:root {
  --bg-1: #f4f7ff;
  --bg-2: #eef8f5;
  --card-bg: #ffffff;
  --border: #d8e1ec;
  --text: #16324a;
  --muted: #5f7388;
  --accent: #1363df;
  --accent-hover: #0d4ea8;
  --danger: #c62828;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
}

body {
  background:
    radial-gradient(60rem 40rem at 15% -10%, rgba(19, 99, 223, 0.14), transparent 65%),
    radial-gradient(56rem 38rem at 110% 8%, rgba(39, 174, 96, 0.13), transparent 70%),
    linear-gradient(165deg, var(--bg-1), var(--bg-2));
}

.login-shell {
  min-height: 100dvh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: max(20px, env(safe-area-inset-top)) 14px max(24px, env(safe-area-inset-bottom));
}

.login-card {
  width: min(420px, 100%);
  margin-top: 6vh;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 16px 16px;
  box-shadow: 0 16px 42px rgba(0, 0, 0, 0.08);
}

.title {
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
}

.subtitle {
  margin: 8px 0 16px;
  font-size: 14px;
  color: var(--muted);
}

.field {
  display: block;
  margin-bottom: 12px;
}

.field span {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  color: var(--muted);
}

.field input {
  width: 100%;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0 12px;
  font-size: 15px;
}

.field input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(19, 99, 223, 0.14);
}

.submit {
  width: 100%;
  height: 42px;
  border: 0;
  border-radius: 10px;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  background: var(--accent);
  cursor: pointer;
}

.submit:hover {
  background: var(--accent-hover);
}

.submit[disabled] {
  cursor: not-allowed;
  opacity: 0.75;
}

.force-tip {
  margin: 0 0 10px;
  padding: 8px 10px;
  border-radius: 8px;
  background: #fff3cd;
  color: #8a6d3b;
  font-size: 13px;
}

.status {
  min-height: 20px;
  margin-top: 10px;
  font-size: 13px;
  color: var(--danger);
}

.hidden {
  display: none;
}

@media (max-width: 720px) {
  .title {
    display: none;
  }

  .login-card {
    margin-top: 0;
    border-radius: 14px;
  }
}