:root {
  --bg: #0a0a0f;
  --bg2: #111118;
  --bg3: #1a1a24;
  --card: #16161f;
  --border: #2a2a3a;
  --accent: #00e5ff;
  --accent2: #7c3aed;
  --accent3: #f59e0b;
  --text: #e8e8f0;
  --text2: #9090a8;
  --text3: #5a5a72;
  --radius: 14px;
  --shadow: 0 8px 32px rgba(0,0,0,0.4);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== HEADER ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10,10,15,0.95);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.header .container {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-top: 14px;
  padding-bottom: 14px;
}
.logo {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--text);
  white-space: nowrap;
}
.logo span { color: var(--accent); }
.nav {
  display: flex;
  gap: 2px;
  flex: 1;
  flex-wrap: wrap;
}
.nav a {
  color: var(--text2);
  font-size: 0.88rem;
  padding: 6px 12px;
  border-radius: 8px;
  transition: all 0.2s;
  white-space: nowrap;
}
.nav a:hover, .nav a.active {
  color: var(--accent);
  background: rgba(0,229,255,0.08);
}
.menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
  margin-left: auto;
}
.mobile-nav {
  display: none;
  flex-direction: column;
  padding: 12px 24px 16px;
  border-top: 1px solid var(--border);
  gap: 2px;
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  color: var(--text2);
  padding: 9px 12px;
  border-radius: 8px;
  font-size: 0.95rem;
}
.mobile-nav a:hover { color: var(--accent); background: rgba(0,229,255,0.06); }

/* ===== HERO ===== */
.hero {
  position: relative;
  padding: 80px 0 60px;
  overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 20% 50%, rgba(0,229,255,0.06) 0%, transparent 60%),
    radial-gradient(ellipse 50% 60% at 80% 30%, rgba(124,58,237,0.07) 0%, transparent 60%);
  pointer-events: none;
}
.hero .container {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 60px;
  align-items: center;
}
.badge {
  display: inline-block;
  background: rgba(0,229,255,0.1);
  border: 1px solid rgba(0,229,255,0.2);
  color: var(--accent);
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 500;
  margin-bottom: 20px;
}
.hero-text h1 {
  font-family: 'Syne', sans-serif;
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1.5px;
  margin-bottom: 18px;
}
.hero-text h1 span { color: var(--accent); }
.hero-text p { color: var(--text2); font-size: 1.05rem; line-height: 1.7; max-width: 480px; }

/* ===== QUICK CONVERTER ===== */
.quick-converter {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.quick-converter::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
}
.quick-converter h2 {
  font-family: 'Syne', sans-serif;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 16px;
}
.qc-tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 20px; }
.qc-tab {
  padding: 6px 13px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: none;
  color: var(--text2);
  cursor: pointer;
  font-size: 0.82rem;
  font-family: 'DM Sans', sans-serif;
  transition: all 0.2s;
}
.qc-tab.active, .qc-tab:hover {
  background: rgba(0,229,255,0.1);
  border-color: var(--accent);
  color: var(--accent);
}
.qc-row { display: flex; gap: 10px; }
.qc-row input {
  flex: 1; min-width: 0;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  color: var(--text);
  font-size: 1rem;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  transition: border-color 0.2s;
}
.qc-row input:focus { border-color: var(--accent); }
.qc-row input[readonly] { color: var(--accent); font-weight: 500; }
.qc-row select {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 10px;
  color: var(--text);
  font-size: 0.82rem;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  cursor: pointer;
  min-width: 110px;
  max-width: 150px;
  transition: border-color 0.2s;
}
.qc-row select:focus { border-color: var(--accent); }
.qc-arrow { text-align: center; font-size: 1.4rem; color: var(--accent); margin: 10px 0; }

/* ===== SECTIONS ===== */
.section-title {
  font-family: 'Syne', sans-serif;
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 24px;
}
.section-title::after {
  content: '';
  display: block;
  width: 36px; height: 3px;
  background: var(--accent);
  margin-top: 8px;
  border-radius: 2px;
}

.common-section { padding: 60px 0 40px; background: var(--bg2); }
.common-grid { display: flex; flex-wrap: wrap; gap: 10px; }
.conv-link {
  display: inline-block;
  padding: 9px 16px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text2);
  font-size: 0.87rem;
  transition: all 0.2s;
}
.conv-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0,229,255,0.05);
  transform: translateY(-1px);
}

.all-section { padding: 60px 0; }
.cat-block { margin-bottom: 44px; }
.cat-title {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--text2);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 8px;
}
.cat-card {
  display: block;
  padding: 13px 16px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.88rem;
  font-weight: 500;
  transition: all 0.2s;
  text-align: center;
}
.cat-card:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0,229,255,0.05);
  transform: translateY(-2px);
}

/* ===== PAGE HERO ===== */
.page-hero {
  padding: 48px 0 36px;
  border-bottom: 1px solid var(--border);
  background: var(--bg2);
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 80% at 80% 50%, rgba(0,229,255,0.04) 0%, transparent 70%);
  pointer-events: none;
}
.breadcrumb {
  color: var(--text3);
  font-size: 0.83rem;
  margin-bottom: 12px;
}
.breadcrumb a { color: var(--text3); transition: color 0.2s; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb span { margin: 0 6px; }
.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 10px;
}
.page-hero .answer-badge {
  display: inline-block;
  background: rgba(0,229,255,0.1);
  border: 1px solid rgba(0,229,255,0.25);
  color: var(--accent);
  padding: 8px 18px;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: 8px;
}
.page-hero p { color: var(--text2); font-size: 0.97rem; line-height: 1.7; margin-top: 10px; max-width: 650px; }

/* ===== CONVERTER BOX ===== */
.converter-section { padding: 48px 0; }
.converter-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 30px;
  max-width: 780px;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
}
.converter-box::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2), var(--accent3));
}
.conv-title {
  font-family: 'Syne', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 22px;
  color: var(--text2);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.82rem;
}
.conv-grid {
  display: grid;
  grid-template-columns: 1fr 52px 1fr;
  gap: 14px;
  align-items: center;
}
.conv-side label {
  display: block;
  color: var(--text3);
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.conv-side input {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  color: var(--text);
  font-size: 1.15rem;
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
  outline: none;
  transition: border-color 0.2s;
  margin-bottom: 10px;
}
.conv-side input:focus { border-color: var(--accent); }
.conv-side input.result-input { color: var(--accent); }
.conv-side select {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 11px 12px;
  color: var(--text);
  font-size: 0.87rem;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s;
}
.conv-side select:focus { border-color: var(--accent); }
.conv-swap {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 20px;
}
.swap-btn {
  background: rgba(0,229,255,0.08);
  border: 1px solid rgba(0,229,255,0.2);
  color: var(--accent);
  width: 42px; height: 42px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.25s;
  display: flex;
  align-items: center;
  justify-content: center;
}
.swap-btn:hover { background: rgba(0,229,255,0.18); transform: rotate(180deg); }

.result-display {
  margin-top: 18px;
  padding: 14px 18px;
  background: var(--bg3);
  border-radius: 12px;
  text-align: center;
  font-size: 1rem;
  min-height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text2);
}

/* ===== ALL UNITS TABLE ===== */
.all-units-section { max-width: 780px; margin: 32px auto 0; }
.all-units-section h3 {
  font-family: 'Syne', sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text2);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 14px;
}
.units-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 8px;
}
.unit-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.87rem;
  cursor: pointer;
  transition: all 0.15s;
}
.unit-row:hover { border-color: var(--accent); background: rgba(0,229,255,0.04); }
.unit-name { color: var(--text2); }
.unit-val { color: var(--accent); font-weight: 600; font-family: 'Syne', sans-serif; font-size: 0.9rem; }

/* ===== CONVERSION TABLE ===== */
.conv-table-section { max-width: 780px; margin: 32px auto 0; }
.conv-table-section h3 {
  font-family: 'Syne', sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text2);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 14px;
}
.conv-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}
.conv-table th {
  background: var(--bg3);
  color: var(--text2);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  border: 1px solid var(--border);
  font-family: 'Syne', sans-serif;
  font-size: 0.82rem;
}
.conv-table td {
  padding: 9px 14px;
  border: 1px solid var(--border);
  background: var(--card);
}
.conv-table td a { color: var(--text2); transition: color 0.2s; }
.conv-table td a:hover { color: var(--accent); }
.conv-table td:last-child { color: var(--accent); font-weight: 600; }
.conv-table tr:hover td { background: rgba(0,229,255,0.03); }

/* ===== RELATED LINKS ===== */
.related-section { padding: 36px 0; }
.related-section .container { max-width: 780px; }
.related-grid { display: flex; flex-wrap: wrap; gap: 8px; }

/* ===== INFO SECTION ===== */
.info-section { padding: 48px 0; background: var(--bg2); }
.info-section .container { max-width: 780px; }
.info-section h2 {
  font-family: 'Syne', sans-serif;
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: -0.3px;
}
.info-section h3 {
  font-family: 'Syne', sans-serif;
  font-size: 1.05rem;
  font-weight: 700;
  margin: 24px 0 10px;
}
.info-section p { color: var(--text2); line-height: 1.8; margin-bottom: 12px; font-size: 0.94rem; }
.info-section ul { color: var(--text2); line-height: 2; padding-left: 20px; font-size: 0.94rem; }

.content-section p { color: var(--text2); line-height: 1.8; margin-bottom: 12px; font-size: 0.94rem; }
.content-section ul { color: var(--text2); line-height: 2; padding-left: 20px; font-size: 0.94rem; }

.content-section {
  padding: 48px;
}

.content-section h2 {
  font-family: 'Syne', sans-serif;
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: -0.3px;
}

/* ===== FOOTER ===== */
.footer { background: var(--bg2); border-top: 1px solid var(--border); padding: 56px 0 28px; }
.footer-grid {
  display: grid;
  grid-template-columns: 1.8fr repeat(5, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}
.footer-brand .logo { font-size: 1.3rem; display: inline-block; margin-bottom: 10px; }
.footer-brand p { color: var(--text2); font-size: 0.87rem; line-height: 1.7; }
.footer-col h4 {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text3);
  margin-bottom: 12px;
}
.footer-col a {
  display: block;
  color: var(--text2);
  font-size: 0.87rem;
  margin-bottom: 7px;
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 22px;
  color: var(--text3);
  font-size: 0.83rem;
  text-align: center;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr 1fr; }
}
@media (max-width: 860px) {
  .hero .container { grid-template-columns: 1fr; }
  .conv-grid { grid-template-columns: 1fr 42px 1fr; }
}
@media (max-width: 640px) {
  .nav { display: none; }
  .menu-btn { display: block; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
  .hero { padding: 44px 0 36px; }
  .cat-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .conv-grid { grid-template-columns: 1fr; }
  .conv-swap { transform: rotate(90deg); }
}

/* ============================================================
   RESPONSIVE — Full Mobile-First Improvements
   ============================================================ */

/* Tablet: 768px - 1024px */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr 1fr; gap: 24px; }
  .footer-brand { grid-column: 1 / -1; }
  .hero .container { gap: 40px; }
  .quick-converter { padding: 22px; }
  .cat-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
}

/* Large Mobile / Small Tablet: 640px - 860px */
@media (max-width: 860px) {
  .hero .container {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .quick-converter { max-width: 100%; }
  .conv-grid {
    grid-template-columns: 1fr 44px 1fr;
    gap: 10px;
  }
  .converter-box { padding: 22px 18px; }
  .page-hero { padding: 36px 0 28px; }
  .page-hero h1 { font-size: 1.7rem; }
  .section-title { font-size: 1.4rem; }
  .units-grid { grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); }
}

/* Mobile: max 640px */
@media (max-width: 640px) {
  /* Header */
  .nav { display: none; }
  .menu-btn { display: block; }
  .header .container { padding-top: 12px; padding-bottom: 12px; }
  .logo { font-size: 1.3rem; }

  /* Hero */
  .hero { padding: 36px 0 28px; }
  .hero-text h1 { font-size: 2rem; letter-spacing: -1px; }
  .hero-text p { font-size: 0.97rem; }
  .badge { font-size: 0.78rem; padding: 5px 12px; }

  /* Quick Converter */
  .quick-converter { padding: 18px 14px; border-radius: 14px; }
  .quick-converter h2 { font-size: 0.97rem; }
  .qc-tabs { gap: 4px; }
  .qc-tab { padding: 5px 10px; font-size: 0.78rem; }
  .qc-row { flex-direction: column; gap: 8px; }
  .qc-row input { width: 100%; font-size: 0.97rem; }
  .qc-row select { width: 100%; max-width: 100%; min-width: unset; }

  /* Sections */
  .common-section { padding: 36px 0 28px; }
  .all-section { padding: 36px 0; }
  .section-title { font-size: 1.3rem; }
  .cat-block { margin-bottom: 28px; }
  .cat-grid { grid-template-columns: repeat(2, 1fr); gap: 8px; }
  .cat-card { padding: 11px 10px; font-size: 0.83rem; }
  .conv-link { padding: 8px 13px; font-size: 0.83rem; }

  /* Page Hero */
  .page-hero { padding: 28px 0 22px; }
  .page-hero h1 { font-size: 1.5rem; letter-spacing: -0.5px; }
  .page-hero .answer-badge { font-size: 0.97rem; padding: 7px 14px; }
  .page-hero p { font-size: 0.9rem; }
  .breadcrumb { font-size: 0.78rem; }

  /* Converter Box */
  .converter-section { padding: 28px 0; }
  .converter-box { padding: 18px 14px; border-radius: 14px; }
  .conv-grid {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .conv-swap {
    transform: none;
    justify-content: center;
    margin: 0;
  }
  .swap-btn { width: 38px; height: 38px; font-size: 0.9rem; }
  .conv-side input { font-size: 1rem; padding: 12px 14px; }
  .conv-side select { font-size: 0.84rem; padding: 10px 10px; }
  .result-display { font-size: 0.9rem; padding: 12px 14px; }

  /* All Units Grid */
  .all-units-section h3 { font-size: 0.78rem; }
  .units-grid { grid-template-columns: 1fr 1fr; gap: 6px; }
  .unit-row { padding: 8px 10px; font-size: 0.82rem; }
  .unit-val { font-size: 0.82rem; }

  /* Conversion Table */
  .conv-table { font-size: 0.84rem; }
  .conv-table th, .conv-table td { padding: 8px 10px; }
  .conv-table-section h3 { font-size: 0.78rem; }

  /* Related */
  .related-section { padding: 24px 0; }
  .related-grid { gap: 6px; }

  /* Info */
  .info-section { padding: 32px 0; }
  .info-section h2 { font-size: 1.15rem; }
  .info-section h3 { font-size: 0.97rem; }
  .info-section p, .info-section ul { font-size: 0.9rem; }

  /* Footer */
  .footer { padding: 36px 0 20px; }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  .footer-brand { grid-column: 1 / -1; }
  .footer-brand p { font-size: 0.84rem; }
  .footer-col h4 { font-size: 0.78rem; margin-bottom: 8px; }
  .footer-col a { font-size: 0.84rem; margin-bottom: 5px; }
  .footer-bottom { font-size: 0.78rem; padding-top: 16px; }
}

/* Very Small Mobile: max 380px */
@media (max-width: 380px) {
  .container { padding: 0 14px; }
  .hero-text h1 { font-size: 1.7rem; }
  .cat-grid { grid-template-columns: 1fr 1fr; }
  .units-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .qc-tabs { gap: 3px; }
  .qc-tab { padding: 4px 8px; font-size: 0.75rem; }
}