/* ============================================
   DPI Analyzer — Stylesheet
   Clean, modern, responsive
   ============================================ */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-surface: #f7f9fc;
  --color-surface-2: #eef2f7;
  --color-border: #e5e9f0;
  --color-text: #0f172a;
  --color-text-muted: #5b6677;
  --color-text-light: #8795a8;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #eff6ff;
  --color-accent: #f59e0b;
  --color-success: #10b981;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 14px rgba(15, 23, 42, 0.07);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.09);
  --shadow-xl: 0 20px 50px rgba(15, 23, 42, 0.12);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --max-width: 1200px;
  --transition: 0.2s ease;
}

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-dark); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.container-narrow { max-width: 800px; margin: 0 auto; padding: 0 20px; }

h1, h2, h3, h4 { line-height: 1.25; color: var(--color-text); font-weight: 700; }
h1 { font-size: clamp(2.1rem, 4.5vw, 3.2rem); letter-spacing: -0.025em; }
h2 { font-size: clamp(1.7rem, 3vw, 2.35rem); letter-spacing: -0.015em; }
h3 { font-size: 1.25rem; }
p { color: var(--color-text-muted); }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 20px; max-width: var(--max-width); margin: 0 auto; gap: 20px;
}

.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 1.18rem; color: var(--color-text);
  letter-spacing: -0.01em;
}
.nav-brand:hover { color: var(--color-primary); }

.nav-brand-icon {
  width: 32px; height: 32px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border-radius: 9px;
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 800; font-size: 0.9rem;
  box-shadow: 0 3px 8px rgba(37, 99, 235, 0.3);
}

.nav-toggle {
  display: none; background: none;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  padding: 8px 10px; cursor: pointer; font-size: 1.1rem; color: var(--color-text);
}

.nav-menu { display: flex; align-items: center; gap: 4px; list-style: none; flex-wrap: wrap; }

.nav-menu a {
  color: var(--color-text-muted); font-size: 0.92rem; font-weight: 500;
  padding: 8px 14px; border-radius: var(--radius-sm); transition: all var(--transition);
}
.nav-menu a:hover, .nav-menu a.active { color: var(--color-primary); background: var(--color-primary-light); }

.nav-dropdown { position: relative; }

.nav-dropdown-toggle {
  background: none; border: none;
  color: var(--color-text-muted); font-size: 0.92rem; font-weight: 500;
  padding: 8px 14px; border-radius: var(--radius-sm); cursor: pointer;
  font-family: inherit; transition: all var(--transition);
}
.nav-dropdown-toggle:hover, .nav-dropdown:hover .nav-dropdown-toggle {
  color: var(--color-primary); background: var(--color-primary-light);
}

.nav-dropdown-menu {
  position: absolute; top: calc(100% + 6px); right: 0;
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-lg);
  padding: 10px; min-width: 540px;
  display: none; grid-template-columns: repeat(2, 1fr); gap: 2px;
}
.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu { display: grid; }

.nav-dropdown-menu a {
  padding: 9px 14px; font-size: 0.88rem;
  color: var(--color-text); border-radius: var(--radius-sm);
}
.nav-dropdown-menu a:hover { background: var(--color-primary-light); color: var(--color-primary); }

.nav-dropdown-group-title {
  grid-column: 1 / -1; font-size: 0.72rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--color-text-light); padding: 10px 14px 4px;
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 24px; border-radius: var(--radius-md);
  font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer;
  transition: all var(--transition); text-decoration: none;
  font-family: inherit; white-space: nowrap;
}
.btn-primary { background: var(--color-primary); color: #fff; box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25); }
.btn-primary:hover { background: var(--color-primary-dark); color: #fff; transform: translateY(-1px); box-shadow: 0 6px 18px rgba(37, 99, 235, 0.35); }
.btn-secondary { background: #fff; color: var(--color-text); border-color: var(--color-border); }
.btn-secondary:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn-ghost { background: transparent; color: var(--color-text); border-color: var(--color-border); }
.btn-ghost:hover { background: var(--color-surface); color: var(--color-primary); }
.btn-lg { padding: 15px 34px; font-size: 1rem; }
.btn:disabled, .btn[aria-disabled="true"] { opacity: 0.5; cursor: not-allowed; pointer-events: none; }

/* Hero */
.hero {
  padding: 88px 0 56px;
  background:
    radial-gradient(ellipse at top right, rgba(37, 99, 235, 0.08), transparent 60%),
    radial-gradient(ellipse at bottom left, rgba(37, 99, 235, 0.05), transparent 60%);
  text-align: center; position: relative;
}

.hero-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--color-primary-light); color: var(--color-primary);
  padding: 7px 16px; border-radius: 999px;
  font-size: 0.82rem; font-weight: 600; margin-bottom: 22px;
}

.hero h1 { max-width: 860px; margin: 0 auto 20px; }

.hero-subtitle {
  max-width: 640px; margin: 0 auto 36px;
  font-size: 1.1rem; color: var(--color-text-muted); line-height: 1.65;
}

/* DPI Analyzer Tool Box */
.dpi-tool {
  max-width: 640px; margin: 44px auto 0;
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-xl); padding: 40px 32px;
  box-shadow: var(--shadow-lg); text-align: center;
}

.dpi-tool-status {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--color-surface); color: var(--color-text-muted);
  padding: 6px 14px; border-radius: 999px;
  font-size: 0.82rem; font-weight: 500; margin-bottom: 20px;
}

.dpi-status-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--color-text-light);
}
.dpi-status-dot.active {
  background: var(--color-success);
  box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.2);
}

.dpi-result {
  font-size: clamp(3rem, 7vw, 4.5rem);
  font-weight: 800; color: var(--color-primary);
  letter-spacing: -0.04em; line-height: 1;
  margin-bottom: 10px; font-variant-numeric: tabular-nums;
}

.dpi-result-label {
  font-size: 1rem; color: var(--color-text-muted);
  font-weight: 500; margin-bottom: 24px;
}

.dpi-drag-area {
  background: var(--color-surface); border-radius: var(--radius-lg);
  padding: 32px 20px; margin-bottom: 20px;
  border: 2px dashed var(--color-border);
  cursor: crosshair; transition: all var(--transition);
  user-select: none; -webkit-user-select: none;
  min-height: 120px;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
}
.dpi-drag-area:hover { border-color: var(--color-primary); background: var(--color-primary-light); }
.dpi-drag-area.dragging {
  border-color: var(--color-primary); background: var(--color-primary-light); border-style: solid;
}

.dpi-drag-icon { font-size: 1.6rem; opacity: 0.6; }
.dpi-drag-text { font-size: 0.95rem; color: var(--color-text-muted); font-weight: 500; }
.dpi-live-count { font-size: 0.85rem; color: var(--color-primary); font-weight: 600; font-variant-numeric: tabular-nums; }

.dpi-controls {
  display: flex; flex-wrap: wrap; gap: 14px;
  align-items: flex-end; justify-content: center; margin-bottom: 20px;
}

.dpi-field { display: flex; flex-direction: column; gap: 6px; text-align: left; }

.dpi-field label {
  font-size: 0.82rem; font-weight: 600; color: var(--color-text);
  text-transform: uppercase; letter-spacing: 0.04em;
}

.dpi-field input, .dpi-field select {
  padding: 10px 14px; border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); font-size: 0.95rem;
  font-family: inherit; background: #fff; min-width: 100px;
}
.dpi-field input:focus, .dpi-field select:focus {
  outline: none; border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.dpi-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

.dpi-helper {
  font-size: 0.85rem; color: var(--color-text-light);
  margin-top: 18px; line-height: 1.55;
}

/* Sections */
.section { padding: 80px 0; }
.section-sm { padding: 56px 0; }
.section-alt { background: var(--color-surface); }

.section-header { text-align: center; max-width: 720px; margin: 0 auto 52px; }
.section-header h2 { margin-bottom: 14px; }
.section-header p { font-size: 1.05rem; }

.section-eyebrow {
  display: inline-block; color: var(--color-primary);
  font-size: 0.82rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 12px;
}

/* How It Works */
.steps-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 28px; counter-reset: step-counter;
}

.step-card {
  position: relative; padding: 32px 24px 24px;
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); counter-increment: step-counter;
}

.step-card::before {
  content: counter(step-counter);
  position: absolute; top: -18px; left: 24px;
  width: 40px; height: 40px;
  background: var(--color-primary); color: #fff;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1.05rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.step-card h3 { margin-bottom: 8px; font-size: 1.1rem; margin-top: 10px; }
.step-card p { font-size: 0.95rem; }

/* Feature Cards */
.features-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}

.feature-card {
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 30px 28px;
  transition: all var(--transition);
}
.feature-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-3px); box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 52px; height: 52px; border-radius: var(--radius-md);
  background: var(--color-primary-light); color: var(--color-primary);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 1.55rem; margin-bottom: 18px;
}

.feature-card h3 { margin-bottom: 8px; font-size: 1.15rem; }
.feature-card p { font-size: 0.95rem; }

/* Content Blocks */
.content-block { max-width: 780px; margin: 0 auto; }
.content-block h2 { margin-bottom: 18px; }
.content-block h3 { margin: 32px 0 12px; font-size: 1.2rem; }
.content-block p { margin-bottom: 16px; color: var(--color-text); font-size: 1rem; line-height: 1.75; }
.content-block ul, .content-block ol { margin: 0 0 20px 24px; color: var(--color-text); }
.content-block li { margin-bottom: 8px; line-height: 1.7; }
.content-block strong { color: var(--color-text); font-weight: 600; }

.content-placeholder {
  background: var(--color-surface); border: 1px dashed var(--color-border);
  border-radius: var(--radius-md); padding: 24px;
  text-align: center; color: var(--color-text-light);
  font-size: 0.9rem; margin: 24px 0;
}

/* Two-column split */
.info-split {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 48px; align-items: center;
}

.info-split .info-text h2 { margin-bottom: 16px; }
.info-split .info-text p { margin-bottom: 14px; font-size: 1rem; }

.info-split-checklist { list-style: none; margin-top: 8px; }
.info-split-checklist li {
  position: relative; padding-left: 30px;
  margin-bottom: 10px; color: var(--color-text);
}
.info-split-checklist li::before {
  content: "✓";
  position: absolute; left: 0; top: 0;
  width: 22px; height: 22px;
  background: var(--color-primary-light); color: var(--color-primary);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.78rem;
}

.info-split-visual {
  background: linear-gradient(135deg, var(--color-primary-light), #fff);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 48px 32px; text-align: center;
  box-shadow: var(--shadow-sm);
}

.info-split-stat {
  font-size: 3.5rem; font-weight: 800;
  color: var(--color-primary);
  line-height: 1; letter-spacing: -0.03em;
}

.info-split-stat-label {
  margin-top: 8px; color: var(--color-text-muted); font-weight: 500;
}

/* Testimonials */
.testimonials-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}

.testimonial {
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 30px 28px;
  transition: all var(--transition);
}
.testimonial:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

.testimonial-stars {
  color: var(--color-accent); font-size: 1rem;
  letter-spacing: 2px; margin-bottom: 14px;
}

.testimonial-text {
  color: var(--color-text); font-size: 1rem; line-height: 1.65;
  margin-bottom: 20px; font-style: italic;
}

.testimonial-author { display: flex; align-items: center; gap: 12px; }

.testimonial-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.95rem;
}

.testimonial-name { font-weight: 600; color: var(--color-text); font-size: 0.95rem; }
.testimonial-role { font-size: 0.85rem; color: var(--color-text-muted); }

/* Articles */
.articles-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px; margin-bottom: 36px;
}

.article-card {
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 30px 28px;
  transition: all var(--transition);
  display: flex; flex-direction: column;
}
.article-card:hover {
  transform: translateY(-3px); box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.article-meta {
  display: flex; gap: 12px;
  font-size: 0.82rem; color: var(--color-text-muted);
  margin-bottom: 12px;
}
.article-meta span + span::before {
  content: "·"; margin-right: 12px; color: var(--color-border);
}

.article-card h3 { margin-bottom: 10px; font-size: 1.15rem; color: var(--color-text); }
.article-card p { font-size: 0.95rem; flex-grow: 1; margin-bottom: 16px; }

.article-link { font-size: 0.9rem; font-weight: 600; color: var(--color-primary); }
.article-link::after { content: " →"; }

.center-action { text-align: center; }

/* FAQ */
.faq-list {
  max-width: 780px; margin: 0 auto;
  display: flex; flex-direction: column; gap: 12px;
}

.faq-item {
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-md); overflow: hidden;
  transition: border-color var(--transition);
}
.faq-item[open] { border-color: var(--color-primary); box-shadow: var(--shadow-sm); }

.faq-item summary {
  padding: 20px 24px; font-weight: 600;
  cursor: pointer; list-style: none;
  position: relative; padding-right: 56px;
  color: var(--color-text); font-size: 1rem;
}
.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: "+";
  position: absolute; right: 24px; top: 50%;
  transform: translateY(-50%);
  font-size: 1.5rem; font-weight: 400;
  color: var(--color-primary); transition: transform var(--transition);
}
.faq-item[open] summary::after { content: "−"; }
.faq-item summary:hover { background: var(--color-surface); }

.faq-answer {
  padding: 0 24px 22px;
  color: var(--color-text-muted);
  font-size: 0.97rem; line-height: 1.7;
}

/* CTA Section */
.cta-section {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  padding: 80px 0; text-align: center; color: #fff;
  position: relative; overflow: hidden;
}
.cta-section::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1), transparent 50%),
    radial-gradient(circle at 80% 50%, rgba(255, 255, 255, 0.08), transparent 50%);
  pointer-events: none;
}
.cta-section .container { position: relative; }
.cta-section h2 { color: #fff; margin-bottom: 14px; }
.cta-section p {
  color: rgba(255, 255, 255, 0.9); font-size: 1.1rem;
  max-width: 580px; margin: 0 auto 28px;
}
.cta-section .btn-primary {
  background: #fff; color: var(--color-primary);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.15);
}
.cta-section .btn-primary:hover { background: var(--color-surface); color: var(--color-primary-dark); }

/* Footer */
.site-footer { background: #0f172a; color: #cbd5e1; padding: 56px 0 26px; }

.footer-grid {
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 44px; margin-bottom: 36px;
}

.footer-brand {
  display: flex; align-items: center; gap: 10px;
  color: #fff; font-weight: 700; font-size: 1.15rem;
  margin-bottom: 14px;
}

.footer-description {
  font-size: 0.92rem; color: #94a3b8;
  line-height: 1.65; max-width: 340px;
}

.footer-col h4 {
  color: #fff; font-size: 0.88rem; margin-bottom: 16px;
  font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em;
}

.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer-col a { color: #94a3b8; font-size: 0.92rem; }
.footer-col a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid #1e293b; padding-top: 24px;
  text-align: center; font-size: 0.88rem; color: #64748b;
}

/* Tool Page */
.tool-page { padding: 56px 0 80px; }

.tool-header { text-align: center; max-width: 740px; margin: 0 auto 40px; }

.tool-breadcrumb { font-size: 0.85rem; color: var(--color-text-muted); margin-bottom: 16px; }
.tool-breadcrumb a { color: var(--color-text-muted); }
.tool-breadcrumb a:hover { color: var(--color-primary); }

.tool-header h1 { margin-bottom: 14px; }
.tool-header p { font-size: 1.05rem; }

.tool-box {
  max-width: 760px; margin: 0 auto;
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-xl); padding: 40px 32px;
  box-shadow: var(--shadow-md); text-align: center;
}

.tool-display {
  font-size: clamp(3rem, 7vw, 4.5rem);
  font-weight: 800; color: var(--color-primary);
  letter-spacing: -0.04em; line-height: 1;
  margin-bottom: 8px; font-variant-numeric: tabular-nums;
}

.tool-display-label { color: var(--color-text-muted); font-weight: 500; margin-bottom: 28px; }

.tool-action-area {
  background: var(--color-surface); border-radius: var(--radius-lg);
  padding: 44px 20px; margin-bottom: 24px;
  border: 2px dashed var(--color-border);
  min-height: 180px;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 12px;
  cursor: pointer; user-select: none; -webkit-user-select: none;
  transition: all var(--transition);
}
.tool-action-area:hover { border-color: var(--color-primary); background: var(--color-primary-light); }
.tool-action-area.active { background: var(--color-primary-light); border-color: var(--color-primary); border-style: solid; }
.tool-action-area.ready { background: #fef3c7; border-color: var(--color-accent); border-style: solid; color: #92400e; }
.tool-action-area.go { background: #d1fae5; border-color: var(--color-success); border-style: solid; color: #065f46; }

.tool-action-title { font-size: 1.3rem; font-weight: 700; color: inherit; }
.tool-action-text { color: var(--color-text-muted); font-size: 0.95rem; }
.tool-action-area.ready .tool-action-text,
.tool-action-area.go .tool-action-text { color: inherit; opacity: 0.9; }

.tool-controls { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-bottom: 20px; }

.tool-fields {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px; margin-bottom: 24px; text-align: left;
}

.tool-field label {
  display: block; font-size: 0.82rem; font-weight: 600;
  color: var(--color-text); text-transform: uppercase;
  letter-spacing: 0.04em; margin-bottom: 6px;
}

.tool-field input, .tool-field select {
  width: 100%; padding: 10px 14px;
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  font-size: 0.95rem; font-family: inherit; background: #fff;
}
.tool-field input:focus, .tool-field select:focus {
  outline: none; border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.tool-output {
  background: var(--color-surface); border-radius: var(--radius-md);
  padding: 18px;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 16px; margin-top: 20px; text-align: center;
}

.tool-output-item .value {
  font-size: 1.6rem; font-weight: 700; color: var(--color-primary);
  line-height: 1; font-variant-numeric: tabular-nums;
}

.tool-output-item .label {
  font-size: 0.78rem; color: var(--color-text-muted);
  text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px;
}

/* Aim trainer canvas */
.aim-canvas {
  position: relative; width: 100%; height: 360px;
  background: var(--color-surface); border: 2px solid var(--color-border);
  border-radius: var(--radius-md); overflow: hidden;
  cursor: crosshair; user-select: none; -webkit-user-select: none;
}

.aim-target {
  position: absolute; width: 48px; height: 48px; border-radius: 50%;
  background: radial-gradient(circle, #ef4444 40%, #b91c1c 70%);
  border: 3px solid #fff; cursor: pointer;
  box-shadow: 0 4px 10px rgba(239, 68, 68, 0.5);
  transform: translate(-50%, -50%);
}

/* Related tools */
.related-tools { max-width: var(--max-width); margin: 64px auto 0; padding: 0 20px; }
.related-tools h2 { text-align: center; font-size: 1.55rem; margin-bottom: 28px; }

.related-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 14px;
}

.related-card {
  background: #fff; border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 18px;
  transition: all var(--transition); color: var(--color-text);
}
.related-card:hover {
  border-color: var(--color-primary); color: var(--color-primary);
  transform: translateY(-2px); box-shadow: var(--shadow-sm);
}

.related-card-title { font-weight: 600; font-size: 0.95rem; margin-bottom: 4px; }
.related-card-desc { font-size: 0.82rem; color: var(--color-text-muted); }

/* Utility */
.text-center { text-align: center; }
.mt-lg { margin-top: 32px; }

/* Responsive */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .info-split { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 768px) {
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }

  .nav-menu {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--color-border);
    flex-direction: column; align-items: stretch;
    padding: 12px; gap: 2px; box-shadow: var(--shadow-md);
  }

  .nav-menu a, .nav-dropdown-toggle { width: 100%; text-align: left; padding: 10px 14px; }

  .nav-dropdown-menu {
    position: static; min-width: 0; box-shadow: none;
    border: none; background: var(--color-surface);
    margin-top: 4px; padding: 6px;
  }

  .hero { padding: 56px 0 44px; }
  .section { padding: 56px 0; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .steps-grid { gap: 38px; }
  .dpi-tool, .tool-box { padding: 28px 20px; }
}

@media (max-width: 480px) {
  .btn-lg { padding: 13px 22px; font-size: 0.95rem; }
  .dpi-controls { flex-direction: column; align-items: stretch; }
  .dpi-field { width: 100%; }
}

#nav-toggle-cb { display: none; }
#nav-toggle-cb:checked ~ .nav-menu { display: flex; }

@media (min-width: 769px) {
  .nav-toggle { display: none !important; }
}