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

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  min-height: 100vh;
  padding: var(--spacing-lg);
  line-height: 1.5;
  transition:
    background-color var(--transition-speed),
    color var(--transition-speed);
}

@media (min-width: 1024px) {
  body {
    padding: var(--spacing-2xl);
  }
}

.container {
  max-width: var(--container-max-width);
  width: 100%;
  margin: 0 auto;
}

/* Header */
header {
  margin-bottom: var(--spacing-2xl);
}

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

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.logo {
  width: 2rem;
  height: 2rem;
  object-fit: contain;
}

@media (min-width: 768px) {
  .logo {
    width: 2.5rem;
    height: 2.5rem;
  }
}

header h1 {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--primary-colour);
}

@media (min-width: 768px) {
  header h1 {
    font-size: 1.875rem;
  }
}

.theme-toggle {
  background: none;
  border: 2px solid var(--border-colour);
  border-radius: var(--border-radius-md);
  padding: var(--spacing-sm);
  cursor: pointer;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-speed);
}

.theme-toggle:hover {
  background-color: var(--bg-subtle);
  color: var(--accent-colour);
}

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

[data-theme="dark"] .theme-toggle .sun-icon {
  display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
  display: block;
}

.header-accent {
  height: 0.25rem;
  width: 5rem;
  background-color: var(--accent-colour);
  margin-top: var(--spacing-md);
}

/* Converter */
.converter {
  background-color: var(--bg-subtle);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  display: grid;
  gap: var(--spacing-lg);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

label {
  font-weight: 600;
  font-size: 0.875rem;
}

textarea {
  width: 100%;
  min-height: 200px;
  padding: 0.75rem;
  border: 1px solid var(--border-colour);
  border-radius: var(--border-radius-md);
  background-color: var(--bg-input);
  color: var(--text-main);
  font-family:
    "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  font-size: 0.9rem;
  resize: vertical;
  transition: border-color 0.2s;
}

textarea:focus {
  outline: none;
  border-color: var(--accent-colour);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
}

.stats {
  display: flex;
  justify-content: flex-end;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-unit);
  align-items: flex-end;
  background-color: var(--bg-main);
  padding: var(--spacing-unit);
  border-radius: var(--border-radius-md);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  flex: 1;
  min-width: 150px;
}

select {
  padding: 0.5rem;
  border: 1px solid var(--border-colour);
  border-radius: var(--border-radius-md);
  background-color: var(--bg-input);
  color: var(--text-main);
  cursor: pointer;
}

.control-actions {
  display: flex;
  gap: 0.5rem;
}

button {
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-md);
  border: none;
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.2s, opacity 0.2s;
}

#swap-btn, #clear-btn {
  background-color: var(--btn-secondary-bg);
  color: var(--btn-secondary-text);
  border: 1px solid var(--btn-secondary-border);
}

#swap-btn:hover, #clear-btn:hover {
  background-color: var(--bg-main);
  opacity: 1;
}

.result-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

#copy-btn, #download-btn {
  background-color: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  flex: 1;
}

#copy-btn:hover, #download-btn:hover {
  opacity: 0.9;
}

.error-message {
  margin-top: var(--spacing-unit);
  padding: 1rem;
  background-color: rgba(239, 68, 68, 0.1);
  color: var(--error-colour);
  border-radius: var(--border-radius-md);
  font-size: 0.875rem;
}

.hidden {
  display: none;
}

footer {
  margin-top: calc(var(--spacing-unit) * 4);
  padding: calc(var(--spacing-unit) * 2) 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Toast Notification Styles */
#toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  padding: 1rem 1.5rem;
  background-color: var(--bg-subtle);
  color: var(--text-main);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-md);
  border-left: 4px solid var(--accent-colour);
  min-width: 250px;
  animation: slideIn 0.3s ease-out;
}

.toast.success {
  border-left-color: var(--success-colour);
}
.toast.error {
  border-left-color: var(--error-colour);
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* Mobile-first adjustments (already mostly responsive via Flex/Grid) */
@media (max-width: 767px) {
  h1 {
    font-size: 2rem;
  }
  .controls {
    flex-direction: column;
    align-items: stretch;
  }
  .control-group {
    min-width: 100%;
  }
  .control-actions {
    justify-content: space-between;
  }
  .control-actions button {
    flex: 1;
  }
  .result-actions {
    flex-direction: column;
  }
}

/* Print Styles */
@media print {
  header, footer, .controls, .result-actions {
    display: none;
  }
  body {
    background-color: white;
    color: black;
  }
  .converter {
    box-shadow: none;
    padding: 0;
  }
  textarea {
    border: 1px solid #ccc;
    height: auto;
    min-height: 100px;
  }
}