:root {
  --bg-color: #f4f4f0;
  --panel-bg: #ffffff;
  --text-color: #000000;
  --border-color: #000000;
  --primary-color: #ffe800;
  --secondary-color: #ff5252;
  --accent-color: #00d4ff;
  --hover-offset: 3px;
  --shadow-offset: 8px;
}

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

body {
  font-family: 'Space Grotesk', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 2rem;
  background-image: radial-gradient(var(--border-color) 1px, transparent 1px);
  background-size: 24px 24px;
}

.container {
  width: 100%;
  max-width: 700px;
  background-color: var(--panel-bg);
  border: 4px solid var(--border-color);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0px var(--border-color);
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  position: relative;
}

.container::after {
  content: "";
  position: absolute;
  top: -15px;
  right: -15px;
  width: 30px;
  height: 30px;
  background-color: var(--accent-color);
  border: 4px solid var(--border-color);
  z-index: 10;
}

header h1 {
  font-size: 3rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -2px;
  border-bottom: 5px solid var(--border-color);
  padding-bottom: 0.5rem;
}

h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  text-transform: uppercase;
  font-weight: 700;
}

.upload-section .drop-zone {
  border: 4px dashed var(--border-color);
  background-color: #f9f9f9;
  padding: 3.5rem 2rem;
  text-align: center;
  cursor: pointer;
  position: relative;
  transition: all 0.2s ease;
  box-shadow: inset 4px 4px 0px rgba(0,0,0,0.05);
}

.upload-section .drop-zone:hover, .upload-section .drop-zone.dragover {
  background-color: var(--accent-color);
  border-style: solid;
}

.drop-zone p {
  font-size: 1.5rem;
  font-weight: 700;
}

.drop-zone .subtitle {
  font-size: 1.1rem;
  margin-top: 0.5rem;
  font-weight: 600;
  background-color: var(--panel-bg);
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border: 2px solid var(--border-color);
  transform: rotate(-2deg);
}

.drop-zone input[type="file"] {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.files-section {
  background-color: #fff;
  border: 4px solid var(--border-color);
  padding: 1.5rem;
  box-shadow: 4px 4px 0px var(--border-color);
}

.file-list {
  list-style: none;
  max-height: 200px;
  overflow-y: auto;
  border-top: 4px solid var(--border-color);
  margin-top: 1rem;
  padding-top: 1rem;
}

.file-list li {
  padding: 0.75rem 0;
  border-bottom: 2px solid var(--border-color);
  font-weight: 600;
  font-size: 1.1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.file-list li:last-child {
  border-bottom: none;
}

.empty-message {
  color: #555;
  font-weight: 600 !important;
  font-style: italic;
}

.remove-btn {
  background-color: var(--secondary-color);
  color: #fff;
  border: 2px solid var(--border-color);
  width: 32px;
  height: 32px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 2px 2px 0px var(--border-color);
  transition: transform 0.1s;
}

.remove-btn:active {
  transform: translate(2px, 2px);
  box-shadow: 0px 0px 0px var(--border-color);
}

.controls-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background-color: var(--bg-color);
  padding: 1.5rem;
  border: 4px solid var(--border-color);
  box-shadow: 4px 4px 0px var(--border-color);
}

.control-group label {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  display: block;
  text-transform: uppercase;
}

.slider-container {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 16px;
  background: var(--panel-bg);
  border: 3px solid var(--border-color);
  outline: none;
  border-radius: 0;
  box-shadow: inset 2px 2px 0px rgba(0,0,0,0.1);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 24px;
  height: 36px;
  background: var(--primary-color);
  border: 3px solid var(--border-color);
  cursor: pointer;
  box-shadow: 2px 2px 0px var(--border-color);
}

#spacing-value {
  font-weight: 700;
  font-size: 1.25rem;
  min-width: 90px;
  text-align: center;
  border: 4px solid var(--border-color);
  padding: 0.5rem 0.75rem;
  background-color: var(--primary-color);
  box-shadow: 4px 4px 0px var(--border-color);
  transform: rotate(2deg);
}

.actions-section {
  display: flex;
  gap: 1.5rem;
  margin-top: 1rem;
}

.btn {
  font-family: inherit;
  font-size: 1.25rem;
  font-weight: 700;
  padding: 1.25rem 1rem;
  border: 4px solid var(--border-color);
  cursor: pointer;
  text-transform: uppercase;
  transition: transform 0.1s, box-shadow 0.1s;
  flex: 1;
}

.primary-btn {
  background-color: var(--primary-color);
  box-shadow: 6px 6px 0px var(--border-color);
}

.secondary-btn {
  background-color: var(--secondary-color);
  color: #fff;
  box-shadow: 6px 6px 0px var(--border-color);
}

.btn:active:not(:disabled) {
  transform: translate(var(--hover-offset), var(--hover-offset));
  box-shadow: calc(6px - var(--hover-offset)) calc(6px - var(--hover-offset)) 0px var(--border-color);
}

.btn:disabled {
  background-color: #dddddd;
  color: #888888;
  cursor: not-allowed;
  transform: none;
  box-shadow: 6px 6px 0px var(--border-color);
}

/* Custom scrollbar for file list */
.file-list::-webkit-scrollbar {
  width: 12px;
}
.file-list::-webkit-scrollbar-track {
  background: var(--panel-bg);
  border-left: 2px solid var(--border-color);
}
.file-list::-webkit-scrollbar-thumb {
  background-color: var(--border-color);
}