:root {
  --bg: #050810;
  --bg-card: #0d1120;
  --bg-card-hover: #111828;
  --cyan: #141414;
  --purple: #7c3aed;
  --purple-light: #a78bfa;
  --border-cyan: rgba(20, 20, 20, 0.3);
  --border-purple: rgba(124, 58, 237, 0.4);
  --border-dim: rgba(255,255,255,0.07);
  --text: #f0f4ff;
  --text-dim: #6b7a9e;
  --glow-cyan: 0 0 30px rgba(0,212,255,0.15);
  --glow-purple: 0 0 30px rgba(124,58,237,0.2);
}

.diagram {
  display: grid;
  grid-template-columns: 1fr 1.4fr 1fr;
  grid-template-rows: auto auto auto auto;
  gap: 5rem;
  position: relative;
}

/* SVG connector layer */
.connectors {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 10;
  overflow: visible;
}

/* ── CARDS ── */
.node {
  position: relative;
  z-index: 1;
  background: var(--bg-card);
  border-radius: 14px;
  padding: 1.6rem 1.8rem;
  box-shadow: rgba(0, 0, 0, 0.16) 0px 3px 6px, rgba(0, 0, 0, 0.23) 0px 3px 6px;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease, background 0.25s ease;
  animation: fadeUp 0.6s ease both;
}

.node:hover, .node.active {
  transform: translateY(-4px) scale(1.01);
  background: #fafafa;
}

.node--cyan {
  border-color: var(--border-cyan);
}
.node--cyan:hover, .node--cyan.active {
  border-color: var(--cyan);
}

.node--purple {
  border-color: var(--border-purple);
}
.node--purple:hover, .node--purple.active {
  border-color: var(--purple-light);
  box-shadow: var(--glow-purple), inset 0 0 40px rgba(124,58,237,0.06);
}

.node--center {
  border-color: rgba(0,212,255,0.2);
  background: #fafafa;
}


.node__label {
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 0.5rem;
  opacity: 0.7;
}

.node--purple .node__label {
  color: var(--purple-light);
}

.node h3 {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
}

.node p {
  font-size: 0.8rem;
  color: #141414;
  line-height: 1.55;
  font-weight: 400;
}

/* Dot indicator */
.node__dot {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  opacity: 0.4;
  transition: opacity 0.25s, transform 0.25s;
}
.node--purple .node__dot { background: var(--purple-light); }
.node:hover .node__dot, .node.active .node__dot {
  opacity: 1;
  transform: scale(1.4);
}

/* ── GRID POSITIONS ── */

/* Row 1: AI spans middle col */
.node--ai {
  grid-column: 2 / 3;
  grid-row: 1;
  animation-delay: 0.05s;
}

/* Spacers row 1 */
.spacer-l { grid-column: 1; grid-row: 1; }
.spacer-r { grid-column: 3; grid-row: 1; }

/* Row 2: Enterprise | Corporate | Advertisers */
.node--enterprise {
  grid-column: 1;
  grid-row: 2;
  animation-delay: 0.15s;
}
.node--corporate {
  grid-column: 2;
  grid-row: 2;
  animation-delay: 0.1s;
}
.node--advertisers {
  grid-column: 3;
  grid-row: 2;
  animation-delay: 0.2s;
}

/* Row 3: Marketplace spans middle */
.node--marketplace {
  grid-column: 2 / 3;
  grid-row: 3;
  animation-delay: 0.25s;
}

/* Row 4: D2C | Publishers */
.node--d2c {
  grid-column: 1 / 2;
  grid-row: 4;
  animation-delay: 0.35s;
}
.node--publishers {
  grid-column: 2 / 4;
  grid-row: 4;
  animation-delay: 0.4s;
}

/* Traffic label between row 3 and 4 */
.traffic-label {
  grid-column: 1 / 4;
  grid-row: 3; /* overlaps visually via margin */
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 0;
  z-index: 2;
  pointer-events: none;
  margin-top: auto;
  padding-top: 0.3rem;
}

/* ── TOOLTIP ── */
.tooltip {
  position: fixed;
  background: #fafafa;
  border-radius: 10px;
  padding: 0.9rem 1.2rem;
  max-width: 260px;
  pointer-events: none;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 999;
  font-size: 0.78rem;
  line-height: 1.55;
  color: #141414;
  box-shadow: rgba(0, 0, 0, 0.1) -4px 9px 25px -6px;
  box-shadow: rgba(100, 100, 111, 0.2) 0px 7px 29px 0px;
}
.tooltip.visible {
  opacity: 1;
  transform: translateY(0);
}
.tooltip strong {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--cyan);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ── ANIMATIONS ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeDown {
  from { opacity: 0; transform: translateY(-16px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes dash {
  to { stroke-dashoffset: 0; }
}
@keyframes pulse-dot {
  0%, 100% { r: 4; opacity: 1; }
  50%       { r: 6; opacity: 0.5; }
}

/* ═══════════════════════════════════════════════════════════
   DIAGRAM 04 — AI ARCHITECTURE LAYOUT
   ═══════════════════════════════════════════════════════════ */

/* Desktop: 2 columns with gap for arrows */
@media (min-width: 721px) {
  #diagram:has(#n-decision) {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto auto auto;
    gap: 2.5rem 8rem; /* horizontal gap for arrows */
    align-items: start;
  }

  /* Intro text spans both columns */
  #diagram:has(#n-decision) .diagram-intro {
    grid-column: 1 / -1;
    grid-row: 1;
  }

  /* Left column: stack */
  .node--decision       { grid-column: 1; grid-row: 2; }
  .node--operational    { grid-column: 1; grid-row: 3; }
  .node--data-integrity { grid-column: 1; grid-row: 4; }

  /* Right column: stack */
  .node--orchestration  { grid-column: 2; grid-row: 2; }
  .node--risk-trust     { grid-column: 2; grid-row: 3; }
}

/* Mobile: single column */
@media (max-width: 720px) {
  #diagram:has(#n-decision) {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }
}

@media (min-width: 721px) {
  #diagram:has(#n-enterprise-app) {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 1.6rem;
    align-items: start;
  }

  .node--enterprise-app { grid-column: 1; grid-row: 1; }
  .node--loyalty-module { grid-column: 2; grid-row: 1; }
  .node--marketplace-er { grid-column: 3; grid-row: 1; }

  .node--end-users      { grid-column: 1; grid-row: 2; }
  .node--integration-er { grid-column: 2; grid-row: 2; }
  .node--ai-control     { grid-column: 3; grid-row: 2; }
}

@media (max-width: 720px) {
  #diagram:has(#n-enterprise-app) {
    display: flex;
    flex-direction: column;
    gap: 0.9rem;
  }
}

/* ── RESPONSIVE ── */
@media (max-width: 720px) {
  body { padding: 2rem 1rem; align-items: flex-start; }

  .diagram {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto auto auto auto;
    gap: 0.85rem;
  }

  /* Row 1: AI full width */
  .node--ai       { grid-column: 1 / 3; grid-row: 1; }
  /* Row 2: Corporate full width */
  .node--corporate{ grid-column: 1 / 3; grid-row: 2; }
  /* Row 3: Partners | Demand */
  .node--enterprise  { grid-column: 1; grid-row: 3; }
  .node--advertisers { grid-column: 2; grid-row: 3; }
  /* Row 4: Marketplace full width */
  .node--marketplace { grid-column: 1 / 3; grid-row: 4; }
  /* Row 5: D2C | Publishers */
  .node--d2c        { grid-column: 1; grid-row: 5; }
  .node--publishers { grid-column: 2; grid-row: 5; }

  .spacer-l, .spacer-r { display: none; }

  .node           { padding: 1rem 1.1rem; }
  .node h3        { font-size: 0.85rem; }
  .node p         { font-size: 0.7rem; }
  .node__label    { font-size: 0.55rem; }
}