/* ============================================================
   Binary Calculator — Page Styles
   Inherits design tokens from index.style.css
   Theme: teal/slate (consistent with all other calculators)
   Unique features vs other pages:
   - select-field (dropdown selects, new element)
   - result-input (monospace body text in result boxes)
   - all-formats-box / all-formats-values (teal-tinted box)
   - result-hero-value: 3rem / 48px Courier New
   - result-hero-sub (secondary label under hero value)
   - download-btn: green gradient (per source spec)
   - FAQ moved to separate .faq-section (border-top pattern)
   ============================================================ */

/* ── Page background ── */
body { background: var(--clr-slate-100); }

/* ════════════════════════════════════════
   PAGE HEADER BANNER
   ════════════════════════════════════════ */
.page-header {
  background: var(--clr-slate-900);
  position: relative;
  overflow: hidden;
  padding: 4.5rem 1.5rem 5.5rem;
  text-align: center;
  color: var(--clr-white);
}
.page-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 65% 85% at 15% 50%, rgba(13,207,180,.13) 0%, transparent 60%),
    radial-gradient(ellipse 45% 60% at 85% 40%, rgba(13,207,180,.08) 0%, transparent 55%);
}
.page-header::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(13,207,180,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(13,207,180,.04) 1px, transparent 1px);
  background-size: 48px 48px;
}
.page-header-inner {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0 auto;
}
.page-header-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 1rem;
  border-radius: var(--radius-pill);
  background: rgba(13,207,180,.1);
  border: 1px solid rgba(13,207,180,.25);
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-display);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-teal);
  margin-bottom: 1.25rem;
}
.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.5vw, 3.5rem);
  font-weight: 800;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  line-height: 1.05;
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
  color: var(--clr-white);
}
.page-header h1 .accent {
  font-family: var(--font-serif);
  font-style: italic;
  text-transform: none;
  font-weight: 700;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, var(--clr-teal) 0%, var(--clr-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.page-header p {
  font-size: 1.05rem;
  color: rgba(255,255,255,.7);
  line-height: 1.7;
  max-width: 720px;
  margin: 0 auto;
  font-weight: 300;
  position: relative;
  z-index: 1;
}

/* ════════════════════════════════════════
   LAYOUT
   ════════════════════════════════════════ */
.calculator-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ════════════════════════════════════════
   AD SLOTS
   ════════════════════════════════════════ */
.ad-slot { margin: 1.75rem 0; text-align: center; }
.ad-label {
  font-size: 0.68rem;
  color: var(--clr-slate-400);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ════════════════════════════════════════
   CALCULATOR CARD
   ════════════════════════════════════════ */
.calculator-card {
  background: var(--clr-white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-lift);
  border: 1px solid var(--clr-slate-200);
  margin-top: -2.5rem;
  position: relative;
  z-index: 10;
}
.calculator-intro {
  color: var(--clr-slate-400);
  font-size: 0.93rem;
  line-height: 1.8;
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--clr-slate-200);
}

/* ════════════════════════════════════════
   OPERATION GRID — no .operation-sub here
   ════════════════════════════════════════ */
.operation-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}
.operation-btn {
  padding: 1.25rem 1rem;
  background: var(--clr-slate-100);
  border: 3px solid var(--clr-slate-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  text-align: center;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.88rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--clr-slate-700);
  transition: all var(--transition);
  user-select: none;
}
.operation-btn:hover {
  background: var(--clr-teal-glow);
  border-color: rgba(13,207,180,.4);
  color: var(--clr-teal-deep);
  transform: translateY(-2px);
}
.operation-btn.active {
  background: var(--clr-teal-deep);
  border-color: var(--clr-teal-deep);
  color: var(--clr-white);
  box-shadow: var(--shadow-teal);
}
.operation-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 0.5rem;
  line-height: 1;
}

/* ════════════════════════════════════════
   INJECTED INPUTS
   ════════════════════════════════════════ */
.input-group { margin-bottom: 1.5rem; }
.input-label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--clr-slate-600);
  margin-bottom: 0.75rem;
}
.input-field {
  width: 100%;
  padding: 1rem;
  border: 2px solid var(--clr-slate-200);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-family: 'Courier New', monospace;
  color: var(--clr-slate-800);
  background: var(--clr-slate-100);
  transition: all var(--transition);
  box-sizing: border-box;
}
.input-field:focus {
  outline: none;
  border-color: var(--clr-teal);
  background: var(--clr-white);
  box-shadow: 0 0 0 3px var(--clr-teal-glow);
}
.input-field::placeholder { color: var(--clr-slate-300); }

/* Select dropdown — unique to binary calculator */
.select-field {
  width: 100%;
  padding: 1rem;
  border: 2px solid var(--clr-slate-200);
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--clr-slate-700);
  background: var(--clr-white);
  cursor: pointer;
  transition: all var(--transition);
  box-sizing: border-box;
}
.select-field:focus {
  outline: none;
  border-color: var(--clr-teal);
  box-shadow: 0 0 0 3px var(--clr-teal-glow);
}

.example-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 0.75rem;
}
.example-btn {
  padding: 0.4rem 0.9rem;
  background: var(--clr-white);
  border: 1px solid var(--clr-slate-200);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  font-family: 'Courier New', monospace;
  color: var(--clr-slate-600);
  transition: all var(--transition);
}
.example-btn:hover {
  background: var(--clr-teal-glow);
  border-color: rgba(13,207,180,.4);
  color: var(--clr-teal-deep);
  transform: translateY(-1px);
}

/* ── Calculate button — teal ── */
.calculate-btn {
  width: 100%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  padding: 1.1rem;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--clr-white);
  background: var(--clr-teal-deep);
  box-shadow: var(--shadow-teal);
  transition: all var(--transition);
}
.calculate-btn:hover {
  background: var(--clr-teal);
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(13,207,180,.35);
}
.calculate-btn:active { transform: scale(0.99); }

/* ════════════════════════════════════════
   RESULTS SECTION
   ════════════════════════════════════════ */
.results-section {
  margin-top: 2rem;
  padding: 1.75rem 1.5rem;
  background: var(--clr-slate-100);
  border: 1px solid var(--clr-slate-200);
  border-left: 3px solid var(--clr-teal);
  border-radius: var(--radius-md);
  display: none;
}
.results-section.show { display: block; }

.result-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clr-slate-600);
  margin-bottom: 1.25rem;
}

/* Hero result — 48px Courier New */
.result-hero {
  background: var(--clr-teal-deep);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.25rem;
  text-align: center;
  color: var(--clr-white);
  margin-bottom: 1.5rem;
}
.result-hero-label {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,.8);
  margin-bottom: 0.4rem;
}
.result-hero-value {
  font-size: 3rem;
  font-weight: 900;
  font-family: 'Courier New', monospace;
  color: var(--clr-white);
  word-break: break-all;
  word-wrap: break-word;
  line-height: 1.2;
}
.result-hero-sub {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-top: 0.5rem;
  font-family: 'Courier New', monospace;
}

/* Result boxes */
.result-box {
  background: var(--clr-white);
  border-radius: var(--radius-sm);
  padding: 1.1rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--clr-slate-200);
}
.result-box:last-child { margin-bottom: 0; }

.result-label {
  font-family: var(--font-display);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clr-slate-500);
  margin-bottom: 0.4rem;
}
.result-value {
  font-size: 1.35rem;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  color: var(--clr-teal-deep);
  word-break: break-all;
}
.result-input {
  font-family: 'Courier New', monospace;
  color: var(--clr-slate-600);
  font-size: 0.95rem;
  line-height: 1.75;
  margin-top: 0.5rem;
}

/* Error */
.result-box.error-box { border-left: 3px solid #ef4444; }
.error-label { color: #b91c1c; }
.error-text { color: #b91c1c; font-size: 0.93rem; font-weight: 500; margin-top: 0.4rem; }

/* All-formats box — teal tinted */
.all-formats-box {
  background: rgba(13,207,180,.05);
  border-left: 3px solid var(--clr-teal);
}
.all-formats-label { color: var(--clr-teal-deep); }
.all-formats-values {
  font-family: 'Courier New', monospace;
  color: var(--clr-slate-600);
  font-size: 0.9rem;
  line-height: 2;
  margin-top: 0.6rem;
}

/* Step-by-step */
.step-by-step {
  background: #111827;
  color: #e5e7eb;
  padding: 1.1rem 1.25rem;
  border-radius: var(--radius-sm);
  font-family: 'Courier New', monospace;
  font-size: 0.86rem;
  line-height: 1.8;
  max-height: 400px;
  overflow-y: auto;
  margin-top: 0.75rem;
}
.step-by-step::-webkit-scrollbar { width: 4px; }
.step-by-step::-webkit-scrollbar-thumb { background: rgba(13,207,180,.3); border-radius: 2px; }
.step {
  position: relative;
  padding-left: 1.2rem;
  margin-bottom: 0.5rem;
}
.step:last-child { margin-bottom: 0; }
.step::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--clr-teal);
  font-weight: 700;
}

/* Download — green gradient per source */
.download-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.25rem;
}
.download-btn {
  flex: 1 1 150px;
  padding: 0.65rem 1rem;
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: var(--clr-white);
  border: none;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  transition: all var(--transition);
}
.download-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(16,185,129,.3);
}

/* ════════════════════════════════════════
   INFO CARDS
   ════════════════════════════════════════ */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0;
}
.info-card {
  background: var(--clr-white);
  padding: 1.4rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--clr-slate-200);
  border-left: 3px solid var(--clr-teal);
  box-shadow: var(--shadow-soft);
  transition: all var(--transition);
}
.info-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-teal);
}
.info-card h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--clr-slate-800);
  margin-bottom: 0.5rem;
}
.info-card p { font-size: 0.875rem; color: var(--clr-slate-400); line-height: 1.7; }

/* ════════════════════════════════════════
   BLOG / ARTICLE
   ════════════════════════════════════════ */
.blog-section {
  max-width: 860px;
  margin: 3rem auto 0;
  padding: 0 1.5rem;
}
.blog-content {
  background: var(--clr-white);
  border-radius: var(--radius-lg);
  padding: 3rem 3.5rem;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--clr-slate-200);
  line-height: 1.85;
}
.blog-content h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  color: var(--clr-slate-800);
  margin-bottom: 1.75rem;
  line-height: 1.15;
}
.blog-content h2 .serif-accent {
  font-family: var(--font-serif);
  font-style: italic;
  text-transform: none;
  background: linear-gradient(135deg, var(--clr-teal-deep), var(--clr-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.meta-line {
  font-size: 0.82rem;
  color: var(--clr-slate-400);
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--clr-slate-200);
}
.meta-line a { color: var(--clr-teal-deep); text-decoration: underline; text-underline-offset: 2px; }
.blog-content h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--clr-slate-800);
  margin-top: 2.5rem;
  margin-bottom: 0.9rem;
}
.blog-content p { color: var(--clr-slate-600); font-size: 0.975rem; margin-bottom: 1.1rem; line-height: 1.85; }
.blog-content ul { color: var(--clr-slate-600); margin-left: 1.5rem; margin-bottom: 1.25rem; }
.blog-content li { margin-bottom: 0.4rem; line-height: 1.75; font-size: 0.975rem; }
.blog-content a { color: var(--clr-teal-deep); text-decoration: underline; text-underline-offset: 2px; }
.blog-content a:hover { color: var(--clr-teal); }
.blog-content strong { color: var(--clr-slate-800); font-weight: 600; }
.blog-content code {
  background: var(--clr-slate-100);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.87em;
  color: var(--clr-teal-deep);
  border: 1px solid var(--clr-slate-200);
}
.formula-box {
  background: #111827;
  color: #e5e7eb;
  border-radius: var(--radius-sm);
  padding: 1.1rem 1.35rem;
  margin: 1.25rem 0;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.7;
  overflow-x: auto;
  white-space: pre-wrap;
}
.formula-box strong { color: var(--clr-teal); font-weight: 700; }
.highlight-box {
  background: rgba(13,207,180,.06);
  border: 1px solid rgba(13,207,180,.2);
  border-left: 3px solid var(--clr-teal);
  padding: 1.1rem 1.3rem;
  border-radius: var(--radius-sm);
  margin-top: 2rem;
  font-size: 0.93rem;
  color: var(--clr-slate-700);
  line-height: 1.7;
}
.highlight-box strong { color: var(--clr-teal-deep); font-weight: 600; }

/* ════════════════════════════════════════
   FAQ SECTION — border-top separator pattern
   (matches algebra-calculator.css)
   h3 used (our standard, converted from source h4)
   ════════════════════════════════════════ */
.faq-section {
  max-width: 860px;
  margin: 2.5rem auto 4rem;
  padding: 0 1.5rem;
}
.faq-inner {
  background: var(--clr-white);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2.5rem;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--clr-slate-200);
}
.faq-inner h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--clr-slate-800);
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--clr-slate-200);
}
.faq-item + .faq-item {
  border-top: 1px solid var(--clr-slate-200);
  padding-top: 1rem;
  margin-top: 1rem;
}
.faq-item h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--clr-slate-800);
  margin-bottom: 0.35rem;
}
.faq-item p { font-size: 0.9rem; color: var(--clr-slate-400); line-height: 1.75; margin: 0; }
.faq-item strong { color: var(--clr-slate-700); font-weight: 600; }
.faq-item code {
  background: var(--clr-slate-100);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.86em;
  color: var(--clr-teal-deep);
  border: 1px solid var(--clr-slate-200);
}
.faq-item a { color: var(--clr-teal-deep); text-decoration: underline; text-underline-offset: 2px; }

/* ════════════════════════════════════════
   RESPONSIVE
   ════════════════════════════════════════ */
@media (max-width: 768px) {
  .page-header { padding: 3rem 1.25rem 4rem; }
  .page-header h1 { font-size: 1.9rem; }
  .calculator-card { padding: 1.5rem 1.25rem; margin-top: -1.5rem; border-radius: var(--radius-md); }
  .operation-grid { grid-template-columns: 1fr; }
  .result-hero-value { font-size: 2rem; word-break: break-all; }
  .blog-section { padding: 0 1rem; }
  .blog-content { padding: 1.75rem 1.25rem; }
  .blog-content h2 { font-size: 1.35rem; }
  .blog-content h3 { font-size: 1.1rem; }
  .faq-section { padding: 0 1rem; }
  .faq-inner { padding: 1.5rem 1.25rem; }
  .info-grid { grid-template-columns: 1fr; }
  .download-buttons { flex-direction: column; }
}
@media (max-width: 480px) {
  .calculator-container { padding: 0 0.75rem; }
  .input-field { font-size: 0.9rem; }
  .example-btn { font-size: 0.78rem; }
  .step-by-step { font-size: 0.78rem; }
}

/* Accessibility */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}