:root {
  --bg: #04080f;
  --surface: #0b1120;
  --card: #101b2e;
  --border: #1a2d4a;
  --accent: #00d4aa;
  --accent2: #3b82f6;
  --accent3: #a855f7;
  --accent4: #f59e0b;
  --text: #e2eaf4;
  --muted: #7a93b4;
  --font: 'Space Grotesk', sans-serif;
  --mono: 'JetBrains Mono', monospace;
  --nav-bg: rgba(4,8,15,0.9);
}
html[data-theme="light"] {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --card: #ffffff;
  --border: #dde4ee;
  --accent: #009e82;
  --accent2: #2563eb;
  --accent3: #9333ea;
  --accent4: #d97706;
  --text: #16202e;
  --muted: #5c6b80;
  --nav-bg: rgba(244,247,251,0.9);
}
html[data-theme="light"] body { background: var(--bg); }
html[data-theme="light"] .card, html[data-theme="light"] .tool-card,
html[data-theme="light"] .calc-card, html[data-theme="light"] .qcm-card,
html[data-theme="light"] .tree-step, html[data-theme="light"] .result-organism {
  box-shadow: 0 2px 10px rgba(20,30,50,0.06);
}
html[data-theme="light"] .grid-bg { opacity: 0.03; }
html[data-theme="light"] .hero::before {
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(0,158,130,0.07) 0%, transparent 65%),
    radial-gradient(ellipse 50% 40% at 80% 50%, rgba(37,99,235,0.05) 0%, transparent 60%);
}
body, .loader-screen, .card, .tool-card, .calc-card, nav, footer, .inquiry-panel, .favorites-panel, .converter-panel {
  transition: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
a, button, input, select, textarea, .tool-card, .feature-pill, .spec-row, .path-chip,
.tab-btn, .tree-btn, .qcm-opt, .ref-table tr, .lang-btn, .btn-reset {
  transition: color 0.22s ease, background-color 0.22s ease, border-color 0.22s ease,
              transform 0.22s cubic-bezier(.2,.8,.2,1), box-shadow 0.22s ease, opacity 0.22s ease;
}
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  min-height: 100vh;
  overflow-x: hidden;
}

/* NAV */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 62px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem;
}
.nav-logo {
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
}
.nav-logo span { color: var(--text); }
.nav-links {
  display: flex; gap: 1.25rem; list-style: none;
  flex: 1; justify-content: center;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
  position: relative;
  padding-bottom: 2px;
}
.nav-links a::after {
  content: '';
  position: absolute; left: 0; bottom: -2px;
  width: 0; height: 1.5px;
  background: currentColor;
  box-shadow: 0 0 8px currentColor;
  transition: width 0.25s ease;
}
.nav-links a:hover { color: var(--accent); }
.nav-links a[style*="color"]::after { width: 100%; }
.nav-links a:hover::after { width: 100%; }
.nav-right { display: flex; align-items: center; gap: 0.75rem; flex-shrink: 0; }
.nav-badge {
  background: rgba(0,212,170,0.12);
  color: var(--accent);
  border: 1px solid rgba(0,212,170,0.3);
  font-size: 0.65rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 20px;
  font-family: var(--mono);
  white-space: nowrap;
}

/* LANG SWITCHER */
.lang-switcher { display: flex; gap: 0.3rem; }
.lang-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  cursor: pointer;
  font-family: var(--font);
  transition: all 0.2s;
}
.lang-btn:hover { border-color: var(--accent); color: var(--accent); }
.lang-btn.active { background: var(--accent); border-color: var(--accent); color: var(--bg); }

/* HAMBURGER */
.hamburger {
  display: none;
  background: none; border: 1px solid var(--border);
  color: var(--text); font-size: 1.1rem;
  width: 36px; height: 36px;
  border-radius: 6px; cursor: pointer;
  align-items: center; justify-content: center;
  flex-shrink: 0;
}

/* MOBILE MENU */
.mobile-menu {
  display: none;
  flex-direction: column;
  position: fixed; top: 62px; left: 0; right: 0; z-index: 99;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 2rem;
  gap: 1rem;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  color: var(--text); text-decoration: none;
  font-size: 1rem; font-weight: 500;
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--border);
}

/* HERO */
.hero {
  min-height: 100vh;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center;
  padding: 6rem 2rem 4rem;
  position: relative; overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(0,212,170,0.09) 0%, transparent 65%),
    radial-gradient(ellipse 50% 40% at 80% 50%, rgba(59,130,246,0.06) 0%, transparent 60%);
  pointer-events: none;
}
.grid-bg {
  position: absolute; inset: 0; pointer-events: none; opacity: 0.05;
  background-image:
    linear-gradient(rgba(255,255,255,0.5) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.5) 1px, transparent 1px);
  background-size: 120px 120px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 0%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 0%, transparent 75%);
}
@media (max-width: 860px) {
  .grid-bg { background-size: 60px 60px; opacity: 0.035; }
}
.hero-eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  display: flex; align-items: center; gap: 0.75rem;
}
.hero-eyebrow::before, .hero-eyebrow::after {
  content: ''; width: 40px; height: 1px;
  background: var(--accent); opacity: 0.4;
}
.hero h1 {
  font-size: clamp(2.5rem, 5.5vw, 4.8rem);
  font-weight: 700;
  line-height: 1.07;
  letter-spacing: -2px;
  margin-bottom: 1.5rem;
}
.hero h1 .accent { color: var(--accent); position: relative; z-index: 1; }
.hero h1 .dim { color: #a8bdd6; font-weight: 400; position: relative; z-index: 1; }
.hero h1 { position: relative; z-index: 1; }
.hero-sub { position: relative; z-index: 1; }
.hero-stats { position: relative; z-index: 1; }
.hero-cta { position: relative; z-index: 1; }
.hero-eyebrow { position: relative; z-index: 1; }
.hero-sub {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 560px;
  line-height: 1.75;
  margin-bottom: 2.75rem;
}
.hero-stats {
  display: flex; gap: 2.5rem;
  margin-bottom: 3rem;
  flex-wrap: wrap; justify-content: center;
}
.stat { text-align: center; }
.stat-num {
  font-family: var(--mono);
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--accent);
  display: block;
}
.stat-label {
  font-size: 0.72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; }

/* BUTTONS */
.btn-primary {
  background: var(--accent);
  color: var(--bg);
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.2s;
  font-family: var(--font);
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.btn-primary:hover { opacity: 0.92; transform: translateY(-2px); box-shadow: 0 8px 24px -4px var(--accent); }
.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.92rem;
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s;
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

/* TOOLS SECTION */
.tools-section {
  padding: 6rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}
.section-header { text-align: center; margin-bottom: 3.5rem; }
.section-eyebrow {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--accent);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}
.section-title {
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: 0.6rem;
}
.section-sub { color: var(--muted); font-size: 0.95rem; }

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.25rem;
}
.tool-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.75rem;
  text-decoration: none;
  color: inherit;
  display: flex; flex-direction: column;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
  position: relative; overflow: hidden;
}
.tool-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: var(--card-accent);
  opacity: 0; transition: opacity 0.25s;
}
.tool-card:hover {
  border-color: var(--card-accent);
  transform: translateY(-6px);
  box-shadow: 0 20px 50px rgba(0,0,0,0.4), 0 0 0 1px var(--card-accent), 0 0 28px -6px var(--card-accent);
}
.tool-card:hover::before { opacity: 1; box-shadow: 0 0 12px 1px var(--card-accent); }
.tool-icon {
  width: 48px; height: 48px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1.1rem;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
}
.tool-tag {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--card-accent);
  margin-bottom: 0.4rem;
}
.tool-name {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.5px;
}
.tool-desc {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.65;
  flex: 1;
  margin-bottom: 1.25rem;
}
.tool-features { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.feature-pill {
  font-size: 0.67rem;
  padding: 2px 9px;
  border-radius: 20px;
  border: 1px solid var(--border);
  color: var(--muted);
  font-family: var(--mono);
  transition: border-color 0.3s ease, color 0.3s ease;
}
.tool-card:hover .feature-pill { border-color: var(--card-accent); color: var(--card-accent); }
.tool-arrow {
  position: absolute; top: 1.6rem; right: 1.6rem;
  color: var(--muted); font-size: 1.1rem;
  transition: transform 0.2s, color 0.2s;
}
.tool-card:hover .tool-arrow { transform: translate(3px,-3px); color: var(--card-accent); }

/* ABOUT */
.about-section {
  padding: 6rem 2rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.about-inner {
  max-width: 900px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 4rem; align-items: center;
}
.about-title { font-size: 1.9rem; font-weight: 700; letter-spacing: -1px; margin-bottom: 1rem; }
.about-text { color: var(--muted); line-height: 1.8; margin-bottom: 0.85rem; font-size: 0.92rem; }
.about-sig { font-family: var(--mono); font-size: 0.75rem; color: var(--accent); margin-top: 1.25rem; }
.about-specs { display: flex; flex-direction: column; gap: 0.75rem; }
.spec-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0.65rem 1rem;
  background: var(--card);
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 0.82rem;
}
.spec-row:hover { border-color: var(--accent); transform: translateX(3px); }
[dir="rtl"] .spec-row:hover { transform: translateX(-3px); }
.spec-key { color: var(--muted); font-family: var(--mono); font-size: 0.72rem; }
.spec-val { color: var(--accent); font-weight: 600; font-size: 0.8rem; }

/* FOOTER */
footer {
  padding: 3rem 2rem;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.8rem;
}
.footer-logo {
  font-family: var(--mono);
  font-size: 1.1rem;
  color: var(--accent);
  margin-bottom: 0.75rem;
  display: block;
  font-weight: 600;
}
.footer-copy { margin-top: 0.5rem; font-size: 0.75rem; opacity: 0.7; }

/* SOCIAL FOLLOW LINK */
.footer-social {
  display: inline-flex; align-items: center; gap: 0.5rem;
  margin: 1rem 0 0.5rem;
  padding: 0.55rem 1.4rem;
  background: rgba(0,212,170,0.08);
  border: 1px solid rgba(0,212,170,0.3);
  border-radius: 30px;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.25s;
}
.footer-social:hover {
  background: rgba(0,212,170,0.16);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0,212,170,0.15);
}
.footer-social svg { width: 16px; height: 16px; fill: currentColor; }

/* FLOATING INQUIRY BUTTON */
.inquiry-fab {
  position: fixed;
  bottom: 24px; right: 24px;
  z-index: 200;
  width: 58px; height: 58px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border: none;
  color: var(--bg);
  font-size: 1.5rem;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 24px rgba(0,212,170,0.35), 0 0 0 0 rgba(0,212,170,0.4);
  transition: transform 0.3s cubic-bezier(.34,1.56,.64,1), box-shadow 0.3s;
  animation: fabPulse 2.8s ease-in-out infinite;
}
.inquiry-fab svg { transition: transform 0.3s cubic-bezier(.34,1.56,.64,1); }
.inquiry-fab:hover { transform: scale(1.1); }
.inquiry-fab:hover svg { transform: scale(1.08); }
.inquiry-fab.open { transform: scale(1.02); }
.inquiry-fab.open:hover { transform: scale(1.1); }
@keyframes fabPulse {
  0%, 100% { box-shadow: 0 8px 24px rgba(0,212,170,0.35), 0 0 0 0 rgba(0,212,170,0.3); }
  50% { box-shadow: 0 8px 24px rgba(0,212,170,0.45), 0 0 0 10px rgba(0,212,170,0); }
}
[dir="rtl"] .inquiry-fab { right: auto; left: 24px; }

/* INQUIRY MODAL */
.inquiry-overlay {
  position: fixed; inset: 0; z-index: 199;
  background: rgba(4,8,15,0.75);
  backdrop-filter: blur(6px);
  display: flex; align-items: flex-end; justify-content: center;
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s;
}
.inquiry-overlay.open { opacity: 1; pointer-events: auto; }
.inquiry-panel {
  width: 100%; max-width: 480px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px 20px 0 0;
  padding: 1.75rem 1.75rem 2rem;
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(.16,1,.3,1);
  max-height: 85vh;
  overflow-y: auto;
}
@media (min-width: 640px) {
  .inquiry-overlay { align-items: center; }
  .inquiry-panel { border-radius: 20px; transform: translateY(24px) scale(0.96); opacity: 0; }
  .inquiry-overlay.open .inquiry-panel { opacity: 1; transform: translateY(0) scale(1); }
}
.inquiry-overlay.open .inquiry-panel { transform: translateY(0); }
.inquiry-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 1.25rem; }
.inquiry-title { font-size: 1.3rem; font-weight: 700; letter-spacing: -0.5px; }
.inquiry-sub { color: var(--muted); font-size: 0.85rem; margin-top: 0.3rem; line-height: 1.5; }
.inquiry-close {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); width: 32px; height: 32px; border-radius: 8px;
  cursor: pointer; font-size: 1rem; flex-shrink: 0;
  transition: all 0.2s;
}
.inquiry-close:hover { border-color: var(--accent); color: var(--accent); }
.inquiry-field { margin-bottom: 1rem; }
.inquiry-field label {
  display: block; font-size: 0.72rem; color: var(--muted);
  text-transform: uppercase; letter-spacing: 1px;
  font-family: var(--mono); margin-bottom: 0.4rem;
}
.inquiry-field input, .inquiry-field select, .inquiry-field textarea {
  width: 100%; background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.65rem 0.85rem; border-radius: 8px;
  font-family: var(--font); font-size: 0.9rem; transition: border-color 0.2s;
  resize: vertical;
}
.inquiry-field input:focus, .inquiry-field select:focus, .inquiry-field textarea:focus { outline: none; border-color: var(--accent); }
.inquiry-submit {
  width: 100%; background: var(--accent); color: var(--bg);
  border: none; padding: 0.8rem; border-radius: 10px;
  font-weight: 700; font-size: 0.95rem; cursor: pointer;
  font-family: var(--font); transition: opacity 0.2s, transform 0.2s;
  margin-top: 0.5rem;
}
.inquiry-submit:hover { opacity: 0.88; transform: translateY(-1px); }
.inquiry-note { font-size: 0.72rem; color: var(--muted); text-align: center; margin-top: 0.75rem; line-height: 1.5; }

/* PRINT EXPORT BUTTON */
.export-btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); padding: 0.4rem 0.9rem;
  border-radius: 8px; cursor: pointer;
  font-family: var(--font); font-size: 0.78rem; font-weight: 500;
  margin-top: 0.75rem;
}
.export-btn:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.export-btn svg { width: 14px; height: 14px; }

@media print {
  nav, .mobile-menu, .hamburger, .lang-switcher, .inquiry-fab, .inquiry-overlay,
  .tool-page-header .export-btn, .tabs, footer, .loader-screen, .btn-reset,
  .tree-options, .qcm-opt:not(.correct):not(.wrong) { display: none !important; }
  body { background: #fff !important; color: #000 !important; }
  .calc-card, .result-organism, .qcm-card {
    background: #fff !important; border: 1px solid #ccc !important;
    color: #000 !important; page-break-inside: avoid;
  }
  .result-box { background: #f0faf7 !important; border-color: #0a8 !important; }
  .result-value, .result-label, h1, h2, h3 { color: #000 !important; }
  .print-header { display: block !important; margin-bottom: 1.5rem; }
}
.print-header { display: none; }

/* FAVORITES / BOOKMARKS */
.fav-btn {
  position: absolute; top: 1.6rem; right: 1.6rem;
  background: transparent; border: none; cursor: pointer;
  font-size: 1.3rem; color: var(--muted);
  transition: color 0.2s ease, transform 0.2s ease;
  z-index: 2; line-height: 1;
}
.fav-btn:hover { transform: scale(1.15); }
.fav-btn.active { color: #f59e0b; }
[dir="rtl"] .fav-btn { right: auto; left: 1.6rem; }
.favorites-panel {
  position: fixed; top: 62px; z-index: 150;
  right: 24px; width: 320px; max-height: 70vh; overflow-y: auto;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 1.25rem;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  transform: translateY(-12px); opacity: 0; pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.favorites-panel.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
[dir="rtl"] .favorites-panel { right: auto; left: 24px; }
.favorites-header { display:flex; justify-content:space-between; align-items:center; margin-bottom: 0.9rem; }
.favorites-title { font-weight: 700; font-size: 0.95rem; }
.favorites-empty { color: var(--muted); font-size: 0.85rem; text-align: center; padding: 1.5rem 0; }
.fav-item {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0.6rem 0.75rem; border-radius: 8px;
  background: var(--surface); border: 1px solid var(--border);
  margin-bottom: 0.5rem; font-size: 0.82rem;
}
.fav-item a { color: var(--text); text-decoration: none; flex: 1; }
.fav-item a:hover { color: var(--accent); }
.fav-item button { background: none; border: none; color: var(--muted); cursor: pointer; font-size: 0.9rem; padding: 0 0.3rem; }
.fav-item button:hover { color: #ef4444; }
.favorites-fab {
  position: fixed; bottom: 24px; right: 92px; z-index: 200;
  width: 50px; height: 50px; border-radius: 50%;
  background: var(--card); border: 1px solid var(--border);
  color: var(--muted); font-size: 1.2rem;
  display: flex; align-items: center; justify-content: center; cursor: pointer;
  transition: all 0.25s ease;
}
.favorites-fab:hover { border-color: #f59e0b; color: #f59e0b; transform: scale(1.08); box-shadow: 0 0 18px -4px #f59e0b; }
.favorites-fab .fav-count {
  position: absolute; top: -4px; right: -4px;
  background: #f59e0b; color: #04080f;
  font-size: 0.62rem; font-weight: 800;
  width: 17px; height: 17px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono);
}
[dir="rtl"] .favorites-fab { right: auto; left: 92px; }
[dir="rtl"] .favorites-fab .fav-count { right: auto; left: -4px; }

/* UNIT CONVERTER WIDGET */
.converter-fab {
  position: fixed; bottom: 24px; right: 160px; z-index: 200;
  width: 50px; height: 50px; border-radius: 50%;
  background: var(--card); border: 1px solid var(--border);
  color: var(--muted); font-size: 1.15rem;
  display: flex; align-items: center; justify-content: center; cursor: pointer;
  transition: all 0.25s ease;
}
.converter-fab:hover { border-color: var(--accent3); color: var(--accent3); transform: scale(1.08); box-shadow: 0 0 18px -4px var(--accent3); }
[dir="rtl"] .converter-fab { right: auto; left: 160px; }
.converter-panel {
  position: fixed; bottom: 86px; right: 24px; z-index: 201;
  width: 320px; background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 1.25rem;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  transform: translateY(12px) scale(0.97); opacity: 0; pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.converter-panel.open { transform: translateY(0) scale(1); opacity: 1; pointer-events: auto; }
[dir="rtl"] .converter-panel { right: auto; left: 24px; }
.converter-tabs { display: flex; gap: 0.35rem; margin-bottom: 1rem; }
.converter-tab {
  flex: 1; background: transparent; border: 1px solid var(--border);
  color: var(--muted); padding: 0.4rem; border-radius: 7px;
  font-family: var(--font); font-size: 0.72rem; cursor: pointer;
}
.converter-tab.active { background: var(--accent3); border-color: var(--accent3); color: #fff; font-weight: 600; }
.converter-body input {
  width: 100%; background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.55rem 0.75rem; border-radius: 8px;
  font-family: var(--font); font-size: 0.9rem; margin-bottom: 0.6rem;
}
.converter-result {
  background: rgba(168,85,247,0.08); border: 1px solid rgba(168,85,247,0.25);
  border-radius: 8px; padding: 0.7rem 0.9rem;
  font-family: var(--mono); font-size: 1rem; color: var(--accent3); font-weight: 700;
  text-align: center;
}

/* STAINING VISUALIZER */
.stain-card { position: relative; }
.stain-visualizer {
  display: flex; flex-direction: column; align-items: center; gap: 1rem;
  padding: 1.25rem 0 1rem;
}
.stain-slide-single, .stain-slide-pair {
  display: flex; gap: 0.6rem; justify-content: center;
}
.stain-slide {
  width: 90px; height: 60px; border-radius: 6px;
  border: 2px solid rgba(0,0,0,0.2);
  box-shadow: 0 6px 20px rgba(0,0,0,0.25), inset 0 0 20px rgba(255,255,255,0.12);
  transition: background-color 0.6s cubic-bezier(.4,0,.2,1), transform 0.4s ease;
  position: relative;
  animation: slideAppear 0.45s cubic-bezier(.34,1.4,.64,1);
}
html[data-theme="light"] .stain-slide {
  border-color: rgba(0,0,0,0.12);
  box-shadow: 0 4px 14px rgba(20,30,50,0.18), inset 0 0 16px rgba(255,255,255,0.25);
}
@keyframes slideAppear {
  from { opacity: 0; transform: scale(0.85) translateY(6px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}
.stain-slide-tag {
  position: absolute; top: 4px; right: 6px;
  font-family: var(--mono); font-weight: 800; font-size: 0.85rem;
  color: rgba(255,255,255,0.85); text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}
.stain-controls {
  display: flex; align-items: center; gap: 1rem;
}
.stain-nav-btn {
  width: 34px; height: 34px; border-radius: 50%;
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text); cursor: pointer; font-size: 1rem;
  display: flex; align-items: center; justify-content: center;
}
.stain-nav-btn:hover { border-color: var(--accent4); color: var(--accent4); transform: scale(1.08); }
.stain-progress { display: flex; gap: 0.4rem; }
.stain-dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--border); cursor: pointer;
  transition: all 0.25s ease;
}
.stain-dot:hover { transform: scale(1.3); }
.stain-dot.active { background: var(--accent4); transform: scale(1.4); box-shadow: 0 0 10px rgba(245,158,11,0.6); }
.stain-dot.done { background: var(--accent); }
.stain-step-label {
  text-align: center; font-size: 0.85rem; color: var(--text);
  padding: 0.6rem 1rem; background: var(--surface); border-radius: 8px;
  margin-bottom: 1rem; min-height: 2.6em;
}
.stain-step-num {
  font-family: var(--mono); font-weight: 700; color: var(--accent4);
  margin-right: 0.4rem;
}
[dir="rtl"] .stain-step-num { margin-right: 0; margin-left: 0.4rem; }
.stain-steplist {
  list-style: none; padding: 0; margin: 0 0 1rem;
  display: flex; flex-direction: column; gap: 0.3rem;
}
.stain-steplist li {
  padding: 0.5rem 0.75rem; border-radius: 7px; cursor: pointer;
  font-size: 0.82rem; color: var(--muted);
  border-left: 2px solid transparent;
  transition: all 0.2s ease;
}
[dir="rtl"] .stain-steplist li { border-left: none; border-right: 2px solid transparent; }
.stain-steplist li:hover { background: var(--surface); color: var(--text); }
.stain-steplist li.past { color: var(--accent); text-decoration: line-through; opacity: 0.6; }
.stain-steplist li.current {
  background: rgba(245,158,11,0.08); color: var(--text); font-weight: 600;
  border-left-color: var(--accent4);
}
[dir="rtl"] .stain-steplist li.current { border-right-color: var(--accent4); }
.stain-swatch {
  width: 18px; height: 18px; border-radius: 50%;
  border: 2px solid rgba(0,0,0,0.2);
  display: inline-block; flex-shrink: 0;
}
html[data-theme="light"] .stain-swatch { border-color: rgba(0,0,0,0.15); }

/* SKELETON LOADERS */
@keyframes skeletonPulse {
  0% { background-position: -200px 0; }
  100% { background-position: calc(200px + 100%) 0; }
}
.skeleton {
  background: linear-gradient(90deg, var(--surface) 25%, rgba(255,255,255,0.06) 50%, var(--surface) 75%);
  background-size: 400px 100%;
  animation: skeletonPulse 1.6s ease-in-out infinite;
  border-radius: 8px;
}
html[data-theme="light"] .skeleton {
  background: linear-gradient(90deg, #eef1f6 25%, #dfe5ee 50%, #eef1f6 75%);
  background-size: 400px 100%;
}
.skeleton-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 16px; padding: 1.75rem; display: flex; flex-direction: column; gap: 0.9rem;
}
.skeleton-line { height: 12px; }
.skeleton-line.w-60 { width: 60%; }
.skeleton-line.w-80 { width: 80%; }
.skeleton-line.w-40 { width: 40%; }
.skeleton-icon { width: 48px; height: 48px; border-radius: 10px; }
.skeleton-pill { height: 20px; width: 70px; border-radius: 20px; }
.skeleton-row { display: flex; gap: 0.5rem; }

/* NEON GLOW UTILITIES */
.neon-text {
  text-shadow: 0 0 8px currentColor, 0 0 22px currentColor;
}
.neon-border {
  box-shadow: 0 0 0 1px currentColor, 0 0 16px -2px currentColor;
}
@keyframes neonFlicker {
  0%, 100% { opacity: 1; }
  92% { opacity: 1; }
  93% { opacity: 0.7; }
  94% { opacity: 1; }
  96% { opacity: 0.85; }
  97% { opacity: 1; }
}

/* DAILY QUIZ WIDGET */
.dailyquiz-fab {
  position: fixed; bottom: 24px; right: 228px; z-index: 200;
  width: 50px; height: 50px; border-radius: 50%;
  background: var(--card); border: 1px solid var(--border);
  color: var(--muted); font-size: 1.15rem;
  display: flex; align-items: center; justify-content: center; cursor: pointer;
  transition: all 0.25s ease;
}
.dailyquiz-fab:hover { border-color: var(--accent4); color: var(--accent4); transform: scale(1.08); box-shadow: 0 0 18px -4px var(--accent4); }
[dir="rtl"] .dailyquiz-fab { right: auto; left: 228px; }
@media (max-width: 480px) {
  .inquiry-fab { bottom: 20px; right: 16px; width: 52px; height: 52px; }
  .favorites-fab, .converter-fab, .dailyquiz-fab { right: 16px; width: 44px; height: 44px; font-size: 1rem; }
  .favorites-fab { bottom: 82px; }
  .converter-fab { bottom: 134px; }
  .dailyquiz-fab { bottom: 186px; }
  [dir="rtl"] .inquiry-fab { right: auto; left: 16px; }
  [dir="rtl"] .favorites-fab, [dir="rtl"] .converter-fab, [dir="rtl"] .dailyquiz-fab { right: auto; left: 16px; }
  .converter-panel, .favorites-panel { right: 12px; left: 12px; width: auto; }
  [dir="rtl"] .converter-panel, [dir="rtl"] .favorites-panel { right: 12px; left: 12px; }
}
.dailyquiz-overlay {
  position: fixed; inset: 0; z-index: 199;
  background: rgba(4,8,15,0.75); backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.3s;
}
.dailyquiz-overlay.open { opacity: 1; pointer-events: auto; }
.dailyquiz-panel {
  width: 92%; max-width: 460px;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 18px; padding: 1.75rem;
  transform: translateY(16px) scale(0.96); opacity: 0;
  transition: transform 0.35s cubic-bezier(.16,1,.3,1), opacity 0.35s;
}
.dailyquiz-overlay.open .dailyquiz-panel { transform: translateY(0) scale(1); opacity: 1; }
.dailyquiz-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.dailyquiz-badge {
  font-family: var(--mono); font-size: 0.65rem; letter-spacing: 1.5px;
  color: var(--accent4); text-transform: uppercase;
  background: rgba(245,158,11,0.1); border: 1px solid rgba(245,158,11,0.3);
  padding: 3px 10px; border-radius: 20px;
}
.dailyquiz-q { font-size: 0.98rem; font-weight: 600; margin-bottom: 1.1rem; line-height: 1.5; }
.dailyquiz-streak {
  font-family: var(--mono); font-size: 0.72rem; color: var(--muted);
  display: flex; align-items: center; gap: 0.3rem;
}
.dailyquiz-streak .flame { filter: drop-shadow(0 0 4px rgba(245,158,11,0.6)); }
.dailyquiz-next {
  width: 100%; background: var(--accent4); color: #1a1206;
  border: none; padding: 0.7rem; border-radius: 10px;
  font-weight: 700; font-size: 0.88rem; cursor: pointer;
  margin-top: 0.5rem; font-family: var(--font);
}
.dailyquiz-next:hover { opacity: 0.9; transform: translateY(-1px); box-shadow: 0 8px 20px -4px var(--accent4); }

/* SUPPORT / DONATION */
.footer-actions {
  display: flex; gap: 0.75rem; flex-wrap: wrap; justify-content: center;
  margin: 1rem 0 0.5rem;
}
.support-btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.55rem 1.4rem;
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.3);
  border-radius: 30px;
  color: var(--accent4);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: all 0.25s;
}
.support-btn:hover {
  background: rgba(245,158,11,0.16);
  border-color: var(--accent4);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px -4px var(--accent4);
}
.support-btn svg { width: 16px; height: 16px; }

.support-overlay {
  position: fixed; inset: 0; z-index: 300;
  background: rgba(4,8,15,0.8); backdrop-filter: blur(8px);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.3s;
  padding: 1rem;
}
.support-overlay.open { opacity: 1; pointer-events: auto; }
.support-panel {
  width: 100%; max-width: 460px; max-height: 88vh; overflow-y: auto;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 20px; padding: 2rem;
  transform: translateY(16px) scale(0.96); opacity: 0;
  transition: transform 0.35s cubic-bezier(.16,1,.3,1), opacity 0.35s;
}
.support-overlay.open .support-panel { transform: translateY(0) scale(1); opacity: 1; }
.support-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 1.25rem; }
.support-icon-badge {
  width: 48px; height: 48px; border-radius: 14px;
  background: linear-gradient(135deg, var(--accent4), #ef4444);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; margin-bottom: 0.9rem;
  box-shadow: 0 8px 20px -4px var(--accent4);
}
.support-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 0.4rem; }
.support-sub { color: var(--muted); font-size: 0.85rem; line-height: 1.6; margin-bottom: 1.4rem; }
.support-quote {
  font-style: italic; font-size: 0.88rem; color: var(--text);
  border-left: 3px solid var(--accent4); padding: 0.75rem 1rem;
  background: rgba(245,158,11,0.06); border-radius: 0 10px 10px 0;
  margin-bottom: 1.5rem; line-height: 1.7;
}
[dir="rtl"] .support-quote { border-left: none; border-right: 3px solid var(--accent4); border-radius: 10px 0 0 10px; }
.support-quote cite { display: block; font-style: normal; font-size: 0.72rem; color: var(--muted); margin-top: 0.5rem; }
.support-method {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; padding: 1rem 1.1rem; margin-bottom: 0.9rem;
}
.support-method-label {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 1.5px;
  color: var(--accent4); text-transform: uppercase; margin-bottom: 0.6rem;
  display: flex; align-items: center; gap: 0.4rem;
}
.support-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0.4rem 0; font-size: 0.85rem;
  border-bottom: 1px solid var(--border);
}
.support-row:last-child { border-bottom: none; }
.support-row-key { color: var(--muted); }
.support-row-val {
  font-family: var(--mono); font-weight: 700; color: var(--text);
  display: flex; align-items: center; gap: 0.5rem;
}
.copy-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); width: 26px; height: 26px; border-radius: 6px;
  cursor: pointer; font-size: 0.78rem; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
}
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
.copy-btn.copied { border-color: var(--accent); color: var(--accent); background: rgba(0,212,170,0.1); }
.support-close-btn {
  width: 100%; background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.7rem; border-radius: 10px;
  font-weight: 600; font-size: 0.85rem; cursor: pointer;
  margin-top: 0.5rem; font-family: var(--font);
}
.support-close-btn:hover { border-color: var(--accent); color: var(--accent); }

/* OTHER PROJECTS / SITES */
.other-sites {
  margin-top: 1.5rem; padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  width: 100%; max-width: 480px;
}
.other-sites-title {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 2px;
  color: var(--muted); text-transform: uppercase;
  text-align: center; margin-bottom: 0.9rem;
}
.other-sites-grid {
  display: flex; flex-wrap: wrap; gap: 0.5rem; justify-content: center;
}
.other-site-link {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.4rem 0.9rem;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 20px; color: var(--muted);
  text-decoration: none; font-size: 0.78rem; font-family: var(--mono);
  transition: all 0.25s;
}
.other-site-link:hover {
  border-color: var(--accent2); color: var(--accent2);
  transform: translateY(-2px); box-shadow: 0 6px 16px -4px var(--accent2);
}
.other-site-link svg { width: 12px; height: 12px; }
.other-site-slot {
  padding: 0.4rem 0.9rem; border-radius: 20px;
  border: 1px dashed var(--border); color: var(--border);
  font-size: 0.78rem; font-family: var(--mono);
}

/* THEME TOGGLE */
.theme-toggle {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); width: 32px; height: 32px;
  border-radius: 7px; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.95rem; flex-shrink: 0;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }

/* PRINTABLE CHEAT SHEET */
.cheatsheet-btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: rgba(0,212,170,0.08); border: 1px solid rgba(0,212,170,0.3);
  color: var(--accent); padding: 0.4rem 0.9rem;
  border-radius: 8px; cursor: pointer;
  font-family: var(--font); font-size: 0.78rem; font-weight: 600;
  margin-top: 0.75rem; margin-left: 0.5rem;
}
[dir="rtl"] .cheatsheet-btn { margin-left: 0; margin-right: 0.5rem; }
.cheatsheet-btn:hover { background: rgba(0,212,170,0.16); transform: translateY(-1px); }
.cheatsheet-page { display: none; }
@media print {
  body.printing-cheatsheet > *:not(.cheatsheet-page) { display: none !important; }
  body.printing-cheatsheet .cheatsheet-page {
    display: block !important; background: #fff !important; color: #000 !important;
    padding: 20px; font-family: var(--font);
  }
  body.printing-cheatsheet .cheatsheet-page table { width: 100%; border-collapse: collapse; margin-bottom: 16px; }
  body.printing-cheatsheet .cheatsheet-page th, body.printing-cheatsheet .cheatsheet-page td {
    border: 1px solid #ccc; padding: 4px 8px; font-size: 11px; text-align: left; color: #000;
  }
  body.printing-cheatsheet .cheatsheet-page th { background: #f0f0f0; font-weight: 700; }
  body.printing-cheatsheet .cheatsheet-page h1 { font-size: 18px; margin-bottom: 4px; }
  body.printing-cheatsheet .cheatsheet-page h2 { font-size: 13px; margin: 12px 0 6px; color: #000; }
  body.printing-cheatsheet .cheatsheet-page .cs-footer { font-size: 9px; color: #666; margin-top: 16px; }
}

/* LOADING SCREEN */
.loader-screen {
  position: fixed; inset: 0; z-index: 999;
  background: var(--bg);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 1.5rem;
  transition: opacity 0.6s ease, visibility 0.6s ease;
  overflow: hidden;
}
.loader-screen.hidden { opacity: 0; visibility: hidden; pointer-events: none; }
.loader-screen::before {
  content: '';
  position: absolute; width: 280px; height: 280px; border-radius: 50%;
  background: radial-gradient(circle, rgba(0,212,170,0.18) 0%, transparent 70%);
  animation: loaderGlowPulse 2.2s ease-in-out infinite;
}
@keyframes loaderGlowPulse {
  0%, 100% { transform: scale(0.9); opacity: 0.6; }
  50% { transform: scale(1.15); opacity: 1; }
}
.loader-mascot {
  font-size: 4.5rem;
  animation: mascotFloat 1.8s ease-in-out infinite;
  filter: drop-shadow(0 0 24px rgba(0,212,170,0.55)) drop-shadow(0 0 48px rgba(59,130,246,0.25));
  position: relative; z-index: 1;
}
@keyframes mascotFloat {
  0%, 100% { transform: translateY(0) rotate(-4deg); }
  50% { transform: translateY(-14px) rotate(4deg); }
}
.loader-bar {
  width: 180px; height: 4px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.loader-bar-fill {
  width: 40%; height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 4px;
  animation: loaderSlide 1.1s ease-in-out infinite;
}
@keyframes loaderSlide {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(250%); }
}
.loader-text {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 2px;
  text-transform: uppercase;
}

/* TOOL PAGES SHARED */
.tool-page-header {
  padding: 7rem 2rem 3rem;
  max-width: 900px; margin: 0 auto;
  text-align: center;
}
.tool-page-eyebrow {
  font-family: var(--mono); font-size: 0.65rem;
  letter-spacing: 3px; text-transform: uppercase;
  margin-bottom: 0.75rem;
}
.tool-page-title { font-size: clamp(2rem,4vw,3rem); font-weight: 700; letter-spacing: -1.5px; margin-bottom: 0.75rem; }
.tool-page-sub { color: var(--muted); font-size: 0.95rem; line-height: 1.7; }
.tool-page-body {
  max-width: 900px; margin: 0 auto;
  padding: 0 2rem 6rem;
}

/* CARDS inside tools */
.calc-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.75rem;
  margin-bottom: 1.25rem;
  transition: border-color 0.25s ease, transform 0.25s ease;
}
.calc-card:hover { border-color: rgba(255,255,255,0.14); }
.calc-card h3 {
  font-size: 1rem; font-weight: 600; margin-bottom: 1rem;
  color: var(--accent); font-family: var(--mono); letter-spacing: -0.3px;
}
.field-row { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-bottom: 1rem; align-items: flex-end; }
.field { display: flex; flex-direction: column; gap: 0.35rem; flex: 1; min-width: 140px; }
.field label { font-size: 0.72rem; color: var(--muted); text-transform: uppercase; letter-spacing: 1px; font-family: var(--mono); }
.field input, .field select {
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.55rem 0.75rem;
  border-radius: 8px; font-family: var(--font);
  font-size: 0.9rem; transition: border-color 0.2s;
  width: 100%;
}
.field input:focus, .field select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0,212,170,0.12); }
.btn-calc {
  background: var(--accent); color: var(--bg);
  border: none; padding: 0.6rem 1.5rem;
  border-radius: 8px; font-weight: 600;
  font-size: 0.88rem; cursor: pointer;
  font-family: var(--font); transition: opacity 0.2s;
  white-space: nowrap;
}
.btn-calc:hover { opacity: 0.85; }
.result-box {
  background: rgba(0,212,170,0.07);
  border: 1px solid rgba(0,212,170,0.25);
  border-radius: 10px; padding: 0; margin-top: 0;
  max-height: 0; overflow: hidden;
  opacity: 0;
  transition: opacity 0.3s ease, max-height 0.35s ease, margin-top 0.3s ease, padding 0.3s ease;
}
.result-box.show { display: block; opacity: 1; max-height: 400px; margin-top: 1rem; padding: 1rem 1.25rem; }
.result-label { font-size: 0.7rem; color: var(--muted); text-transform: uppercase; letter-spacing: 1px; font-family: var(--mono); margin-bottom: 0.3rem; }
.result-value {
  font-size: 1.3rem; font-weight: 700; color: var(--accent); font-family: var(--mono);
  text-shadow: 0 0 14px rgba(0,212,170,0.25);
  animation: resultPop 0.35s cubic-bezier(.34,1.4,.64,1);
}
@keyframes resultPop {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}
.result-sub { font-size: 0.8rem; color: var(--muted); margin-top: 0.25rem; }
.verdict { font-size: 1rem; font-weight: 700; padding: 0.4rem 0.8rem; border-radius: 6px; display: inline-block; margin-top: 0.4rem; }
.verdict.ok { background: rgba(0,212,170,0.15); color: #00d4aa; }
.verdict.warn { background: rgba(245,158,11,0.15); color: #f59e0b; }
.verdict.fail { background: rgba(239,68,68,0.15); color: #ef4444; }

/* DECISION TREE */
.tree-step {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 1.75rem; margin-bottom: 1rem;
}
.tree-question { font-size: 1rem; font-weight: 600; margin-bottom: 1.25rem; }
.tree-options { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.tree-btn {
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.55rem 1.25rem;
  border-radius: 8px; font-size: 0.88rem;
  cursor: pointer; font-family: var(--font);
  font-weight: 500;
}
.tree-btn:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); box-shadow: 0 6px 16px rgba(0,212,170,0.12); }
.tree-path {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  margin-bottom: 1.5rem;
}
.path-chip {
  font-size: 0.7rem; font-family: var(--mono);
  background: rgba(0,212,170,0.1); color: var(--accent);
  border: 1px solid rgba(0,212,170,0.2);
  padding: 2px 10px; border-radius: 20px;
}
.result-organism {
  background: var(--card); border: 2px solid var(--accent);
  border-radius: 14px; padding: 2rem; text-align: center;
}
.result-organism h2 { font-size: 1.8rem; color: var(--accent); font-style: italic; margin-bottom: 0.5rem; }
.result-organism p { color: var(--muted); font-size: 0.9rem; line-height: 1.7; }
.btn-reset {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); padding: 0.5rem 1.25rem;
  border-radius: 8px; cursor: pointer;
  font-family: var(--font); font-size: 0.85rem;
  margin-top: 1rem; transition: all 0.2s;
}
.btn-reset:hover { border-color: var(--accent); color: var(--accent); }

/* TABS */
.tabs { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-bottom: 1.5rem; }
.tab-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); padding: 0.45rem 1rem;
  border-radius: 8px; cursor: pointer;
  font-family: var(--font); font-size: 0.82rem;
  font-weight: 500;
}
.tab-btn:hover:not(.active) { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.tab-btn.active { background: var(--accent); border-color: var(--accent); color: var(--bg); font-weight: 600; box-shadow: 0 0 16px -4px var(--accent); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* REFERENCE TABLE */
.ref-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
.ref-table th {
  background: var(--surface); color: var(--muted);
  font-family: var(--mono); font-size: 0.7rem;
  text-transform: uppercase; letter-spacing: 1px;
  padding: 0.6rem 0.75rem; text-align: left;
  border-bottom: 1px solid var(--border);
}
.ref-table td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid rgba(26,45,74,0.5);
  color: var(--text); vertical-align: middle;
}
.ref-table tr:hover td { background: rgba(255,255,255,0.03); }
.badge-s { color: #00d4aa; font-weight: 700; font-family: var(--mono); font-size: 0.85rem; }
.badge-i { color: #f59e0b; font-weight: 700; font-family: var(--mono); font-size: 0.85rem; }
.badge-r { color: #ef4444; font-weight: 700; font-family: var(--mono); font-size: 0.85rem; }

/* QCM */
.qcm-card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 1.75rem; margin-bottom: 1rem; }
.qcm-q { font-size: 0.95rem; font-weight: 600; margin-bottom: 1rem; line-height: 1.5; }
.qcm-options { display: flex; flex-direction: column; gap: 0.5rem; }
.qcm-opt {
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.55rem 1rem;
  border-radius: 8px; cursor: pointer;
  font-family: var(--font); font-size: 0.87rem;
  text-align: left;
}
.qcm-opt:hover { border-color: var(--accent); transform: translateX(4px); }
[dir="rtl"] .qcm-opt:hover { transform: translateX(-4px); }
.qcm-opt.correct { background: rgba(0,212,170,0.1); border-color: #00d4aa; color: #00d4aa; }
.qcm-opt.wrong { background: rgba(239,68,68,0.1); border-color: #ef4444; color: #ef4444; }
.qcm-explain { font-size: 0.82rem; color: var(--muted); margin-top: 0.75rem; padding: 0.6rem 0.75rem; background: var(--surface); border-radius: 8px; display: none; line-height: 1.6; }
.qcm-score { font-family: var(--mono); font-size: 1.4rem; color: var(--accent); font-weight: 700; text-align: center; padding: 1.5rem; }

/* ANIMATIONS */
@keyframes fadeUp { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }
.hero > * { animation: fadeUp 0.55s ease both; }
.hero > *:nth-child(1) { animation-delay: 0.1s; }
.hero > *:nth-child(2) { animation-delay: 0.2s; }
.hero > *:nth-child(3) { animation-delay: 0.3s; }
.hero > *:nth-child(4) { animation-delay: 0.4s; }
.hero > *:nth-child(5) { animation-delay: 0.5s; }

/* RTL SUPPORT */
[dir="rtl"] .hero-eyebrow::before, [dir="rtl"] .hero-eyebrow::after { content: none; }
[dir="rtl"] .tool-arrow { right: auto; left: 1.6rem; }
[dir="rtl"] .field-row { flex-direction: row-reverse; }
[dir="rtl"] .about-sig { font-family: var(--font); }
[dir="rtl"] .spec-key { font-family: var(--font); }

/* RESPONSIVE */
@media (max-width: 860px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .about-inner { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero-stats { gap: 1.5rem; }
  .tools-grid { grid-template-columns: 1fr; }
  .field-row { flex-direction: column; }
}
@media (max-width: 480px) {
  nav { padding: 0 1rem; }
  .hero { padding: 5rem 1.25rem 3rem; }
  .tools-section { padding: 4rem 1.25rem; }
  .tool-page-body { padding: 0 1.25rem 4rem; }
}