body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #121212;
  color: #eee;
  margin: 0; 
  padding: 0;
}

#input-area {
  background: #1a1a1a;
  padding: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  box-shadow: 0 0 20px #ccff00aa;
  border-bottom: 2px solid #a8e500;
}

#input-area input, #input-area button {
  font-size: 16px;
  padding: 10px 14px;
  border-radius: 8px;
  border: none;
}

#input-area input {
  flex: 1;
  min-width: 150px;
  background: #2a2a2a;
  color: #fff;
}

#input-area button {
  background:  #a0e627;
  color: #000;
  cursor: pointer;
  transition: transform 0.2s;
}

#input-area button:hover {
  transform: scale(1.05);
}

#tasks-list {
  background: #1e1e1e;
  color: #eee;
  padding: 20px;
  width: 600px;
  max-width: 50%;
  margin: 40px 20px;
  border-radius: 12px;
  box-shadow: 0 0 15px #22e5ff;
  display: flex;
  flex-direction: column;
  justify-self: center;
}

.task-item {
  background: #2c2c2c;
  margin: 10px 0;
  padding: 10px;
  border-radius: 10px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.task-prereq-list {
  background: #3a3a3a;
  margin-top: 5px;
  border-radius: 6px;
  padding: 5px 10px;
}

.prereq-item {
  display: inline-block;
  background: #0059bf;
  padding: 2px 8px;
  border-radius: 12px;
  margin-right: 6px;
  cursor: pointer;
  position: relative;
  transition: background 0.2s;
}

.prereq-item:hover {
  background: #0091e5;
}

.prereq-remove {
  position: absolute;
  top: -6px;
  right: -6px;
  background: #ff5252;
  border-radius: 50%;
  width: 16px;
  height: 16px;
  text-align: center;
  font-weight: bold;
  color: white;
  font-size: 12px;
  line-height: 14px;
  cursor: pointer;
  user-select: none;
}

#start-btn {
  background: #22e5ff !important;
  padding: 12px 24px;
  border-radius: 10px;
  border: none;
  transition: transform 0.2s;
}

#start-btn:hover {
  transform: scale(1.05);
}

svg {
  background: #1e1e1e;
  border-radius: 10px;
  margin: 20px auto;
  display: block;
  box-shadow: 0 0 30px #aeff00aa;
}

.node rect {
  fill: #009688;
  stroke: #004d40;
  stroke-width: 2px;
  rx: 12px;
  ry: 12px;
}

.node text {
  fill: #e0f7fa;
  font-weight: 600;
  font-size: 14px;
  pointer-events: none;
}

.link {
  fill: none;
  stroke: #00bfa5;
  stroke-width: 3px;
}

.tooltip {
  position: absolute;
  background: #333;
  padding: 10px 14px;
  border-radius: 10px;
  color: #eee;
  pointer-events: none;
  font-size: 14px;
  box-shadow: 0 0 10px #ff5722aa;
  user-select: none;
}

.edit-btn, .delete-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 18px;
  padding: 8px;
  margin-left: 4px;
  border-radius: 8px;
  transition: background 0.3s;
}

.edit-btn {
  color: #4caf50;
}
.edit-btn:hover {
  background: #2e7d32aa;
}

.delete-btn {
  color: #f44336;
}
.delete-btn:hover {
  background: #c62828aa;
}

select {
  background-color: #1e1e2f;
  color: #ffffff;
  border: 1px solid #444;
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 16px;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  cursor: pointer;
  transition: border 0.3s, box-shadow 0.3s;
}

select:focus {
  outline: none;
  border-color: #6c63ff;
  box-shadow: 0 0 5px #6c63ff99;
}