/* ============================================================
   BASE — Design Tokens, Reset, Layout Utilities
   ============================================================ */

:root {
  /* Brand Colors */
  --color-primary:       #0057FF;
  --color-primary-dark:  #003FBF;
  --color-primary-light: #4D8AFF;
  --color-accent:        #00D4A0;
  --color-accent-dark:   #00A87E;
  --color-danger:        #CC2020;
  --color-warning:       #FF9A00;
  --color-success:       #00C46A;

  /* Light Mode Surfaces */
  --bg-base:      #F6F8FC;
  --bg-surface:   #FFFFFF;
  --bg-elevated:  #FFFFFF;
  --bg-subtle:    #EEF2FA;
  --bg-muted:     #E3E9F4;

  /* Light Mode Text */
  --text-primary:   #0D1B2A;
  --text-secondary: #4A5568;
  --text-muted:     #5C6B82;
  --text-inverse:   #FFFFFF;

  /* Borders */
  --border-light:  rgba(0,0,0,0.07);
  --border-medium: rgba(0,0,0,0.13);
  --border-focus:  var(--color-primary);

  /* Shadows */
  --shadow-xs:  0 1px 3px rgba(0,0,0,0.06);
  --shadow-sm:  0 2px 8px rgba(0,0,0,0.08);
  --shadow-md:  0 4px 20px rgba(0,0,0,0.10);
  --shadow-lg:  0 8px 40px rgba(0,0,0,0.12);
  --shadow-xl:  0 16px 60px rgba(0,0,0,0.15);

  /* Radius */
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  28px;
  --radius-full: 9999px;

  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Typography */
  --font-display: 'Sora', 'DM Sans', system-ui, sans-serif;
  --font-body:    'DM Sans', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', monospace;

  /* Transitions */
  --transition-fast:   150ms cubic-bezier(0.4,0,0.2,1);
  --transition-normal: 250ms cubic-bezier(0.4,0,0.2,1);
  --transition-slow:   400ms cubic-bezier(0.4,0,0.2,1);

  /* Layout */
  --container-max:    1200px;
  --sidebar-width:    320px;
  --header-height:    70px;

  /* Progress */
  --progress-height:  6px;
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-base:      #0A0F1E;
  --bg-surface:   #111827;
  --bg-elevated:  #1A2234;
  --bg-subtle:    #1E2A3E;
  --bg-muted:     #253048;
  --text-primary:   #F0F4FF;
  --text-secondary: #A8B5CC;
  --text-muted:     #8A9AB5;
  --border-light:  rgba(255,255,255,0.06);
  --border-medium: rgba(255,255,255,0.12);
  --shadow-xs:  0 1px 3px rgba(0,0,0,0.3);
  --shadow-sm:  0 2px 8px rgba(0,0,0,0.4);
  --shadow-md:  0 4px 20px rgba(0,0,0,0.5);
  --shadow-lg:  0 8px 40px rgba(0,0,0,0.6);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

html {
  overflow-x: hidden;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.65;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

img, video, svg { display: block; max-width: 100%; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
ul, ol { list-style: none; }

/* ---- Layout Utilities ---- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.screen-reader-text {
  position: absolute;
  clip: rect(1px,1px,1px,1px);
  overflow: hidden;
  width: 1px;
  height: 1px;
}

/* ---- Reading Progress Bar ---- */
#reading-progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  z-index: 9999;
  transition: width 0.1s linear;
}

/* ---- Buttons (shared) ---- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-6);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  text-decoration: none;
}
.btn-primary:hover { background: var(--color-primary-dark); text-decoration: none; transform: translateY(-1px); box-shadow: 0 4px 16px rgba(0,87,255,0.3); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid var(--border-medium);
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-6);
  font-weight: 600;
  font-size: 0.95rem;
  transition: border-color var(--transition-fast), background var(--transition-fast);
  text-decoration: none;
}
.btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--bg-subtle); text-decoration: none; }

/* ---- Download Button ---- */
.guide-downloads {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  background: var(--bg-surface);
  border: 1.5px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-5);
  color: var(--text-primary);
  text-decoration: none;
  transition: all var(--transition-fast);
  font-size: 0.9rem;
  flex: 1 1 200px; /* grow to fill, shrink if needed, min 200px before wrap */
}
.download-btn:hover { border-color: var(--color-primary); color: var(--color-primary); background: rgba(0,87,255,0.04); text-decoration: none; }
.download-btn .dl-icon { color: var(--color-primary); }
.download-btn strong { font-weight: 700; }
.download-btn small { display: block; font-size: 0.78rem; color: var(--text-muted); }

/* ---- Animations ---- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeInUp 0.4s ease forwards; }

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

/* Skeleton loading */
.skeleton {
  background: linear-gradient(90deg, var(--bg-muted) 25%, var(--bg-subtle) 50%, var(--bg-muted) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}
@keyframes shimmer {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}

/* ---- Print ---- */
@media print {
  #site-header, .guide-sidebar, #reading-progress-bar, .step-confirm-btn,
  .faq-icon, .proceed-btn, .hero-actions, #site-footer { display: none !important; }
  .guide-layout { grid-template-columns: 1fr; }
  .step-body { max-height: none !important; }
  body { background: #fff; color: #000; }
}

/* ---- Guide Cards & Grid (shared: home + archive) ---- */
.guides-section { padding: var(--space-12) 0; }

.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: var(--space-8);
  gap: var(--space-4);
  flex-wrap: wrap;
}

.section-title { font-family: var(--font-display); font-size: 1.7rem; font-weight: 700; letter-spacing: -0.02em; }
.section-title span { color: var(--color-primary); }

.guides-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
}

.guide-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  text-decoration: none;
  display: flex;
  flex-direction: column;
  position: relative;
}
.guide-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: rgba(0,87,255,0.2); text-decoration: none; }

.guide-card-header { padding: var(--space-5) var(--space-5) 0; display: flex; align-items: flex-start; justify-content: space-between; gap: var(--space-3); }

.tool-icon { width: 48px; height: 48px; border-radius: var(--radius-md); display: grid; place-items: center; font-size: 1.4rem; flex-shrink: 0; }

.difficulty-badge { display: inline-flex; align-items: center; gap: var(--space-1); padding: var(--space-1) var(--space-3); border-radius: var(--radius-full); font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; }
.difficulty-beginner    { background: rgba(0,196,106,0.12);  color: var(--color-success); }
.difficulty-intermediate{ background: rgba(255,154,0,0.12);  color: var(--color-warning); }
.difficulty-advanced    { background: rgba(255,59,59,0.12);   color: var(--color-danger); }

.guide-card-body { padding: var(--space-4) var(--space-5); flex: 1; }
.guide-card-title { font-family: var(--font-display); font-size: 1.05rem; font-weight: 700; color: var(--text-primary); margin-bottom: var(--space-2); line-height: 1.35; }
.guide-card-excerpt { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.6; }

.guide-card-meta { padding: var(--space-4) var(--space-5); border-top: 1px solid var(--border-light); display: flex; align-items: center; gap: var(--space-4); flex-wrap: wrap; }
.meta-item { display: flex; align-items: center; gap: var(--space-1); font-size: 0.78rem; color: var(--text-muted); }
.meta-item svg { width: 13px; height: 13px; stroke: currentColor; fill: none; flex-shrink: 0; }

.guide-card-footer { padding: var(--space-3) var(--space-5); background: var(--bg-subtle); display: flex; align-items: center; justify-content: space-between; font-size: 0.8rem; }
.guide-card-footer .read-more { color: var(--color-primary); font-weight: 600; display: flex; align-items: center; gap: var(--space-1); }
.guide-card-footer .read-more svg { width: 14px; height: 14px; stroke: currentColor; fill: none; transition: transform var(--transition-fast); }
.guide-card:hover .read-more svg { transform: translateX(3px); }

@media (max-width: 768px) {
  .guides-grid { grid-template-columns: 1fr; }
}
/* ---- Pagination ---- */
.pagination {
  margin-top: var(--space-10);
  padding-top: var(--space-6);
  border-top: 1px solid var(--border-light);
}

.pagination ul {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  list-style: none;
  padding: 0;
  margin: 0;
}

.pagination ul li a,
.pagination ul li span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 var(--space-3);
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-fast);
  border: 1.5px solid var(--border-medium);
  color: var(--text-secondary);
  background: var(--bg-surface);
}

.pagination ul li a:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: rgba(0,87,255,0.04);
}

/* Current page */
.pagination ul li span.current {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  cursor: default;
}

/* Prev / Next — wider pills */
.pagination ul li:first-child a,
.pagination ul li:last-child a {
  padding: 0 var(--space-4);
  gap: var(--space-1);
}

/* Dots */
.pagination ul li span.dots {
  border: none;
  background: none;
  color: var(--text-muted);
  min-width: auto;
  padding: 0 var(--space-1);
}