/* ============================================ */
/* ASSIGNMENT CONTAINER STYLES */
/* DO NOT MODIFY THIS SECTION */
/* ============================================ */

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: #f5f5f5;
}

.assignment-container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px;
}

.main-title {
  text-align: center;
  color: #222;
  font-size: 2.5rem;
  margin-bottom: 40px;
  padding: 20px;
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.demo-video-container {
  background: white;
  border-radius: 8px;
  padding: 30px;
  margin-bottom: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.demo-video-container h2 {
  color: #3498db;
  margin-top: 0;
  margin-bottom: 15px;
  font-size: 1.8rem;
}

.demo-video-container p {
  color: #555;
  margin-bottom: 20px;
  font-size: 1.1rem;
}

.demo-video-container video {
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  background: #000;
}

.important-notice {
  background: #fff3cd;
  border: 3px solid #ffc107;
  border-radius: 8px;
  padding: 20px 30px;
  margin-bottom: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.important-notice h2 {
  color: #856404;
  margin-top: 0;
  margin-bottom: 15px;
  font-size: 1.5rem;
}

.important-notice p {
  color: #856404;
  margin: 0;
  font-size: 1.1rem;
  line-height: 1.6;
}

.important-notice code {
  background: #fff;
  padding: 2px 6px;
  border-radius: 3px;
  border: 1px solid #ffc107;
  font-family: "Courier New", monospace;
}

.question {
  background: white;
  border-radius: 8px;
  padding: 30px;
  margin-bottom: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.question-title {
  color: #1abc9c;
  border-bottom: 3px solid #1abc9c;
  padding-bottom: 10px;
  margin-bottom: 20px;
}

.question-brief {
  line-height: 1.6;
  color: #333;
}

.question-brief h3 {
  color: #555;
  margin-top: 20px;
}

.question-brief ul {
  margin-left: 20px;
}

.question-brief li {
  margin-bottom: 10px;
}

.question-brief code {
  background: #f4f4f4;
  padding: 2px 6px;
  border-radius: 3px;
  color: #e83e8c;
  font-family: "Courier New", monospace;
}

.demo-label {
  margin-top: 20px;
  color: #666;
  font-size: 0.95rem;
}

.demo-area {
  background: #1a1a2e;
  padding: 40px;
  border-radius: 6px;
  margin-top: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.demo-nav {
  background: #f5f5f5;
  padding: 0;
}

.demo-loader {
  background: transparent;
  min-height: 180px;
  padding: 0;
}

.demo-clock {
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.grading {
  background: white;
  border-radius: 8px;
  padding: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.grading h2 {
  color: #e74c3c;
  border-bottom: 3px solid #e74c3c;
  padding-bottom: 10px;
  margin-bottom: 20px;
}

.grading h3 {
  color: #555;
  margin-top: 25px;
}

.grading table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}

.grading th, .grading td {
  border: 1px solid #ddd;
  padding: 12px;
  text-align: left;
}

.grading th {
  background-color: #f8f9fa;
  font-weight: bold;
}

.grading ul {
  margin-left: 20px;
}

.grading li {
  margin-bottom: 8px;
}


/* ============================================ */
/* QUESTION 1: PULSING DOTS LOADER */
/* YOUR CODE STARTS HERE */
/* ============================================ */

/* TODO: CSS variables */
:root{
  --dot-size: 20px;
  --dot-color-1: red;
  --dot-color-2: cyan;
  --dot-color-3: yellow;
  --background-color: linear-gradient(90deg, #1f1e33, #2c325a);
}

/* TODO: .loader */
.loader {
  display: flex;
  gap: 50px;
  justify-content: center;
  align-items: center;
  height: 200px;
  width: 100%;
  background: var(--background-color);
}
/* TODO: .loader__element */
.loader__element{
  width: var(--dot-size);
  height: var(--dot-size);
  border-radius: 50%;
  background-color: transparent;
  animation: pulse 0.8s ease-in-out infinite alternate;
}

/* TODO: .loader__element:nth-child(1) */
.loader__element:nth-child(1){
  background-color: var(--dot-color-1);
  box-shadow: 0 0 10px var(--dot-color-1), 0 0 20px var(--dot-color-1);
  animation-delay: 0s;
}

/* TODO: .loader__element:nth-child(2) */
.loader__element:nth-child(2){
  background-color: var(--dot-color-2);
  box-shadow: 0 0 10px var(--dot-color-2), 0 0 20px var(--dot-color-2);
  animation-delay: 0.27s;
}

/* TODO: .loader__element:nth-child(3) */
.loader__element:nth-child(3){
  background-color: var(--dot-color-3);
  box-shadow: 0 0 10px var(--dot-color-3), 0 0 20px var(--dot-color-3);
  animation-delay: 0.53s;
}

/* TODO: @keyframes preloader */
@keyframes pulse {
  0% {
    transform: scale(1);
    filter: brightness(1);
  }
100% {
    transform: scale(2);
    filter: brightness(1.5);
  }
}


/* ============================================ */
/* QUESTION 2: NAVIGATION MENU */
/* YOUR CODE STARTS HERE */
/* ============================================ */

/* TODO: nav */
nav{
  background: #333333;
  width: 100%;
  height: 50px;
  font-weight: bold;
}

/* TODO: #wrapper */
#wrapper {
  display: flex;
  justify-content: center;
  height: 100%;
  width: 100%;
}

/* TODO: #wrapper ul */
#wrapper ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
}

/* TODO: #wrapper li */
#wrapper li{
  position: relative;
}

/* TODO: #wrapper a */
#wrapper a{
  text-decoration: none;
  color: white;
  padding: 15px 30px;
  display: block;
  position: relative;
}

/* TODO: #wrapper li::after */
#wrapper li::after{
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 0;
  height: 4px;
  background-color: cyan;
  transition: width 0.2s ease, left 0.2s ease;
}

/* TODO: #wrapper li:hover::after */
#wrapper li:hover::after{
  width: 100%;
  left: 0;
}


/* ============================================ */
/* QUESTION 3: SVG ANIMATION */
/* YOUR CODE STARTS HERE */
/* ============================================ */

/* TODO: @import Google Font */
@import url('https://fonts.googleapis.com/css2?family=Roboto&display=swap');

/* TODO: .svg-container */
.svg-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* TODO: .svg-container h1 */
.svg-container h1 {
  font-family: "Roboto", sans-serif;
  font-size: 20px;
  color: #fff;
}

/* TODO: .player */
.player {
  width: 130px;
  height: 130px;
  cursor: pointer;
}

/* TODO: .player .background */
.player .background {
  fill: none;
  stroke: #9b59b6;
  stroke-width: 3;
  transition: 250ms ease;
}

/* TODO: .player .foreground */
.player .foreground {
  fill: none;
  stroke: #f39c12;
  stroke-width: 3;
  stroke-dasharray: 0 350;
  stroke-dashoffset: 175;
  transition: 1s ease;
}

/* TODO: .player .play-icon */
.player .play-icon {
  fill: #9b59b6;
  opacity: 1;
  transform-origin: center;
  transition: opacity 250ms ease, transform 400ms ease;
}

/* TODO: .player .pause-bar */
.player .pause-bar {
  fill: #f39c12;
  opacity: 0;
  transform-origin: center;
  transform: scale(0);
  transition: opacity 250ms ease, transform 400ms ease;
}

/* TODO: .player:hover */
.player:hover {

}

/* TODO: .player:hover .background */
.player:hover .background {
  stroke: #1a1a2e;
}

/* TODO: .player:hover .foreground */
.player:hover .foreground {
  stroke-dasharray: 350 0;
  stroke-dashoffset: 0;
}

/* TODO: .player:hover .play-icon */
.player:hover .play-icon {
  opacity: 0;
  transform: scale(0);
}

/* TODO: .player:hover .pause-bar */
.player:hover .pause-bar {
  opacity: 1;
  transform: scale(1);
}


/* ============================================ */
/* QUESTION 4: CLOCK WITH MILLISECOND TIMER */
/* YOUR CODE STARTS HERE */
/* ============================================ */

/* TODO: .clock-container */
.clock-container {
  position: relative;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  border: 8px solid white;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  box-shadow: 0 10px 50px rgba(0, 0, 0, 0.3);
}

/* TODO: .clock-center */
.clock-center {
  position: absolute;
  width: 20px;
  height: 20px;
  background: white;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 10;
}

/* TODO: .clock-hand */
.clock-hand {
  position: absolute;
  left: 50%;
  bottom: 50%;
  transform-origin: center bottom;
  background: white;
  border-radius: 10px;
  z-index: 10;
}

/* TODO: .hour-hand */
.hour-hand {
  width: 8px;
  height: 80px;
  margin-left: -4px;
  box-shadow: rgba(0, 0, 0, 0.5) 0px 0px 5px;
  animation: rotate-hour-hand 120s linear infinite;
}

/* TODO: .minute-hand */
.minute-hand {
  width: 6px;
  height: 100px;
  margin-left: -3px;
  box-shadow: rgba(0, 0, 0, 0.5) 0px 0px 5px;
  animation: rotate-minute-hand 60s linear infinite;
}

/* TODO: .second-hand */
.second-hand {
  width: 4px;
  height: 120px;
  margin-left: -2px;
  background: #ff6b6b;
  box-shadow: rgba(0, 0, 0, 0.5) 0px 0px 5px;
  animation: rotate-second-hand 10s linear infinite;
}

/* TODO: .hour-marker */
.hour-marker {
  position: absolute;
  width: 4px;
  height: 20px;
  background: rgba(255, 255, 255, 0.8);
  left: 50%;
  top: 10px;
  margin-left: -2px;
  transform-origin: center 132px;
  border-radius: 2px;
}

/* TODO: .hour-marker:nth-child(1) through :nth-child(12) */
.hour-marker:nth-child(1) {
  transform: rotate(0deg);
}

.hour-marker:nth-child(2) {
  transform: rotate(30deg);
}

.hour-marker:nth-child(3) {
  transform: rotate(60deg);
}

.hour-marker:nth-child(4) {
  transform: rotate(90deg);
}

.hour-marker:nth-child(5) {
  transform: rotate(120deg);
}

.hour-marker:nth-child(6) {
  transform: rotate(150deg);
}

.hour-marker:nth-child(7) {
  transform: rotate(180deg);
}

.hour-marker:nth-child(8) {
  transform: rotate(210deg);
}

.hour-marker:nth-child(9) {
  transform: rotate(240deg);
}

.hour-marker:nth-child(10) {
  transform: rotate(270deg);
}

.hour-marker:nth-child(11) {
  transform: rotate(300deg);
}

.hour-marker:nth-child(12) {
  transform: rotate(330deg);
}

/* TODO: .millisecond-circle */
.millisecond-circle {
  position: absolute;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(66, 153, 225, 0.3);
  border: 2px solid rgba(255, 255, 255, 0.6);
  right: 25%;
  top: 50%;
  transform: translate(50%, -50%);
}

/* TODO: .millisecond-label */
.millisecond-label {
  position: absolute;
  top: 15px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 10px;
  color: white;
  font-weight: bold;
}

/* TODO: .millisecond-center */
.millisecond-center {
  position: absolute;
  width: 6px;
  height: 6px;
  background: white;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: rgba(0, 0, 0, 0.5) 0px 0px 5px;
  z-index: 5;
}

/* TODO: .millisecond-hand */
.millisecond-hand {
  position: absolute;
  width: 2px;
  height: 30px;
  background: yellow;
  left: 50%;
  bottom: 50%;
  margin-left: -1px;
  transform-origin: center bottom;
  border-radius: 2px;
  box-shadow: yellow 0 0 3px;
  animation: rotate-millisecond 1s linear infinite;
}

/* TODO: .minute-timer-circle */
.minute-timer-circle {
  position: absolute;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(159, 122, 234, 0.3);
  border: 2px solid rgba(255, 255, 255, 0.6);
  left: 50%;
  top: 75%;
  transform: translate(-50%, -50%);
}

/* TODO: .minute-timer-label */
.minute-timer-label {
  position: absolute;
  top: 15px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 10px;
  color: white;
  font-weight: bold;
}

/* TODO: .minute-timer-center */
.minute-timer-center {
  position: absolute;
  width: 6px;
  height: 6px;
  background: white;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: rgba(0, 0, 0, 0.5) 0px 0px 5px;
  z-index: 5;
}

/* TODO: .minute-timer-hand */
.minute-timer-hand {
  position: absolute;
  width: 2px;
  height: 30px;
  background: purple;
  left: 50%;
  bottom: 50%;
  margin-left: -1px;
  transform-origin: center bottom;
  border-radius: 2px;
  box-shadow: purple 0 0 3px;
  animation: rotate-minute-timer 30s linear infinite;
}

/* TODO: @keyframes rotate-hour-hand */
@keyframes rotate-hour-hand {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* TODO: @keyframes rotate-minute-hand */
@keyframes rotate-minute-hand {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* TODO: @keyframes rotate-second-hand */
@keyframes rotate-second-hand {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* TODO: @keyframes rotate-millisecond */
@keyframes rotate-millisecond {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* TODO: @keyframes rotate-minute-timer */
@keyframes rotate-minute-timer {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* YOUR CODE ENDS HERE */