/* ============================================================
   Mensura — Precision Measurement & Calculation Tools
   Global stylesheet · Dark-first · Responsive · v1
   ============================================================ */

:root {
  --bg:            #0B1120;
  --bg-soft:       #0F172A;
  --card:          #141B2D;
  --card-2:        #1B2438;
  --border:        #243044;
  --border-soft:   #1C2537;

  --text:          #E8EDF5;
  --text-2:        #B4C0D4;
  --muted:         #8593AB;

  --primary:       #4F8DF7;
  --primary-dark:  #2E6FE0;
  --primary-soft:  rgba(79, 141, 247, 0.12);

  --accent:        #F0B429;
  --accent-soft:   rgba(240, 180, 41, 0.12);

  --ok:            #34D399;
  --warn:          #FBBF24;
  --err:           #F87171;

  --radius:        14px;
  --radius-sm:     10px;
  --shadow:        0 4px 20px rgba(0, 0, 0, 0.28);
  --shadow-lg:     0 12px 40px rgba(0, 0, 0, 0.40);

  --maxw:          1180px;
  --transition:    all 0.22s cubic-bezier(0.4, 0, 0.2, 1);

  --mono: 'SF Mono', 'JetBrains Mono', 'Fira Code', Menlo, Consolas, monospace;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
          'Helvetica Neue', Arial, sans-serif;
}

/* Light theme ------------------------------------------------ */
[data-theme="light"] {
  --bg:            #F5F7FB;
  --bg-soft:       #FFFFFF;
  --card:          #FFFFFF;
  --card-2:        #F0F3F9;
  --border:        #DDE3EE;
  --border-soft:   #E8EDF5;
  --text:          #111827;
  --text-2:        #374151;
  --muted:         #6B7280;
  --primary:       #2563EB;
  --primary-dark:  #1D4ED8;
  --primary-soft:  rgba(37, 99, 235, 0.10);
  --shadow:        0 2px 12px rgba(16, 24, 40, 0.06);
  --shadow-lg:     0 12px 32px rgba(16, 24, 40, 0.12);
}

/* Reset ------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }
h1, h2, h3, h4 { line-height: 1.3; margin: 0 0 0.5em; font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: 2.1rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.18rem; }
p  { margin: 0 0 1em; color: var(--text-2); }
ul, ol { color: var(--text-2); padding-left: 1.35em; }
li { margin-bottom: 0.45em; }
code {
  font-family: var(--mono); font-size: 0.9em;
  background: var(--card-2); color: var(--accent);
  padding: 0.15em 0.45em; border-radius: 5px;
}
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* Header ----------------------------------------------------- */
.site-header {
  background: rgba(11, 17, 32, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
[data-theme="light"] .site-header { background: rgba(255,255,255,0.94); }
.nav-inner {
  display: flex; align-items: center; gap: 20px;
  min-height: 64px; flex-wrap: wrap;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.32rem; font-weight: 800; letter-spacing: -0.02em;
  color: var(--text); text-decoration: none; flex-shrink: 0;
}
.brand:hover { color: var(--text); }
.brand-mark {
  width: 32px; height: 32px; border-radius: 9px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--primary), #7C5CFF);
  display: grid; place-items: center;
  font-weight: 800; font-size: 1.05rem; color: #fff;
}
.brand-sub {
  display: block; font-size: 0.68rem; font-weight: 500;
  color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase;
  line-height: 1; margin-top: 2px;
}
.nav-links { display: flex; gap: 4px; flex-wrap: wrap; margin-left: auto; }
.nav-links a {
  color: var(--text-2); font-size: 0.92rem; font-weight: 500;
  padding: 8px 13px; border-radius: 8px; white-space: nowrap;
}
.nav-links a:hover { background: var(--card-2); color: var(--text); }
.nav-links a.active { color: var(--primary); background: var(--primary-soft); }

.nav-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn {
  width: 38px; height: 38px; border-radius: 9px; border: 1px solid var(--border);
  background: var(--card); color: var(--text-2); cursor: pointer;
  display: grid; place-items: center; font-size: 1rem; transition: var(--transition);
}
.icon-btn:hover { background: var(--card-2); color: var(--text); }

.menu-toggle { display: none; }

/* Buttons ---------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: var(--radius-sm); border: none;
  background: var(--primary); color: #fff; font-size: 0.98rem; font-weight: 600;
  cursor: pointer; transition: var(--transition); font-family: var(--sans);
}
.btn:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-ghost {
  background: var(--card-2); color: var(--text); border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--border); }
.btn-sm { padding: 8px 14px; font-size: 0.88rem; }

/* Hero ------------------------------------------------------- */
.hero {
  padding: 56px 0 40px; text-align: center;
  background: radial-gradient(ellipse 80% 60% at 50% -10%, var(--primary-soft), transparent 70%);
}
.hero h1 { font-size: 2.5rem; margin-bottom: 0.35em; }
.hero p {
  font-size: 1.08rem; color: var(--muted); max-width: 640px;
  margin: 0 auto 24px;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px; border-radius: 999px; font-size: 0.82rem; font-weight: 600;
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid rgba(240, 180, 41, 0.25); margin-bottom: 18px;
}

/* Search ----------------------------------------------------- */
.search-wrap { max-width: 520px; margin: 0 auto; position: relative; }
.search-input {
  width: 100%; padding: 14px 18px 14px 46px; font-size: 1rem;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--card); color: var(--text); font-family: var(--sans);
}
.search-input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }
.search-icon { position: absolute; left: 16px; top: 50%; transform: translateY(-50%); color: var(--muted); }
#searchResults {
  position: absolute; top: calc(100% + 8px); left: 0; right: 0;
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  box-shadow: var(--shadow-lg); max-height: 340px; overflow-y: auto; z-index: 50;
  text-align: left; display: none;
}
#searchResults.show { display: block; }
#searchResults a {
  display: block; padding: 11px 16px; color: var(--text);
  border-bottom: 1px solid var(--border-soft); font-size: 0.94rem;
}
#searchResults a:last-child { border-bottom: none; }
#searchResults a:hover { background: var(--card-2); }
#searchResults .sr-cat { font-size: 0.76rem; color: var(--muted); display: block; }

/* Section ---------------------------------------------------- */
.section { padding: 44px 0; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 22px; flex-wrap: wrap; gap: 10px; }
.section-head h2 { margin: 0; }
.section-head .count { color: var(--muted); font-size: 0.9rem; }

/* Grid ------------------------------------------------------- */
.grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
}
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px;
  transition: var(--transition); display: flex; flex-direction: column;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.card-icon {
  width: 42px; height: 42px; border-radius: 11px; margin-bottom: 14px;
  display: grid; place-items: center; font-size: 1.25rem;
  background: var(--primary-soft); color: var(--primary);
}
.card h3 { font-size: 1.02rem; margin: 0 0 6px; color: var(--text); }
.card h3 a { color: var(--text); }
.card h3 a:hover { color: var(--primary); }
.card p { font-size: 0.88rem; color: var(--muted); margin: 0; flex: 1; line-height: 1.6; }
.card-tag {
  display: inline-block; margin-top: 12px; font-size: 0.74rem;
  color: var(--muted); background: var(--card-2);
  padding: 3px 9px; border-radius: 6px;
}

/* Tool page -------------------------------------------------- */
.tool-wrap { padding: 32px 0 60px; }
.breadcrumb { font-size: 0.86rem; color: var(--muted); margin-bottom: 18px; }
.breadcrumb a { color: var(--text-2); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 7px; opacity: 0.5; }

.page-title { font-size: 1.95rem; margin-bottom: 8px; }
.page-desc { color: var(--muted); font-size: 1.02rem; max-width: 760px; margin-bottom: 26px; }

.tool-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 26px; margin-bottom: 26px;
  box-shadow: var(--shadow);
}
.io-grid {
  display: grid; gap: 16px; margin-bottom: 20px;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
}
.field label {
  display: block; font-size: 0.85rem; font-weight: 600;
  color: var(--text-2); margin-bottom: 7px;
}
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px; font-size: 1rem;
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--bg-soft); color: var(--text); font-family: var(--sans);
  transition: var(--transition);
}
.field textarea { font-family: var(--mono); font-size: 0.9rem; resize: vertical; min-height: 120px; line-height: 1.6; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft);
}
.field .hint { font-size: 0.78rem; color: var(--muted); margin-top: 6px; }

.swap-row { display: flex; justify-content: center; margin: 4px 0; }
.swap-btn {
  width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border);
  background: var(--card-2); color: var(--primary); cursor: pointer;
  font-size: 1rem; transition: var(--transition);
}
.swap-btn:hover { transform: rotate(180deg); }

.result-box {
  background: var(--card-2); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 20px; margin-top: 20px;
  border-left: 3px solid var(--primary);
}
.result-box:empty { display: none; }
.result-main {
  font-size: 1.75rem; font-weight: 800; color: var(--text);
  word-break: break-word; margin-bottom: 6px; font-variant-numeric: tabular-nums;
}
.result-main .unit { font-size: 1rem; font-weight: 600; color: var(--muted); margin-left: 6px; }
.result-note { font-size: 0.88rem; color: var(--muted); }

.result-table { width: 100%; border-collapse: collapse; margin-top: 14px; font-size: 0.92rem; }
.result-table th, .result-table td {
  padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border-soft);
}
.result-table th { color: var(--muted); font-weight: 600; font-size: 0.84rem; text-transform: uppercase; letter-spacing: 0.04em; }
.result-table td { color: var(--text); font-variant-numeric: tabular-nums; }
.result-table tr:last-child td { border-bottom: none; }
.result-table td.val { font-weight: 700; color: var(--primary); }

.copy-btn { margin-top: 14px; }

/* Content ---------------------------------------------------- */
.content {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 30px; margin-bottom: 22px;
}
.content h2 {
  font-size: 1.35rem; margin-top: 1.6em; padding-bottom: 10px;
  border-bottom: 1px solid var(--border-soft);
}
.content h2:first-child { margin-top: 0; }
.content h3 { font-size: 1.08rem; margin-top: 1.3em; color: var(--text); }
.content p, .content li { color: var(--text-2); }
.content strong { color: var(--text); }

.table-wrap { overflow-x: auto; margin: 18px 0; }
table.data { width: 100%; border-collapse: collapse; font-size: 0.92rem; }
table.data th, table.data td { padding: 11px 13px; border: 1px solid var(--border-soft); text-align: left; }
table.data th { background: var(--card-2); color: var(--text); font-weight: 600; }
table.data td { color: var(--text-2); font-variant-numeric: tabular-nums; }

.note-box {
  background: var(--primary-soft); border-left: 3px solid var(--primary);
  padding: 15px 18px; border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 18px 0; font-size: 0.93rem; color: var(--text-2);
}
.note-box.warn { background: rgba(251, 191, 36, 0.10); border-left-color: var(--warn); }
.note-box strong { color: var(--text); }

/* FAQ -------------------------------------------------------- */
.faq { margin-top: 1.6em; }
.faq-item { border-bottom: 1px solid var(--border-soft); }
.faq-item:last-child { border-bottom: none; }
.faq-q {
  width: 100%; text-align: left; background: none; border: none;
  padding: 16px 0; font-size: 1rem; font-weight: 600; color: var(--text);
  cursor: pointer; display: flex; justify-content: space-between; align-items: center;
  gap: 14px; font-family: var(--sans);
}
.faq-q:hover { color: var(--primary); }
.faq-q::after { content: '+'; font-size: 1.35rem; color: var(--primary); flex-shrink: 0; font-weight: 400; }
.faq-item.open .faq-q::after { content: '−'; }
.faq-a { display: none; padding: 0 0 16px; color: var(--text-2); font-size: 0.95rem; }
.faq-item.open .faq-a { display: block; }

/* Ad slots --------------------------------------------------- */
.ad-slot {
  margin: 24px 0; text-align: center;
  padding: 12px; border-radius: var(--radius-sm);
  background: var(--card); border: 1px dashed var(--border);
}
.ad-slot .ad-label {
  font-size: 0.68rem; color: var(--muted); text-transform: uppercase;
  letter-spacing: 0.08em; margin-bottom: 8px;
}
.ad-slot ins { display: block; min-height: 90px; }
.ad-top { margin-top: 0; margin-bottom: 26px; }

/* Related ---------------------------------------------------- */
.related { margin-top: 34px; }
.related h2 { font-size: 1.2rem; margin-bottom: 16px; }

/* Disclaimer ------------------------------------------------- */
.disclaimer {
  font-size: 0.86rem; color: var(--muted); background: var(--card);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 16px 18px; margin-top: 22px;
}

/* Footer ----------------------------------------------------- */
.site-footer {
  background: var(--bg-soft); border-top: 1px solid var(--border);
  padding: 44px 0 24px; margin-top: 50px;
}
.footer-grid {
  display: grid; gap: 30px; margin-bottom: 30px;
  grid-template-columns: 2fr 1fr 1fr 1fr;
}
.footer-col h4 { font-size: 0.95rem; margin-bottom: 14px; color: var(--text); }
.footer-col p { font-size: 0.88rem; color: var(--muted); }
.footer-col a {
  display: block; color: var(--muted); font-size: 0.88rem;
  margin-bottom: 9px;
}
.footer-col a:hover { color: var(--primary); }
.footer-bottom {
  border-top: 1px solid var(--border); padding-top: 22px;
  text-align: center; font-size: 0.84rem; color: var(--muted);
}
.ad-disclosure {
  margin: 8px auto 0; max-width: 860px; text-align: center;
  font-size: 0.84rem; color: var(--muted); line-height: 1.6;
}

/* Responsive ------------------------------------------------- */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .hero { padding: 38px 0 30px; }
  .hero h1 { font-size: 1.85rem; }
  .page-title { font-size: 1.55rem; }
  h1 { font-size: 1.7rem; }
  .nav-links {
    display: none; width: 100%; flex-direction: column;
    margin: 0; padding: 10px 0 16px; gap: 2px;
    border-top: 1px solid var(--border); order: 3;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 11px 14px; }
  .menu-toggle { display: grid; }
  .nav-inner { padding: 10px 0; }
  .tool-card { padding: 18px; }
  .content { padding: 20px; }
  .grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 14px; }
  .card { padding: 16px; }
  .io-grid { grid-template-columns: 1fr; }
  .result-main { font-size: 1.45rem; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; gap: 22px; }
  .container { padding: 0 14px; }
}

/* Print ------------------------------------------------------ */
@media print {
  .site-header, .site-footer, .ad-slot, .btn, .nav-actions { display: none !important; }
  body { background: #fff; color: #000; }
}