:root{--ink:#183449;--muted:#607888;--sea:#0f7892;--sea-dark:#095b70;--line:#dce8ec;--danger:#9b3232;--shadow:0 22px 60px rgba(18,67,86,.15)}
*{box-sizing:border-box}
body{margin:0;min-height:100vh;background:linear-gradient(150deg,#eefbff 0,#fffaf1 55%,#fff 100%);color:var(--ink);font-family:Inter,"Noto Sans TC",system-ui,sans-serif}
.teacher-login-shell{width:min(100% - 28px,560px);min-height:100vh;margin:0 auto;display:grid;place-items:center;padding:36px 0}
.teacher-login-card{width:100%;overflow:hidden;background:rgba(255,255,255,.97);border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow)}
.teacher-brand{display:flex;align-items:center;gap:13px;padding:22px 26px;background:var(--ink);color:#fff}
.teacher-mark{display:grid;place-items:center;width:46px;height:46px;border-radius:15px;background:#13a6bd;font-weight:900}
.teacher-brand strong,.teacher-brand span{display:block}.teacher-brand strong{font-size:1.08rem}.teacher-brand div span{margin-top:2px;color:#9edee8;font-size:.76rem;font-weight:850;letter-spacing:.14em}
.teacher-login-content{padding:clamp(26px,7vw,44px)}
.eyebrow{margin:0 0 8px;color:var(--sea-dark);font-size:.78rem;font-weight:850;letter-spacing:.12em;text-transform:uppercase}
h1{margin:0;font-size:clamp(2rem,7vw,3rem);line-height:1.1}.intro{margin:14px 0 28px;color:var(--muted);font-weight:650;line-height:1.65}
.teacher-login-form{display:grid;gap:10px}.teacher-login-form label{font-weight:800}.teacher-login-form input{width:100%;margin-bottom:7px;padding:14px 15px;border:1px solid #b9d1d9;border-radius:11px;background:#fff;color:var(--ink);font:inherit}.teacher-login-form input:focus{outline:3px solid rgba(15,120,146,.15);border-color:var(--sea)}
.teacher-login-form button{min-height:52px;margin-top:7px;border:0;border-radius:12px;background:var(--sea);color:#fff;font:inherit;font-weight:850;cursor:pointer}.teacher-login-form button:hover:not(:disabled){background:var(--sea-dark)}.teacher-login-form button:disabled{opacity:.55;cursor:wait}
.teacher-login-message{min-height:26px;margin:16px 0 8px;color:var(--danger);font-weight:750}.back-link{color:var(--sea-dark);font-weight:800;text-decoration:none}.back-link:hover{text-decoration:underline}
.teacher-apply-link{margin:2px 0 16px;color:var(--muted);font-size:.92rem;font-weight:700}.teacher-apply-link a{color:var(--sea-dark);font-weight:850;text-decoration:none}.teacher-apply-link a:hover{text-decoration:underline}
.forgot-password-link{justify-self:end;display:inline-flex;gap:7px;align-items:baseline;margin:-4px 0 3px;color:var(--sea-dark);font-size:.88rem;text-decoration:none}.forgot-password-link span{color:var(--muted);font-size:.78rem}.forgot-password-link:hover strong{text-decoration:underline}.forgot-password-link:focus-visible,.back-link:focus-visible,.teacher-apply-link a:focus-visible{outline:3px solid rgba(15,120,146,.2);outline-offset:3px;border-radius:4px}
.teacher-login-form .secondary-button{background:#fff;color:var(--sea-dark);border:1px solid #a8cbd5}.teacher-login-form .secondary-button:hover:not(:disabled){background:#eefbff}
.teacher-login-message.neutral{margin-top:18px;padding:14px 15px;border:1px solid #b9dbe3;border-radius:12px;background:#f1fbfd;color:var(--ink);font-weight:700;line-height:1.6}.teacher-login-message.success{margin-top:18px;padding:14px 15px;border:1px solid #a8d7bd;border-radius:12px;background:#f1fbf5;color:#205f3b}.teacher-login-message.error{color:var(--danger)}
.password-guidance{margin:-2px 0 5px;color:var(--muted);font-size:.84rem;line-height:1.5}.form-actions{display:grid;gap:10px;margin-top:7px}.form-actions .back-link{justify-self:center;padding:8px}
.is-hidden{display:none!important}
@media(max-width:520px){.teacher-login-shell{width:100%;padding:0;place-items:stretch}.teacher-login-card{min-height:100vh;border:0;border-radius:0}.teacher-brand{padding:18px 20px}.teacher-login-content{padding:32px 20px}}