/* 登入頁（沿用原 report.php 登入頁的視覺） */
:root{
  --background:#FBFAFF; --surface:#FFFFFF; --border:#E6E0F5;
  --text:#1A1A2E; --text-muted:#5C5473; --accent:#7C5CFC; --red:#E0475E;
  --grad:linear-gradient(120deg,#7C5CFC,#FF6FB5);
  --sh-card:0 10px 40px rgba(124,92,252,.12);
}
[data-theme="dark"]{
  --background:#14121F; --surface:#1A1A2E; --border:#272338;
  --text:#FBFAFF; --text-muted:#A99FC4; --red:#FF7A8C;
  --sh-card:0 10px 40px rgba(0,0,0,.4);
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Noto Sans JP',sans-serif;background:var(--background);color:var(--text);min-height:100vh;
  transition:background-color .3s}
.center{display:flex;align-items:center;justify-content:center;padding:20px;min-height:100vh;position:relative;overflow:hidden}
.center::before,.center::after{content:'';position:absolute;width:500px;height:500px;z-index:-1}
.center::before{background:radial-gradient(circle,rgba(124,92,252,.15) 0%,transparent 70%);top:-100px;left:-100px}
.center::after{background:radial-gradient(circle,rgba(255,111,181,.12) 0%,transparent 70%);bottom:-100px;right:-100px}
.card{background:var(--surface);border:1px solid var(--border);border-radius:24px;padding:40px 32px;width:100%;
  max-width:400px;box-shadow:var(--sh-card);position:relative;z-index:1}
.logo{font-family:'Baloo 2',cursive;font-weight:800;font-size:40px;background:var(--grad);-webkit-background-clip:text;
  background-clip:text;color:transparent;display:block;text-align:center}
h1{font-size:18px;font-weight:700;text-align:center;margin:4px 0 24px}
label{display:block;font-size:13px;font-weight:700;color:var(--text-muted);margin:0 0 8px}
.field{margin-bottom:24px}
input{width:100%;padding:14px 16px;border:1px solid var(--border);border-radius:12px;background:var(--background);
  color:var(--text);font:inherit;font-size:16px;outline:none;transition:border-color .2s,box-shadow .2s}
input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(124,92,252,.15)}
.btn{background:var(--grad);color:#fff;border:0;padding:14px;border-radius:12px;font:inherit;font-size:16px;font-weight:700;
  cursor:pointer;width:100%;box-shadow:0 4px 15px rgba(124,92,252,.3);transition:transform .2s}
.btn:hover{transform:translateY(-2px)}
.btn:disabled{opacity:.6;cursor:wait;transform:none}
.msg{padding:12px;border-radius:10px;font-size:14px;margin-bottom:20px;line-height:1.6}
.msg.err{background:rgba(255,92,114,.1);border-left:4px solid var(--red);color:var(--red)}
.hidden{display:none!important}
.theme-toggle{position:fixed;top:18px;right:18px;background:var(--surface);border:1px solid var(--border);width:40px;
  height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:18px;z-index:5}