/* ============================================================
   CalcPro Main Stylesheet
   Mobile-First | Dark Mode | Core Web Vitals Optimized
   ============================================================ */

/* ── CSS Variables (Light Theme) ──────────────────────────── */
:root {
  --color-primary:    #2563EB;
  --color-primary-h:  #1D4ED8;
  --color-accent:     #06B6D4;
  --color-success:    #10B981;
  --color-warning:    #F59E0B;
  --color-danger:     #EF4444;

  --bg-base:          #FFFFFF;
  --bg-surface:       #F8FAFC;
  --bg-card:          #FFFFFF;
  --bg-muted:         #F1F5F9;

  --text-primary:     #0F172A;
  --text-secondary:   #475569;
  --text-muted:       #94A3B8;
  --text-inverse:     #FFFFFF;

  --border-color:     #E2E8F0;
  --border-radius:    10px;
  --border-radius-lg: 16px;

  --shadow-sm:   0 1px 3px rgba(0,0,0,.08);
  --shadow-md:   0 4px 16px rgba(0,0,0,.10);
  --shadow-lg:   0 8px 32px rgba(0,0,0,.12);

  --font-sans:   'Inter', system-ui, -apple-system, sans-serif;
  --font-display:'Sora', 'Inter', sans-serif;

  --navbar-h: 64px;
  --transition: 200ms ease;
}

/* ── Dark Theme ───────────────────────────────────────────── */
[data-theme="dark"] {
  --bg-base:        #0F172A;
  --bg-surface:     #1E293B;
  --bg-card:        #1E293B;
  --bg-muted:       #334155;
  --text-primary:   #F1F5F9;
  --text-secondary: #94A3B8;
  --text-muted:     #64748B;
  --border-color:   #334155;
  --shadow-sm:      0 1px 3px rgba(0,0,0,.3);
  --shadow-md:      0 4px 16px rgba(0,0,0,.4);
  --shadow-lg:      0 8px 32px rgba(0,0,0,.5);
}

/* ── Reset & Base ─────────────────────────────────────────── */
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition), color var(--transition);
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
ul { list-style: none; }

/* ── Skip Nav ─────────────────────────────────────────────── */
.skip-nav {
  position: absolute; top: -40px; left: 8px; z-index: 9999;
  background: var(--color-primary); color: #fff;
  padding: 8px 16px; border-radius: 0 0 8px 8px;
  transition: top var(--transition);
}
.skip-nav:focus { top: 0; }

/* ── Container ────────────────────────────────────────────── */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 640px)  { .container { padding: 0 24px; } }
@media (min-width: 1024px) { .container { padding: 0 32px; } }

/* ── Navbar ───────────────────────────────────────────────── */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  height: var(--navbar-h);
  box-shadow: var(--shadow-sm);
}
.navbar .container { display: flex; align-items: center; justify-content: space-between; height: 100%; }

.navbar-brand { display: flex; align-items: center; gap: 8px; font-weight: 700; color: var(--text-primary); text-decoration: none; }
.brand-text { font-family: var(--font-display); font-size: 1.35rem; color: var(--color-primary); }
.brand-text i { color: var(--color-primary); }

.nav-toggle { display: flex; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--text-primary); border-radius: 2px; transition: transform var(--transition); }

.nav-menu {
  display: none; position: fixed; inset: var(--navbar-h) 0 0 0;
  background: var(--bg-card); padding: 24px; overflow-y: auto;
  flex-direction: column; gap: 24px;
  border-top: 1px solid var(--border-color);
}
.nav-menu.open { display: flex; }

.nav-list { display: flex; flex-direction: column; gap: 4px; }
.nav-link { display: block; padding: 10px 12px; color: var(--text-secondary); font-weight: 500; border-radius: 8px; transition: all var(--transition); }
.nav-link:hover { background: var(--bg-muted); color: var(--color-primary); text-decoration: none; }

.has-dropdown { position: relative; }
.dropdown-mega {
  background: var(--bg-surface); border: 1px solid var(--border-color);
  border-radius: var(--border-radius); padding: 8px;
  display: none; flex-direction: column; gap: 2px; margin-top: 4px;
}
.has-dropdown:hover .dropdown-mega,
.has-dropdown:focus-within .dropdown-mega { display: flex; }
.dropdown-item { display: flex; align-items: center; gap: 8px; padding: 10px 12px; color: var(--text-secondary); border-radius: 6px; font-size: .9rem; }
.dropdown-item:hover { background: var(--bg-muted); color: var(--color-primary); text-decoration: none; }
.dropdown-item i { width: 18px; text-align: center; }

.nav-actions { display: flex; gap: 8px; align-items: center; }
.btn-icon { background: var(--bg-muted); border: none; border-radius: 8px; width: 38px; height: 38px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--text-secondary); transition: all var(--transition); font-size: 1rem; }
.btn-icon:hover { background: var(--color-primary); color: #fff; }

@media (min-width: 1024px) {
  .nav-toggle { display: none; }
  .nav-menu { display: flex; position: static; inset: auto; background: none; padding: 0; overflow: visible; flex-direction: row; align-items: center; border: none; }
  .nav-list { flex-direction: row; gap: 0; }
  .dropdown-mega { position: absolute; top: 100%; left: 0; min-width: 220px; z-index: 50; margin-top: 8px; box-shadow: var(--shadow-lg); }
}

/* ── Search Overlay ────────────────────────────────────────── */
.search-overlay {
  display: none; position: fixed; inset: 0; z-index: 200;
  background: rgba(15,23,42,.8); backdrop-filter: blur(4px);
  align-items: flex-start; justify-content: center; padding-top: 80px;
}
.search-overlay.open { display: flex; }
.search-container { width: 100%; max-width: 640px; padding: 0 16px; }
.search-input-wrap {
  display: flex; align-items: center; gap: 12px;
  background: var(--bg-card); border-radius: var(--border-radius-lg);
  padding: 14px 20px; box-shadow: var(--shadow-lg);
}
.search-input-wrap i { color: var(--text-muted); font-size: 1.1rem; }
.search-input { flex: 1; border: none; background: none; color: var(--text-primary); font-size: 1.1rem; outline: none; }
.search-close { background: none; border: none; cursor: pointer; color: var(--text-muted); font-size: 1.1rem; padding: 4px; }
.search-hints { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; align-items: center; color: var(--text-muted); font-size: .85rem; }
.search-hints a { background: var(--bg-card); border-radius: 20px; padding: 4px 12px; font-size: .85rem; color: var(--text-secondary); }

/* ── Hero Section ─────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, #7C3AED 100%);
  color: #fff; padding: 64px 0;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-content { position: relative; text-align: center; }
.hero h1 { font-family: var(--font-display); font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; line-height: 1.15; margin-bottom: 20px; }
.hero p { font-size: clamp(1rem, 2vw, 1.2rem); opacity: .9; max-width: 560px; margin: 0 auto 32px; }
.hero-search {
  display: flex; gap: 8px; max-width: 540px; margin: 0 auto;
  background: rgba(255,255,255,.15); border-radius: 50px; padding: 6px 6px 6px 20px;
  backdrop-filter: blur(8px); border: 1px solid rgba(255,255,255,.3);
}
.hero-search input { flex: 1; background: none; border: none; color: #fff; outline: none; font-size: 1rem; min-width: 0; }
.hero-search input::placeholder { color: rgba(255,255,255,.7); }
.hero-search button { background: #fff; color: var(--color-primary); border: none; border-radius: 40px; padding: 10px 24px; font-weight: 600; cursor: pointer; white-space: nowrap; transition: all var(--transition); }
.hero-search button:hover { background: var(--color-accent); color: #fff; }
.hero-stats { display: flex; justify-content: center; gap: 40px; margin-top: 48px; }
.hero-stat { text-align: center; }
.hero-stat strong { display: block; font-family: var(--font-display); font-size: 2rem; font-weight: 800; }
.hero-stat span { font-size: .85rem; opacity: .8; }

/* ── Section Titles ───────────────────────────────────────── */
.section { padding: 64px 0; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-tag { display: inline-block; background: var(--color-primary); color: #fff; font-size: .75rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; padding: 4px 12px; border-radius: 20px; margin-bottom: 12px; }
.section-title { font-family: var(--font-display); font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.section-subtitle { font-size: 1.05rem; color: var(--text-secondary); max-width: 540px; margin: 0 auto; }

/* ── Cards ────────────────────────────────────────────────── */
.card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg); overflow: hidden;
  box-shadow: var(--shadow-sm); transition: all var(--transition);
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); border-color: var(--color-primary); }
.card-body { padding: 20px; }

/* ── Category Grid ─────────────────────────────────────────── */
.category-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
}
@media (min-width: 640px) { .category-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1024px) { .category-grid { grid-template-columns: repeat(5, 1fr); } }

.category-card {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  padding: 24px 16px; border-radius: var(--border-radius-lg);
  border: 1px solid var(--border-color); background: var(--bg-card);
  color: var(--text-primary); cursor: pointer; text-decoration: none;
  transition: all var(--transition);
}
.category-card:hover { text-decoration: none; transform: translateY(-3px); box-shadow: var(--shadow-md); }
.category-icon {
  width: 56px; height: 56px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem; margin-bottom: 12px; color: #fff;
}
.category-card h3 { font-size: .92rem; font-weight: 600; color: var(--text-primary); margin-bottom: 4px; }
.category-card span { font-size: .8rem; color: var(--text-muted); }

/* ── Calculator Grid ───────────────────────────────────────── */
.calc-grid {
  display: grid; grid-template-columns: 1fr; gap: 20px;
}
@media (min-width: 640px) { .calc-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .calc-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1280px) { .calc-grid { grid-template-columns: repeat(4, 1fr); } }

.calc-card { text-decoration: none; color: var(--text-primary); }
.calc-card .card-body { display: flex; flex-direction: column; gap: 8px; }
.calc-card h3 { font-size: 1rem; font-weight: 600; color: var(--text-primary); line-height: 1.4; }
.calc-card p { font-size: .875rem; color: var(--text-secondary); line-height: 1.5; flex: 1; }
.calc-card .calc-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 4px; }
.calc-badge { font-size: .75rem; font-weight: 600; padding: 3px 10px; border-radius: 20px; background: var(--bg-muted); color: var(--text-secondary); }
.calc-views { font-size: .75rem; color: var(--text-muted); }
.calc-card:hover { text-decoration: none; }

/* ── Calculator Page ───────────────────────────────────────── */
.calc-layout { display: grid; gap: 32px; }
@media (min-width: 1024px) { .calc-layout { grid-template-columns: 1fr 340px; } }

.calc-main { min-width: 0; }
.calc-sidebar { display: flex; flex-direction: column; gap: 24px; }

.calc-tool-box {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg); overflow: hidden;
}
.calc-tool-header { background: linear-gradient(135deg, var(--color-primary), #7C3AED); padding: 20px 24px; }
.calc-tool-header h1 { font-family: var(--font-display); font-size: 1.5rem; font-weight: 700; color: #fff; margin: 0; }
.calc-tool-body { padding: 24px; }

/* Calculator form elements */
.calc-form-group { margin-bottom: 20px; }
.calc-label { display: block; font-size: .875rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 6px; }
.calc-input, .calc-select {
  width: 100%; padding: 12px 16px;
  background: var(--bg-surface); border: 1px solid var(--border-color);
  border-radius: var(--border-radius); color: var(--text-primary);
  font-size: 1rem; font-family: var(--font-sans);
  transition: border-color var(--transition);
  outline: none;
}
.calc-input:focus, .calc-select:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(37,99,235,.15); }

.calc-btn-primary {
  width: 100%; padding: 14px; background: var(--color-primary); color: #fff;
  border: none; border-radius: var(--border-radius); font-size: 1rem; font-weight: 600;
  cursor: pointer; transition: all var(--transition); font-family: var(--font-sans);
}
.calc-btn-primary:hover { background: var(--color-primary-h); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,.4); }

.calc-result-box {
  margin-top: 20px; padding: 20px; background: var(--bg-muted);
  border-radius: var(--border-radius); border: 1px solid var(--border-color);
  display: none;
}
.calc-result-box.visible { display: block; }
.calc-result-label { font-size: .85rem; color: var(--text-secondary); font-weight: 500; }
.calc-result-value { font-family: var(--font-display); font-size: 2rem; font-weight: 800; color: var(--color-primary); margin: 4px 0; }

/* ── Prose Content Sections ───────────────────────────────── */
.prose-section { margin: 32px 0; }
.prose-section h2 { font-family: var(--font-display); font-size: 1.5rem; font-weight: 700; color: var(--text-primary); margin-bottom: 16px; }
.prose-section h3 { font-size: 1.15rem; font-weight: 600; color: var(--text-primary); margin-bottom: 10px; margin-top: 20px; }
.prose-section p { color: var(--text-secondary); line-height: 1.75; margin-bottom: 14px; }
.prose-section ul, .prose-section ol { padding-left: 20px; color: var(--text-secondary); line-height: 2; }
.prose-section li { margin-bottom: 4px; }

/* ── FAQ Accordion ─────────────────────────────────────────── */
.faq-section h2 { font-family: var(--font-display); font-size: 1.5rem; font-weight: 700; margin-bottom: 24px; }
.faq-item { border: 1px solid var(--border-color); border-radius: var(--border-radius); margin-bottom: 10px; overflow: hidden; }
.faq-question {
  width: 100%; text-align: left; background: var(--bg-card); border: none;
  padding: 18px 20px; font-size: 1rem; font-weight: 600; color: var(--text-primary);
  cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 12px;
  transition: background var(--transition);
}
.faq-question:hover { background: var(--bg-muted); }
.faq-question i { transition: transform var(--transition); color: var(--text-muted); flex-shrink: 0; }
.faq-item.open .faq-question i { transform: rotate(180deg); }
.faq-answer { display: none; padding: 0 20px 18px; color: var(--text-secondary); line-height: 1.75; }
.faq-item.open .faq-answer { display: block; }

/* ── Breadcrumb ────────────────────────────────────────────── */
.breadcrumb-nav { padding: 12px 0; }
.breadcrumb { display: flex; flex-wrap: wrap; gap: 4px; align-items: center; }
.breadcrumb-item { display: flex; align-items: center; gap: 4px; font-size: .85rem; color: var(--text-muted); }
.breadcrumb-item a { color: var(--text-secondary); }
.breadcrumb-item a:hover { color: var(--color-primary); text-decoration: none; }
.breadcrumb-item:not(:last-child)::after { content: '/'; margin-left: 4px; color: var(--text-muted); }
.breadcrumb-item.active { color: var(--text-primary); font-weight: 500; }

/* ── Blog Grid ─────────────────────────────────────────────── */
.blog-grid { display: grid; gap: 24px; }
@media (min-width: 640px) { .blog-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .blog-grid { grid-template-columns: repeat(3, 1fr); } }

.post-card { text-decoration: none; color: var(--text-primary); display: flex; flex-direction: column; }
.post-card img { width: 100%; height: 200px; object-fit: cover; border-radius: var(--border-radius) var(--border-radius) 0 0; }
.post-card .card-body { flex: 1; }
.post-meta { font-size: .8rem; color: var(--text-muted); margin-bottom: 8px; }
.post-card h3 { font-size: 1.05rem; font-weight: 600; line-height: 1.4; margin-bottom: 8px; }
.post-card p { font-size: .875rem; color: var(--text-secondary); }
.post-card:hover { text-decoration: none; }

/* ── Sidebar Widgets ───────────────────────────────────────── */
.widget { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--border-radius-lg); padding: 20px; }
.widget-title { font-size: 1rem; font-weight: 700; color: var(--text-primary); margin-bottom: 16px; padding-bottom: 12px; border-bottom: 2px solid var(--color-primary); }
.widget-list { display: flex; flex-direction: column; gap: 8px; }
.widget-list a { display: flex; align-items: flex-start; gap: 8px; padding: 8px; border-radius: 6px; color: var(--text-secondary); font-size: .9rem; transition: all var(--transition); }
.widget-list a:hover { background: var(--bg-muted); color: var(--color-primary); text-decoration: none; }
.widget-list a i { margin-top: 2px; color: var(--color-primary); flex-shrink: 0; }

/* ── Buttons ──────────────────────────────────────────────── */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 20px; border-radius: var(--border-radius); font-weight: 600; font-size: .95rem; cursor: pointer; border: none; transition: all var(--transition); text-decoration: none; }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-h); color: #fff; text-decoration: none; }
.btn-outline { background: transparent; color: var(--color-primary); border: 2px solid var(--color-primary); }
.btn-outline:hover { background: var(--color-primary); color: #fff; text-decoration: none; }
.btn-sm { padding: 6px 14px; font-size: .85rem; }
.btn-lg { padding: 14px 28px; font-size: 1.05rem; }

/* ── Newsletter ────────────────────────────────────────────── */
.newsletter-section { background: linear-gradient(135deg, var(--color-primary), #7C3AED); padding: 64px 0; text-align: center; }
.newsletter-section h2 { font-family: var(--font-display); font-size: 2rem; font-weight: 700; color: #fff; margin-bottom: 12px; }
.newsletter-section p { color: rgba(255,255,255,.85); margin-bottom: 28px; }
.newsletter-form { display: flex; gap: 8px; max-width: 460px; margin: 0 auto; }
.newsletter-form input { flex: 1; padding: 12px 18px; border-radius: var(--border-radius); border: none; background: rgba(255,255,255,.15); color: #fff; font-size: 1rem; outline: none; border: 1px solid rgba(255,255,255,.3); }
.newsletter-form input::placeholder { color: rgba(255,255,255,.6); }
.newsletter-form button { background: #fff; color: var(--color-primary); border: none; padding: 12px 24px; border-radius: var(--border-radius); font-weight: 600; cursor: pointer; white-space: nowrap; transition: all var(--transition); }
.newsletter-form button:hover { background: var(--color-accent); color: #fff; }

/* ── Footer ───────────────────────────────────────────────── */
.site-footer { background: var(--bg-surface); border-top: 1px solid var(--border-color); padding: 64px 0 0; }
.footer-grid { display: grid; gap: 40px; }
@media (min-width: 640px) { .footer-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; } }
.footer-col {}
.footer-brand { display: flex; flex-direction: column; gap: 16px; }
.footer-logo { font-family: var(--font-display); font-size: 1.3rem; font-weight: 700; color: var(--color-primary); display: flex; align-items: center; gap: 8px; text-decoration: none; }
.footer-brand p { color: var(--text-secondary); font-size: .9rem; line-height: 1.7; }
.social-links { display: flex; gap: 10px; }
.social-links a { width: 36px; height: 36px; background: var(--bg-muted); border-radius: 8px; display: flex; align-items: center; justify-content: center; color: var(--text-secondary); transition: all var(--transition); }
.social-links a:hover { background: var(--color-primary); color: #fff; text-decoration: none; }
.footer-heading { font-size: .9rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; color: var(--text-primary); margin-bottom: 16px; }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-links a { font-size: .9rem; color: var(--text-secondary); transition: color var(--transition); }
.footer-links a:hover { color: var(--color-primary); text-decoration: none; }
.footer-bottom { margin-top: 48px; border-top: 1px solid var(--border-color); padding: 24px 0; display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.footer-bottom p { font-size: .85rem; color: var(--text-muted); }

/* ── Pagination ────────────────────────────────────────────── */
.pagination { display: flex; gap: 6px; justify-content: center; flex-wrap: wrap; margin: 32px 0; }
.page-item .page-link { display: block; padding: 8px 14px; border-radius: var(--border-radius); border: 1px solid var(--border-color); color: var(--text-secondary); font-size: .9rem; transition: all var(--transition); text-decoration: none; }
.page-item .page-link:hover { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.page-item.active .page-link { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* ── Page Header ───────────────────────────────────────────── */
.page-header { background: var(--bg-surface); border-bottom: 1px solid var(--border-color); padding: 32px 0; }
.page-header h1 { font-family: var(--font-display); font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 700; margin: 8px 0; }
.page-header p { color: var(--text-secondary); }

/* ── Alerts ───────────────────────────────────────────────── */
.alert { padding: 14px 18px; border-radius: var(--border-radius); font-size: .9rem; margin-bottom: 16px; display: flex; align-items: flex-start; gap: 10px; }
.alert-success { background: #d1fae5; color: #065f46; border: 1px solid #a7f3d0; }
.alert-danger  { background: #fee2e2; color: #991b1b; border: 1px solid #fca5a5; }
.alert-info    { background: #dbeafe; color: #1e40af; border: 1px solid #93c5fd; }
[data-theme="dark"] .alert-success { background: #064e3b; color: #6ee7b7; border-color: #065f46; }
[data-theme="dark"] .alert-danger  { background: #7f1d1d; color: #fca5a5; border-color: #991b1b; }

/* ── Lazy Load ─────────────────────────────────────────────── */
img[loading="lazy"] { background: var(--bg-muted); }

/* ── Utility ──────────────────────────────────────────────── */
.text-center { text-align: center; }
.mt-4 { margin-top: 16px; }
.mt-8 { margin-top: 32px; }
.mb-4 { margin-bottom: 16px; }
.mb-8 { margin-bottom: 32px; }
.text-muted { color: var(--text-muted); }
.d-none { display: none; }
.view-all-wrap { text-align: center; margin-top: 40px; }

/* ── Formula Box ───────────────────────────────────────────── */
.formula-box {
  background: var(--bg-surface); border: 1px solid var(--border-color);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--border-radius); padding: 20px 24px; font-family: monospace;
  font-size: 1.1rem; color: var(--color-primary); margin: 16px 0;
}

/* ── Table ─────────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: .9rem; }
th { background: var(--bg-muted); padding: 12px 16px; text-align: left; font-weight: 600; color: var(--text-primary); border-bottom: 2px solid var(--border-color); }
td { padding: 12px 16px; border-bottom: 1px solid var(--border-color); color: var(--text-secondary); }
tr:hover td { background: var(--bg-muted); }

/* ── Animations ────────────────────────────────────────────── */
@media (prefers-reduced-motion: no-preference) {
  .fade-in { animation: fadeIn .4s ease forwards; }
  @keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
}