:root {
      --bg: #081122;
      --bg-deep: #050b17;
      --card: rgba(12, 21, 35, 0.78);
      --border: rgba(120, 182, 255, 0.16);
      --control: rgba(9, 19, 33, 0.88);
      --control-border: rgba(120, 182, 255, 0.16);
      --ink: #eef4fb;
      --muted: #8ea4bc;
      --accent: #60d7f6;
      --accent-strong: #8dd8ff;
      --shadow: rgba(0, 0, 0, 0.34);
    }
    * { box-sizing: border-box; }
    body {
      margin: 0;
      min-height: 100vh;
      font-family: "Segoe UI", "Noto Sans", sans-serif;
      background:
        radial-gradient(circle at top center, rgba(69, 162, 255, 0.16) 0%, rgba(8, 17, 34, 0) 34%),
        radial-gradient(circle at 20% 15%, rgba(96, 215, 246, 0.12) 0%, rgba(8, 17, 34, 0) 24%),
        linear-gradient(180deg, var(--bg) 0%, var(--bg-deep) 100%);
      color: var(--ink);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 24px 16px;
    }

    .auth-shell {
      width: 100%;
      max-width: 460px;
      display: grid;
      gap: 12px;
      align-items: start;
    }

    .brand-block {
      display: flex;
      justify-content: center;
      align-items: center;
      width: 100%;
      padding: 0;
    }

    .brand-logo {
      width: 100%;
      max-width: 100%;
      height: auto;
      max-height: none;
      display: block;
      object-fit: contain;
      border-radius: 18px;
      filter: drop-shadow(0 20px 36px rgba(0, 0, 0, 0.32));
    }

    .card {
      width: 100%;
      backdrop-filter: blur(18px);
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: 8px;
      box-shadow: 0 24px 64px var(--shadow);
      padding: 18px;
    }

    .card-head {
      margin-bottom: 12px;
    }

    h1 {
      margin: 0;
      font-size: 1.3rem;
      color: var(--ink);
    }

    .subtitle {
      margin: 6px 0 0;
      color: var(--muted);
      font-size: 0.92rem;
      line-height: 1.4;
    }

    form {
      display: grid;
      gap: 10px;
    }

    input {
      border: 1px solid var(--control-border);
      border-radius: 8px;
      padding: 11px 12px;
      font-size: 0.95rem;
      background: var(--control);
      color: var(--ink);
      outline: none;
      transition: border-color 0.16s ease, box-shadow 0.16s ease, background 0.16s ease;
    }

    input:focus {
      border-color: rgba(96, 215, 246, 0.55);
      box-shadow: 0 0 0 3px rgba(96, 215, 246, 0.12);
      background: rgba(11, 22, 37, 0.96);
    }

    button {
      border: 1px solid rgba(141, 216, 255, 0.42);
      border-radius: 8px;
      background: linear-gradient(180deg, rgba(96, 215, 246, 0.28) 0%, rgba(80, 169, 255, 0.18) 100%);
      color: #eff8ff;
      padding: 10px 12px;
      font-weight: 700;
      cursor: pointer;
      transition: transform 0.16s ease, box-shadow 0.16s ease, border-color 0.16s ease;
    }

    button:hover {
      border-color: rgba(141, 216, 255, 0.62);
      box-shadow: 0 12px 22px rgba(30, 111, 193, 0.18);
      transform: translateY(-1px);
    }

    .error {
      min-height: 18px;
      margin-top: 8px;
      color: #fb7185;
      font-size: 0.85rem;
    }

    @media (max-width: 640px) {
      body {
        padding: 20px 12px;
      }

      .auth-shell {
        gap: 10px;
      }

      .brand-logo {
        border-radius: 16px;
      }

      .card {
        padding: 16px 14px;
      }
    }