:root { color-scheme: light; font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; color: #20242b; background: #f4f5f6; }
.login-shell { min-height: 100vh; display: grid; place-items: center; padding: 32px 20px; }
.login-card { width: min(100%, 390px); padding: 36px; border: 1px solid #e2e4e8; border-radius: 18px; background: #fff; box-shadow: 0 18px 60px rgb(27 32 42 / 9%); }
.mark { width: 48px; height: 48px; display: grid; place-items: center; border-radius: 13px; color: #fff; background: #26303f; font-weight: 750; letter-spacing: -.04em; }
h1 { margin: 20px 0 4px; font-size: 25px; letter-spacing: -.02em; }
.subtitle { margin: 0 0 26px; color: #707783; font-size: 14px; }
label { display: grid; gap: 8px; margin-top: 16px; color: #4d5561; font-size: 13px; font-weight: 650; }
input { width: 100%; min-height: 44px; border: 1px solid #d7dae0; border-radius: 9px; padding: 9px 12px; color: #20242b; background: #fff; font: inherit; outline: none; }
input:focus { border-color: #526b92; box-shadow: 0 0 0 3px rgb(82 107 146 / 14%); }
.captcha-row { display: grid; grid-template-columns: minmax(0, 1fr) 160px; gap: 10px; align-items: center; }
.captcha-image { width: 160px; height: 52px; padding: 0; overflow: hidden; border: 1px solid #d7dae0; border-radius: 9px; background: #f4f5f7; cursor: pointer; }
.captcha-image img { display: block; width: 160px; height: 52px; }
.message { min-height: 20px; margin: 14px 0 0; color: #b42318; font-size: 13px; }
.submit { width: 100%; min-height: 46px; margin-top: 5px; border: 0; border-radius: 9px; color: #fff; background: #26303f; font: inherit; font-weight: 700; cursor: pointer; }
.submit:hover { background: #1d2530; }
.submit:disabled { opacity: .6; cursor: wait; }
button:focus-visible { outline: 3px solid rgb(82 107 146 / 28%); outline-offset: 2px; }
@media (max-width: 480px) { .login-card { padding: 28px 22px; } .captcha-row { grid-template-columns: 1fr; } }