/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --background: #fafafa;
  --foreground: #111827;
  --muted: #f3f4f6;
  --muted-foreground: #6b7280;
  --card: #ffffff;
  --card-foreground: #111827;
  --border: #e5e7eb;
  --input: #e5e7eb;
  --primary: #3b82f6;
  --primary-foreground: #f9fafb;
  --secondary: #f3f4f6;
  --secondary-foreground: #111827;
  --accent: #f3f4f6;
  --accent-foreground: #111827;
  --destructive: #f43f5e;
  --destructive-foreground: #f9fafb;
  --ring: #3b82f6;
  --radius: 0.5rem;

  --success: #10b981;
  --success-foreground: #f9fafb;
  --warning: #f59e0b;
  --warning-foreground: #f9fafb;
  
  --font-sans: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --font-heading: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.dark {
  --background: #111827;
  --foreground: #f9fafb;
  --muted: #1f2937;
  --muted-foreground: #9ca3af;
  --card: #1f2937;
  --card-foreground: #f9fafb;
  --border: #374151;
  --input: #374151;
  --primary: #3b82f6;
  --primary-foreground: #f9fafb;
  --secondary: #1f2937;
  --secondary-foreground: #f9fafb;
  --accent: #1f2937;
  --accent-foreground: #f9fafb;
  --destructive: #f43f5e;
  --destructive-foreground: #f9fafb;
  --ring: #93c5fd;
  
  --success: #059669;
  --success-foreground: #f9fafb;
  --warning: #d97706;
  --warning-foreground: #f9fafb;
}

html, body {
  font-family: var(--font-sans);
  background-color: var(--background);
  color: var(--foreground);
  line-height: 1.5;
  font-size: 16px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
}

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

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

/* Layout */
#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* Header */
.header {
  background-color: var(--card);
  box-shadow: var(--shadow-sm);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--border);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header h1 {
  font-size: 1.5rem;
  color: var(--primary);
}

.theme-toggle {
  background: var(--secondary);
  border: none;
  border-radius: 9999px;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--foreground);
  transition: background-color 0.2s;
}

.theme-toggle:hover {
  background: var(--muted);
}

.theme-toggle .sun-icon {
  display: none;
}

.theme-toggle .moon-icon {
  display: block;
}

.dark .theme-toggle .sun-icon {
  display: block;
  color: #f59e0b;
}

.dark .theme-toggle .moon-icon {
  display: none;
}

/* Main content */
.main {
  flex: 1;
  padding: 2rem 0;
}

.welcome {
  text-align: center;
  margin-bottom: 2rem;
}

.welcome h2 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--foreground);
}

.welcome p {
  color: var(--muted-foreground);
}

/* Tabs */
.tabs {
  margin-bottom: 2rem;
}

.tab-buttons {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--muted);
  padding: 0.25rem;
}

.tab-button {
  padding: 0.75rem 1rem;
  background: transparent;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted-foreground);
  transition: all 0.2s;
  text-align: center;
}

.tab-button:hover {
  color: var(--foreground);
}

.tab-button.active {
  background-color: var(--card);
  color: var(--foreground);
  box-shadow: var(--shadow-sm);
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(5px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Calculator cards */
.calculator-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}

@media (min-width: 768px) {
  .calculator-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.calculator-single {
  margin-bottom: 3rem;
}

.calculator-card {
  background-color: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  transition: box-shadow 0.3s, transform 0.3s;
}

.calculator-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-5px);
}

.calculator-card.full-width {
  width: 100%;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.card-header h3 {
  font-size: 1.125rem;
  color: var(--foreground);
}

.card-description {
  font-size: 0.875rem;
  color: var(--muted-foreground);
  margin-bottom: 1.5rem;
}

.button-group {
  display: flex;
  gap: 0.5rem;
}

.copy-button, .reset-button {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.375rem 0.75rem;
  background-color: var(--secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--foreground);
  cursor: pointer;
  transition: background-color 0.2s;
}

.copy-button:hover, .reset-button:hover {
  background-color: var(--muted);
}

.copy-button svg, .reset-button svg {
  width: 0.875rem;
  height: 0.875rem;
}

.copy-button.copied {
  background-color: var(--success);
  color: var(--success-foreground);
}

/* Form elements */
.input-group {
  margin-bottom: 1rem;
}

.input-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--foreground);
  margin-bottom: 0.25rem;
}

.input-with-suffix {
  display: flex;
}

.input-with-suffix input {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
  flex: 1;
}

.input-suffix {
  display: inline-flex;
  align-items: center;
  padding: 0 0.75rem;
  background-color: var(--muted);
  border: 1px solid var(--border);
  border-left: none;
  border-top-right-radius: var(--radius);
  border-bottom-right-radius: var(--radius);
  color: var(--muted-foreground);
}

input[type="number"], input[type="text"] {
  width: 100%;
  padding: 0.5rem 0.75rem;
  background-color: var(--background);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--foreground);
}

input[type="number"]:focus, input[type="text"]:focus {
  outline: 2px solid var(--ring);
  outline-offset: -1px;
}

.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.radio-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.radio-item input[type="radio"] {
  width: 1rem;
  height: 1rem;
  cursor: pointer;
}

.radio-item label {
  margin-bottom: 0;
  cursor: pointer;
  font-weight: normal;
}

/* Results */
.result-area {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.result-box {
  background-color: #ebf5ff;
  padding: 1rem;
  border-radius: var(--radius);
}

.dark .result-box {
  background-color: rgba(59, 130, 246, 0.1);
}

.result-text {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--primary);
}

.result-direction {
  font-size: 0.875rem;
  color: var(--muted-foreground);
  margin-top: 0.25rem;
}

.result-heading {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--foreground);
}

.result-details {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

@media (min-width: 640px) {
  .result-details {
    flex-direction: row;
    justify-content: space-between;
  }
}

.result-column {
  flex: 1;
}

.result-label {
  font-size: 0.875rem;
  color: var(--muted-foreground);
}

.result-value {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--primary);
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .result-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.result-item {
  text-align: center;
}

/* Info sections */
.info-section {
  background-color: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  margin-top: 3rem;
}

.info-section h3 {
  font-size: 1.125rem;
  margin-bottom: 1rem;
  color: var(--foreground);
}

.info-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .info-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .info-grid.three-columns {
    grid-template-columns: repeat(3, 1fr);
  }
}

.info-item h4 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: var(--foreground);
}

.info-item p {
  font-size: 0.875rem;
  color: var(--muted-foreground);
  margin-bottom: 0.5rem;
}

.gst-rates {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.gst-rates h4 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
  color: var(--foreground);
}

.rate-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

@media (min-width: 768px) {
  .rate-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.rate-item {
  background-color: var(--muted);
  padding: 0.75rem;
  border-radius: var(--radius);
  text-align: center;
}

.rate {
  font-size: 1rem;
  font-weight: 500;
  color: var(--foreground);
}

.rate-desc {
  font-size: 0.75rem;
  color: var(--muted-foreground);
}

.tips-section {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.tips-section h4 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
  color: var(--foreground);
}

.tips-list {
  padding-left: 1.5rem;
}

.tips-list li {
  font-size: 0.875rem;
  color: var(--muted-foreground);
  margin-bottom: 0.5rem;
}

/* Footer */
.footer {
  background-color: var(--card);
  border-top: 1px solid var(--border);
  padding: 1.5rem 0;
  margin-top: auto;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

@media (min-width: 640px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
  }
}

.copyright {
  font-size: 0.875rem;
  color: var(--muted-foreground);
}

.footer-links {
  display: flex;
  gap: 1rem;
}

.footer-link {
  font-size: 0.875rem;
  color: var(--muted-foreground);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--primary);
}

/* Toast notification */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100%);
  background-color: var(--card);
  color: var(--foreground);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  font-size: 0.875rem;
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  z-index: 100;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* Helper classes */
.profit {
  color: var(--success) !important;
}

.loss {
  color: var(--destructive) !important;
}