body {
    font-family: Arial, sans-serif;
    background: #f4f4f9;
    margin: 0;
    padding: 0;
}
#toolbox {
    background: #e3e3e3;
    padding: 20px;
    width: 175px;
    float: left;
    height: 75vh;
    box-sizing: border-box;
}
@keyframes pulse-green {
    0% { box-shadow: 0 0 0 0 rgba(40, 167, 69, 0.7); background: #caffd0; }
    50% { box-shadow: 0 0 20px 10px rgba(40, 167, 69, 0.8); background: #7fff9b; }
    100% { box-shadow: 0 0 0 0 rgba(40, 167, 69, 0.7); background: #caffd0; }
}

.pulse-green {
    animation: pulse-green 0.7s infinite;
    border-color: #28a745 !important;
}

#toolbox h2 {
    margin-top: 0;
}
.draggable {
    background: #cce5ff;
    border: 1px solid #3399ff;
    padding: 10px;
    margin-bottom: 10px;
    cursor: grab;
    border-radius: 6px;
    text-align: center;
}
#puzzle-area {
    margin-left: 175px;
    margin-top: 0;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    box-sizing: border-box;
    padding: 20px;
    width: calc(85vw - 175px);
    height: 75vh;
    background: #f4f4f9;
    margin-bottom: 60px;
}

#puzzle-canvas-wrapper {
    width: 100%;
    height: 100%;
    flex: 1 1 auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

#puzzle-canvas {
    width: 100%;
    height: 100%;
    display: block;
    border: 3px solid #3399ff;
    background: #fff;
    max-width: 100%;
    max-height: 100%;
}

#puzzle-canvas-wrapper {
    width: 100%;
    height: 100%;
    flex: 1 1 auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

#puzzle-canvas {
    width: 100%;
    height: 100%;
    display: block;
    border: 3px solid #3399ff;
    background: #fff;
    max-width: 100%;
    height: auto;
}
.dropzone {
    background: #fff;
    border: 2px dashed #aaa;
    border-radius: 6px;
    min-height: 50px;
    margin-bottom: 16px;
    padding: 10px;
    text-align: center;
    transition: background 0.2s;
}
.dropzone.active {
    background: #d4edda;
    border-color: #28a745;
}

.page-footer {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100vw;
  z-index: 1000;
  text-align: center;
  font-size: 0.8em;
  color: #1a1a1a;
  background: #e6f2fb;
  padding: 4px 0 2px 0;
  border-top: 2px solid #b3d9f7;
}
.footer-link {
  color: #0074D9;
  font-weight: bold;
  text-decoration: underline;
}

.main-title {
  text-align: center;
  display: block;
  margin: 24px auto 12px auto;
}