body { min-height: 100vh; display: flex; flex-direction: column; background: var(--bg-base); }
    .auth-shell {
      flex: 1;
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      min-height: calc(100vh - 0px);
    }
    /* LEFT — brand panel */
    .auth-left {
      position: relative;
      padding: 40px 48px;
      background: var(--bg-section);
      border-right: 1px solid var(--border-subtle);
      display: flex; flex-direction: column;
      isolation: isolate;
      overflow: hidden;
    }
    /* Aurora Background */
    .auth-aurora {
      position: absolute; inset: -150px;
      z-index: -1;
      overflow: hidden;
      filter: blur(80px);
      pointer-events: none;
    }
    .orb {
      position: absolute;
      border-radius: 50%;
      opacity: 0.6;
      animation: float-orb 20s infinite ease-in-out alternate;
    }
    .orb-1 {
      width: 400px; height: 400px;
      background: rgba(75, 217, 248, 0.25);
      top: -10%; left: -10%;
    }
    .orb-2 {
      width: 500px; height: 500px;
      background: rgba(78, 106, 222, 0.2);
      bottom: -20%; right: -10%;
      animation-delay: -5s;
    }
    .orb-3 {
      width: 300px; height: 300px;
      background: rgba(139, 92, 246, 0.2);
      top: 40%; left: 40%;
      animation-delay: -10s;
      animation-duration: 25s;
    }
    @keyframes float-orb {
      0% { transform: translate(0, 0) scale(1); }
      50% { transform: translate(50px, 50px) scale(1.1); }
      100% { transform: translate(-30px, -20px) scale(0.9); }
    }
    [data-theme="light"] .orb { opacity: 0.8; }

    /* Grid overlay */
    .auth-left::before {
      content: '';
      position: absolute; inset: 0;
      background-image: 
        linear-gradient(to right, rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
      mask-image: radial-gradient(ellipse 80% 80% at center, black 10%, transparent 80%);
      z-index: -1;
    }
    [data-theme="light"] .auth-left::before {
      background-image: 
        linear-gradient(to right, rgba(0,0,0,0.03) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(0,0,0,0.03) 1px, transparent 1px);
    }

    .auth-left-head { display: flex; align-items: center; gap: 14px; position: relative; z-index: 10; }
    .auth-left-head .brand { display: flex; align-items: center; gap: 14px; }
    
    .auth-left-content {
      margin: auto 0;
      display: flex;
      flex-direction: column;
      max-width: 520px;
      position: relative;
    }

    /* Premium Glass Card */
    .premium-glass-card {
      position: relative;
      background: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.01) 100%);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border: 1px solid rgba(255, 255, 255, 0.08);
      border-top: 1px solid rgba(255, 255, 255, 0.2);
      border-left: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: 24px;
      padding: 44px 40px;
      box-shadow: 
        0 40px 80px rgba(0, 0, 0, 0.4), 
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
      z-index: 2;
    }
    [data-theme="light"] .premium-glass-card {
      background: linear-gradient(135deg, rgba(255, 255, 255, 0.8) 0%, rgba(255, 255, 255, 0.4) 100%);
      box-shadow: 0 40px 80px rgba(0, 0, 0, 0.08), inset 0 1px 0 rgba(255, 255, 255, 0.5);
      border: 1px solid rgba(0, 0, 0, 0.05);
      border-top: 1px solid rgba(255, 255, 255, 0.8);
      border-left: 1px solid rgba(255, 255, 255, 0.5);
    }

    .premium-glass-card .q {
      font-family: var(--font-display);
      font-size: 34px;
      font-weight: 400;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--text-primary);
    }
    .premium-glass-card .q .accent {
      background: linear-gradient(110deg, var(--mbc-light-blue), #d8b4fe);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      font-weight: 500;
    }
    .premium-glass-card .author {
      margin-top: 36px;
      display: flex; align-items: center; gap: 16px;
    }
    .premium-glass-card .author .av {
      width: 48px; height: 48px;
      border-radius: 50%;
      border: 2px solid rgba(255,255,255,0.1);
      box-shadow: 0 0 20px rgba(75, 217, 248, 0.2);
    }
    .premium-glass-card .author .meta { font-size: 13.5px; }
    .premium-glass-card .author .name { font-weight: 600; color: var(--text-primary); }
    .premium-glass-card .author .role { color: var(--text-tertiary); font-size: 12.5px; margin-top: 2px; }

    /* Floating Badges */
    .floating-badge {
      position: absolute;
      background: rgba(20, 20, 25, 0.6);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-top: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: 12px;
      padding: 12px 20px;
      box-shadow: 0 16px 32px rgba(0,0,0,0.3);
      z-index: 3;
      transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s ease;
    }
    [data-theme="light"] .floating-badge {
      background: rgba(255, 255, 255, 0.85);
      border: 1px solid rgba(0, 0, 0, 0.08);
      border-top: 1px solid rgba(255, 255, 255, 0.8);
      box-shadow: 0 16px 32px rgba(0,0,0,0.06);
    }
    .floating-badge:hover {
      transform: translateY(-5px) scale(1.05) !important;
      z-index: 10;
      box-shadow: 0 24px 48px rgba(0,0,0,0.4);
    }
    [data-theme="light"] .floating-badge:hover { box-shadow: 0 24px 48px rgba(0,0,0,0.1); }
    .floating-badge .v { font-family: var(--font-display); font-size: 24px; font-weight: 600; line-height: 1; color: var(--text-primary); }
    .floating-badge .v .cyan { color: var(--mbc-cyan); }
    .floating-badge .l { font-size: 10.5px; color: var(--text-tertiary); margin-top: 4px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; }

    /* Badge Positioning */
    .badge-1 { top: -20px; right: -30px; transform: rotate(3deg); }
    .badge-2 { bottom: -20px; right: 20px; transform: rotate(-2deg); }
    .badge-3 { bottom: -30px; left: -20px; transform: rotate(-4deg); }

    .auth-footer-links {
      margin-top: auto; font-size: 12px; color: var(--text-tertiary); display: flex; gap: 16px; align-items: center;
    }
    .auth-footer-links a:hover { color: var(--text-primary); }

    /* RIGHT — auth form */
    .auth-right {
      display: grid;
      place-items: center;
      padding: 40px;
    }
    .auth-card {
      width: 100%;
      max-width: 460px;
    }
    .auth-tabs {
      display: flex;
      background: var(--bg-card);
      border: 1px solid var(--border-default);
      border-radius: 10px;
      padding: 4px;
      margin-bottom: 32px;
      position: relative;
    }
    [data-theme="light"] .auth-tabs {
      background: rgba(0, 0, 0, 0.03);
      border: 1px solid rgba(0, 0, 0, 0.04);
    }
    .auth-tab {
      flex: 1;
      padding: 10px 14px;
      border-radius: 6px;
      font-size: 13.5px;
      font-weight: 600;
      background: transparent;
      border: 0;
      color: var(--text-tertiary);
      cursor: pointer;
      transition: background 0.2s, color 0.2s, box-shadow 0.2s;
    }
    .auth-tab.active {
      background: var(--bg-elevated);
      color: var(--text-primary);
      box-shadow: 0 2px 8px rgba(0,0,0,0.2), inset 0 1px 1px rgba(255,255,255,0.05);
      border: 1px solid rgba(255,255,255,0.05);
    }
    [data-theme="light"] .auth-tab.active {
      background: #ffffff;
      border: 1px solid rgba(0,0,0,0.05);
      box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    }
    h1.auth-title { font-size: 28px; margin-bottom: 8px; }
    .auth-sub { color: var(--text-secondary); font-size: 14px; margin-bottom: 32px; }

    .field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
    .field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 16px; }
    .field-row .field { margin-bottom: 0; }
    label {
      font-family: var(--font-display);
      font-size: 11.5px;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.06em;
      color: var(--text-secondary);
    }
    .label-row { display: flex; justify-content: space-between; align-items: center; }
    .label-row a { font-size: 11.5px; color: var(--mbc-cyan); text-transform: none; letter-spacing: 0; }
    .label-row a:hover { color: var(--mbc-light-blue); }

    input[type=text], input[type=email], input[type=password], input[type=tel] {
      height: 48px;
      padding: 0 16px;
      background: var(--bg-card);
      border: 1px solid var(--border-default);
      border-radius: 10px;
      color: var(--text-primary);
      font-size: 14.5px;
      transition: border-color .3s, box-shadow .3s, background .3s;
      outline: 0;
      width: 100%;
      box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
    }
    input::placeholder { color: var(--text-muted); }
    input:hover { border-color: var(--border-strong); }
    input:focus {
      border-color: var(--mbc-cyan);
      box-shadow: 0 0 0 4px rgba(75, 217, 248, 0.15), inset 0 2px 4px rgba(0,0,0,0.1);
      background: var(--bg-elevated);
    }
    [data-theme="light"] input[type=text], [data-theme="light"] input[type=email], [data-theme="light"] input[type=password], [data-theme="light"] input[type=tel] {
      background: #ffffff;
      border: 1px solid rgba(0,0,0,0.12);
      box-shadow: inset 0 1px 3px rgba(0,0,0,0.03);
    }
    [data-theme="light"] input:hover { border-color: rgba(0,0,0,0.25); }
    [data-theme="light"] input:focus {
      border-color: var(--mbc-light-blue);
      box-shadow: 0 0 0 4px rgba(75, 217, 248, 0.25), inset 0 1px 3px rgba(0,0,0,0.03);
    }

    .checkbox {
      display: flex; align-items: flex-start; gap: 10px;
      margin-bottom: 18px;
      font-size: 12.5px;
      color: var(--text-secondary);
      line-height: 1.5;
    }
    .checkbox input[type="checkbox"] {
      appearance: none; -webkit-appearance: none;
      width: 18px; height: 18px; margin-top: 1px;
      border: 1px solid var(--border-strong);
      border-radius: 4px;
      background: var(--bg-card);
      cursor: pointer;
      display: grid; place-items: center;
      transition: background 0.2s, border-color 0.2s;
      flex-shrink: 0;
    }
    .checkbox input[type="checkbox"]::before {
      content: "";
      width: 10px; height: 10px;
      background: white;
      clip-path: polygon(14% 44%, 0 65%, 50% 100%, 100% 16%, 80% 0%, 43% 62%);
      transform: scale(0);
      transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
    }
    .checkbox input[type="checkbox"]:checked {
      background: var(--mbc-light-blue);
      border-color: var(--mbc-light-blue);
    }
    .checkbox input[type="checkbox"]:checked::before {
      transform: scale(1);
    }
    .checkbox a { color: var(--mbc-cyan); }

    .btn-full { width: 100%; height: 46px; font-size: 14.5px; }

    /* Premium Button Override */
    .auth-card .btn-primary {
      background: linear-gradient(135deg, var(--mbc-cyan), var(--mbc-medium-blue));
      box-shadow: 0 4px 12px rgba(75, 217, 248, 0.2), inset 0 1px 1px rgba(255, 255, 255, 0.3);
      border: 1px solid rgba(0, 0, 0, 0.1);
      transition: all 0.3s ease;
      color: #fff;
    }
    .auth-card .btn-primary:hover {
      background: linear-gradient(135deg, var(--mbc-light-blue), #3b82f6);
      transform: translateY(-2px);
      box-shadow: 0 8px 24px rgba(75, 217, 248, 0.3), inset 0 1px 1px rgba(255, 255, 255, 0.4);
    }

    .divider-h {
      display: flex; align-items: center; gap: 12px;
      margin: 24px 0;
      color: var(--text-tertiary);
      font-size: 11px;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      font-family: var(--font-display);
      font-weight: 600;
    }
    .divider-h::before, .divider-h::after {
      content: '';
      flex: 1;
      height: 1px;
      background: var(--border-subtle);
    }

    .sso-row {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 8px;
    }
    .sso {
      height: 42px;
      display: flex; align-items: center; justify-content: center; gap: 8px;
      background: rgba(255, 255, 255, 0.02);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      border: 1px solid var(--border-default);
      border-radius: 8px;
      color: var(--text-primary);
      font-size: 12.5px;
      font-weight: 500;
      transition: all .2s cubic-bezier(0.34, 1.56, 0.64, 1);
      cursor: pointer;
    }
    [data-theme="light"] .sso {
      background: #ffffff;
      border: 1px solid rgba(0,0,0,0.1);
      box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    }
    .sso:hover { 
      background: var(--bg-elevated); 
      border-color: var(--border-strong); 
      transform: translateY(-3px);
      box-shadow: 0 8px 16px rgba(0,0,0,0.15);
    }
    [data-theme="light"] .sso:hover {
      border-color: rgba(0,0,0,0.2);
      box-shadow: 0 8px 16px rgba(0,0,0,0.06);
    }
    .sso svg { flex-shrink: 0; }

    .magic-card {
      margin-top: 22px;
      padding: 14px;
      background: linear-gradient(180deg, rgba(75,217,248,0.06), var(--bg-card) 70%);
      border: 1px solid rgba(75,217,248,0.22);
      border-radius: 10px;
      display: flex; gap: 12px; align-items: center;
      transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
    }
    .magic-card:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(75,217,248,0.1);
      border-color: rgba(75,217,248,0.4);
    }
    .magic-card .ico { width: 32px; height: 32px; border-radius: 8px; background: rgba(75,217,248,0.15); border: 1px solid rgba(75,217,248,0.4); display: grid; place-items: center; color: var(--mbc-cyan); flex-shrink: 0; }
    .magic-card .info { flex: 1; }
    .magic-card .info b { display: block; font-weight: 600; font-size: 13px; color: var(--text-primary); }
    .magic-card .info span { font-size: 11.5px; color: var(--text-tertiary); }

    .footer-mini {
      margin-top: 32px;
      font-size: 12px;
      color: var(--text-tertiary);
      text-align: center;
    }
    .footer-mini a { color: var(--text-secondary); }
    .footer-mini a:hover { color: var(--mbc-cyan); }

    /* 2FA step */
    .otp-row {
      display: flex; gap: 8px;
      justify-content: center;
      margin: 24px 0;
    }
    .otp-row input {
      width: 48px; height: 56px;
      text-align: center;
      font-family: var(--font-mono);
      font-size: 20px;
      font-weight: 600;
      padding: 0;
    }

    @media (max-width: 880px) {
      .auth-shell { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
      .auth-left { 
        padding: 24px; 
        padding-bottom: 24px;
        min-height: auto; 
        border-right: none; 
        border-bottom: 1px solid var(--border-subtle); 
        overflow: visible;
      }
      .auth-left-content, .auth-footer-links, .auth-aurora, .auth-left::before { 
        display: none !important; 
      }
      .auth-right { 
        padding: 32px 24px; 
        align-items: start; 
      }
      /* Mobile Brand text override to "MBC" */
      .auth-left-head .brand-text span { display: none !important; }
      .auth-left-head .brand-text::before { content: "MBC"; }
    }