/* PearBlog v5.1 — Base Styles
 * Core foundation styles and CSS variables
 * Fonts: Poppins (display) · Inter (UI)
 */

:root {
  /* Primary Brand Colors */
  --pb-primary: #2563eb;
  --pb-primary-hover: #1d4ed8;
  --pb-secondary: #7c3aed;
  --pb-secondary-hover: #6d28d9;
  --pb-accent: #f59e0b;

  /* Background Colors */
  --pb-bg: #ffffff;
  --pb-bg-alt: #f9fafb;
  --pb-bg-dark: #111827;

  /* Text Colors */
  --pb-text: #1f2937;
  --pb-text-light: #6b7280;
  --pb-text-white: #ffffff;

  /* Border & Radius */
  --pb-radius: 0.5rem;
  --pb-radius-sm: 0.25rem;
  --pb-radius-md: 0.5rem;
  --pb-radius-lg: 0.75rem;
  --pb-radius-xl: 1rem;

  /* Shadows */
  --pb-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --pb-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --pb-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --pb-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --pb-shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

  /* Typography — Brand System */
  --pb-font-display: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
  --pb-font-ui: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --pb-font-base: var(--pb-font-ui);
  --pb-font-heading: var(--pb-font-display);
  --pb-font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', Courier, monospace;

  /* Spacing */
  --pb-space-xs: 0.25rem;
  --pb-space-sm: 0.5rem;
  --pb-space-md: 1rem;
  --pb-space-lg: 1.5rem;
  --pb-space-xl: 2rem;
  --pb-space-2xl: 3rem;
  --pb-space-3xl: 4rem;

  /* Container */
  --pb-container-max: 1200px;
  --pb-container-padding: 1rem;

  /* Transitions */
  --pb-transition: all 0.2s ease;
  --pb-transition-slow: all 0.3s ease;

  /* Header */
  --pb-header-height: 64px;
  --pb-header-height-scrolled: 52px;
  --pb-progress-height: 3px;
}

/* Dark Mode Variables */
@media (prefers-color-scheme: dark) {
  body.pb-dark-mode-auto {
    --pb-bg: #111827;
    --pb-bg-alt: #1f2937;
    --pb-text: #f9fafb;
    --pb-text-light: #d1d5db;
  }
}

body.pb-dark-mode {
  --pb-bg: #111827;
  --pb-bg-alt: #1f2937;
  --pb-text: #f9fafb;
  --pb-text-light: #d1d5db;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--pb-font-base);
  color: var(--pb-text);
  background-color: var(--pb-bg);
  line-height: 1.6;
  font-size: 1rem;
  min-height: 100vh;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Typography - Mobile First */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--pb-font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--pb-space-lg);
  color: var(--pb-text);
}

h1 {
  font-size: 2rem;
  margin-bottom: var(--pb-space-xl);
}

h2 {
  font-size: 1.5rem;
}

h3 {
  font-size: 1.25rem;
}

h4 {
  font-size: 1.125rem;
}

p {
  margin-bottom: var(--pb-space-md);
}

a {
  color: var(--pb-primary);
  text-decoration: none;
  transition: var(--pb-transition);
}

a:hover {
  color: var(--pb-primary-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Tablet & Desktop */
@media (min-width: 768px) {
  :root {
    --pb-container-padding: 1.5rem;
  }

  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2rem;
  }

  h3 {
    font-size: 1.5rem;
  }

  body {
    font-size: 18px;
  }
}

@media (min-width: 1024px) {
  :root {
    --pb-container-padding: 2rem;
  }

  h1 {
    font-size: 3.5rem;
  }
}

/* Container */
.pb-container {
  max-width: var(--pb-container-max);
  margin: 0 auto;
  padding: 0 var(--pb-container-padding);
  width: 100%;
}

/* Layout */
.pb-main {
  min-height: calc(100vh - 400px);
}

/* Loading States */
.pb-loading {
  opacity: 0.6;
  pointer-events: none;
}

.pb-skeleton {
  background: linear-gradient(90deg, var(--pb-bg-alt) 25%, var(--pb-bg) 50%, var(--pb-bg-alt) 75%);
  background-size: 200% 100%;
  animation: pb-skeleton-loading 1.5s ease-in-out infinite;
}

@keyframes pb-skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* Focus Styles for Accessibility */
*:focus {
  outline: 2px solid var(--pb-primary);
  outline-offset: 2px;
}

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

/* Print Styles */
@media print {
  .pb-nav,
  .pb-ad-slot,
  .pb-cta,
  .pb-footer {
    display: none !important;
  }
}

/* -----------------------------------------------------------------------
   Reading Progress Bar
   ----------------------------------------------------------------------- */
#pb-reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--pb-progress-height);
  background: rgba(0, 0, 0, 0.08);
  z-index: 9999;
  pointer-events: none;
}

#pb-reading-progress {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--pb-primary), var(--pb-secondary));
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

/* -----------------------------------------------------------------------
   Sticky Header
   ----------------------------------------------------------------------- */
.pb-nav {
  position: sticky;
  top: var(--pb-progress-height);
  z-index: 1000;
  background: var(--pb-bg);
  border-bottom: 1px solid transparent;
  transition: box-shadow 0.25s ease, border-color 0.25s ease, padding 0.25s ease;
}

.pb-nav--sticky {
  box-shadow: var(--pb-shadow-md);
  border-bottom-color: rgba(0, 0, 0, 0.08);
}

.pb-nav-container {
  display: flex;
  align-items: center;
  gap: var(--pb-space-md);
  min-height: var(--pb-header-height);
  padding: var(--pb-space-sm) 0;
  transition: min-height 0.25s ease;
}

.pb-nav--sticky .pb-nav-container {
  min-height: var(--pb-header-height-scrolled);
}

/* Nav actions cluster */
.pb-nav-actions {
  display: flex;
  align-items: center;
  gap: var(--pb-space-sm);
  margin-left: auto;
}

/* Icon buttons (search, dark mode) */
.pb-icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: none;
  background: transparent;
  color: var(--pb-text);
  border-radius: var(--pb-radius);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}

.pb-icon-btn:hover {
  background: var(--pb-bg-alt);
  color: var(--pb-primary);
}

/* Hamburger icon */
.pb-hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 20px;
  height: 20px;
}

.pb-hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.pb-menu-toggle[aria-expanded="true"] .pb-hamburger span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.pb-menu-toggle[aria-expanded="true"] .pb-hamburger span:nth-child(2) {
  opacity: 0;
}

.pb-menu-toggle[aria-expanded="true"] .pb-hamburger span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* -----------------------------------------------------------------------
   Search Panel
   ----------------------------------------------------------------------- */
.pb-search-panel {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--pb-bg);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  box-shadow: var(--pb-shadow-lg);
  z-index: 1100;
  padding: var(--pb-space-lg) 0;
  transform: translateY(-100%);
  transition: transform 0.25s ease;
}

.pb-search-panel.is-open {
  transform: translateY(0);
}

.pb-search-panel .pb-container {
  display: flex;
  align-items: center;
  gap: var(--pb-space-md);
}

.pb-search-form {
  display: flex;
  align-items: center;
  flex: 1;
  gap: var(--pb-space-sm);
  background: var(--pb-bg-alt);
  border: 2px solid transparent;
  border-radius: var(--pb-radius-lg);
  padding: var(--pb-space-sm) var(--pb-space-md);
  transition: border-color 0.2s ease;
}

.pb-search-form:focus-within {
  border-color: var(--pb-primary);
}

.pb-search-input {
  flex: 1;
  border: none;
  background: transparent;
  font-family: var(--pb-font-ui);
  font-size: 1rem;
  color: var(--pb-text);
  outline: none;
}

.pb-search-input::placeholder {
  color: var(--pb-text-light);
}

.pb-search-submit {
  display: flex;
  align-items: center;
  border: none;
  background: transparent;
  color: var(--pb-text-light);
  cursor: pointer;
  padding: 0;
  transition: color 0.2s;
}

.pb-search-submit:hover {
  color: var(--pb-primary);
}

.pb-search-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background: var(--pb-bg-alt);
  border-radius: var(--pb-radius);
  cursor: pointer;
  font-size: 1rem;
  color: var(--pb-text-light);
  transition: background 0.2s, color 0.2s;
  flex-shrink: 0;
}

.pb-search-close:hover {
  background: var(--pb-primary);
  color: white;
}

/* -----------------------------------------------------------------------
   Improved Footer
   ----------------------------------------------------------------------- */
.pb-footer {
  background: var(--pb-bg-dark);
  color: var(--pb-text-white);
  padding: var(--pb-space-3xl) 0 0;
  margin-top: var(--pb-space-3xl);
}

.pb-footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--pb-space-2xl);
  margin-bottom: var(--pb-space-2xl);
}

@media (min-width: 768px) {
  .pb-footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
  }
}

.pb-footer-brand .pb-footer-logo a {
  color: var(--pb-text-white);
  text-decoration: none;
  font-family: var(--pb-font-display);
  font-weight: 700;
  font-size: 1.25rem;
}

.pb-footer-desc {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.9rem;
  line-height: 1.7;
  margin-top: var(--pb-space-md);
}

.pb-footer-widgets .footer-widget-title {
  color: var(--pb-text-white);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--pb-space-md);
}

.pb-footer-nav {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--pb-space-lg) 0;
}

.pb-footer-nav .pb-menu {
  display: flex;
  flex-wrap: wrap;
  gap: var(--pb-space-md);
  list-style: none;
  padding: 0;
  margin: 0;
}

.pb-footer-nav .pb-menu a {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.875rem;
  transition: color 0.2s;
}

.pb-footer-nav .pb-menu a:hover {
  color: var(--pb-text-white);
}

.pb-footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--pb-space-lg) 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--pb-space-md);
}

.pb-footer-copyright {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.875rem;
  margin: 0;
}

.pb-footer-copyright a {
  color: rgba(255, 255, 255, 0.75);
}

.pb-footer-copyright a:hover {
  color: var(--pb-text-white);
}

.pb-footer-powered {
  color: rgba(255, 255, 255, 0.35);
  font-size: 0.8rem;
}

/* -----------------------------------------------------------------------
   Back to Top Button
   ----------------------------------------------------------------------- */
.pb-back-to-top {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: transparent;
  color: rgba(255, 255, 255, 0.6);
  border-radius: var(--pb-radius);
  cursor: pointer;
  font-size: 1rem;
  flex-shrink: 0;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.pb-back-to-top:hover {
  background: var(--pb-primary);
  border-color: var(--pb-primary);
  color: white;
}

/* -----------------------------------------------------------------------
   Dark Mode — enhanced
   ----------------------------------------------------------------------- */
body.pb-dark-mode {
  --pb-bg: #111827;
  --pb-bg-alt: #1f2937;
  --pb-text: #f9fafb;
  --pb-text-light: #d1d5db;
  --pb-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --pb-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
}

body.pb-dark-mode .pb-nav {
  border-bottom-color: rgba(255, 255, 255, 0.08);
}

body.pb-dark-mode .pb-search-panel {
  background: var(--pb-bg);
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

/* -----------------------------------------------------------------------
   Page Body offset for sticky header + progress bar
   ----------------------------------------------------------------------- */
body {
  padding-top: calc(var(--pb-progress-height));
}