body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

body.dark {
  background: #121212;
  color: #e0e0e0;
}
body.light {
  background: #f5f5f5;
  color: #222;
}

.container {
  max-width: 700px;
  margin: 60px auto;
  background: #1e1e1e;
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.4);
  text-align: center;
  position: relative;
  z-index: 1;
  transition: background 0.3s, color 0.3s;
}
body.light .container {
  background: #ffffff;
  color: #222;
}

h1 {
  margin-bottom: 25px;
  font-size: 2em;
  font-weight: bold;
}

.background .circle {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle at center, #ff7e5f, #feb47b);
  opacity: 0.2;
  animation: float 8s infinite ease-in-out;
}
.background .circle:nth-child(1) { width: 300px; height: 300px; top: -100px; left: -100px; }
.background .circle:nth-child(2) { width: 200px; height: 200px; bottom: -80px; right: -80px; animation-duration: 10s; }
.background .circle:nth-child(3) { width: 150px; height: 150px; top: 50%; left: 80%; transform: translate(-50%, -50%); animation-duration: 12s; }
@keyframes float { 0%{transform:translateY(0px)} 50%{transform:translateY(-20px)} 100%{transform:translateY(0px)} }

.file-upload-wrapper {
  position: relative;
  width: 300px;
  margin: 10px auto;
}
.file-upload-button {
  display: block;
  width: 100%;
  padding: 12px 25px;
  border-radius: 25px;
  border: none;
  background: linear-gradient(135deg, #ff7e5f, #feb47b);
  color: white;
  font-size: 1em;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.25);
  transition: 0.3s;
}
.file-upload-button:hover { background: linear-gradient(135deg, #feb47b, #ff7e5f); }
.file-upload-input { opacity: 0; position: absolute; left: 0; top: 0; width: 100%; height: 100%; cursor: pointer; }
#filename { margin-top: 8px; font-style: italic; color: #bbb; }

.action-btn {
  margin-top: 20px;
  padding: 12px 30px;
  border-radius: 25px;
  border: none;
  background: linear-gradient(135deg, #43cea2, #185a9d);
  color: white;
  font-size: 1em;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
  transition: 0.3s;
}
.action-btn:hover { background: linear-gradient(135deg, #185a9d, #43cea2); transform: translateY(-2px); }

.progress { width: 100%; background: #2c2c2c; border-radius: 10px; margin: 20px 0; height: 15px; overflow: hidden; }
.progress-bar { height: 100%; width: 0%; background: linear-gradient(135deg, #43cea2, #185a9d); transition: width 0.3s; }
body.light .progress { background: #ddd; }
body.light .progress-bar { background: linear-gradient(135deg, #43cea2, #185a9d); }

#output {
  display: none;
  text-align: left;
  padding: 15px;
  background: #2a2a2a;
  border-radius: 10px;
  max-height: 300px;
  overflow-y: auto;
  font-size: 0.9em;
  margin-top: 20px;
  color: #e0e0e0;
}
#output.show {
  display: block;
}

body.light #output { background: #f5f5f5; color: #222; }

a#download.download-btn {
  display: none;
  margin-top: 15px;
  padding: 12px 25px;
  border-radius: 25px;
  background: linear-gradient(135deg, #6a11cb, #2575fc);
  color: white !important;
  text-decoration: none !important;
  font-size: 1em;
  font-weight: 600;
  box-shadow: 0 6px 16px rgba(0,0,0,0.25);
  transition: transform 0.2s, opacity 0.3s;
  cursor: pointer;
  text-align: center;
  opacity: 0;
}
a#download.download-btn.show {
  display: inline-block;
  opacity: 1;
}
a#download.download-btn:hover { background: linear-gradient(135deg, #2575fc, #6a11cb); transform: translateY(-3px); }

.documentation {
  text-align: left;
  margin-top: 30px;
  padding: 20px;
  background: #1a1a1a;
  border-radius: 15px;
  color: #ddd;
}
body.light .documentation { background: #f0f0f0; color: #222; }
.documentation h2 { text-align: center; color: #fff; margin-bottom: 15px; }
body.light .documentation h2 { color: #222; }
.documentation ol li { margin-bottom: 10px; line-height: 1.5em; }
.documentation a { color: #43cea2; text-decoration: underline; }
.documentation a:hover { color: #2575fc; }

.theme-toggle-wrapper {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 8px;
}

.theme-switch {
  position: relative;
  display: inline-block;
  width: 3.5em;
  height: 2em;
}

.theme-switch input { 
  opacity: 0; 
  width: 0; 
  height: 0; 
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: #303136;
  transition: 0.4s;
  border-radius: 30px;
}

.slider::before {
  position: absolute;
  content: "";
  height: 1.4em;
  width: 1.4em;
  border-radius: 20px;
  bottom: 0.3em;
  left: 0.3em;
  background: #303136;
  box-shadow: inset -3px -2px 5px -2px #8983f7,
              inset -10px -5px 0 0 #a3dafb;
  transition: 0.4s;
}

.theme-switch input:checked + .slider {
  background-color: #f7ded7;
}

.theme-switch input:checked + .slider::before {
  transform: translateX(1.5em);
  background: linear-gradient(40deg, #ff0080, #ff8c00 70%);
  box-shadow: none;
}