* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f1f2f3;
}

.container {
  box-sizing: border-box;
  max-width: 1560px;
  min-width: 1240px;
  width: 100%;
  margin: 20px auto;
  color: #333;
  line-height: 1.6;
}

.container *{
  box-sizing: border-box;
}

header {
  margin-bottom: 25px;
  text-align: center;
}

header h1 {
  font-size: 2.1rem;
  margin-bottom: 5px;
}

header p{
  font-size: 1rem;
  opacity: 0.9;
  margin: 0 auto;
}

.tool-container {
  display: flex;
  flex-direction: column;
  min-height: 600px;
}

.input-section,
.preview-section {
  padding: 20px;
  flex: 1;
  background: #fff;
  border-radius: 12px;
  margin-bottom: 25px;
}

.section-title {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
  font-size: 1.3rem;
  color: #2c3e50;
}

.editor-container {
  border: 1px solid #ddd;
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 20px;
  height: 450px;
}

#html-input {
  width: 100%;
  height: 100%;
  padding: 20px;
  font-family: 'Courier New', monospace;
  font-size: 15px;
  border: none;
  resize: none;
  background: #fff;
  line-height: 1.6;
}

#html-input:focus {
  outline: none;
  background: #fffff8;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.btn {
  padding: 14px 38px;
  border: none;
  border-radius: 6px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  color: white;
  box-shadow: 0 4px 6px rgba(50, 50, 93, 0.11), 0 1px 3px rgba(0, 0, 0, 0.08);
}

.btn-convert {
  background: linear-gradient(to right, #00b09b, #96c93d);
}

.btn-file {
  background: linear-gradient(to right, #2193b0, #6dd5ed);
}

.btn-download {
  background: linear-gradient(to right, #ff512f, #f09819);
}

.btn-example {
  background: linear-gradient(to right, #614385, #516395);
}

.btn-clear {
  background: linear-gradient(to right, #ff416c, #ff4b2b);
}

.btn:hover {
  box-shadow: 0 7px 14px rgba(50, 50, 93, 0.1), 0 3px 6px rgba(0, 0, 0, 0.08);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.preview-container {
  height: 500px;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: white;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05);
}

.preview-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: #aaa;
  text-align: center;
}

.preview-placeholder span {
  font-size: 5rem;
  margin-bottom: 20px;
}

.preview-placeholder p {
  font-size: 1.2rem;
  max-width: 80%;
  line-height: 1.6;
}

.features {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 25px;
}

.features-title {
  text-align: center;
  margin-bottom: 25px;
  font-size: 2rem;
  color: #2c3e50;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 0 auto;
}

.feature-card {
  background: white;
  border-radius: 10px;
  padding: 20px;
  text-align: center;
  border: 1px solid #eee;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease;
}


.feature-icon {
  font-size: 3.5rem;
  margin-bottom: 20px;
}

.feature-title {
  font-size: 1.5rem;
  margin-bottom: 15px;
  color: #3498db;
}

.feature-desc {
  color: #666;
  font-size: 1rem;
  line-height: 1.6;
}

footer {
  text-align: center;
  font-size: 1rem;
  color: #8a8a8a;
}

#file-input {
  display: none;
}

.notice-container {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
}

.notice {
  background: rgba(0, 0, 0, 0.85);
  color: white;
  padding: 16px 32px;
  border-radius: 50px;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 12px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.notice.show {
  opacity: 1;
}