/* Modern CSS Reset */
*, *::before, *::after {
  box-sizing: border-box;
}

/* Modern Color Palette inspired by screenshots */
:root {
  /* Light theme colors - updated to match second screenshot */
  --primary-light: #3F8CFF;
  --primary-dark-light: #1971f2;
  --secondary-light: #FF9564;
  --accent-light: #FF6B6B;
  --background-light: #F5F7FA;
  --card-bg-light: #FFFFFF;
  --text-dark-light: #333333;
  --text-light-light: #7E8299;
  --success-light: #0BB783;
  --error-light: #F64E60;
  --border-light: #E5EAEE;
  --shadow-light: rgba(0, 0, 0, 0.05);
  --card-hover-light: #FFFFFF;
  --input-bg-light: #F3F6F9;
  
  /* Dark theme colors based on the first screenshot */
  --primary-dark: #4CAF50;
  --primary-dark-dark: #2E7D32;
  --secondary-dark: #FF9800;
  --accent-dark: #F44336;
  --background-dark: #121212;
  --card-bg-dark: #222222;
  --text-dark-dark: #FFFFFF;
  --text-light-dark: #AAAAAA;
  --success-dark: #66BB6A;
  --error-dark: #EF5350;
  --border-dark: #333333;
  --shadow-dark: rgba(0, 0, 0, 0.3);
  --card-hover-dark: #2A2A2A;
  --input-bg-dark: #333333;
  
  /* Default to light theme */
  --primary: var(--primary-light);
  --primary-dark: var(--primary-dark-light);
  --secondary: var(--secondary-light);
  --accent: var(--accent-light);
  --background: var(--background-light);
  --card-bg: var(--card-bg-light);
  --text-dark: var(--text-dark-light);
  --text-light: var(--text-light-light);
  --success: var(--success-light);
  --error: var(--error-light);
  --border: var(--border-light);
  --shadow: var(--shadow-light);
  --card-hover: var(--card-hover-light);
  --input-bg: var(--input-bg-light);
}

/* Dark Mode Class */
.dark-mode {
  --primary: var(--primary-dark);
  --primary-dark: var(--primary-dark-dark);
  --secondary: var(--secondary-dark);
  --accent: var(--accent-dark);
  --background: var(--background-dark);
  --card-bg: var(--card-bg-dark);
  --text-dark: var(--text-dark-dark);
  --text-light: var(--text-light-dark);
  --success: var(--success-dark);
  --error: var(--error-dark);
  --border: var(--border-dark);
  --shadow: var(--shadow-dark);
  --card-hover: var(--card-hover-dark);
  --input-bg: var(--input-bg-dark);
}

body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background: var(--background);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  transition: background 0.3s ease, color 0.3s ease;
}

.container {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

/* Theme Toggle */
.theme-toggle {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: transparent;
  border: none;
  color: var(--text-dark);
  font-size: 1.5rem;
  cursor: pointer;
  z-index: 100;
}

/* Card Effect */
.split-expense-app {
  background: var(--card-bg);
  border-radius: 16px;
  box-shadow: 0 8px 30px var(--shadow);
  padding: 2rem;
  transition: background 0.3s ease;
  position: relative;
  overflow: hidden;
}

.split-expense-app:hover {
  /* Remove the animation that causes up/down movement */
  /* transform: translateY(-5px); */
  /* box-shadow: 0 12px 40px var(--shadow); */
}

/* Typography */
h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--primary);
  margin-top: 0;
  margin-bottom: 0.5rem;
  transition: color 0.3s ease;
  display: flex;
  align-items: center;
}

h1 i {
  margin-right: 0.5rem;
}

.subtitle {
  color: var(--text-light);
  margin-top: 0;
  margin-bottom: 1.5rem;
  transition: color 0.3s ease;
}

/* Form Elements */
.form-group {
  margin-bottom: 1.5rem;
  position: relative;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--text-dark);
  transition: color 0.3s ease;
}

input, select {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background-color: var(--input-bg);
  color: var(--text-dark);
  transition: border-color 0.2s, box-shadow 0.2s, background-color 0.3s, color 0.3s;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.2);
}

input[type="number"] {
  -moz-appearance: textfield;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease;
  border: none;
}

.button i {
  margin-right: 0.5rem;
}

.primary {
  background-color: var(--primary);
  color: white;
}

.primary:hover {
  background-color: var(--primary-dark);
}

.secondary {
  background-color: var(--secondary);
  color: white;
}

.secondary:hover {
  filter: brightness(90%);
}

/* Setup Section */
.setup-section {
  margin-bottom: 1.5rem;
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.5rem;
}

.setup-section .form-group {
  flex: 1 1 100%;
}

/* Setup buttons container */
.setup-buttons {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

#quick-reset-button {
  background-color: var(--secondary);
  color: white;
}

#quick-reset-button:hover {
  filter: brightness(90%);
}

#set-button {
  background-color: var(--primary);
  color: white;
}

#set-button:hover {
  background-color: var(--primary-dark);
}

#update-button {
  background-color: var(--secondary);
  color: white;
  transition: background-color 0.3s ease;
}

#update-button:hover {
  background-color: var(--accent);
}

/* Expense Input Section */
.expense-inputs {
  margin-top: 2rem;
}

.expense-item {
  display: flex;
  align-items: center;
  padding: 1rem;
  margin-bottom: 1rem;
  background: var(--card-hover);
  border-radius: 8px;
  border: 1px solid var(--border);
  position: relative;
}

.expense-item label {
  margin-bottom: 0;
  margin-right: 1rem;
  min-width: 120px;
}

.expense-item input {
  flex: 1;
}

.expense-status {
  margin-left: 1rem;
  font-weight: 500;
  display: flex;
  align-items: center;
}

.expense-status i {
  margin-right: 0.5rem;
}

/* Results Section */
.results-container {
  margin-top: 2rem;
}

.result-summary {
  background-color: var(--card-hover);
  padding: 1.5rem;
  border-radius: 12px;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
}

.result-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  font-weight: 500;
}

.result-header strong {
  color: var(--primary);
}

.transactions {
  margin-top: 1.5rem;
}

.transaction-item {
  background-color: var(--card-hover);
  padding: 1rem;
  border-radius: 8px;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  border-left: 4px solid var(--primary);
}

.transaction-item i {
  margin-right: 0.75rem;
  color: var(--primary);
}

.transaction-amount {
  font-weight: 600;
  color: var(--primary);
}

/* Credit/Debit Indicators */
.credit {
  color: var(--success);
}

.debit {
  color: var(--error);
}

/* Zero payer highlight */
.zero-payer {
  position: relative;
}

.zero-payer strong:first-child {
  color: var(--accent);
  font-weight: 700;
  border-bottom: 1px dashed var(--accent);
}

.zero-payer::after {
  content: "* paid nothing";
  font-size: 0.7rem;
  color: var(--accent);
  display: block;
  margin-top: 0.2rem;
  font-style: italic;
}

/* Tooltip */
.tooltip-container {
  position: relative;
}

.tooltip {
  display: none;
}

/* Footer */
footer {
  margin-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.attribution {
  color: var(--text-light);
  font-size: 0.875rem;
}

.attribution i {
  color: var(--accent);
}

/* Error message */
.error-message {
  padding: 0.75rem 1rem;
  border-radius: 6px;
  margin-bottom: 1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }
  
  .split-expense-app {
    padding: 1.5rem;
  }
  
  .expense-item {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .expense-item label {
    margin-bottom: 0.5rem;
    margin-right: 0;
  }
  
  .expense-status {
    margin-left: 0;
    margin-top: 0.5rem;
  }
  
  .theme-toggle {
    top: 0.5rem;
    right: 0.5rem;
  }

  .setup-section {
    flex-direction: column;
    align-items: stretch;
    gap: 1rem; /* Increase gap when stacked */
  }

  .setup-section .form-group {
    flex-basis: auto; /* Allow form group to take full width */
  }

  .setup-buttons {
    justify-content: space-between; /* Space out buttons */
  }
  
  .setup-buttons .button {
    flex-grow: 1; /* Allow buttons to grow */
    justify-content: center; /* Center button text/icon */
    padding: 0.6rem 1rem; /* Slightly smaller padding */
  }

  .expense-item .person-details {
    flex-direction: column; /* Stack name and amount vertically */
    align-items: stretch; /* Stretch labels/inputs */
    gap: 0.5rem;
  }

  .expense-item .person-details label {
    margin-bottom: 0.25rem; /* Add space below labels */
  }
  
  .expense-item .person-details input[type="text"],
  .expense-item .person-details input[type="number"] {
    width: 100%; /* Make inputs take full width */
    margin-right: 0; /* Remove right margin */
    box-sizing: border-box; /* Include padding/border in width */
  }

  .results-summary h2 {
    font-size: 1.25rem;
  }

  .results-summary p {
    font-size: 1rem;
  }

  #results-container h3 {
    font-size: 1.1rem;
  }
  
  .transaction-list li {
    font-size: 0.95rem; /* Slightly smaller transaction text */
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0.5rem;
  }

  .split-expense-app {
    padding: 1rem;
    border-radius: 8px;
  }
  
  header h1 {
    font-size: 1.5rem; 
  }

  header .subtitle {
    font-size: 0.85rem;
  }

  .setup-buttons {
    flex-direction: column; /* Stack setup buttons */
    gap: 0.5rem;
  }

  .title-container {
    flex-direction: column; /* Stack title and clear button */
    align-items: flex-start;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
  }

  .clear-button {
    width: 100%; /* Make clear button full width */
    justify-content: center;
  }

  #expense-form button[type="submit"] {
    width: 100%; /* Make calculate button full width */
    justify-content: center;
  }

  #reset-button {
    width: 100%; /* Make footer reset button full width */
    justify-content: center;
    margin-bottom: 1rem;
  }
  
  footer .attribution {
    font-size: 0.8rem;
  }
}

/* Clear button styling */
.clear-button {
  background-color: var(--text-light);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  border: none;
  display: inline-flex;
  align-items: center;
  font-size: 0.9rem;
  margin-bottom: 1rem;
  transition: background-color 0.3s ease;
}

.clear-button:hover {
  background-color: var(--accent);
}

.clear-button i {
  margin-right: 0.5rem;
}

/* Disabled button styling */
.button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}