgba(0,30,90,.22)}
.homebtn.on-blue:hover{color:#fff;background:rgba(255,255,255,.22);box-shadow:inset 0 0 0 1.5px #fff}
@media (prefers-color-scheme:dark){
  .homebtn:not(.on-blue){color:#a9c8ff;background:linear-gradient(180deg,#183057 0%,#122646 100%);border-color:rgba(169,200,255,.28);box-shadow:0 1px 2px rgba(0,0,0,.4),0 4px 10px rgba(0,0,0,.25)}
  .homebtn:not(.on-blue):hover{color:#fff;background:linear-gradient(135deg,#4a8bff,#2f5fe0);border-color:transparent}
}
:root[data-theme="dark"] .homebtn:not(.on-blue){color:#a9c8ff;background:linear-gradient(180deg,#183057 0%,#122646 100%);border-color:rgba(169,200,255,.28);box-shadow:0 1px 2px rgba(0,0,0,.4),0 4px 10px rgba(0,0,0,.25)}
:root[data-theme="dark"] .homebtn:not(.on-blue):hover{color:#fff;background:linear-gradient(135deg,#4a8bff,#2f5fe0);border-color:transparent}
:root[data-theme="light"] .homebtn:not(.on-blue){color:#1b49c8;background:linear-gradient(180deg,#fff 0%,#eaf1ff 100%);border-color:rgba(27,73,200,.22)}
:root[data-theme="light"] .homebtn:not(.on-blue):hover{color:#fff;background:linear-gradient(135deg,#4a8bff,#1b49c8);border-color:transparent}
@media (max-width:480px){.homebtn{width:36px;padding:0}.homebtn span{display:none}}  /* จอเล็ก: เหลือไอคอนบ้าน (ยังมี aria-label/ชื่อกำกับ) */
@media (prefers-reduced-motion:reduce){.homebtn{transition:none}.homebtn:hover{transform:none}}