/* ===== THEME STYLES (from your CSS) ===== */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: 'Poppins', sans-serif;
    }

    body {
      background: #f0f4f8;
      color: #333;
      scroll-behavior: smooth;
    }

    a { text-decoration: none; color: inherit; }

    .container {
  width: 100%;
  max-width: 100%;
  max-height: 100%;
  min-height: 100%; /* full-screen height */
  margin: 0;
  border-radius: 0;
  padding: 3rem 2rem;
  background: #fff;
}

/* === HEADER STYLING (fixed layout) === */
.main-header {
  width: 100%;
  max-width: 1100px;
  margin: 1rem auto;
  background: #1E90FF;
  border-radius: 20px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.1);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
}

.logo {
  font-weight: 700;
  font-size: 1.5rem;
  color: #fff;
}

.nav-menu ul {
  list-style: none;
  display: flex;
  gap: 2rem;
  margin: 0;
  padding: 0;
}

.nav-menu ul li a {
  color: #fff;
  font-weight: 600;
  transition: 0.3s;
}

.nav-menu ul li a:hover {
  color: #FFD700;
}

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-menu ul {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
  }
}

    h1 {
      color: #1E90FF;
      text-align: center;
      margin-bottom: 1.5rem;
    }

    h2 {
      color: #00BFFF;
      text-align: center;
      margin-bottom: 1rem;
    }

    button {
      cursor: pointer;
      border: none;
      padding: 0.8rem 1.5rem;
      border-radius: 10px;
      font-weight: 600;
      transition: 0.3s;
    }

    #login-btn {
      background: #1E90FF;
      color: #fff;
      display: block;
      margin: 2rem auto;
      font-size: 1.1rem;
    }
    #login-btn:hover {
      background: #FFD700;
      color: #1E90FF;
    }

    #logout-btn {
      background: #FF8C00;
      color: #fff;
      margin-top: 1rem;
    }
    #logout-btn:hover {
      background: #FFD700;
      color: #1E90FF;
    }

    #pay-btn, #renew-btn {
      background: #1E90FF;
      color: #fff;
      margin: 10px 5px;
    }
    #pay-btn:hover, #renew-btn:hover {
      background: #FFD700;
      color: #1E90FF;
    }

    /* Tabs */
    .tabs {
      display: flex;
      justify-content: center;
      gap: 1rem;
      margin-top: 2rem;
      border-bottom: 2px solid #f0f0f0;
      padding-bottom: 1rem;
    }

    .tab-btn {
      background: none;
      color: #333;
      font-size: 1rem;
    }

    .tab-btn.active {
      color: #1E90FF;
      border-bottom: 3px solid #1E90FF;
      font-weight: bold;
    }

    .tab-content {
      margin-top: 20px;
      padding: 1rem;
      border-radius: 10px;
      background: #f9f9f9;
      min-height: 150px;
    }

    .status-msg {
      color: red;
      font-weight: bold;
      margin: 10px 0;
      text-align: center;
    }

    iframe {
      border-radius: 10px;
      box-shadow: 0 0 10px rgba(0,0,0,0.1);
    }

    /* Restricted notice */
    .restricted {
      color: #FF8C00;
      font-weight: bold;
      text-align: center;
      background: #fff3cd;
      border-radius: 8px;
      padding: 1rem;
    }

    .hidden { display: none; }

    /* Plan Selection Dropdown */
    #plan-selection-container {
      background: #f9f9f9;
      padding: 1.5rem;
      border-radius: 10px;
      margin: 1rem 0;
      box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    }

    #course-plan-select {
      background: #fff;
      color: #333;
      cursor: pointer;
    }

    #course-plan-select:focus {
      outline: none;
      border-color: #FFD700;
      box-shadow: 0 0 0 3px rgba(30, 144, 255, 0.1);
    }

    /* Footer */
    footer {
      background: #1E90FF;
      color: #fff;
      text-align: center;
      padding: 2rem 1rem;
      font-size: 0.9rem;
      margin-top: 3rem;
      border-radius: 15px;
    }

    @media (max-width: 600px) {
      .container {
        padding: 1.5rem;
      }
      button {
        width: 100%;
      }
      iframe {
        height: 300px;
      }
    }