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

body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  background: #111;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: 2rem;
  padding: 1rem;
}

.container {
  width: 100%;
  max-width: 535px;
  padding: 0 1rem;
}

h1 {
  color: rgba(255, 255, 255, .87);
}

.intro {
  text-align: center;
}

.intro p {
  color: rgba(255, 255, 255, .6);
}

.graph-container {
  padding: 1rem;
  scale: .5;
  /* Dirty hack to handle height scale decrease */
  margin: -7.5rem 0;
}

.graph {
  position: relative;
  width: 500px;
  height: 500px;
  animation: fadeIn 1s forwards ease-in-out;
}

@keyframes fadeIn {
  0% {
    opacity: 0;
  }
  25%, 100% {
    opacity: 1;
  }
}

/* Nodes */
.node {
  position: absolute;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: #242424;
  color: rgba(255, 255, 255, .87);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 24px;
  font-weight: bold;
  border: 1px solid transparent;
  box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
  transition: all 1.5s ease-in-out;
  z-index: 10;
  animation: node 20s forwards;
}

/* Node positions and delay to animate */
#node-a {
  top: 0;
  left: 225px;
  animation-name: nodeShortest;
  animation-delay: 0s;
}

#node-b {
  top: 125px;
  left: 110px;
  animation-delay: 1.5s;
}

#node-c {
  top: 125px;
  right: 110px;
  animation-name: nodeShortest;
  animation-delay: 3s;
}

#node-d {
  top: 280px;
  left: 50px;
  animation-delay: 4.5s;
}

#node-e {
  top: 280px;
  right: 50px;
  animation-name: nodeShortest;
  animation-delay: 5.5s;
}

#node-f {
  bottom: 0;
  left: 110px;
  animation-name: nodeShortest;
  animation-delay: 7s;
}

#node-g {
  bottom: 0;
  right: 110px;
  animation-name: nodeShortestTarget;
  animation-delay: 7.5s;
}

/* Color changes during animation */
@keyframes node {
  0% {
    background: #242424;
    border-color: transparent;
    box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
    scale: 1;
  }
  5%, 7% {
    background: #3700b3;
    border-color: rgba(255, 255, 255, .87);
    box-shadow: 2px 2px 60px rgba(0, 0, 0, .75);
    scale: 1.1;
  }
  10%, 100% {
    background: #cf6679;
    border-color: transparent;
    box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
    scale: 1;
  }
}

/* Highlight shortest path node (A->C->E->F->G) */
@keyframes nodeShortest {
  0% {
    background: #242424;
    border-color: transparent;
    box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
    color: rgba(255, 255, 255, .87);
    scale: 1;
  }
  5%, 7% {
    background: #3700b3;
    border-color: rgba(255, 255, 255, .87);
    box-shadow: 2px 2px 60px rgba(0, 0, 0, .75);
    color: rgba(255, 255, 255, .87);
    scale: 1.1;
  }
  10%, 50% {
    background: #cf6679;
    border-color: transparent;
    box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
    color: rgba(255, 255, 255, .87);
    scale: 1;
  }
  55%, 100% {
    background: #03dac6;
    border-color: transparent;
    box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
    color: #1e1e1e;
    scale: 1;
  }
}

@keyframes nodeShortestTarget {
  0%, 50% {
    background: #242424;
    color: rgba(255, 255, 255, .87);
  }
  55%, 100% {
    background: #03dac6;
    color: #1e1e1e;
  }
}

/* Node labels */
.node::after {
  content: attr(data-label);
  position: absolute;
  top: -30px;
  font-size: 1.5rem;
  color: #bb86fc;
  font-weight: 600;
}


#node-b::after {
  animation: nodeLabelB 20s forwards ease-in-out;
  animation-delay: 0.5s;
}

#node-c::after {
  animation: nodeLabelC 20s forwards ease-in-out;
  animation-delay: 1s;
}

#node-d::after {
  animation: nodeLabelD 20s forwards ease-in-out;
  animation-delay: 2s;
}

#node-e::after {
  animation: nodeLabelE 20s forwards ease-in-out;
  animation-delay: 2.5s;
}

#node-f::after {
  animation: nodeLabelF 20s forwards ease-in-out;
  animation-delay: 5s;
}

#node-g::after {
  animation: nodeLabelG 20s forwards ease-in-out;
  animation-delay: 6.5s;
}

@keyframes nodeLabelB {
  0% {
    content: attr(data-label);
  }
  5%, 100% {
    content: '4';
  }
}

@keyframes nodeLabelC {
  0% {
    content: attr(data-label);
  }
  5%, 100% {
    content: '2';
  }
}

@keyframes nodeLabelD {
  0% {
    content: attr(data-label);
  }
  5% {
    content: '12';
  }
  15%, 100% {
    content: '7';
  }
}

@keyframes nodeLabelE {
  0% {
    content: attr(data-label);
  }
  5% {
    content: '7';
  }
  15%, 100% {
    content: '3';
  }
}

@keyframes nodeLabelF {
  0% {
    content: attr(data-label);
  }
  5% {
    content: '13';
  }
  10%, 100% {
    content: '10';
  }
}

@keyframes nodeLabelG {
  0% {
    content: attr(data-label);
  }
  5% {
    content: '12';
  }
  10%, 100% {
    content: '11';
  }
}

/* Edges */
.edge {
  position: absolute;
  background: rgba(255,255,255,.6);
  width: 100%;
  height: 100%;
  transform-origin: 0 0;
  transition: all 1.5s ease;
  z-index: 1;
  animation: edge 20s forwards;
}

/* Edge positions and animation delay */
#edge-ab {
  clip-path: polygon(250px 15px, 125px 160px, 135px 160px, 260px 15px);
  -webkit-clip-path: polygon(250px 15px, 125px 160px, 135px 160px, 260px 15px);
  animation-delay: 0.5s;
}

#edge-ac {
  clip-path: polygon(240px 15px, 365px 160px, 375px 160px, 250px 15px);
  -webkit-clip-path: polygon(240px 15px, 365px 160px, 375px 160px, 250px 15px);
  animation-delay: 1s;
}

#edge-bd {
  clip-path: polygon(125px 160px, 65px 295px, 75px 295px, 135px 160px);
  -webkit-clip-path: polygon(125px 160px, 65px 295px, 75px 295px, 135px 160px);
  animation-delay: 2s;

}

#edge-be {
  clip-path: polygon(135px 160px, 415px 305px, 415px 295px, 135px 150px);
  -webkit-clip-path: polygon(135px 160px, 415px 305px, 415px 295px, 135px 150px);
  animation-delay: 2.5s;

}

#edge-cd {
  clip-path: polygon(365px 160px, 65px 305px, 65px 295px, 365px 150px);
  -webkit-clip-path: polygon(365px 160px, 65px 305px, 65px 295px, 365px 150px);
  animation-delay: 3.5s;
}

#edge-ce {
  clip-path: polygon(365px 160px, 415px 305px, 425px 305px, 375px 160px);
  -webkit-clip-path: polygon(365px 160px, 415px 305px, 425px 305px, 375px 160px);
  animation-delay: 4s;
}

#edge-df {
  clip-path: polygon(65px 295px, 125px 475px, 135px 475px, 75px 295px);
  -webkit-clip-path: polygon(65px 295px, 125px 475px, 135px 475px, 75px 295px);
  animation-delay: 5s;
}

#edge-ef {
  clip-path: polygon(415px 300px, 125px 465px, 125px 475px, 415px 310px);
  -webkit-clip-path: polygon(415px 300px, 125px 465px, 125px 475px, 415px 310px);
  animation-delay: 6s;
}

#edge-fg {
  clip-path: polygon(125px 475px, 375px 475px, 375px 465px, 125px 465px);
  -webkit-clip-path: polygon(125px 475px, 375px 475px, 375px 465px, 125px 465px);
  animation-delay: 7.5s;
}

#edge-eg {
  clip-path: polygon(415px 305px, 365px 475px, 375px 475px, 425px 305px);
  -webkit-clip-path: polygon(415px 305px, 365px 475px, 375px 475px, 425px 305px);
  animation-delay: 6.5s;
}

/* Highlight shortest path edges (A->C->E->F->G) */
#edge-ac, #edge-ce, #edge-ef, #edge-fg {
  animation-name: edgeShortest;
}

@keyframes edge {
  0% {
    background: rgba(255,255,255,.6);
  }
  5%, 100% {
    background: #3700b3;
  }
}

/* Edge animation for shortest path */
@keyframes edgeShortest {
  0% {
    background: rgba(255, 255, 255, .6);
  }
  5%, 50% {
    background: #3700b3;
  }
  55%, 100% {
    background: #03dac6;
  }
}
 
/* Edge weights */
.weight {
  position: absolute;
  color: rgba(255, 255, 255, .87);;
  font-size: 1rem;
  font-weight: bold;
}

#weight-ab {
  top: 60px;
  left: 175px;
}

#weight-ac {
  top: 60px;
  right: 175px;
}

#weight-bd {
  top: 200px;
  left: 85px;
}

#weight-be {
  top: 190px;
  left: 180px;
}

#weight-cd {
  top: 190px;
  right: 180px;
}

#weight-ce {
  top: 200px;
  right: 85px;
}

#weight-df {
  top: 390px;
  left: 85px;
}

#weight-ef {
  top: 390px;
  left: 280px;
}

#weight-fg {
  top: 480px;
  left: 250px;
}

#weight-eg {
  top: 390px;
  right: 85px;
}

/* Legend */
.legend {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  background: rgba(255, 255, 255, 0.95);
  border-radius: 24px;
  padding: 1.25rem;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: .5rem;
}

.legend-color {
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 6px;
}

.legend-color.visited {
  background: #cf6679;
}

.legend-color.current {
  background: #3700b3;
}

.legend-color.shortest {
  background: #03dac6;
}

.legend-label {
  font-size: 1rem;
  color: #2d3748;
  font-weight: 500;
}

@media (min-width: 375px) {
  .graph-container {
    scale: .6;
    margin: -6.25rem 0;
  }
}

@media (min-width: 475px) {
  .graph-container {
    scale: .75;
    margin: -4.5rem 0;
  }
}

@media (min-width: 640px) {
  .graph-container {
    scale: 1;
    margin: 0;
  }
}