/* --- Global Reset & Basic Styles --- */
:root {
  --primary-color: #00a08a;
  --dark-text: #333;
  --light-text: #666;
  --bg-light-gray: #f8f9fa;
}

/* Animation styles removed */

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

html,
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    sans-serif;
  color: var(--dark-text);
  background-color: #fff;
  line-height: 1.8;
  overflow-x: hidden;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

section {
  padding: 10px 0;
  position: relative;
}

h2 {
  font-size: 36px;
  color: var(--dark-text);
  text-align: center;
  margin-bottom: 20px;
  font-weight: 500;
}

h3 {
  font-size: 24px;
  color: var(--primary-color);
  margin-bottom: 15px;
  font-weight: 500;
}

p {
  font-size: 18px;
  color: var(--light-text);
  margin-bottom: 1em;
  line-height: 1.8;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Header styles removed - no longer needed */

/* Hero section styles removed - no longer needed */

/* --- Feature Sections --- */
.feature-section .container {
  display: flex;
  align-items: flex-start;
  gap: 60px;
}
.feature-text,
.feature-image {
  flex: 1;
}
.feature-section.reverse .container {
  flex-direction: row-reverse;
}
.feature-text {
  font-size: 20px; /* 增加到20px，变化更明显 */
  line-height: 1.7; /* 稍微紧凑的行高 */
  font-weight: 400; /* 稍微加粗 */
}

.feature-text p {
  margin-bottom: 1.8em; /* 增加段落间距 */
  letter-spacing: 0.5px; /* 增加字母间距 */
}
.feature-text h3 {
  margin-bottom: 30px;
  letter-spacing: 0.5px;
}

/* Apply left-align to headings within feature sections */
.feature-section h2,
.feature-section h3 {
  text-align: left;
}

#platycladus {
  padding-top: 100px;
}
#tdn-tech {
  background-color: var(--bg-light-gray);
}

/* --- Section: Formula & R&D (MODIFIED) --- */
#formula-rd h2,
#formula-rd h3 {
  font-size: 32px;
  margin-bottom: 15px;
} /* Reset heading styles */
.formula-highlights {
  color: var(--primary-color);
  font-weight: bold;
}
.rd-team {
  margin-top: 40px;
} /* Adjusted margin */

/* --- Section: Rigor & Quality (MODIFIED) --- */
#quality {
  background-color: var(--bg-light-gray);
}
#quality h2 {
  font-size: 32px;
  margin-bottom: 15px;
} /* Reset heading styles */

/* --- Section: Testing --- */
#testing {
  text-align: center;
}
#testing > .container > p {
  margin-bottom: 50px;
}
.report-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}
.report-gallery img {
  border: 1px solid #eee;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s, box-shadow 0.3s;
}
.report-gallery img:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

/* --- Section: Instructions --- */
#instructions {
  background-color: var(--bg-light-gray);
}
.steps-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}
.step-item {
  background-color: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.07);
  text-align: center;
  width: 100%;
  max-width: 250px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.step-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.step-icon-wrapper {
  background-color: #f0f0f0;
  border-radius: 50%;
  width: 120px;
  height: 120px;
  margin: 0 auto 15px auto;
  display: flex;
  justify-content: center;
  align-items: center;
}
.step-icon-wrapper img {
  width: 60%;
}
.step-item .step-label {
  font-size: 18px;
  font-weight: bold;
  color: #ccc;
  margin-bottom: 5px;
}
.step-item .step-desc {
  font-size: 14px;
  color: var(--light-text);
  line-height: 1.5;
}
.step-item:not(:last-child)::after {
  content: "↓";
  display: block;
  font-size: 30px;
  margin-top: 20px;
  color: var(--primary-color);
}
.step-arrow {
  display: none;
}

/* Footer styles removed - no longer needed */

/* --- Responsive Styles --- */
@media (max-width: 991px) {
  h2 {
    font-size: 30px;
  }
  .feature-text {
    font-size: 17px;
    line-height: 1.85;
  }
  .feature-text p {
    margin-bottom: 1.3em;
  }
  /* Removed hero and navigation responsive styles */
}

@media (max-width: 767px) {
  section {
    padding: 50px 0;
  }
  /* Removed hero responsive styles */
  .feature-section .container,
  .feature-section.reverse .container {
    flex-direction: column;
    gap: 40px;
  }
  .feature-section h2,
  .feature-section h3 {
    text-align: center;
  }
  .feature-text {
    text-align: center;
    font-size: 16px;
    line-height: 1.8;
  }
  .feature-text p {
    text-align: justify;
    margin-bottom: 1.2em;
    letter-spacing: 0.2px;
  }
  .feature-text h3 {
    font-size: 22px;
    margin-bottom: 16px;
  }
  /* Removed footer responsive styles */
}

@media (min-width: 992px) {
  .step-item:not(:last-child)::after {
    display: none;
  }
  .step-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
    color: var(--primary-color);
  }
  .step-arrow.reverse {
    transform: scaleX(-1);
  }
  .steps-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr auto 1fr;
    grid-template-rows: auto 60px auto;
    gap: 20px 30px;
    align-items: stretch;
    grid-template-areas: "step1 arrow12 step2 arrow23 step3" ". . . . arrow34" "step6 arrow56 step5 arrow45 step4";
  }
  .step-item {
    max-width: none;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
  }
  #step1 {
    grid-area: step1;
  }
  #step2 {
    grid-area: step2;
  }
  #step3 {
    grid-area: step3;
  }
  #step4 {
    grid-area: step4;
  }
  #step5 {
    grid-area: step5;
  }
  #step6 {
    grid-area: step6;
  }
  #arrow12 {
    grid-area: arrow12;
  }
  #arrow23 {
    grid-area: arrow23;
  }
  #arrow34 {
    grid-area: arrow34;
  }
  #arrow45 {
    grid-area: arrow45;
  }
  #arrow56 {
    grid-area: arrow56;
  }
}