:root {
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --blue-primary: #007aff;
    --blue-hover: #005bb5;
    --gray-light: #f2f2f7;
    --gray-medium: #e5e5ea;
    --gray-dark: #d1d1d6;
    --gray-text: #555;
    --white: #ffffff;
  }
  
  /* General body style */
  body {
    font-family: var(--font-primary);
    background-color: var(--gray-light);
    background: linear-gradient(to bottom, var(--gray-light) 0%, var(--white) 100%);
    color: #1c1c1e;
    transition: opacity 0.5s ease;
  }
  
  body.fade-out {
    opacity: 0;
  }
  
  /* Login / Signup Card Styles */
  .login-card,
  .signup-card {
    background-color: var(--white);
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    width: 100%;
    max-width: 400px;
    opacity: 0.95;
  }
  
  /* Form Controls */
  .form-control {
    background-color: var(--gray-light);
    border: none;
    border-radius: 12px;
    padding: 0.75rem;
    font-size: 1rem;
    color: #1c1c1e;
  }
  
  .form-control:focus {
    background-color: var(--gray-medium);
    box-shadow: 0 0 0 0.25rem rgba(0, 122, 255, 0.25);
  }
  
  .form-control.error {
    background-color: #f8d7da;
    border: 1px solid #dc3545;
  }
  
  /* Apple Style Blue Button */
  .btn-apple {
    background-color: var(--blue-primary) !important;
    color: var(--white) !important;
    border-radius: 12px !important;
    padding: 0.75rem 1.5rem !important;
    font-weight: 500 !important;
    font-size: 1rem !important;
    border: none !important;
    transition: background-color 0.3s ease;
  }
  
  .btn-apple:hover {
    background-color: var(--blue-hover) !important;
  }
  
  /* Section Content Visibility */
  .section-content {
    display: none;
    opacity: 0;
  
  }
  
  .section-content.show {
    display: block;
    opacity: 1;
  }
  
  .section-content.fade-in {
    opacity: 1;
  }
  
  .section-content.fade-out {
    opacity: 0;
  }
  
  /* Section Title */
  .section-title {
    text-align: center;
    font-size: 2rem;
    font-weight: 600;
    color: #323643;
    margin-bottom: 1rem;
  }
  
  /* Accordion */
  .accordion-item {
    border: none;
    margin-bottom: 1.5rem;
    background-color: var(--white);
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
  }
  
  .accordion-button {
    background-color: var(--gray-light);
    color: #1c1c1e;
    border-radius: 16px !important;
    font-weight: 500;
    transition: background-color 0.3s ease;
  }
  
  .accordion-button:hover {
    background-color: var(--gray-medium);
  }
  
  .accordion-button:not(.collapsed) {
    background-color: var(--gray-medium);
  }
  
  .accordion-body {
    background-color: var(--white);
    padding: 2rem;
    border-top: 1px solid #dee2e6;
    border-radius: 0 0 20px 20px;
  }
  
  .accordion-body label {
    font-weight: 500;
    color: #1c1c1e;
    margin-top: 0.75rem;
    display: block;
  }
  
  .accordion-body input,
  .accordion-body select {
    background-color: var(--gray-light);
    border: none;
    border-radius: 12px;
    padding: 0.75rem;
    font-size: 1rem;
    color: #1c1c1e;
    width: 100%;
  }
  
  .accordion-body input:focus {
    background-color: var(--gray-medium);
    box-shadow: 0 0 0 0.25rem rgba(0, 122, 255, 0.25);
    outline: none;
  }
  
  input[type="file"] {
    background-color: var(--gray-light);
    color: #1c1c1e;
    cursor: pointer;
  }
  
  .accordion-button::after {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='currentColor' class='bi bi-chevron-down' viewBox='0 0 16 16'%3E%3Cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3E%3C/svg%3E");
  }
  
  /* General Shadow Utility */
  .shadow-soft {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
  }
  
  /* Navigation */
  .navbar {
    border-radius: 1rem;
    padding: 1rem 2rem;
    position: relative;
    background-color: var(--white);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.08);
  }
  
  .nav-link {
    color: var(--gray-text);
    font-weight: 500;
    position: relative;
  }
  
  .nav-link.active,
  .nav-link:hover {
    color: var(--blue-primary);
  }
  
  /* Animated underline */
  .navbar .line {
    position: absolute;
    bottom: 0;
    height: 3px;
    background-color: var(--blue-primary);
    transition: all 0.3s ease;
    border-radius: 2px;
    left: 0;
    width: 0;
  }
  
  .form-label {
    font-weight: 500;
    color: #606470;
    margin-bottom: 0.5rem;
    display: block;
  }
  
  /* Save Button (Primary Blue) */
  #physical-save-btn,
  #save-btn {
    background-color: var(--blue-primary);
    color: var(--white);
    border-radius: 14px;
    padding: 0.75rem 1.7rem;
    font-weight: 600;
    font-size: 1rem;
    border: none;
    box-shadow: 0 8px 20px rgba(0, 122, 255, 0.3);
    transition: background-color 0.3s ease, transform 0.2s ease;
  }
  
  #physical-save-btn:hover,
  #save-btn:hover {
    background-color: var(--blue-hover);
    transform: translateY(-2px);
  }
  
  /* Edit Button (Gray Secondary) */
  #physical-edit-btn,
  #edit-btn,
  #submit {
    background-color: var(--gray-medium);
    color: #1c1c1e;
    border-radius: 14px;
    padding: 0.75rem 1.7rem;
    font-weight: 500;
    font-size: 1rem;
    border: none;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
    transition: background-color 0.3s ease, transform 0.2s ease;
  }
  
  #physical-edit-btn:hover,
  #edit-btn:hover,
  #submit:hover {
    background-color: var(--gray-dark);
    transform: translateY(-2px);
  }
  
  /* Welcome Message */
  .welcome-message {
    display: none;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    background-color: var(--white);
    color: #333;
    margin-bottom: 1.5rem;
    border-radius: 0.8rem;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  }
  
  .welcome-user {
    font-size: 2.2rem;
    font-weight: 700;
    color: #222;
  }
  
  .welcome-right {
    text-align: right;
  }
  
  .welcome-time {
    font-size: 1.4rem;
    color: #777;
  }
  
  .welcome-date {
    font-size: 1.3rem;
    color: #555;
    font-weight: 500;
  }

  .highlight {
    background-color: #fff3b0 !important; 
    border: 2px solid #ffcc80 !important; 
    transition: background-color 0.3s ease-in-out, border 0.3s ease-in-out;
}
/* title */
.group-code-wrapper {
  text-align: center;
}

.group-code {
  font-size: 1.05rem;
  font-weight: 600;
  color: #1f2937; /* dark gray-blue */

  padding: 6px 20px;
  border-radius: 999px;
  display: inline-block;
  letter-spacing: 1px;

}

.group-subtext {
  margin-top: 4px;
  font-size: 0.9rem;
  color: #4b5563; /* medium neutral gray */
  font-weight: 500;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}