/* CSS Variables for consistent theming */
:root {
  --primary-color: #1e40af;
  --secondary-color: #156bac;
  --accent-color: #8180c6;
  --background-color: #3e5382;
  --card-bg: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-light: #64748b;
  --border-radius: 4px;
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.15);
  --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.2);
  --transition-fast: 0.2s ease;
  --transition-medium: 0.4s ease;
  --transition-slow: 0.6s ease;
  --max-width: 1400px;
  --container-padding: 2rem;
  --grid-gap: 2rem;
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background: url(../i/banner.jpg) no-repeat top center var(--background-color);
  background-size: 100%;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

ul,
li {
  list-style: none;
}

.pc_box {
  display: block;
}

.wap_box {
  display: none;
}

.editor_notes {
  position: relative;
  max-width: var(--max-width);
  margin: 26% auto 0;
  padding: 2.5rem 3rem;
  background: rgba(7, 93, 163, 0.85);
  box-shadow: var(--shadow-heavy);
  border-radius: var(--border-radius);
  text-align: left;
  color: #fff;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.editor_notes h3 {
  font-size: 28px;
  line-height: 36px;
  margin-bottom: 1rem;
}

.editor_notes p {
  font-size: 23px;
  line-height: 34px;
}

/* Main container */
.neir {
  max-width: var(--max-width);
  margin: 0 auto;
  background: var(--card-bg);
  box-shadow: var(--shadow-heavy);
  border-radius: var(--border-radius);
  overflow: hidden;
  margin-top: 2rem;
  margin-bottom: 2rem;
  position: relative;
}

/* Tips section */
.bu {
  padding: var(--container-padding);
  border-bottom: 1px solid #e9ecef;
}

.bu p {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-secondary);
  text-align: justify;
  max-width: 100%;
  margin: 0 auto;
  position: relative;
  padding-left: 1rem;
  /* border-left: 4px solid var(--primary-color); */
}

/* Content section */
.M_data {
  padding: var(--container-padding);
}

/* Card grid */
.data_list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
  gap: var(--grid-gap);
  /* padding: 1rem 0; */
}

/* Individual cards */
.data_li {
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 2.6;
  /* aspect-ratio: 1 / 1; */
  position: relative;
  perspective: 1000px;
  cursor: pointer;
  transition: var(--transition-medium);
}

/* 卡片悬停效果已通过JavaScript控制 */

.rotate-box {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform var(--transition-slow);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-medium);
}

/* 桌面端hover效果 */
@media (min-width: 769px) {
  .data_li:hover .rotate-box {
    transform: rotateY(180deg);
  }
}

/* 键盘导航和移动端点击效果 */
.data_li.keyboard-hover .card-inner,
.data_li.mobile-flipped .rotate-box {
  transform: rotateY(180deg);
}

.data_mob,
.data_con {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--border-radius);
  overflow: hidden;
}

.data_mob {
  background: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  transform: rotateY(0deg);
}

.data_mob img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition-medium);
}

/* 移除图片缩放效果 */

.data_con {
  background: linear-gradient(135deg, var(--secondary-color) 0%, var(--accent-color) 100%);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 600;
  transform: rotateY(180deg);
  text-align: center;
  padding: 2rem;
}

.data_con p {
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.data_con a {
  color: inherit;
  text-decoration: none;
  display: block;
  width: 100%;
  /* height: 100%; */
  transition: var(--transition-fast);
  border-radius: 8px;
  padding: 0.5rem;
  border: 2px solid transparent;
}

.data_con a:hover,
.data_con a:focus {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.3);
  transform: scale(1.05);
  outline: none;
}

.data_con a:active {
  transform: scale(0.98);
  background: rgba(255, 255, 255, 0.2);
}

/* Footer */
.footer-zx {
  background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
  padding: 2rem 0;
  color: #ecf0f1;
  text-align: center;
  font-size: 0.9rem;
  margin-top: auto;
}

/* Loading animation for images */
.data_mob img {
  opacity: 0;
  animation: fadeIn 0.6s ease forwards;
}

@-webkit-keyframes fadeIn {
  to {
    opacity: 1;
  }
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

/* Card entrance animations */
.data_li.fade-in {
  opacity: 0;
  transform: translateY(30px);
  animation: cardFadeIn 0.6s ease forwards;
}

@-webkit-keyframes cardFadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes cardFadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Keyboard navigation styles */
.keyboard-navigation .card:focus {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
  box-shadow: 0 0 0 6px rgba(30, 64, 175, 0.2);
}

/* High contrast mode */
.high-contrast {
  --primary-color: #000000;
  --secondary-color: #ffffff;
  --text-primary: #000000;
  --background-color: #ffffff;
}

/* Page hidden state optimizations */
.page-hidden * {
  animation-play-state: paused !important;
  transition: none !important;
}

/* Accessibility improvements */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.skip-link:focus {
  position: absolute !important;
  left: 8px !important;
  top: 8px !important;
  z-index: 9999 !important;
  padding: 8px 16px !important;
  background: var(--primary-color) !important;
  color: white !important;
  text-decoration: none !important;
  border-radius: 4px !important;
  font-weight: 600 !important;
}

.card-inner:focus-within {
  transform: rotateY(180deg);
}

.card:focus-visible .rotate-box {
  transform: rotateY(180deg);
}

/* Mobile-first responsive design */
@media (max-width: 768px) {
  :root {
    --container-padding: 1rem;
    --grid-gap: 1rem;
  }

  .pc_box {
    display: none;
  }

  .wap_box {
    display: block;
  }

  .editor_notes {
    margin-left: 1rem;
    margin-right: 1rem;
    padding: 1.5rem 2rem;
  }

  .editor_notes h3 {
    font-size: 24px;
    line-height: 32px;
  }

  .editor_notes p {
    font-size: 18px;
    line-height: 26px;
  }

  .neir {
    margin: 1rem;
    border-radius: 8px;
  }

  .bu p {
    font-size: 1rem;
    line-height: 1.6;
    padding-left: 0.75rem;
    border-left-width: 3px;
  }

  .data_list {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .data_li {
    max-width: 100%;
  }

  .data_con {
    font-size: 1.25rem;
    padding: 1.5rem;
  }

  .footer-zx {
    padding: 1.5rem 1rem;
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  :root {
    --container-padding: 0.75rem;
  }

  .editor_notes {
    padding: 1rem 1.5rem;
  }

  .editor_notes h3 {
    font-size: 20px;
    line-height: 28px;
    margin-bottom: 0.75rem;
  }

  .editor_notes p {
    font-size: 16px;
    line-height: 24px;
  }

  .bu p {
    font-size: 0.9rem;
    text-align: left;
  }

  .data_con {
    font-size: 1.1rem;
    padding: 1rem;
  }
}

/* Tablet styles */
@media (min-width: 769px) and (max-width: 1024px) {
  .editor_notes {
    margin-left: 1.5rem;
    margin-right: 1.5rem;
    padding: 1.75rem 2.5rem;
  }

  .editor_notes h3 {
    font-size: 26px;
    line-height: 34px;
  }

  .editor_notes p {
    font-size: 19px;
    line-height: 27px;
  }

  .data_list {
    grid-template-columns: repeat(2, 1fr);
  }

  .neir {
    margin: 1.5rem;
  }
}

/* Large desktop styles */
@media (min-width: 1400px) {
  .data_list {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* High DPI displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .data_mob img {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
  }
}