:root {
      --primary-color: #1a73e8;
      --primary-dark: #1557b0;
      --success-color: #34a853;
      --danger-color: #dc2626;
      --text-dark: #1f2937;
      --text-muted: #6b7280;
      --border-color: #d1d5db;
      --bg-light: #f3f6fb;
      --white: #ffffff;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: 'Source Sans Pro', sans-serif;
      min-height: 100vh;
      background:
        radial-gradient(circle at top right, rgba(26,115,232,.08), transparent 30%),
        radial-gradient(circle at bottom left, rgba(52,168,83,.05), transparent 30%),
        var(--bg-light);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 40px 20px;
    }

    .signup-container {
      width: 100%;
      max-width: 1150px;
    }

    .signup-card {
      display: flex;
      overflow: hidden;
      border-radius: 30px;
      background: rgba(255,255,255,.88);
      backdrop-filter: blur(18px);
      box-shadow:
        0 20px 60px rgba(0,0,0,.08),
        inset 0 1px 0 rgba(255,255,255,.7);
      min-height: 760px;
    }

    .signup-left {
      width: 42%;
      background:
            linear-gradient(135deg, rgba(3, 151, 197, 0.984), rgba(2,72,92,.94)),
    url('../logo/logo-2.png');
      background-size: cover;
      color: white;
      padding: 80px 45px 45px;
      display: flex;
      flex-direction: column;
      justify-content: flex-start;
      align-items: center;
      position: relative;
    }

    .signup-left::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(0,0,0,.12);
    }

    .signup-left-content {
      position: relative;
      z-index: 2;
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .school-logo {
      width: 95px;
      margin-bottom: 25px;
    }

    .signup-left h1 {
      font-size: 38px;
      line-height: 1.2;
      margin-bottom: 15px;
      font-weight: 700;
      text-align: center;
    }

    .signup-left p {
      font-size: 17px;
      opacity: .92;
      line-height: 1.7;
      text-align: left;
      width: 100%;
      max-width: 420px;
    }

    .signup-left p {
      font-size: 17px;
      opacity: .92;
      line-height: 1.7;
    }

    .signup-right {
      width: 58%;
      padding: 55px;
      background: rgba(255,255,255,.92);
    }

    .form-title {
      margin-bottom: 35px;
    }

    .form-title h2 {
      font-size: 32px;
      color: var(--text-dark);
      margin-bottom: 8px;
    }

    .form-title p {
      color: var(--text-muted);
      font-size: 15px;
    }

    .form-row {
      display: flex;
      gap: 18px;
    }

    .form-col {
      flex: 1;
    }

    .form-group {
      margin-bottom: 22px;
    }

    .modern-field {
      position: relative;
    }

    .modern-field input,
    .modern-field select {
      width: 100%;
      height: 60px;
      border: 1.5px solid var(--border-color);
      border-radius: 18px;
      background: var(--white);
      padding: 0 16px 0 52px;
      font-size: 15px;
      line-height: 60px;
      color: var(--text-dark);
      transition: .25s ease;
      appearance: none;
    }

    .modern-field select {
      cursor: pointer;
    }

    .modern-field input::placeholder {
      color: transparent;
    }

    .modern-field label {
      position: absolute;
      top: 19px;
      left: 52px;
      color: var(--text-muted);
      pointer-events: none;
      transition: .2s ease;
      background: white;
      padding: 0 6px;
      font-size: 15px;
    }

    .modern-field i {
      position: absolute;
      top: 50%;
      left: 18px;
      transform: translateY(-50%);
      color: #94a3b8;
      font-size: 15px;
      transition: .2s ease;
    }

    .modern-field input:focus,
    .modern-field select:focus {
      outline: none;
      border-color: var(--primary-color);
      box-shadow:
        0 0 0 4px rgba(26,115,232,.10),
        0 8px 20px rgba(26,115,232,.08);
    }

    .modern-field input:focus + label,
    .modern-field input:not(:placeholder-shown) + label,
    .modern-field select:focus + label,
    .modern-field select:valid + label {
      top: -9px;
      left: 45px;
      font-size: 12px;
      font-weight: 700;
      color: var(--primary-color);
    }

    .modern-field input:focus ~ i,
    .modern-field select:focus ~ i {
      color: var(--primary-color);
    }

    .is-invalid {
      border-color: var(--danger-color) !important;
      box-shadow: 0 0 0 4px rgba(220,38,38,.08);
    }

    .terms-section {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin: 25px 0;
    }

    .terms-section input {
      width: 18px;
      height: 18px;
      margin-top: 2px;
      accent-color: var(--primary-color);
    }

    .terms-section label {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.5;
    }

    .terms-section a {
      color: var(--primary-color);
      text-decoration: none;
      font-weight: 600;
    }

    .btn-register {
      width: 100%;
      height: 58px;
      border: none;
      border-radius: 18px;
      background: linear-gradient(135deg,#01313f,#02455a);
      color: white;
      font-size: 16px;
      font-weight: 700;
      cursor: pointer;
      transition: .25s ease;
      box-shadow: 0 14px 28px rgba(26,115,232,.18);
    }

    .btn-register:hover {
      transform: translateY(-1px);
      box-shadow: 0 18px 35px rgba(26,115,232,.25);
    }

    .btn-register:disabled {
      opacity: .7;
      cursor: not-allowed;
    }

    .divider {
      display: flex;
      align-items: center;
      gap: 15px;
      margin: 30px 0;
      color: var(--text-muted);
      font-size: 14px;
    }

    .divider::before,
    .divider::after {
      content: '';
      flex: 1;
      height: 1px;
      background: #e5e7eb;
    }

    .social-buttons {
      display: flex;
      gap: 14px;
    }

    .btn-social {
      flex: 1;
      height: 54px;
      border-radius: 16px;
      border: 1px solid #e5e7eb;
      background: white;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      cursor: pointer;
      font-size: 15px;
      font-weight: 600;
      transition: .25s ease;
    }

    .btn-social:hover {
      transform: translateY(-1px);
      box-shadow: 0 10px 20px rgba(0,0,0,.06);
    }

    .login-section {
      text-align: center;
      margin-top: 28px;
      color: var(--text-muted);
      font-size: 15px;
    }

    .login-section a {
      color: var(--primary-color);
      font-weight: 700;
      text-decoration: none;
    }

    .alert {
      padding: 16px 18px;
      border-radius: 16px;
      margin-bottom: 25px;
      font-size: 14px;
      font-weight: 600;
    }

    .alert-error {
      background: #fee2e2;
      color: #b91c1c;
    }

    .alert-success {
      background: #dcfce7;
      color: #166534;
    }

    #loadingOverlay {
      position: fixed;
      inset: 0;
      background: rgba(255,255,255,.75);
      backdrop-filter: blur(6px);
      display: none;
      align-items: center;
      justify-content: center;
      z-index: 9999;
    }

    .spinner {
      width: 55px;
      height: 55px;
      border: 4px solid #e5e7eb;
      border-top: 4px solid var(--primary-color);
      border-radius: 50%;
      animation: spin .8s linear infinite;
    }

    @keyframes spin {
      100% {
        transform: rotate(360deg);
      }
    }

    @media(max-width: 992px) {
      .signup-card {
        flex-direction: column;
      }

      .signup-left,
      .signup-right {
        width: 100%;
      }
    }

    @media(max-width: 768px) {
      .form-row {
        flex-direction: column;
      }

      .signup-right {
        padding: 35px 25px;
      }

      .signup-left {
        padding: 45px 30px;
      }

      .social-buttons {
        flex-direction: column;
      }
    }