/**
 * Guanyiai Design System - Base Styles
 * CSS Reset, Typography, Utilities, Responsive
 * Version: 2.0
 * Date: 2026-05-30
 */

/* ============================================
   CSS RESET (Modern / Normalize Hybrid)
   ============================================ */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  tab-size: 4;
  line-height: 1.15;
}

/* Remove default margin and padding on body */

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--font-weight-regular);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color var(--duration-normal) var(--ease-default),
              color var(--duration-normal) var(--ease-default);
}

/* Headings */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: var(--font-weight-semibold);
  line-height: var(--leading-tight);
  color: var(--color-text-primary);
  text-wrap: balance;
}

h1 {
  font-size: var(--text-3xl);
  letter-spacing: var(--tracking-tight);
}

h2 {
  font-size: var(--text-2xl);
  letter-spacing: var(--tracking-tight);
}

h3 {
  font-size: var(--text-xl);
  font-family: var(--font-sans);
}

h4 {
  font-size: var(--text-lg);
  font-family: var(--font-sans);
}

h5 {
  font-size: var(--text-base);
  font-family: var(--font-sans);
}

h6 {
  font-size: var(--text-sm);
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
}

/* Paragraph */

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
  text-wrap: pretty;
}

/* Links */

a {
  color: var(--color-text-link);
  text-decoration: none;
  transition: var(--transition-colors);
}

a:hover {
  color: var(--color-text-link-hover);
}

a:active {
  color: var(--color-text-link-active);
}

/* Inline / Bold */

strong, b {
  font-weight: var(--font-weight-semibold);
}

small {
  font-size: var(--text-sm);
}

code, kbd, samp, pre {
  font-family: var(--font-mono);
}

code {
  font-size: 0.875em;
  padding: var(--space-0-5) var(--space-1-5);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-sm);
  color: var(--color-primary-600);
}

pre {
  overflow-x: auto;
  padding: var(--space-4);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

pre code {
  padding: 0;
  background: none;
  border: none;
  border-radius: 0;
}

/* ============================================
   LISTS
   ============================================ */

ul, ol {
  list-style: none;
}

/* ============================================
   MEDIA
   ============================================ */

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

/* ============================================
   TABLES
   ============================================ */

table {
  border-collapse: collapse;
  border-spacing: 0;
  width: 100%;
}

/* ============================================
   FORMS
   ============================================ */

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

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

fieldset {
  border: none;
}

legend {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

/* Remove inner spin buttons on number inputs */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

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

/* ============================================
   FOCUS STATES
   ============================================ */

:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* ============================================
   SELECTION
   ============================================ */

::selection {
  background-color: var(--color-primary-100);
  color: var(--color-primary-900);
}

[data-theme="dark"] ::selection {
  background-color: var(--color-primary-800);
  color: var(--color-primary-100);
}

/* ============================================
   SCROLLBAR
   ============================================ */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--color-neutral-400);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-neutral-500);
}

/* Firefox scrollbar */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-neutral-400) var(--color-bg-secondary);
}

/* ============================================
   RESPONSIVE TYPOGRAPHY
   ============================================ */

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

@media (min-width: 1440px) {
  html {
    font-size: 18px;
  }
}

/* ============================================
   RESPONSIVE BREAKPOINTS REFERENCE
   ============================================
   -- bp-xs:  480px   (portrait phones)
   -- bp-sm:  640px   (landscape phones)
   -- bp-md:  768px   (tablets)
   -- bp-lg:  1024px  (small laptops)
   -- bp-xl:  1280px  (desktops)
   -- bp-2xl: 1440px  (large desktops)
   ============================================ */

/* ============================================
   UTILITY CLASSES
   ============================================ */

/* --- Display --- */
.hidden { display: none !important; }
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.contents { display: contents; }

/* --- Flexbox --- */
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-col-reverse { flex-direction: column-reverse; }
.flex-row-reverse { flex-direction: row-reverse; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }
.flex-1 { flex: 1 1 0%; }
.flex-auto { flex: 1 1 auto; }
.flex-none { flex: none; }
.flex-shrink-0 { flex-shrink: 0; }
.flex-grow { flex-grow: 1; }

/* --- Alignment --- */
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }
.items-baseline { align-items: baseline; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.justify-start { justify-content: flex-start; }
.justify-evenly { justify-content: space-evenly; }
.self-center { align-self: center; }
.self-start { align-self: flex-start; }
.self-end { align-self: flex-end; }

/* --- Gap --- */
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-5 { gap: var(--space-5); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }
.gap-10 { gap: var(--space-10); }
.gap-12 { gap: var(--space-12); }

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

/* --- Text Colors --- */
.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-tertiary { color: var(--color-text-tertiary); }
.text-muted { color: var(--color-text-muted); }
.text-link { color: var(--color-text-link); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-error { color: var(--color-error); }
.text-info { color: var(--color-info); }

/* --- Font Sizes --- */
.text-2xs { font-size: var(--text-2xs); }
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.text-2xl { font-size: var(--text-2xl); }
.text-3xl { font-size: var(--text-3xl); }
.text-4xl { font-size: var(--text-4xl); }
.text-5xl { font-size: var(--text-5xl); }

/* --- Font Families --- */
.font-serif { font-family: var(--font-serif); }
.font-sans { font-family: var(--font-sans); }
.font-mono { font-family: var(--font-mono); }
.font-display { font-family: var(--font-display); }

/* --- Font Weights --- */
.font-light { font-weight: var(--font-weight-light); }
.font-regular { font-weight: var(--font-weight-regular); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

/* --- Text Transform --- */
.uppercase { text-transform: uppercase; }
.lowercase { text-transform: lowercase; }
.capitalize { text-transform: capitalize; }
.normal-case { text-transform: none; }

/* --- Text Decoration --- */
.underline { text-decoration: underline; }
.no-underline { text-decoration: none; }

/* --- Whitespace --- */
.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.whitespace-normal { white-space: normal; }
.whitespace-nowrap { white-space: nowrap; }

/* --- Line Clamp --- */
.line-clamp-1 {
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.line-clamp-3 {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* --- Spacing: Margin --- */
.m-0 { margin: 0; }
.m-auto { margin: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }
.my-auto { margin-top: auto; margin-bottom: auto; }
.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mt-10 { margin-top: var(--space-10); }
.mt-12 { margin-top: var(--space-12); }
.mt-16 { margin-top: var(--space-16); }
.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-10 { margin-bottom: var(--space-10); }
.mb-12 { margin-bottom: var(--space-12); }
.mb-16 { margin-bottom: var(--space-16); }
.ml-auto { margin-left: auto; }
.mr-auto { margin-right: auto; }
.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.-mt-1 { margin-top: calc(var(--space-1) * -1); }
.-mt-2 { margin-top: calc(var(--space-2) * -1); }

/* --- Spacing: Padding --- */
.p-0 { padding: 0; }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-5 { padding: var(--space-5); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }
.px-2 { padding-left: var(--space-2); padding-right: var(--space-2); }
.px-3 { padding-left: var(--space-3); padding-right: var(--space-3); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.px-5 { padding-left: var(--space-5); padding-right: var(--space-5); }
.px-6 { padding-left: var(--space-6); padding-right: var(--space-6); }
.px-8 { padding-left: var(--space-8); padding-right: var(--space-8); }
.py-2 { padding-top: var(--space-2); padding-bottom: var(--space-2); }
.py-3 { padding-top: var(--space-3); padding-bottom: var(--space-3); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.py-5 { padding-top: var(--space-5); padding-bottom: var(--space-5); }
.py-6 { padding-top: var(--space-6); padding-bottom: var(--space-6); }
.py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }
.pt-4 { padding-top: var(--space-4); }
.pt-6 { padding-top: var(--space-6); }
.pb-4 { padding-bottom: var(--space-4); }
.pb-6 { padding-bottom: var(--space-6); }

/* --- Width --- */
.w-full { width: 100%; }
.w-auto { width: auto; }
.w-screen { width: 100vw; }
.max-w-none { max-width: none; }
.max-w-xs { max-width: var(--container-xs); }
.max-w-sm { max-width: var(--container-sm); }
.max-w-md { max-width: var(--container-md); }
.max-w-lg { max-width: var(--container-lg); }
.max-w-xl { max-width: var(--container-xl); }
.max-w-2xl { max-width: var(--container-2xl); }
.min-w-0 { min-width: 0; }

/* --- Height --- */
.h-full { height: 100%; }
.h-screen { height: 100vh; }
.min-h-screen { min-height: 100vh; }

/* --- Overflow --- */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-scroll { overflow: scroll; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* --- Position --- */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }
.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }
.top-0 { top: 0; }
.right-0 { right: 0; }
.bottom-0 { bottom: 0; }
.left-0 { left: 0; }

/* --- Border Radius --- */
.rounded-none { border-radius: var(--radius-none); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-2xl { border-radius: var(--radius-2xl); }
.rounded-full { border-radius: var(--radius-full); }

/* --- Shadows --- */
.shadow-none { box-shadow: none; }
.shadow-xs { box-shadow: var(--shadow-xs); }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-md); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }
.shadow-2xl { box-shadow: var(--shadow-2xl); }
.shadow-inner { box-shadow: var(--shadow-inner); }

/* --- Borders --- */
.border { border: 1px solid var(--color-border); }
.border-0 { border: 0; }
.border-t { border-top: 1px solid var(--color-border); }
.border-b { border-bottom: 1px solid var(--color-border); }
.border-l { border-left: 1px solid var(--color-border); }
.border-r { border-right: 1px solid var(--color-border); }
.border-subtle { border-color: var(--color-border-subtle); }
.border-strong { border-color: var(--color-border-strong); }

/* --- Background Colors --- */
.bg-primary { background-color: var(--color-bg-primary); }
.bg-secondary { background-color: var(--color-bg-secondary); }
.bg-tertiary { background-color: var(--color-bg-tertiary); }
.bg-surface { background-color: var(--color-surface); }
.bg-elevated { background-color: var(--color-surface-elevated); }
.bg-inverse { background-color: var(--color-bg-inverse); }

/* --- Transitions --- */
.transition-none { transition: none; }
.transition-all { transition: var(--transition-all); }
.transition-colors { transition: var(--transition-colors); }
.transition-shadow { transition: var(--transition-shadow); }
.transition-transform { transition: var(--transition-transform); }
.transition-opacity { transition: var(--transition-opacity); }

/* --- Animations --- */
.animate-fade-in { animation: fadeIn var(--duration-normal) var(--ease-out) forwards; }
.animate-fade-in-up { animation: fadeInUp var(--duration-slow) var(--ease-out) forwards; }
.animate-fade-in-down { animation: fadeInDown var(--duration-slow) var(--ease-out) forwards; }
.animate-slide-in-left { animation: slideInLeft var(--duration-slow) var(--ease-out) forwards; }
.animate-slide-in-right { animation: slideInRight var(--duration-slow) var(--ease-out) forwards; }
.animate-scale-in { animation: scaleIn var(--duration-normal) var(--ease-spring) forwards; }
.animate-bounce-in { animation: bounceIn var(--duration-slower) var(--ease-bounce) forwards; }
.animate-spin { animation: spin 1s linear infinite; }
.animate-pulse { animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite; }

/* --- Cursor --- */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }
.cursor-default { cursor: default; }

/* --- User Select --- */
.select-none { user-select: none; }
.select-all { user-select: all; }
.select-text { user-select: text; }

/* --- Opacity --- */
.opacity-0 { opacity: 0; }
.opacity-25 { opacity: 0.25; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* --- Visually Hidden (screen reader only) --- */
.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;
}

/* ============================================
   KEYFRAME ANIMATIONS
   ============================================ */

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes bounceIn {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  50% {
    opacity: 1;
    transform: scale(1.05);
  }
  70% {
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideUp {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(-8px);
  }
}

/* ============================================
   REDUCED MOTION
   ============================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}