/* ==========================================================================
   DailyCalculator — Design System
   Mirrors the original Tailwind (Inter font, slate/blue palette) visuals
   without a build step.
   ========================================================================== */

/* Metric-matched fallback for Inter: sized so the fallback occupies the same
   width/height as Inter, eliminating layout shift when the webfont swaps in. */
@font-face {
  font-family: 'Inter Fallback';
  src: local('Arial');
  size-adjust: 107%;
  ascent-override: 90%;
  descent-override: 22%;
  line-gap-override: 0%;
}

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --color-card: #ffffff;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #eff6ff;
  --color-accent: #3b82f6;
  --color-success: #16a34a;
  --color-danger: #dc2626;
  --color-warning: #d97706;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.05);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.05);
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --font-sans: 'Inter', 'Inter Fallback', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

html[data-theme="dark"] {
  --color-bg: #020617;
  --color-bg-alt: #0f172a;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-border: #1e293b;
  --color-card: #0f172a;
  --color-primary: #3b82f6;
  --color-primary-dark: #60a5fa;
  --color-primary-light: #172554;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color .2s ease, color .2s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}
.site-header .header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 4.25rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  white-space: nowrap;
}
.brand .brand-mark {
  width: 2rem;
  height: 2rem;
  border-radius: .6rem;
  background: linear-gradient(135deg, var(--color-primary), #06b6d4);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 900;
  font-size: 1rem;
  flex-shrink: 0;
}
.brand .brand-highlight { color: var(--color-primary); }

.main-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-left: 1rem;
  flex: 1;
}
.main-nav a {
  font-size: .9rem;
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active { color: var(--color-primary); }

.header-actions {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-left: auto;
}

.search-box {
  position: relative;
  display: none;
}
@media (min-width: 768px) {
  .search-box { display: block; }
}
.search-box input {
  width: 220px;
  padding: .5rem .75rem .5rem 2.2rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-size: .85rem;
  font-family: var(--font-sans);
}
.search-box input:focus { outline: 2px solid var(--color-primary); outline-offset: 1px; }
.search-box .icon {
  position: absolute;
  left: .75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-size: .9rem;
  pointer-events: none;
}

.icon-btn {
  width: 2.35rem;
  height: 2.35rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  cursor: pointer;
  font-size: 1.05rem;
  transition: background .15s ease, transform .1s ease;
}
.icon-btn:hover { background: var(--color-primary-light); color: var(--color-primary); }
.icon-btn:active { transform: scale(.94); }

.menu-toggle { display: inline-flex; }
@media (min-width: 900px) { .menu-toggle { display: none; } }
@media (max-width: 899px) { .main-nav { display: none; } }

/* Mobile drawer */
.mobile-nav {
  display: none;
  flex-direction: column;
  gap: .25rem;
  padding: .75rem 1.25rem 1.25rem;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  padding: .6rem .5rem;
  font-weight: 600;
  border-radius: .5rem;
  color: var(--color-text);
}
.mobile-nav a:hover { background: var(--color-bg-alt); }

/* ---------- Hero ---------- */
.hero {
  text-align: center;
  padding: 3.5rem 1rem 2.5rem;
}
.hero h1 {
  font-size: clamp(2.2rem, 6vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin: 0 0 1rem;
}
.hero h1 .highlight { color: var(--color-primary); }
.hero p {
  max-width: 46rem;
  margin: 0 auto;
  color: var(--color-text-muted);
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.6;
}
.hero .hero-search {
  max-width: 34rem;
  margin: 2rem auto 0;
  position: relative;
}
.hero .hero-search input {
  width: 100%;
  padding: .95rem 1.25rem .95rem 3rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-size: 1rem;
  font-family: var(--font-sans);
  box-shadow: var(--shadow-sm);
}
.hero .hero-search .icon {
  position: absolute;
  left: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
}

/* ---------- Section headings ---------- */
.section-title {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 .35rem;
}
.section-sub {
  color: var(--color-text-muted);
  margin: 0 0 1.5rem;
  font-size: .98rem;
}

/* ---------- Category pills ---------- */
.category-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin: 1.5rem 0 2rem;
}
.category-tabs a, .category-tabs button {
  padding: .5rem 1.1rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-weight: 600;
  font-size: .88rem;
  cursor: pointer;
  font-family: var(--font-sans);
}
.category-tabs a.active, .category-tabs button.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

/* ---------- Cards / grid ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.1rem;
}
.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.4rem;
  box-shadow: var(--shadow-sm);
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
  display: flex;
  flex-direction: column;
  gap: .6rem;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}
.card .card-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 800;
}
.card h3 { margin: 0; font-size: 1.05rem; font-weight: 700; }
.card p { margin: 0; color: var(--color-text-muted); font-size: .88rem; line-height: 1.5; flex: 1; }
.card .card-cta { font-size: .85rem; font-weight: 700; color: var(--color-primary); }

.category-hub-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: .5rem;
}
.category-hub-header .card-icon { width: 3.5rem; height: 3.5rem; font-size: 1.6rem; }

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
  font-size: .85rem;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  align-items: center;
}
.breadcrumbs a { color: var(--color-text-muted); font-weight: 600; }
.breadcrumbs a:hover { color: var(--color-primary); }
.breadcrumbs .sep { opacity: .5; }
.breadcrumbs .current { color: var(--color-text); font-weight: 600; }

/* ---------- Calculator layout ---------- */
.calc-page { padding: 2.25rem 0 4rem; }
.calc-header { margin-bottom: 1.75rem; }
.calc-header h1 {
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 .5rem;
  display: flex;
  align-items: center;
  gap: .75rem;
}
.calc-header p { color: var(--color-text-muted); font-size: 1rem; max-width: 46rem; }

.calc-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}
@media (min-width: 900px) {
  .calc-layout.with-panel { grid-template-columns: minmax(0,1fr) minmax(0,1fr); }
}

.panel {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
}
.panel h2 { font-size: 1.1rem; font-weight: 700; margin: 0 0 1.1rem; }

.field { margin-bottom: 1.1rem; }
.field label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: .4rem;
}
.field .input-wrap { position: relative; }
.field input[type="text"],
.field input[type="number"],
.field input[type="date"],
.field input[type="email"],
.field select,
.field textarea {
  width: 100%;
  padding: .7rem .85rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  font-size: .98rem;
  font-family: var(--font-sans);
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
  background: var(--color-bg);
}
.field .prefix, .field .suffix {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: .9rem;
  pointer-events: none;
}
.field .prefix { left: .85rem; }
.field .suffix { right: .85rem; }
.field.has-prefix input { padding-left: 1.75rem; }
.field.has-suffix input { padding-right: 2.5rem; }

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.radio-group { display: flex; gap: .5rem; flex-wrap: wrap; }
.radio-group label {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .5rem .9rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--color-text);
}
.radio-group input { accent-color: var(--color-primary); }
.radio-group input:checked + span {}
.radio-group label:has(input:checked) {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .8rem 1.4rem;
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: .95rem;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: background .15s ease, transform .1s ease;
}
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-primary:active { transform: scale(.98); }
.btn-secondary {
  background: var(--color-bg-alt);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn-block { width: 100%; }
.btn-row { display: flex; gap: .75rem; margin-top: .5rem; flex-wrap: wrap; }

/* ---------- Results panel ---------- */
.result-panel {
  background: linear-gradient(160deg, var(--color-primary-light), var(--color-card));
  border: 1px solid var(--color-border);
}
.result-hero {
  text-align: center;
  padding: 1rem 0 1.5rem;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 1.25rem;
}
.result-hero .result-label {
  font-size: .85rem;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: .04em;
}
.result-hero .result-value {
  font-size: clamp(2rem, 5vw, 2.9rem);
  font-weight: 900;
  color: var(--color-primary);
  letter-spacing: -0.02em;
  margin-top: .35rem;
}
.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: .9rem;
}
.result-item {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: .9rem 1rem;
}
.result-item .label { font-size: .78rem; color: var(--color-text-muted); font-weight: 600; }
.result-item .value { font-size: 1.15rem; font-weight: 800; margin-top: .2rem; }

.result-table { width: 100%; border-collapse: collapse; font-size: .88rem; margin-top: 1rem; }
.result-table th, .result-table td { padding: .55rem .6rem; text-align: left; border-bottom: 1px solid var(--color-border); }
.result-table th { color: var(--color-text-muted); font-weight: 700; font-size: .78rem; text-transform: uppercase; letter-spacing: .03em; }
.table-scroll { overflow-x: auto; max-height: 360px; overflow-y: auto; border-radius: var(--radius-md); border: 1px solid var(--color-border); margin-top: 1rem; }
.table-scroll .result-table { margin-top: 0; }
.table-scroll th { position: sticky; top: 0; background: var(--color-card); }

.note {
  font-size: .8rem;
  color: var(--color-text-muted);
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  padding: .75rem .9rem;
  margin-top: 1rem;
  line-height: 1.5;
}
.note.warn { background: #fef3c7; color: #92400e; }
html[data-theme="dark"] .note.warn { background: #451a03; color: #fcd34d; }

/* ---------- Info / content section ---------- */
.info-section {
  margin-top: 3rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--color-border);
}
.info-section h2 { font-size: 1.4rem; font-weight: 800; margin: 0 0 .75rem; }
.info-section h3 { font-size: 1.1rem; font-weight: 700; margin: 1.5rem 0 .5rem; }
.info-section p, .info-section li { color: var(--color-text-muted); line-height: 1.7; font-size: .97rem; }
.info-section ul, .info-section ol { padding-left: 1.4rem; }
.info-section .formula-box {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-family: 'Courier New', monospace;
  font-size: .92rem;
  margin: 1rem 0;
  overflow-x: auto;
}

.faq-item { border-bottom: 1px solid var(--color-border); padding: 1rem 0; }
.faq-item summary { font-weight: 700; cursor: pointer; font-size: .98rem; }
.faq-item p { margin-top: .6rem; }

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .8rem;
  margin-top: 1rem;
}
.related-grid a {
  padding: .9rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: .88rem;
  background: var(--color-card);
}
.related-grid a:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* ---------- Ad slot ---------- */
.ad-slot {
  min-height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  margin: 1.75rem 0;
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 4rem;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  padding: 3rem 0 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(4, 1fr);
  gap: 2rem;
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; }
}
.footer-grid h4 { font-size: .85rem; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; margin: 0 0 1rem; color: var(--color-text-muted); }
.footer-grid ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: .6rem; }
.footer-grid a { font-size: .88rem; color: var(--color-text); }
.footer-grid a:hover { color: var(--color-primary); }
.footer-about p { color: var(--color-text-muted); font-size: .88rem; line-height: 1.6; max-width: 26rem; }
.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: .82rem;
  color: var(--color-text-muted);
}

/* ---------- Misc pages ---------- */
.static-page { padding: 3rem 0 4rem; max-width: 860px; margin: 0 auto; }
.static-page h1 { font-size: 2.2rem; font-weight: 900; margin-bottom: .5rem; }
.static-page .updated { color: var(--color-text-muted); font-size: .85rem; margin-bottom: 2rem; }
.static-page h2 { font-size: 1.3rem; font-weight: 800; margin: 2rem 0 .75rem; }
.static-page p, .static-page li { color: var(--color-text-muted); line-height: 1.75; }

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}
@media (max-width: 800px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-info .item { display: flex; gap: .9rem; margin-bottom: 1.25rem; }
.contact-info .icon-badge {
  width: 2.75rem; height: 2.75rem; border-radius: var(--radius-md);
  background: var(--color-primary-light); color: var(--color-primary);
  display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-size: 1.2rem;
}
.contact-info .item h4 { margin: 0 0 .2rem; font-size: .95rem; }
.contact-info .item p, .contact-info .item a { margin: 0; color: var(--color-text-muted); font-size: .9rem; }

.form-status { font-size: .88rem; margin-top: 1rem; padding: .75rem 1rem; border-radius: var(--radius-sm); display: none; }
.form-status.success { display: block; background: #dcfce7; color: #166534; }
.form-status.error { display: block; background: #fee2e2; color: #991b1b; }
html[data-theme="dark"] .form-status.success { background: #052e16; color: #4ade80; }
html[data-theme="dark"] .form-status.error { background: #450a0a; color: #f87171; }

/* ---------- 404 ---------- */
.not-found { text-align: center; padding: 5rem 1rem; }
.not-found .code { font-size: 6rem; font-weight: 900; color: var(--color-primary); line-height: 1; }
.not-found h1 { font-size: 1.6rem; margin: 1rem 0 .5rem; }
.not-found p { color: var(--color-text-muted); margin-bottom: 2rem; }

/* ---------- Utility ---------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.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;
}
.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--color-primary); color: #fff;
  padding: .6rem 1rem; z-index: 100; border-radius: 0 0 .5rem 0;
}
.skip-link:focus { left: 0; }