/* ============================================================
   PassBy — USE CASES PAGES
   Reuses tokens from shared.css, components from index.css.
   Adds use-case-specific classes:
     - .uc-hero — landing-style hero with hero-grid + breadcrumb
     - .uc-stats-strip — 4 metrics row
     - .uc-problem — 3 problem cards
     - .uc-solution — split: features list + visualization card
     - .uc-steps — numbered steps grid (01-05)
     - .uc-comparison — comparison table
     - .uc-related — related use cases grid
     - .uc-viz-* — visualization cards (speed/ping/security/money/setup)

   Design rules (CRITICAL — PassBy design system):
     - No gradients except hero-grid (already in index.css)
     - Pill-forms for buttons & badges (reuses .btn-primary, .eyebrow)
     - Surface-cards with border-soft (reuses --surface-1/2/3, --border-soft)
     - Fonts: Unbounded (display) / Inter (body) / JetBrains Mono (mono)
     - cubic-bezier easing for all transitions
   ============================================================ */

/* ── HERO ─────────────────────────────────────────────────── */
.uc-hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-top: 140px;
  padding-bottom: var(--sp-7);
  isolation: isolate;
}
.uc-hero .hero-grid {
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0.55;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(55% 45% at 50% 30%, black, transparent 75%);
  -webkit-mask-image: radial-gradient(55% 45% at 50% 30%, black, transparent 75%);
  animation: gridDrift 30s linear infinite;
}
.uc-hero .wrap {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.uc-hero .eyebrow {
  margin-top: var(--sp-4);
}
.uc-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  letter-spacing: 0.03em;
  flex-wrap: wrap;
  justify-content: center;
}
.uc-breadcrumb a {
  color: var(--text-secondary);
  transition: color .2s var(--ease);
}
.uc-breadcrumb a:hover { color: var(--accent-2); }
.uc-breadcrumb .sep { color: var(--text-tertiary); opacity: 0.6; }
.uc-breadcrumb .current { color: var(--text-primary); }

.uc-hero-title {
  font-family: var(--font-display);
  font-size: clamp(36px, 6vw, 68px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  margin-top: var(--sp-3);
  max-width: 920px;
  opacity: 0;
  animation: fadeUp .7s .08s var(--ease-out) forwards;
}
.uc-hero-emoji {
  font-size: 0.7em;
  vertical-align: middle;
  margin-right: 12px;
}
.uc-hero-sub {
  margin-top: var(--sp-4);
  font-size: clamp(16px, 2vw, 19px);
  color: var(--text-secondary);
  max-width: 620px;
  line-height: 1.6;
  opacity: 0;
  animation: fadeUp .7s .16s var(--ease-out) forwards;
}
.uc-hero-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: var(--sp-5);
  flex-wrap: wrap;
  justify-content: center;
  opacity: 0;
  animation: fadeUp .7s .24s var(--ease-out) forwards;
}

/* ── STATS STRIP ──────────────────────────────────────────── */
.uc-stats-section {
  padding: var(--sp-6) 0;
  border-bottom: 1px solid var(--border-soft);
}
.uc-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--sp-3);
}
@media (max-width: 720px) {
  .uc-stats-grid { grid-template-columns: repeat(2, 1fr); }
}
.uc-stat {
  text-align: center;
  padding: var(--sp-3);
}
.uc-stat-num {
  font-family: var(--font-display);
  font-size: clamp(32px, 4.5vw, 44px);
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1;
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
}
.uc-stat-num small {
  font-size: 0.45em;
  font-weight: 600;
  color: var(--text-tertiary);
}
.uc-stat-label {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-tertiary);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ── PROBLEM CARDS ────────────────────────────────────────── */
.uc-problem { padding: var(--sp-9) 0; }
.uc-problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-3);
}
@media (max-width: 820px) {
  .uc-problem-grid { grid-template-columns: 1fr; }
}
.uc-problem-card {
  background: var(--surface-1);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-xl);
  padding: var(--sp-5);
  transition: transform .3s var(--ease-out), border-color .25s var(--ease), background .25s var(--ease);
}
.uc-problem-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-med);
  background: var(--surface-2);
}
.uc-problem-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--r-md);
  background: color-mix(in srgb, var(--signal-red) 12%, transparent);
  color: var(--signal-red);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--sp-3);
}
.uc-problem-card-icon svg { width: 22px; height: 22px; }
.uc-problem-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
  color: var(--text-primary);
}
.uc-problem-card p {
  font-size: 14.5px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ── SOLUTION SPLIT ───────────────────────────────────────── */
.uc-solution { padding: var(--sp-9) 0; }
.uc-solution-split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 0;
  border: 1px solid var(--border-soft);
  border-radius: var(--r-xl);
  overflow: hidden;
}
@media (max-width: 820px) {
  .uc-solution-split { grid-template-columns: 1fr; }
}
.uc-solution-features {
  background: var(--surface-1);
  padding: var(--sp-5);
  border-right: 1px solid var(--border-soft);
}
@media (max-width: 820px) {
  .uc-solution-features {
    border-right: none;
    border-bottom: 1px solid var(--border-soft);
  }
}
/* Reuse .feat-list / .feat-row / .feat-idx / .feat-body / .feat-tag
   from index.css — already styled identically. */
.uc-solution-features .feat-list { display: flex; flex-direction: column; }
.uc-solution-features .feat-row:last-child { border-bottom: none; }

.uc-solution-viz {
  background: var(--surface-0);
  padding: var(--sp-5);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ── VIZ CARDS (speed/ping/security/money/setup) ──────────── */
.uc-viz-card {
  width: 100%;
  max-width: 360px;
  background: var(--surface-1);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-xl);
  padding: var(--sp-4);
}
.uc-viz-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-3);
}
.uc-viz-tag {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}
.uc-viz-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--signal-green);
}
.uc-viz-status .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--signal-green);
  animation: pulse 2.2s infinite;
}

/* speed_card */
.uc-viz-speed-num {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: var(--sp-3);
}
.uc-viz-speed-num .num {
  font-family: var(--font-display);
  font-size: 52px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1;
}
.uc-viz-speed-num .unit {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-tertiary);
}
.uc-viz-speed-bar {
  width: 100%;
  height: 6px;
  background: var(--surface-3);
  border-radius: var(--r-pill);
  overflow: hidden;
  margin-bottom: var(--sp-3);
}
.uc-viz-speed-bar-fill {
  height: 100%;
  background: var(--signal-green);
  border-radius: var(--r-pill);
  transition: width 1s var(--ease-out);
}
.uc-viz-speed-meta {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-tertiary);
}

/* ping_card */
.uc-viz-ping-num {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: var(--sp-3);
}
.uc-viz-ping-num .num {
  font-family: var(--font-display);
  font-size: 52px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1;
}
.uc-viz-ping-num .unit {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-tertiary);
}
.uc-viz-ping-graph {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  height: 70px;
  margin-bottom: var(--sp-3);
}
.uc-viz-ping-bar {
  flex: 1;
  background: var(--accent);
  border-radius: 2px 2px 0 0;
  opacity: 0.7;
  transition: height .5s var(--ease-out);
}
.uc-viz-ping-bar:nth-child(odd) { opacity: 0.9; }
.uc-viz-ping-meta {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-tertiary);
}

/* security_card */
.uc-viz-security-rows {
  display: flex;
  flex-direction: column;
  gap: 1px;
}
.uc-viz-security-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 11px 0;
  border-bottom: 1px solid var(--border-soft);
  font-size: 14px;
}
.uc-viz-security-row:last-child { border-bottom: none; }
.uc-viz-security-row .lbl {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  letter-spacing: 0.03em;
}
.uc-viz-security-row .val {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 13.5px;
}

/* money_card */
.uc-viz-money-num {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 4px;
}
.uc-viz-money-num .currency {
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 600;
  color: var(--text-secondary);
}
.uc-viz-money-num .num {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1;
}
.uc-viz-money-period {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  margin-bottom: var(--sp-4);
}
.uc-viz-money-compare {
  display: flex;
  flex-direction: column;
  gap: 1px;
}
.uc-viz-money-row {
  display: flex;
  justify-content: space-between;
  padding: 10px 12px;
  border-radius: var(--r-md);
  background: var(--surface-2);
  font-size: 14px;
}
.uc-viz-money-row.highlight {
  background: var(--accent-soft);
}
.uc-viz-money-row .name {
  color: var(--text-secondary);
}
.uc-viz-money-row.highlight .name {
  color: var(--accent-2);
  font-weight: 600;
}
.uc-viz-money-row .price {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-primary);
}
.uc-viz-money-row.highlight .price {
  color: var(--accent-2);
}

/* setup_card */
.uc-viz-setup-steps {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
}
.uc-viz-setup-step {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}
.uc-viz-setup-step .num {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--accent-2);
  background: var(--accent-soft);
  padding: 4px 9px;
  border-radius: var(--r-sm);
  flex-shrink: 0;
  font-weight: 600;
}
.uc-viz-setup-step b {
  display: block;
  font-family: var(--font-display);
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}
.uc-viz-setup-step span {
  font-size: 12.5px;
  color: var(--text-tertiary);
}

.uc-viz-default {
  padding: var(--sp-4);
}
.uc-viz-default p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ── STEPS GRID ───────────────────────────────────────────── */
.uc-steps {
  padding: var(--sp-9) 0;
  background: var(--surface-0);
  border-top: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
}
.uc-steps-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--sp-3);
}
@media (max-width: 1024px) {
  .uc-steps-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 540px) {
  .uc-steps-grid { grid-template-columns: 1fr; }
}
.uc-step {
  background: var(--surface-1);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: var(--sp-4);
  transition: transform .25s var(--ease-out), border-color .25s var(--ease);
}
.uc-step:hover {
  transform: translateY(-2px);
  border-color: var(--border-med);
}
.uc-step-num {
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 700;
  color: var(--border-strong);
  line-height: 1;
  margin-bottom: var(--sp-3);
}
.uc-step h3 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  color: var(--text-primary);
}
.uc-step p {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ── COMPARISON TABLE ─────────────────────────────────────── */
.uc-comparison { padding: var(--sp-9) 0; }
.uc-comparison-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border-soft);
  border-radius: var(--r-xl);
  background: var(--surface-1);
}
.uc-comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  min-width: 600px;
}
.uc-comparison-table th,
.uc-comparison-table td {
  padding: 16px 18px;
  text-align: left;
  border-bottom: 1px solid var(--border-soft);
}
.uc-comparison-table th {
  background: var(--surface-2);
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 14px;
  letter-spacing: -0.005em;
}
.uc-comparison-table th.highlight {
  background: var(--accent-soft);
  color: var(--accent-2);
}
.uc-comparison-table td.highlight {
  background: color-mix(in srgb, var(--accent-soft) 50%, transparent);
}
.uc-comparison-table tr:last-child td { border-bottom: none; }
.uc-comparison-feature {
  color: var(--text-secondary);
  font-weight: 500;
}
.uc-comparison-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--signal-green);
  background: color-mix(in srgb, var(--signal-green) 14%, transparent);
  padding: 3px 8px;
  border-radius: var(--r-pill);
  margin-right: 6px;
  text-transform: uppercase;
}
.uc-check {
  width: 18px; height: 18px;
  color: var(--signal-green);
  display: inline-block;
  vertical-align: middle;
}
.uc-x {
  width: 18px; height: 18px;
  color: var(--text-tertiary);
  opacity: 0.5;
  display: inline-block;
  vertical-align: middle;
}

/* ── FAQ (reuses .faq-list from index.css) ────────────────── */
.uc-faq { padding: var(--sp-9) 0; }

/* ── RELATED ──────────────────────────────────────────────── */
.uc-related {
  padding: var(--sp-9) 0;
  border-top: 1px solid var(--border-soft);
}
.uc-related-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--sp-3);
}
@media (max-width: 900px) {
  .uc-related-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 540px) {
  .uc-related-grid { grid-template-columns: 1fr; }
}
.uc-related-card {
  display: flex;
  flex-direction: column;
  background: var(--surface-1);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: var(--sp-4);
  position: relative;
  transition: transform .25s var(--ease-out), border-color .25s var(--ease), background .25s var(--ease);
}
.uc-related-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-med);
  background: var(--surface-2);
}
.uc-related-emoji {
  font-size: 28px;
  margin-bottom: var(--sp-3);
}
.uc-related-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-2);
  background: var(--accent-soft);
  padding: 3px 8px;
  border-radius: var(--r-pill);
  margin-bottom: 8px;
  align-self: flex-start;
}
.uc-related-card h3 {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
  color: var(--text-primary);
}
.uc-related-card:hover h3 { color: var(--accent-2); }
.uc-related-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
  flex: 1;
}
.uc-related-arrow {
  width: 16px; height: 16px;
  color: var(--text-tertiary);
  margin-top: var(--sp-3);
  align-self: flex-end;
  transition: transform .2s var(--ease), color .2s var(--ease);
}
.uc-related-card:hover .uc-related-arrow {
  transform: translateX(3px);
  color: var(--accent-2);
}

/* ── CATALOG GRID (use_cases_list.html) ───────────────────── */
.uc-catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--sp-3);
  padding-bottom: var(--sp-9);
}
@media (max-width: 640px) {
  .uc-catalog-grid { grid-template-columns: 1fr; }
}
.uc-catalog-card {
  display: flex;
  flex-direction: column;
  background: var(--surface-1);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: var(--sp-4);
  transition: transform .3s var(--ease-out), border-color .25s var(--ease), background .25s var(--ease);
}
.uc-catalog-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-med);
  background: var(--surface-2);
}
.uc-catalog-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-3);
  min-height: 36px;
}
.uc-catalog-emoji {
  font-size: 32px;
  line-height: 1;
}
.uc-catalog-badge {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-2);
  background: var(--accent-soft);
  padding: 4px 9px;
  border-radius: var(--r-pill);
}
.uc-catalog-card h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  color: var(--text-primary);
  line-height: 1.25;
}
.uc-catalog-card:hover h3 { color: var(--accent-2); }
.uc-catalog-card p {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.55;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.uc-catalog-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--sp-3);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color .2s var(--ease);
}
.uc-catalog-card:hover .uc-catalog-card-footer { color: var(--accent-2); }
.uc-catalog-card-footer svg {
  width: 14px; height: 14px;
  transition: transform .2s var(--ease);
}
.uc-catalog-card:hover .uc-catalog-card-footer svg { transform: translateX(3px); }