:root {
    --bg-primary: #0d1117; --bg-secondary: #161b22; --bg-tertiary: #1c2128;
    --border: #30363d; --text-primary: #e6edf3; --text-secondary: #c9d1d9; --text-muted: #8b949e;
    --accent: #58a6ff; --green: #238636; --green-hover: #2ea043; --red: #f85149;
    --shadow: rgba(0,0,0,0.4);
  }
  *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  @media (max-width: 768px) { input, textarea, select { font-size: 16px !important; } }
  body {
    font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary); color: var(--text-secondary);
    min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 24px;
  }
  .login-container {
    width: 100%; max-width: 380px; text-align: center;
  }
  .login-logo {
    height: 120px; width: auto; filter: invert(1); mix-blend-mode: screen; margin-bottom: 32px;
  }
  .login-card {
    background: var(--bg-secondary); border: 1px solid var(--border); border-radius: 12px;
    padding: 32px 28px; box-shadow: 0 8px 24px var(--shadow);
  }
  .login-card h2 {
    font-size: 18px; color: var(--text-primary); margin-bottom: 24px; font-weight: 600;
  }
  .form-group { margin-bottom: 18px; text-align: left; }
  .form-group label { display: block; font-size: 13px; color: var(--text-muted); margin-bottom: 6px; }
  .form-group input {
    width: 100%; padding: 10px 14px; background: var(--bg-primary); border: 1px solid var(--border);
    border-radius: 8px; color: var(--text-primary); font-size: 15px; font-family: inherit; outline: none;
    transition: border-color 0.15s;
  }
  .form-group input:focus { border-color: var(--accent); }
  .login-btn {
    width: 100%; padding: 12px; background: var(--green); color: #fff; border: none; border-radius: 8px;
    font-size: 15px; font-weight: 600; font-family: inherit; cursor: pointer; transition: background 0.15s;
  }
  .login-btn:hover { background: var(--green-hover); }
  .login-btn:disabled { opacity: 0.6; cursor: not-allowed; }
  .error-msg {
    color: var(--red); font-size: 13px; margin-top: 14px; display: none;
  }
  .error-msg.visible { display: block; }
  #totp-section { display: none; }
  #totp-section.active { display: block; }
  .totp-label {
    font-size: 14px; color: var(--text-secondary); margin-bottom: 16px;
  }
  .totp-input {
    width: 100%; padding: 14px; background: var(--bg-primary); border: 1px solid var(--border);
    border-radius: 8px; color: var(--text-primary); font-size: 24px; font-family: 'DM Sans', monospace;
    text-align: center; letter-spacing: 8px; outline: none; transition: border-color 0.15s;
  }
  .totp-input:focus { border-color: var(--accent); }
  .totp-back {
    display: inline-block; margin-top: 12px; font-size: 13px; color: var(--text-muted);
    cursor: pointer; text-decoration: underline; background: none; border: none; font-family: inherit;
  }
  .totp-back:hover { color: var(--text-secondary); }
  .remember-row {
    display: flex; align-items: center; gap: 10px; margin-bottom: 18px; text-align: left;
  }
  .remember-row input {
    width: 18px; height: 18px; accent-color: var(--accent); cursor: pointer; flex-shrink: 0;
  }
  .remember-row label {
    font-size: 14px; color: var(--text-secondary); cursor: pointer; margin-bottom: 0;
  }
  .toggle-link {
    text-align: center; margin-top: 16px; font-size: 13px;
  }
  .toggle-link a {
    color: var(--accent); text-decoration: none;
  }
  .toggle-link a:hover { text-decoration: underline; }
  .success-msg {
    color: var(--green); font-size: 13px; margin-top: 14px; text-align: center;
  }
  .forgot-link {
    text-align: center; margin-top: 12px; font-size: 13px;
  }
  .forgot-link a {
    color: var(--text-muted); text-decoration: none;
  }
  .forgot-link a:hover { color: var(--accent); text-decoration: underline; }
  .forgot-desc {
    color: var(--text-secondary); font-size: 14px; line-height: 1.5; margin-bottom: 18px; text-align: left;
  }
  .info-msg {
    color: var(--accent); font-size: 13px; margin-top: 14px; text-align: center;
    background: rgba(88, 166, 255, 0.08); padding: 10px; border-radius: 6px;
  }