:root{color-scheme:light;--ink:#223a31;--muted:#64756d;--line:#d8e4dc;--green:#176446;--pale:#f2fee6;--bg:#f7faf7}
*{box-sizing:border-box}
html,body{min-height:100%;margin:0}
body{font-family:"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",Meiryo,sans-serif;color:var(--ink);background:var(--bg);font-size:15px}
.shell{min-height:100vh;min-height:100dvh;display:flex}
.auth-area{flex:1;display:flex;align-items:center;justify-content:center;flex-direction:column;padding:44px 28px}
.auth-card{width:100%;max-width:465px;background:#fff;padding:45px clamp(24px,3.8vw,49px);border:1px solid #e5ede7;border-radius:20px;box-shadow:0 18px 68px rgba(35,69,47,.075)}
.security-label{display:inline-flex;align-items:center;gap:9px;background:#e8f4ea;color:#145d41;border:2px solid #8fbca1;border-radius:9px;padding:9px 13px;font-size:16px;font-weight:800;letter-spacing:.035em}
.security-label svg{flex-shrink:0}
.brand{display:flex;align-items:center;gap:13px;margin-top:28px;font-weight:800;letter-spacing:.04em;font-size:24px}
.brand-mark{display:inline-grid;place-items:center;width:40px;height:40px;background:#176446;border-radius:10px;color:white;font-weight:800;font-size:21px}
h2{margin:18px 0 10px;font-size:30px;letter-spacing:.03em}
.intro{color:#63756c;font-size:13px;line-height:1.9;margin:0 0 29px}
.field{margin-bottom:19px}
.field label{display:block;font-size:14px;font-weight:700;margin-bottom:8px}
.field input{display:block;width:100%;font-family:inherit;font-size:16px;color:#223a31;min-height:50px;padding:12px 14px;border:1px solid #cad8cf;border-radius:9px;outline:none;background:#fff;transition:border-color .15s,box-shadow .15s}
.field input:focus{border-color:#19744f;box-shadow:0 0 0 3px #deefe4}
button[type=submit]{font-family:inherit;display:flex;align-items:center;justify-content:center;gap:13px;width:100%;min-height:53px;border:0;border-radius:10px;background:#176446;color:#fff;font-size:16px;font-weight:800;cursor:pointer;transition:background .15s,transform .15s;margin-top:28px}
button[type=submit]:hover{background:#115136}
button[type=submit]:active{transform:translateY(1px)}
button[type=submit]:focus-visible{outline:3px solid #9fd0b2;outline-offset:3px}
.note{color:#718079;font-size:12px;line-height:1.9;margin:25px 0 0}
.error-message{border:1px solid #f4b9af;color:#942f23;background:#fff4f1;padding:12px 14px;margin:0 0 24px;border-radius:8px;font-size:13px;line-height:1.7}
.footer{font-size:11px;color:#76877d;margin:30px 0 0;text-align:center}
/* /sp.php 入口（モバイル）: 黄色基調の背景と「モバイル」表示。PC 入口（entry-pc）は従来のまま */
body.entry-sp{background:#fff6c7}
.entry-sp .auth-card{border-color:#f0dc8a;box-shadow:0 18px 68px rgba(120,96,10,.10)}
.mobile-badge{display:inline-flex;align-items:center;margin-left:auto;background:#ffd84d;color:#4d3b00;border:2px solid #e3b800;border-radius:999px;padding:4px 14px;font-size:15px;font-weight:800;letter-spacing:.06em}
@media(max-width:850px){.auth-area{padding:24px 16px 44px}.auth-card{max-width:520px;padding:32px 24px}.brand{font-size:20px}.brand-mark{width:35px;height:35px;font-size:18px}}
@media(max-width:430px){.auth-card{padding:27px 20px;border-radius:14px}.security-label{font-size:15px}h2{font-size:27px}.intro{font-size:12px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}