/* Base styles and layout */
@import url('variables.css');

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Base */
html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  height: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Layout */
.app-container {
  display: flex;
  flex-direction: column;
  height: 100%;
  width: 100%;
  overflow: hidden;
}

.header {
  height: var(--header-height);
  background-color: var(--color-bg-white);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 var(--spacing-4);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: var(--max-width-chat);
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.header-logo {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
}

.header-title {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-height: 0; /* Allow flex shrinking to prevent clipping */
}

/* Utility classes */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2) var(--spacing-4);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  line-height: var(--line-height-tight);
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
}

.btn-secondary {
  background-color: var(--color-bg-secondary);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-border);
}

.btn-sm {
  padding: var(--spacing-1) var(--spacing-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--spacing-3) var(--spacing-6);
  font-size: var(--font-size-base);
}

/* Form elements */
.input {
  width: 100%;
  padding: var(--spacing-3);
  font-family: inherit;
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.input::placeholder {
  color: var(--color-text-muted);
}

.input-error {
  border-color: var(--color-error);
}

.input-error:focus {
  box-shadow: 0 0 0 3px var(--color-error-bg);
}

/* Error message */
.error-text {
  font-size: var(--font-size-sm);
  color: var(--color-error);
  margin-top: var(--spacing-1);
}

/* Loading spinner */
.spinner {
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Mobile responsive */
@media (max-width: 640px) {
  html {
    font-size: 14px;
  }

  .header {
    padding: 0 var(--spacing-3);
  }

  .header-title {
    display: none;
  }
}