:root {
      --navy:        #0a1628;
      --navy-mid:    #122040;
      --navy-light:  #1c3060;
      --accent:      #2a5caa;
      --accent-bright: #4a8cff;
      --white:       #ffffff;
      --offwhite:    #e8edf8;
      --gray:        #8a9bbf;
      --error:       #ff5c72;
      --success:     #4affb4;
    }

    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }

    body {
      font-family: 'DM Sans', sans-serif;
      background: var(--navy);
      color: var(--white);
      min-height: 100vh;
      overflow-x: hidden;
    }

    /* ── NAV ── */
    nav {
      position: fixed;
      top: 0; left: 0; right: 0;
      z-index: 100;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 5%;
      height: 72px;
      background: rgba(10, 22, 40, 0.9);
      backdrop-filter: blur(14px);
      border-bottom: 1px solid rgba(74, 140, 255, 0.15);
    }

    .logo {
      font-family: 'Cormorant Garamond', serif;
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--white);
      text-decoration: none;
    }
    .logo span { color: var(--accent-bright); }

    .nav-links { display: flex; gap: 12px; list-style: none; }
    .nav-links a {
      text-decoration: none;
      font-size: 0.88rem;
      font-weight: 500;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      padding: 9px 24px;
      border-radius: 40px;
      transition: all 0.3s ease;
    }
    .nav-links a.home-btn {
      color: var(--white);
      border: 1px solid rgba(255,255,255,0.25);
    }
    .nav-links a.home-btn:hover {
      border-color: var(--accent-bright);
      color: var(--accent-bright);
    }
    .nav-links a.login-btn {
      background: var(--accent);
      color: var(--white);
      border: 1px solid var(--accent);
    }
    .nav-links a.login-btn:hover {
      background: var(--accent-bright);
      box-shadow: 0 0 18px rgba(74,140,255,0.5);
    }

    /* ── PAGE WRAPPER ── */
    .page {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 100px 20px 50px;
      position: relative;
    }

    /* Animated background grid */
    .page::before {
      content: '';
      position: fixed;
      inset: 0;
      background-image:
        linear-gradient(rgba(74,140,255,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(74,140,255,0.04) 1px, transparent 1px);
      background-size: 60px 60px;
      pointer-events: none;
      z-index: 0;
    }

    .glow-orb {
      position: fixed;
      border-radius: 50%;
      filter: blur(100px);
      pointer-events: none;
      z-index: 0;
    }
    .glow-orb-1 {
      width: 500px; height: 500px;
      background: rgba(42, 92, 170, 0.25);
      top: -100px; left: -100px;
    }
    .glow-orb-2 {
      width: 400px; height: 400px;
      background: rgba(74, 140, 255, 0.15);
      bottom: -80px; right: -80px;
    }

    /* ── AUTH CARD ── */
    .auth-card {
      position: relative;
      z-index: 10;
      width: 100%;
      max-width: 480px;
      background: rgba(18, 32, 64, 0.7);
      border: 1px solid rgba(74, 140, 255, 0.2);
      border-radius: 16px;
      backdrop-filter: blur(20px);
      overflow: hidden;
      animation: cardIn 0.7s ease forwards;
    }

    @keyframes cardIn {
      from { opacity: 0; transform: translateY(30px); }
      to   { opacity: 1; transform: translateY(0); }
    }

    /* Tabs */
    .tabs {
      display: flex;
      border-bottom: 1px solid rgba(74, 140, 255, 0.15);
    }

    .tab-btn {
      flex: 1;
      padding: 20px;
      background: none;
      border: none;
      color: var(--gray);
      font-family: 'DM Sans', sans-serif;
      font-size: 0.88rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      cursor: pointer;
      position: relative;
      transition: color 0.3s;
    }
    .tab-btn::after {
      content: '';
      position: absolute;
      bottom: 0; left: 20%; right: 20%;
      height: 2px;
      background: var(--accent-bright);
      border-radius: 2px;
      transform: scaleX(0);
      transition: transform 0.3s ease;
    }
    .tab-btn.active {
      color: var(--white);
    }
    .tab-btn.active::after {
      transform: scaleX(1);
    }

    /* Forms */
    .form-panel {
      display: none;
      padding: 38px 40px 42px;
      flex-direction: column;
      gap: 0;
    }
    .form-panel.active { display: flex; }

    .form-header {
      margin-bottom: 30px;
    }
    .form-header h2 {
      font-family: 'Cormorant Garamond', serif;
      font-size: 2rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 6px;
    }
    .form-header h2 span { color: var(--accent-bright); }
    .form-header p {
      color: var(--gray);
      font-size: 0.88rem;
    }

    /* Input groups */
    .input-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
    }

    .input-group {
      margin-bottom: 18px;
      position: relative;
    }

    .input-group label {
      display: block;
      font-size: 0.75rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--gray);
      margin-bottom: 8px;
    }

    .input-wrap {
      position: relative;
    }

    .input-wrap .icon {
      position: absolute;
      left: 14px;
      top: 50%;
      transform: translateY(-50%);
      font-size: 1rem;
      color: var(--gray);
      pointer-events: none;
      transition: color 0.3s;
    }

    .input-wrap input {
      width: 100%;
      background: rgba(10, 22, 40, 0.6);
      border: 1px solid rgba(74, 140, 255, 0.2);
      border-radius: 8px;
      padding: 12px 14px 12px 42px;
      font-family: 'DM Sans', sans-serif;
      font-size: 0.92rem;
      color: var(--white);
      outline: none;
      transition: border-color 0.3s, box-shadow 0.3s;
    }
    .input-wrap input::placeholder { color: rgba(138,155,191,0.5); }
    .input-wrap input:focus {
      border-color: var(--accent-bright);
      box-shadow: 0 0 0 3px rgba(74,140,255,0.12);
    }
    .input-wrap input:focus ~ .icon,
    .input-wrap input:focus + .icon { color: var(--accent-bright); }

    /* Eye toggle */
    .toggle-eye {
      position: absolute;
      right: 12px;
      top: 50%;
      transform: translateY(-50%);
      background: none;
      border: none;
      color: var(--gray);
      cursor: pointer;
      font-size: 0.9rem;
      padding: 4px;
      transition: color 0.3s;
    }
    .toggle-eye:hover { color: var(--accent-bright); }

    /* Password strength */
    .strength-bar {
      display: flex;
      gap: 4px;
      margin-top: 8px;
    }
    .strength-seg {
      flex: 1;
      height: 3px;
      border-radius: 2px;
      background: rgba(255,255,255,0.08);
      transition: background 0.3s;
    }
    .strength-label {
      font-size: 0.7rem;
      color: var(--gray);
      margin-top: 5px;
      text-align: right;
    }

    /* Options row */
    .options-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 24px;
    }

    .checkbox-wrap {
      display: flex;
      align-items: center;
      gap: 8px;
      cursor: pointer;
      font-size: 0.85rem;
      color: var(--gray);
      user-select: none;
    }
    .checkbox-wrap input[type="checkbox"] {
      accent-color: var(--accent-bright);
      width: 14px; height: 14px;
      cursor: pointer;
    }

    .forgot-link {
      font-size: 0.82rem;
      color: var(--accent-bright);
      text-decoration: none;
      transition: opacity 0.3s;
    }
    .forgot-link:hover { opacity: 0.75; }

    /* Submit button */
    .submit-btn {
      width: 100%;
      padding: 14px;
      background: var(--accent);
      border: none;
      border-radius: 8px;
      color: var(--white);
      font-family: 'DM Sans', sans-serif;
      font-size: 0.92rem;
      font-weight: 500;
      letter-spacing: 0.08em;
      text-transform: uppercase;
      cursor: pointer;
      position: relative;
      overflow: hidden;
      transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
      margin-bottom: 24px;
    }
    .submit-btn:hover {
      background: var(--accent-bright);
      box-shadow: 0 0 28px rgba(74, 140, 255, 0.45);
      transform: translateY(-1px);
    }
    .submit-btn:active { transform: translateY(0); }

    /* Ripple effect */
    .submit-btn .ripple {
      position: absolute;
      border-radius: 50%;
      background: rgba(255,255,255,0.25);
      transform: scale(0);
      animation: ripple 0.6s linear;
      pointer-events: none;
    }
    @keyframes ripple {
      to { transform: scale(4); opacity: 0; }
    }

    /* Divider */
    .divider {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-bottom: 20px;
    }
    .divider::before, .divider::after {
      content: '';
      flex: 1;
      height: 1px;
      background: rgba(74,140,255,0.15);
    }
    .divider span {
      font-size: 0.75rem;
      color: var(--gray);
      white-space: nowrap;
      letter-spacing: 0.08em;
    }

    /* Social buttons */
    .social-row {
      display: flex;
      gap: 12px;
    }
    .social-auth-btn {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 11px;
      background: rgba(10,22,40,0.5);
      border: 1px solid rgba(74,140,255,0.18);
      border-radius: 8px;
      color: var(--offwhite);
      font-family: 'DM Sans', sans-serif;
      font-size: 0.82rem;
      cursor: pointer;
      text-decoration: none;
      transition: all 0.3s;
    }
    .social-auth-btn:hover {
      border-color: rgba(74,140,255,0.5);
      background: rgba(74,140,255,0.08);
    }
    .social-auth-btn .s-icon { font-size: 1rem; }

    /* Terms */
    .terms-note {
      margin-top: 18px;
      text-align: center;
      font-size: 0.78rem;
      color: var(--gray);
      line-height: 1.6;
    }
    .terms-note a {
      color: var(--accent-bright);
      text-decoration: none;
    }
    .terms-note a:hover { text-decoration: underline; }

    /* Alert */
    .alert {
      display: none;
      align-items: center;
      gap: 10px;
      padding: 12px 16px;
      border-radius: 8px;
      font-size: 0.85rem;
      margin-bottom: 18px;
    }
    .alert.error {
      background: rgba(255,92,114,0.12);
      border: 1px solid rgba(255,92,114,0.3);
      color: var(--error);
    }
    .alert.success {
      background: rgba(74,255,180,0.1);
      border: 1px solid rgba(74,255,180,0.25);
      color: var(--success);
    }
    .alert.show { display: flex; }

    /* ── Responsive ── */
    @media (max-width: 520px) {
      .form-panel { padding: 28px 24px 32px; }
      .input-row { grid-template-columns: 1fr; gap: 0; }
      .auth-card { border-radius: 12px; }
    }