:root {
      color-scheme: light;
      --page: #f4f7fb;
      --panel: #ffffff;
      --line: #d3dce8;
      --text: #122033;
      --muted: #5c6c82;
      --blue: #315d93;
      --red: #a93322;
    }

    * { box-sizing: border-box; }

    body {
      margin: 0;
      min-height: 100vh;
      background: var(--page);
      color: var(--text);
      font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
      letter-spacing: 0;
      display: grid;
      place-items: center;
      padding: 24px;
    }

    .login-card {
      width: min(420px, 100%);
      background: var(--panel);
      border: 1px solid var(--line);
      border-radius: 8px;
      padding: 28px;
    }

    h1 {
      margin: 0 0 8px;
      font-size: 24px;
      line-height: 1.25;
    }

    .subtitle {
      margin: 0 0 24px;
      color: var(--muted);
      font-size: 14px;
    }

    form {
      display: grid;
      gap: 16px;
    }

    label {
      display: grid;
      gap: 8px;
      color: #344762;
      font-size: 15px;
    }

    input {
      height: 44px;
      border: 1px solid var(--line);
      border-radius: 7px;
      padding: 0 14px;
      color: var(--text);
      background: #fff;
      font: inherit;
      outline: none;
      width: 100%;
    }

    input:focus {
      border-color: var(--blue);
      box-shadow: 0 0 0 3px rgba(49, 93, 147, 0.14);
    }

    button {
      height: 44px;
      border: 1px solid var(--blue);
      border-radius: 7px;
      background: var(--blue);
      color: #fff;
      font: inherit;
      cursor: pointer;
    }

    .error {
      color: var(--red);
      min-height: 20px;
      font-size: 14px;
    }