:root {
  color-scheme: dark;
  font-family: "Microsoft YaHei", Arial, sans-serif;
  background: #081424;
  color: #edf7fa;
}

* { box-sizing: border-box; }

body { margin: 0; min-width: 320px; min-height: 100vh; }

.login-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
  background-color: #081424;
}

.login-panel {
  width: min(420px, 100%);
  padding: 36px;
  border: 1px solid #285b70;
  border-radius: 8px;
  background: #0d2133;
  box-shadow: 0 18px 54px rgba(0, 0, 0, 0.34);
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid #5bcfd8;
  color: #79e5eb;
  font-size: 22px;
  font-weight: 700;
}

.eyebrow { margin: 24px 0 10px; color: #80aebd; font-size: 12px; }
h1 { margin: 0; font-size: 30px; }
.subtitle { margin: 9px 0 30px; color: #aac6d0; }
form { display: grid; gap: 18px; }
label { display: grid; gap: 8px; color: #cbe4eb; font-size: 14px; }
input { width: 100%; min-height: 44px; padding: 10px 12px; border: 1px solid #39697d; border-radius: 4px; background: #071724; color: #edf7fa; font: inherit; }
input:focus { outline: 2px solid #5bcfd8; outline-offset: 2px; }
button { min-height: 44px; border: 0; border-radius: 4px; background: #36b5c0; color: #041218; font: inherit; font-weight: 700; cursor: pointer; }
button:hover { background: #66d7de; }
button:disabled { cursor: wait; opacity: 0.65; }
.form-message { min-height: 20px; margin: -6px 0 0; color: #ffac99; font-size: 14px; }
.boundary-note { margin: 28px 0 0; color: #7ba2ae; font-size: 13px; line-height: 1.6; }

@media (max-width: 480px) {
  .login-shell { padding: 16px; }
  .login-panel { padding: 28px 22px; }
}