/* ==========================================================================
   Base Styles
   Reset, Typography, and Utilities
   ========================================================================== */

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

/* ========================================
   Theme Transitions
   Smooth color changes when switching themes
   ======================================== */

/* Theme transition class - applied during theme switch */
.theme-transitioning,
.theme-transitioning *,
.theme-transitioning *::before,
.theme-transitioning *::after {
  transition:
    background-color 0.3s ease !important,
    border-color 0.3s ease !important,
    color 0.3s ease !important,
    box-shadow 0.3s ease !important,
    fill 0.3s ease !important,
    stroke 0.3s ease !important;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  overflow-x: hidden;
  max-width: 100vw;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

input,
button,
textarea,
select {
  font: inherit;
}

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  list-style: none;
}

button {
  background: none;
  border: none;
  cursor: pointer;
}

/* ========================================
   Typography
   ======================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
}

h1 {
  font-size: var(--font-size-6xl);
  letter-spacing: var(--tracking-tight);
}

h2 {
  font-size: var(--font-size-4xl);
  letter-spacing: var(--tracking-tight);
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

h5 {
  font-size: var(--font-size-lg);
}

h6 {
  font-size: var(--font-size-base);
}

p {
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

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

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

.text-accent {
  color: var(--color-accent-primary);
}

/* ========================================
   Container & Layout
   ======================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-4xl) 0;
}

.section-alt {
  background-color: var(--color-bg-secondary);
}

/* ========================================
   Utility Classes
   ======================================== */

/* Flex */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-xs {
  gap: var(--spacing-xs);
}

.gap-sm {
  gap: var(--spacing-sm);
}

.gap-md {
  gap: var(--spacing-md);
}

.gap-lg {
  gap: var(--spacing-lg);
}

.gap-xl {
  gap: var(--spacing-xl);
}

.gap-2xl {
  gap: var(--spacing-2xl);
}

/* Text Alignment */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

/* Spacing */
.mt-sm {
  margin-top: var(--spacing-sm);
}

.mt-md {
  margin-top: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

.mt-2xl {
  margin-top: var(--spacing-2xl);
}

.mb-sm {
  margin-bottom: var(--spacing-sm);
}

.mb-md {
  margin-bottom: var(--spacing-md);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

.mb-xl {
  margin-bottom: var(--spacing-xl);
}

.mb-2xl {
  margin-bottom: var(--spacing-2xl);
}

/* Display */
.hidden {
  display: none;
}

.block {
  display: block;
}

/* Width */
.w-full {
  width: 100%;
}

/* Visually Hidden (Accessibility) */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ========================================
   Selection
   ======================================== */
::selection {
  background-color: var(--color-accent-primary);
  color: var(--color-text-inverse);
}

/* ========================================
   Scrollbar (Webkit)
   ======================================== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* ========================================
   Focus States
   ======================================== */
:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 2px;
}

/* ========================================
   Links
   ======================================== */
.link {
  color: var(--color-accent-primary);
  transition: color var(--transition-fast);
}

.link:hover {
  color: var(--color-accent-secondary);
}

/* Text Gradient */
.text-gradient {
  background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}