/* ============================================================
   EasyCalc — shared styles for the tool site
   Static, dependency-free. Light theme, tool-focused layout.
   ============================================================ */

:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --border: #e5e8ee;
  --text: #1f2937;
  --text-muted: #4b5563;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --accent-soft: #eff4ff;
  --green: #047857;
  --green-soft: #ecfdf5;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(16, 24, 40, 0.06), 0 1px 2px rgba(16, 24, 40, 0.04);
  --shadow-lg: 0 12px 32px rgba(16, 24, 40, 0.10);
}

* { box-sizing: border-box; }

/* Skip link for keyboard users */
.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  border-radius: 8px;
  font-weight: 600;
  z-index: 200;
  text-decoration: none;
}
.skip-link:focus {
  top: 12px;
}

html { scroll-behavior: smooth; scroll-padding-top: 76px; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Header ---------- */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
}
.site-nav {
  margin-left: auto;
  display: flex;
  gap: 18px;
  align-items: center;
}
.site-nav a { color: var(--text-muted); font-weight: 500; font-size: 0.95rem; }
.site-nav a:hover { color: var(--accent); text-decoration: none; }

/* ---------- Layout ---------- */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 32px 24px 56px;
}

/* ---------- Home ---------- */
.hero {
  padding: 48px 24px 24px;
  text-align: center;
}
.hero h1 {
  font-size: 2.1rem;
  line-height: 1.25;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
.hero p {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 8px;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 22px;
}
@media (max-width: 480px) {
  .hero-cta { flex-direction: column; align-items: stretch; }
  .hero-cta .btn { width: 100%; }
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr));
  gap: 20px;
  margin-top: 28px;
}
.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.tool-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.tool-card .icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 12px;
}
.tool-card h3 { margin: 0 0 6px; font-size: 1.15rem; }
.tool-card h3 a { color: var(--text); }
.tool-card h3 a:hover { color: var(--accent); text-decoration: none; }
.tool-card p { margin: 0 0 14px; color: var(--text-muted); font-size: 0.95rem; }
.tool-card .meta { font-size: 0.85rem; color: var(--text-muted); display: flex; gap: 14px; flex-wrap: wrap; }
.tool-card .badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
}
.badge-live { background: var(--green-soft); color: var(--green); }
.badge-soon { background: #f3f4f6; color: var(--text-muted); }
.badge-new { background: #fef3c7; color: #92400e; }

/* ---------- Tool page ---------- */
.tool-shell {
  max-width: 900px;
  margin: 0 auto;
}
.tool-title {
  margin: 8px 0 4px;
  font-size: 1.7rem;
  letter-spacing: -0.02em;
}
.tool-subtitle { color: var(--text-muted); margin: 0 0 24px; }

.tool-layout {
  display: grid;
  grid-template-columns: 5fr 4fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 760px) {
  .tool-layout { grid-template-columns: 1fr; }
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* Inputs panel */
.input-panel { padding: 24px; }

/* Unit switch — imperial / metric */
.unit-switch {
  display: flex;
  gap: 4px;
  padding: 4px;
  margin-bottom: 20px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.unit-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
  padding: 8px 6px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--text-muted);
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.unit-btn small { font-weight: 400; font-size: 0.74rem; opacity: 0.85; }
.unit-btn:hover { background: rgba(31, 41, 55, 0.06); color: var(--text); }
.unit-btn.is-active {
  background: var(--surface);
  color: var(--text);
  box-shadow: var(--shadow);
}
.unit-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.field-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
@media (max-width: 480px) { .field-group { grid-template-columns: 1fr; } }
.field { margin-bottom: 14px; }
.field label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 6px;
}
.field .hint { font-weight: 400; color: var(--text-muted); font-size: 0.8rem; }
.field input,
.field select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  color: var(--text);
  background: #fff;
}
.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

/* ---------- Inline form validation ---------- */
.field-error {
  display: block;
  color: #b91c1c;
  font-size: 0.825rem;
  font-weight: 500;
  margin-top: 6px;
  line-height: 1.3;
}
.field-error:empty { display: none; }
.field input[aria-invalid="true"],
.field select[aria-invalid="true"] {
  border-color: #dc2626;
  background: #fef2f2;
}
.field input[aria-invalid="true"]:focus,
.field select[aria-invalid="true"]:focus {
  border-color: #dc2626;
  box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.18);
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; appearance: textfield; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: 8px;
  padding: 11px 20px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: #f3f4f6; }
.btn-block { width: 100%; }
.btn { min-height: 44px; }
.btn { box-sizing: border-box; }

.actions { display: flex; gap: 10px; margin-top: 4px; }
.actions .btn { flex: 1; }

/* Results panel */
.result-panel {
  padding: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #fafbfd 100%);
  position: sticky;
  top: 80px;
}
@media (max-width: 760px) { .result-panel { position: static; } }
.result-hero { text-align: center; padding: 6px 0 18px; }
.result-big {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--accent);
  line-height: 1.1;
}
.result-big small { font-size: 1rem; font-weight: 600; color: var(--text-muted); }
.result-label { color: var(--text-muted); font-size: 0.95rem; margin-top: 2px; }

.result-rows { border-top: 1px solid var(--border); }
.result-row {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.95rem;
}
.result-row dt { color: var(--text-muted); }
.result-row dd { margin: 0; font-weight: 600; }

/* ---------- Result change micro-feedback ---------- */
/* transform/opacity only — never affects layout, so CLS stays at 0 */
.result-big { display: inline-block; }
.result-big.is-updated { animation: result-pop 0.34s cubic-bezier(0.22, 1, 0.36, 1); }
.result-row dd.is-updated { animation: result-nudge 0.5s ease-out; }
@keyframes result-pop {
  0%   { transform: scale(1); }
  32%  { transform: scale(1.07); }
  100% { transform: scale(1); }
}
@keyframes result-nudge {
  0%   { color: var(--accent); }
  55%  { color: var(--accent); }
  100% { color: var(--text); }
}
@media (prefers-reduced-motion: reduce) {
  .result-big.is-updated,
  .result-row dd.is-updated { animation: none; }
}

.result-cans { margin-top: 16px; }
.result-cans h4 { margin: 0 0 8px; font-size: 0.95rem; }
.can-list { list-style: none; margin: 0; padding: 0; }
.can-list li {
  display: flex;
  justify-content: space-between;
  padding: 8px 10px;
  background: var(--green-soft);
  border-radius: 8px;
  margin-bottom: 6px;
  font-size: 0.95rem;
}
.can-list li span:last-child { font-weight: 700; color: var(--green); }

.share-bar {
  margin-top: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.share-bar input {
  flex: 1;
  min-width: 0;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  background: #f9fafb;
}
.share-bar .btn { padding: 9px 14px; font-size: 0.85rem; }
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: #111827;
  color: #fff;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 0.9rem;
  opacity: 0;
  transition: all 0.25s ease;
  pointer-events: none;
  z-index: 50;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- Content / SEO sections ---------- */
.tool-content { margin-top: 32px; }
.tool-content h2 { font-size: 1.35rem; margin: 28px 0 10px; letter-spacing: -0.01em; }
.tool-content h3 { font-size: 1.1rem; margin: 20px 0 8px; }
.tool-content p, .tool-content li { color: #374151; }
.tool-content ul, .tool-content ol { padding-left: 22px; }
.tool-content a {
  text-decoration: underline;
  text-decoration-color: rgba(37, 99, 235, 0.35);
  text-underline-offset: 3px;
}
.tool-content a:hover {
  text-decoration-color: var(--accent);
}
.tool-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.95rem;
}
.tool-content th, .tool-content td {
  border: 1px solid var(--border);
  padding: 9px 12px;
  text-align: left;
}
.tool-content th { background: #f3f4f6; }

.faq-item { margin-bottom: 8px; }
.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; float: right; color: var(--accent); font-weight: 700; }
.faq-item[open] summary::after { content: "−"; }
.faq-item .faq-a { padding: 12px 16px; color: #374151; font-size: 0.95rem; }

/* ---------- Related tools ---------- */
.related {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.related h2 { font-size: 1.25rem; margin: 0 0 16px; }
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 240px), 1fr));
  gap: 14px;
}
.related-grid a {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  color: var(--text);
  font-weight: 600;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 10px;
}
.related-grid a:hover { border-color: var(--accent); text-decoration: none; }

/* ---------- 404 ---------- */
.notfound-hero {
  padding: 64px 24px 24px;
  text-align: center;
}
.notfound-code {
  font-size: 6rem;
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
  letter-spacing: -0.04em;
}
.notfound-hero h1 { margin-top: 0; }
.notfound-actions {
  margin-top: 24px;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  margin-top: 40px;
}
.site-footer .inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.site-footer a { color: var(--text-muted); }
.site-footer a:hover { color: var(--accent); }

/* ---------- Utility ---------- */
.center { text-align: center; }
.muted { color: var(--text-muted); }
.note {
  background: var(--accent-soft);
  border: 1px solid #dbe6ff;
  color: #1e40af;
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 0.9rem;
  margin: 14px 0;
}

/* ============================================================
   Mobile navigation
   ============================================================ */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  margin-left: auto;
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: transparent;
  cursor: pointer;
}
.nav-toggle:hover { background: rgba(31, 41, 55, 0.06); }
.nav-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.2s ease, opacity 0.2s ease;
}
.nav-toggle.is-open .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle.is-open .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 640px) {
  .nav-toggle { display: flex; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    padding: 6px 16px 14px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
  }
  .site-nav.is-open { display: flex; }
  .site-nav a {
    padding: 13px 8px;
    font-size: 1rem;
    color: var(--text);
    border-bottom: 1px solid var(--border);
  }
  .site-nav a:hover { color: var(--accent); }
  .site-nav a:last-child { border-bottom: 0; }
}

/* ============================================================
   Scrollable tables on small screens
   ============================================================ */
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 16px 0;
}
.table-scroll table {
  margin: 0;
  min-width: 560px;
}

/* ============================================================
   Responsive refinements
   ============================================================ */
@media (max-width: 640px) {
  .container { padding: 24px 16px 40px; }
  .hero { padding: 32px 16px 20px; }
  .hero h1 { font-size: 1.6rem; }
  .hero p { font-size: 1rem; }
  .tool-title { font-size: 1.45rem; }
  .tool-subtitle { font-size: 0.95rem; }
  .tool-content h2 { font-size: 1.2rem; }
  .input-panel, .result-panel { padding: 18px; }
  .site-footer .inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    padding: 20px 16px;
  }
  .site-footer nav { display: flex; flex-wrap: wrap; gap: 2px 16px; }
}

@media (max-width: 480px) {
  .result-big { font-size: 2.4rem; }
  .actions { flex-wrap: wrap; }
  .share-bar { flex-wrap: wrap; }
  .share-bar input { flex: 1 1 100%; }
}