/* =========================================================
   DOTS Calculator — Design System & Base Styles
   Mobile-first. WCAG AA. Original design (no third-party code).
   ========================================================= */

:root {
  /* Brand gradient: deep indigo -> electric violet -> coral accent */
  --c-primary-900: #1a1145;
  --c-primary-700: #3a1f8c;
  --c-primary-500: #6d3bf0;
  --c-primary-400: #8b5cf6;
  --c-accent-500: #ff5d73;
  --c-accent-400: #ff8a65;

  --c-bg: #f7f7fb;
  --c-bg-elevated: #ffffff;
  --c-text: #17152b;
  --c-text-muted: #5b5876;
  --c-border: #e6e4f0;

  --c-success: #16a34a;
  --c-warning: #d97706;

  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-border: rgba(255, 255, 255, 0.4);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;

  --shadow-sm: 0 1px 2px rgba(23, 21, 43, 0.06);
  --shadow-md: 0 8px 24px rgba(23, 21, 43, 0.08);
  --shadow-lg: 0 20px 48px rgba(23, 21, 43, 0.14);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --header-height: 72px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

[data-theme="dark"] {
  --c-bg: #100c24;
  --c-bg-elevated: #191233;
  --c-text: #f3f2fb;
  --c-text-muted: #b6b2d6;
  --c-border: #2c2455;
  --glass-bg: rgba(25, 18, 51, 0.6);
  --glass-border: rgba(255, 255, 255, 0.08);
}

/* Respect default OS preference only when no explicit choice saved (see main.js) */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--transition-base), color var(--transition-base);
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--c-primary-500); text-decoration: none; }
a:hover { color: var(--c-accent-500); }
h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 var(--space-4); font-weight: 800; }
p { margin: 0 0 var(--space-4); }
ul, ol { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; cursor: pointer; }

/* Accessible focus ring everywhere, mouse-click doesn't show it (via :focus-visible) */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 3px solid var(--c-accent-500);
  outline-offset: 2px;
}

.screen-reader-text {
  position: absolute !important;
  clip: rect(1px, 1px, 1px, 1px);
  width: 1px; height: 1px; overflow: hidden; white-space: nowrap;
}
.skip-link {
  position: fixed; top: -100px; left: var(--space-4); z-index: 9999;
  background: var(--c-primary-500); color: #fff; padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm); transition: top var(--transition-fast);
}
.skip-link:focus { top: var(--space-4); clip: auto; width: auto; height: auto; }

.container { width: 100%; max-width: 1240px; margin: 0 auto; padding: 0 var(--space-4); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
  padding: 0.7rem 1.4rem; border-radius: var(--radius-md); font-weight: 700; font-size: 0.95rem;
  border: 2px solid transparent; transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500));
  color: #fff; box-shadow: var(--shadow-md);
}
.btn-primary:hover { color: #fff; box-shadow: var(--shadow-lg); }
.btn-outline { border-color: var(--c-border); color: var(--c-text); background: transparent; }
.btn-outline:hover { border-color: var(--c-primary-500); color: var(--c-primary-500); }
.btn-lg { padding: 0.9rem 1.8rem; font-size: 1.05rem; }
.btn-sm { padding: 0.45rem 0.9rem; font-size: 0.85rem; }

/* ---------- Glassmorphism ---------- */
.glass {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100; background: var(--c-bg-elevated);
  border-bottom: 1px solid var(--c-border); transition: box-shadow var(--transition-base);
}
.site-header[data-stuck] { box-shadow: var(--shadow-md); }
.header-inner {
  display: flex; align-items: center; gap: var(--space-4);
  height: var(--header-height);
}
.site-branding { flex-shrink: 0; }
.site-title-link { font-size: 1.3rem; font-weight: 800; color: var(--c-text); }
.primary-navigation { display: none; flex: 1; }
.header-actions { display: flex; align-items: center; gap: var(--space-2); margin-left: auto; }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 999px; border: none; background: transparent; color: var(--c-text);
}
.icon-btn:hover { background: var(--c-border); }
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
.header-cta { display: none; }
.mobile-menu-toggle { display: inline-flex; }
.hamburger, .hamburger::before, .hamburger::after {
  content: ""; display: block; width: 20px; height: 2px; background: currentColor; border-radius: 2px;
}
.hamburger { position: relative; }
.hamburger::before { position: absolute; top: -6px; }
.hamburger::after { position: absolute; top: 6px; }

.mobile-menu { border-top: 1px solid var(--c-border); padding: var(--space-4); background: var(--c-bg-elevated); }
.mobile-menu-list li { border-bottom: 1px solid var(--c-border); }
.mobile-menu-list a { display: block; padding: var(--space-3) 0; font-weight: 600; color: var(--c-text); }

/* Mega menu (desktop) */
.primary-menu { display: flex; gap: var(--space-2); align-items: center; }
.primary-menu > .menu-item { position: relative; }
.menu-link { display: flex; align-items: center; gap: 6px; padding: var(--space-2) var(--space-3); border-radius: var(--radius-sm); font-weight: 600; color: var(--c-text); }
.menu-link:hover { background: var(--c-border); color: var(--c-text); }
.mega-menu-panel {
  position: absolute; top: 100%; left: 0; min-width: 280px;
  background: var(--c-bg-elevated); border: 1px solid var(--c-border); border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg); padding: var(--space-3); opacity: 0; visibility: hidden;
  transform: translateY(8px); transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
}
.menu-item-has-children:hover > .mega-menu-panel,
.menu-item-has-children:focus-within > .mega-menu-panel {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.mega-menu-list .menu-item-desc { display: block; font-size: 0.78rem; color: var(--c-text-muted); padding: 0 var(--space-3) var(--space-2); }

/* Breadcrumbs */
.breadcrumbs { padding: var(--space-3) 0; font-size: 0.85rem; color: var(--c-text-muted); }
.breadcrumbs ol { display: flex; flex-wrap: wrap; gap: 6px; }
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: 6px; color: var(--c-border); }
.breadcrumbs a { color: var(--c-text-muted); }
.breadcrumbs a:hover { color: var(--c-primary-500); }

/* ---------- Search form ---------- */
.search-form { display: flex; gap: var(--space-2); }
.search-field {
  flex: 1; padding: 0.7rem 1rem; border-radius: var(--radius-md); border: 1px solid var(--c-border);
  background: var(--c-bg); color: var(--c-text); font-size: 1rem;
}

/* ---------- Hero ---------- */
.hero { padding: var(--space-16) 0 var(--space-12); background: radial-gradient(circle at 20% 20%, rgba(109, 59, 240, 0.12), transparent 60%), var(--c-bg); overflow: hidden; }
.hero-inner { display: flex; flex-direction: column; gap: var(--space-8); align-items: center; text-align: center; }
.hero-title { font-size: clamp(2rem, 5vw, 3.2rem); background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-subtitle { font-size: 1.1rem; color: var(--c-text-muted); max-width: 560px; margin-inline: auto; }
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; }
.hero-visual { width: 100%; max-width: 340px; }
.hero-card { padding: var(--space-6); animation: fadeInUp 0.6s ease both; }
.hero-card-row { display: flex; justify-content: space-between; padding: var(--space-2) 0; border-bottom: 1px solid var(--c-border); }
.hero-card-row:last-child { border-bottom: none; }

@keyframes fadeInUp { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }
.section { padding: var(--space-12) 0; }
.section-title { font-size: clamp(1.5rem, 3vw, 2rem); text-align: center; margin-bottom: var(--space-8); }

/* ---------- Cards / Grids ---------- */
.post-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-6); }
.card {
  background: var(--c-bg-elevated); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
  overflow: hidden; transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card-thumb { display: block; aspect-ratio: 4/3; background: var(--c-border); overflow: hidden; }
.card-thumb img { width: 100%; height: 100%; object-fit: cover; }
.calc-thumb-fallback { display: flex; align-items: center; justify-content: center; height: 100%; color: var(--c-primary-500); }
.card-body { padding: var(--space-5, var(--space-4)); }
.card-title { font-size: 1.05rem; margin-bottom: var(--space-2); }
.card-excerpt { color: var(--c-text-muted); font-size: 0.92rem; }
.card-link { font-weight: 700; }

/* ---------- Feature grid / steps / testimonials / FAQ ---------- */
.feature-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-6); }
.feature-card { padding: var(--space-6); text-align: left; }
.feature-icon { color: var(--c-primary-500); display: inline-block; margin-bottom: var(--space-3); }
.steps { display: grid; grid-template-columns: 1fr; gap: var(--space-8); counter-reset: step; }
.step-num {
  display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px;
  border-radius: 50%; background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); color: #fff; font-weight: 800; margin-bottom: var(--space-3);
}
.testimonial-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-6); }
.testimonial-card { padding: var(--space-6); margin: 0; }
.testimonial-card footer { margin-top: var(--space-3); font-weight: 700; }
.testimonial-card footer span { display: block; font-weight: 400; color: var(--c-text-muted); font-size: 0.85rem; }
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: var(--space-3); }
.faq-item { border: 1px solid var(--c-border); border-radius: var(--radius-md); padding: var(--space-4); background: var(--c-bg-elevated); }
.faq-item summary { cursor: pointer; font-weight: 700; }
.faq-answer { margin-top: var(--space-3); color: var(--c-text-muted); }
.empty-state, .empty-state-block { text-align: center; color: var(--c-text-muted); padding: var(--space-8) 0; }

/* ---------- Newsletter ---------- */
.newsletter-cta .newsletter-inner { text-align: center; padding: var(--space-12) var(--space-6); }
.newsletter-form { display: flex; flex-wrap: wrap; gap: var(--space-2); justify-content: center; margin-top: var(--space-4); }
.newsletter-form input { padding: 0.7rem 1rem; border-radius: var(--radius-md); border: 1px solid var(--c-border); min-width: 240px; background: var(--c-bg); color: var(--c-text); }

/* ---------- Footer ---------- */
.site-footer { background: var(--c-primary-900); color: #efe9ff; margin-top: var(--space-16); }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: var(--space-8); padding: var(--space-12) 0; }
.footer-col .widget-title { color: #fff; font-size: 1rem; margin-bottom: var(--space-3); }
.footer-menu li { margin-bottom: var(--space-2); }
.footer-menu a { color: #cabdf7; }
.footer-menu a:hover { color: #fff; }
.footer-tagline { color: #b6a8ea; }
.social-icons { display: flex; gap: var(--space-3); margin-top: var(--space-4); }
.social-icon { width: 36px; height: 36px; display: inline-flex; align-items: center; justify-content: center; border-radius: 50%; background: rgba(255,255,255,0.08); color: #efe9ff; }
.social-icon:hover { background: var(--c-accent-500); color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); }
.footer-bottom-inner { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: space-between; padding: var(--space-4) 0; font-size: 0.85rem; color: #b6a8ea; }
.footer-legal-menu { display: flex; flex-wrap: wrap; gap: var(--space-4); }
.footer-legal-menu a { color: #b6a8ea; }
.footer-legal-menu a:hover { color: #fff; }

/* ---------- Content pages / single / calculators ---------- */
.content-layout { display: grid; grid-template-columns: 1fr; gap: var(--space-8); padding: var(--space-8) 0 var(--space-16); }
.content-layout-page { max-width: 820px; margin: 0 auto; }
.entry-title, .archive-title, .page-title { font-size: clamp(1.6rem, 4vw, 2.4rem); }
.entry-content, .page-content { font-size: 1.05rem; }
.entry-content > * + * { margin-top: var(--space-4); }
.entry-thumbnail { border-radius: var(--radius-lg); overflow: hidden; margin-bottom: var(--space-6); }
.author-box { display: flex; gap: var(--space-4); align-items: flex-start; padding: var(--space-6); border-top: 1px solid var(--c-border); border-bottom: 1px solid var(--c-border); margin: var(--space-8) 0; }
.author-box img { border-radius: 50%; }

.calculator-app {
  min-height: 320px; border: 1px dashed var(--c-border); border-radius: var(--radius-lg);
  display: flex; align-items: center; justify-content: center; color: var(--c-text-muted);
  background: var(--c-bg-elevated); margin: var(--space-6) 0;
}

.error-404-content { text-align: center; padding: var(--space-16) 0; }
.error-code { font-size: 5rem; background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.error-search { max-width: 480px; margin: var(--space-6) auto; }
.calc-chip { display: inline-block; margin: var(--space-2); padding: var(--space-2) var(--space-4); border-radius: 999px; border: 1px solid var(--c-border); }
.calc-chip:hover { background: var(--c-primary-500); color: #fff; border-color: var(--c-primary-500); }

/* ---------- Comments ---------- */
.comments-area { margin-top: var(--space-12); }
.comment-form textarea, .comment-form input[type="text"], .comment-form input[type="email"], .comment-form input[type="url"] {
  width: 100%; padding: var(--space-3); border-radius: var(--radius-sm); border: 1px solid var(--c-border); background: var(--c-bg); color: var(--c-text);
}

/* ---------- Responsive ---------- */
@media (min-width: 768px) {
  .content-layout { grid-template-columns: 2.4fr 1fr; }
  .post-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .testimonial-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-inner { flex-direction: row; text-align: left; justify-content: space-between; }
  .hero-copy { max-width: 560px; }
  .hero-subtitle { margin-inline: 0; }
  .hero-actions { justify-content: flex-start; }
}

@media (min-width: 1024px) {
  .primary-navigation { display: block; }
  .header-cta { display: inline-flex; }
  .mobile-menu-toggle, .mobile-menu { display: none; }
  .post-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr 1.4fr; }
}

/* =========================================================
   Phase 2 — Calculator UI (forms, results, tables, plates, search)
   ========================================================= */

.calculator-app { display: block; padding: var(--space-6); text-align: left; }
.calc-form { display: grid; grid-template-columns: 1fr; gap: var(--space-4); margin-bottom: var(--space-6); }
.calc-field { display: flex; flex-direction: column; gap: 6px; }
.calc-field label, .calc-field-label-inline { font-weight: 700; font-size: 0.88rem; color: var(--c-text); }
.calc-input {
  padding: 0.7rem 0.9rem; border-radius: var(--radius-md); border: 1px solid var(--c-border);
  background: var(--c-bg); color: var(--c-text); font-size: 1rem; width: 100%;
}
.calc-input:focus { border-color: var(--c-primary-500); }
.calc-hint { font-size: 0.78rem; color: var(--c-text-muted); }

.calc-unit-toggle, .calc-mode-toggle { display: inline-flex; border: 1px solid var(--c-border); border-radius: var(--radius-md); overflow: hidden; width: fit-content; }
.calc-mode-toggle { margin-bottom: var(--space-4); }
.unit-btn { padding: 0.5rem 1rem; border: none; background: var(--c-bg-elevated); color: var(--c-text-muted); font-weight: 700; }
.unit-btn[aria-pressed="true"] { background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); color: #fff; }
.calc-field-unit { flex-direction: row; align-items: center; gap: var(--space-3); }

.calc-results {
  padding: var(--space-6); text-align: center; display: flex; flex-direction: column; gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.calc-result-label { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--c-text-muted); }
.calc-result-value { font-size: clamp(2rem, 6vw, 3rem); background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.calc-result-sub { color: var(--c-text-muted); font-size: 0.9rem; margin: 0; }

.calc-table-wrap { overflow-x: auto; }
.calc-table-title { font-size: 1.1rem; margin-bottom: var(--space-3); }
.calc-table { width: 100%; border-collapse: collapse; }
.calc-table th, .calc-table td { padding: 0.6rem 0.8rem; text-align: left; border-bottom: 1px solid var(--c-border); }
.calc-table th { font-size: 0.8rem; text-transform: uppercase; color: var(--c-text-muted); }

.calc-plate-visual { display: flex; flex-wrap: wrap; gap: var(--space-4); align-items: flex-end; margin-top: var(--space-4); }
.plate-stack { display: flex; flex-direction: column; align-items: center; gap: 6px; }
.plate-bar {
  width: 44px; display: flex; align-items: center; justify-content: center; border-radius: 6px;
  background: linear-gradient(135deg, var(--c-primary-500), var(--c-accent-500)); color: #fff; font-weight: 800; font-size: 0.75rem;
}
.plate-stack span { font-size: 0.8rem; color: var(--c-text-muted); }

/* Homepage calculator search */
.calculator-search-section { padding-top: 0; padding-bottom: var(--space-8); }
.calculator-search-box { position: relative; max-width: 640px; margin: 0 auto; padding: var(--space-2); }
.calculator-search-input {
  width: 100%; padding: 1rem 1.2rem; border-radius: var(--radius-md); border: none;
  background: var(--c-bg-elevated); color: var(--c-text); font-size: 1.05rem;
}
.calculator-search-results {
  position: absolute; top: calc(100% + 8px); left: var(--space-2); right: var(--space-2);
  background: var(--c-bg-elevated); border: 1px solid var(--c-border); border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg); max-height: 320px; overflow-y: auto; z-index: 20;
}
.calculator-search-results li { border-bottom: 1px solid var(--c-border); }
.calculator-search-results li:last-child { border-bottom: none; }
.calculator-search-results a { display: block; padding: var(--space-3) var(--space-4); color: var(--c-text); font-weight: 600; }
.calculator-search-results a:hover { background: var(--c-bg); color: var(--c-primary-500); }
.search-no-results { padding: var(--space-3) var(--space-4); color: var(--c-text-muted); }

@media (min-width: 640px) {
  .calc-form { grid-template-columns: repeat(2, 1fr); }
  .calc-field-unit { grid-column: 1 / -1; }
}