@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;600;700;800&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;1,9..40,300&display=swap');

:root {
  --bg: #ffffff;
  --bg2: #f7f8fa;
  --bg3: #eef0f4;
  --text: #0d0f14;
  --text2: #444658;
  --muted: #888ea8;
  --accent: #1a56e8;
  --accent-light: #e8effe;
  --accent2: #f5a623;
  --green: #16a34a;
  --green-light: #dcfce7;
  --red: #dc2626;
  --border: #e2e5ef;
  --card: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.07), 0 4px 16px rgba(0,0,0,0.04);
  --shadow-hover: 0 4px 12px rgba(0,0,0,0.1), 0 12px 32px rgba(0,0,0,0.06);
  --radius: 12px;
  --radius-lg: 20px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: 16px;
  line-height: 1.65;
}
h1,h2,h3,h4,h5 { font-family: 'Syne', sans-serif; line-height: 1.2; }
a { color: inherit; }
img { max-width: 100%; }

/* ── NAV ── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 200;
  background: #fff;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(0,0,0,0.04);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.site-logo {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: 1.35rem;
  text-decoration: none;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}
.site-logo .dot { color: var(--accent); }

.nav-menu {
  display: flex;
  list-style: none;
  gap: 0;
  flex: 1;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 0 1rem;
  height: 64px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text2);
  text-decoration: none;
  transition: color 0.15s;
  cursor: pointer;
  white-space: nowrap;
  border: none;
  background: none;
  font-family: inherit;
}
.nav-link:hover, .nav-item:hover .nav-link { color: var(--accent); }
.nav-link svg { width: 14px; height: 14px; transition: transform 0.2s; flex-shrink: 0; }
.nav-item:hover .nav-link svg { transform: rotate(180deg); }

/* MEGA DROPDOWN */
.mega-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  min-width: 380px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 8px 40px rgba(0,0,0,0.12);
  padding: 1rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.15s, visibility 0.15s, transform 0.15s;
  transform: translateX(-50%) translateY(8px);
  pointer-events: none;
}

.nav-item:hover .mega-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}

.mega-menu-header {
  padding: 0.5rem 0.75rem 0.75rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.5rem;
}

.mega-menu-header p {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 2px;
}

.mega-menu-header strong {
  font-family: 'Syne', sans-serif;
  font-size: 0.85rem;
  color: var(--text);
}

.mega-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 0.65rem 0.75rem;
  border-radius: 10px;
  text-decoration: none;
  color: var(--text);
  transition: background 0.12s;
}

.mega-item:hover { background: var(--bg2); }

.mega-item-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.mega-item:hover .mega-item-icon { background: var(--accent); filter: saturate(0) brightness(2); }

.mega-item-text strong {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 1px;
}

.mega-item-text span {
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.3;
}

.mega-footer {
  margin-top: 0.5rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.mega-footer a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  border-radius: 8px;
  transition: background 0.12s;
}
.mega-footer a:hover { background: var(--accent-light); }

.nav-right { margin-left: auto; display: flex; align-items: center; gap: 0.75rem; }

.nav-search {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 6px 14px;
  font-size: 0.85rem;
  color: var(--muted);
  cursor: text;
  transition: border-color 0.2s;
  min-width: 160px;
}
.nav-search:hover { border-color: var(--accent); }
.nav-search svg { width: 15px; height: 15px; flex-shrink: 0; }

/* ── LAYOUT ── */
.container { max-width: 1200px; margin: 0 auto; padding: 0 2rem; }
.container-sm { max-width: 800px; margin: 0 auto; padding: 0 2rem; }

/* ── SECTIONS ── */
.section { padding: 3.5rem 0; }
.section-sm { padding: 2rem 0; }

.section-head { margin-bottom: 2rem; }
.section-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}
.section-title { font-size: clamp(1.5rem, 2.5vw, 2rem); font-weight: 800; color: var(--text); margin-bottom: 0.5rem; }
.section-sub { font-size: 0.95rem; color: var(--muted); font-weight: 300; }

/* ── CARDS ── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.2s, transform 0.2s, border-color 0.2s;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
}
.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: rgba(26,86,232,0.15);
}

.card-thumb {
  aspect-ratio: 16/9;
  background: var(--bg3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  position: relative;
  overflow: hidden;
}

.card-thumb::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(0,0,0,0.04), transparent);
}

.card-body { padding: 1.25rem; flex: 1; display: flex; flex-direction: column; }
.card-tag {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}
.card-title { font-size: 1rem; font-weight: 700; margin-bottom: 0.5rem; line-height: 1.35; }
.card-excerpt { font-size: 0.85rem; color: var(--text2); font-weight: 300; line-height: 1.5; flex: 1; }

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--muted);
}

.card-meta .read-time {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ── BUTTONS ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.9rem;
  padding: 12px 24px;
  border-radius: 100px;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: #1240c4; box-shadow: 0 6px 20px rgba(26,86,232,0.3); transform: translateY(-1px); }

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
}
.btn-outline:hover { background: var(--accent-light); }

.btn-ghost {
  background: transparent;
  color: var(--text2);
  border: 1.5px solid var(--border);
}
.btn-ghost:hover { background: var(--bg2); border-color: var(--text2); }

/* ── GRIDS ── */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }

@media (max-width: 900px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .nav-menu { display: none; }
  .container { padding: 0 1rem; }
}

/* ── FOOTER ── */
.site-footer {
  background: var(--text);
  color: rgba(255,255,255,0.7);
  padding: 3rem 0 1.5rem;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.footer-brand .site-logo { color: #fff; margin-bottom: 0.75rem; }
.footer-brand p { font-size: 0.85rem; line-height: 1.6; }

.footer-col h5 {
  font-family: 'Syne', sans-serif;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 1rem;
}

.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.footer-col ul a { font-size: 0.85rem; color: rgba(255,255,255,0.6); text-decoration: none; transition: color 0.2s; }
.footer-col ul a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
}

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 0.5rem; text-align: center; }
}

/* ── CALCULATOR PAGE ── */
.calc-page-hero {
  background: linear-gradient(135deg, var(--accent-light) 0%, #f0f4ff 100%);
  border-bottom: 1px solid var(--border);
  padding: 3rem 0 2rem;
}

.calc-page-hero .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 1rem;
}
.calc-page-hero .breadcrumb a { color: var(--accent); text-decoration: none; }
.calc-page-hero .breadcrumb a:hover { text-decoration: underline; }

.calc-page-hero h1 {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.calc-page-hero p {
  color: var(--text2);
  font-size: 1.05rem;
  max-width: 580px;
  font-weight: 300;
}

.calc-layout {
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 3rem;
  align-items: start;
  padding: 3rem 0;
}

@media (max-width: 900px) {
  .calc-layout { grid-template-columns: 1fr; }
}

.calc-widget {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow);
  position: sticky;
  top: 80px;
}

.calc-widget h2 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

.calc-widget .field { margin-bottom: 1.25rem; }
.calc-widget label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text2);
  margin-bottom: 6px;
}

.calc-widget input[type="number"],
.calc-widget select {
  width: 100%;
  padding: 11px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.95rem;
  color: var(--text);
  background: var(--bg);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  -moz-appearance: textfield;
}

.calc-widget input::-webkit-outer-spin-button,
.calc-widget input::-webkit-inner-spin-button { -webkit-appearance: none; }

.calc-widget input:focus,
.calc-widget select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(26,86,232,0.1);
}

.calc-widget select { cursor: pointer; }

.calc-widget .calc-btn {
  width: 100%;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 100px;
  padding: 13px;
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.2s, transform 0.15s, box-shadow 0.2s;
  margin-top: 0.5rem;
}
.calc-widget .calc-btn:hover { background: #1240c4; transform: translateY(-1px); box-shadow: 0 6px 20px rgba(26,86,232,0.25); }

.calc-result-box {
  margin-top: 1.5rem;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  display: none;
}
.calc-result-box.show { display: block; }

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
  font-size: 0.88rem;
}
.result-row + .result-row { border-top: 1px solid var(--border); }
.result-row .label { color: var(--text2); }
.result-row .value { font-weight: 700; color: var(--text); font-family: 'Syne', sans-serif; }
.result-row.highlight .value { color: var(--accent); font-size: 1.3rem; }
.result-row.highlight { margin-top: 0.5rem; padding-top: 0.75rem; border-top: 2px solid var(--border) !important; }

/* SEO CONTENT */
.seo-content { color: var(--text2); }
.seo-content h2 { font-size: 1.4rem; font-weight: 800; color: var(--text); margin: 2rem 0 0.75rem; }
.seo-content h3 { font-size: 1.1rem; font-weight: 700; color: var(--text); margin: 1.5rem 0 0.5rem; }
.seo-content p { margin-bottom: 1rem; font-size: 0.95rem; line-height: 1.75; }
.seo-content ul { margin: 0.75rem 0 1rem 1.5rem; display: flex; flex-direction: column; gap: 0.4rem; }
.seo-content ul li { font-size: 0.95rem; }
.seo-content .highlight-box {
  background: var(--accent-light);
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  font-size: 0.9rem;
  color: var(--text);
}
.seo-content .highlight-box strong { color: var(--accent); }

.related-calcs {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.related-calcs h3 { font-size: 1rem; font-weight: 700; margin-bottom: 1rem; }
.related-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.75rem; }
.related-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  text-decoration: none;
  color: var(--text);
  font-size: 0.85rem;
  font-weight: 600;
  transition: border-color 0.15s, background 0.15s;
}
.related-card:hover { border-color: var(--accent); background: var(--accent-light); }
.related-card span { font-size: 1.2rem; }

/* ARTICLE PAGE */
.article-hero {
  padding: 2.5rem 0 2rem;
  border-bottom: 1px solid var(--border);
}

.article-body {
  max-width: 720px;
  margin: 2.5rem auto;
  padding: 0 2rem;
  font-size: 1.02rem;
  line-height: 1.8;
  color: var(--text2);
}
.article-body h2 { font-size: 1.5rem; color: var(--text); margin: 2.5rem 0 1rem; }
.article-body h3 { font-size: 1.15rem; color: var(--text); margin: 2rem 0 0.75rem; }
.article-body p { margin-bottom: 1.25rem; }
.article-body ul, .article-body ol { margin: 0.75rem 0 1.25rem 1.5rem; display: flex; flex-direction: column; gap: 0.4rem; }
.article-body .info-box {
  background: var(--accent-light);
  border-left: 4px solid var(--accent);
  border-radius: 0 12px 12px 0;
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  font-size: 0.92rem;
}
.article-body .warn-box {
  background: #fff8ec;
  border-left: 4px solid var(--accent2);
  border-radius: 0 12px 12px 0;
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  font-size: 0.92rem;
}