/* 每日大赛公益行动挑战 - 主样式表 */
:root {
  --primary: #0EA5E9;
  --secondary: #22C55E;
  --bg: #ECFEFF;
  --card: #FFFFFF;
  --accent: #F59E0B;
  --text: #064E3B;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0,0,0,0.12);
  --font-title: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: "JetBrains Mono", "Courier New", monospace;
  --transition: all 0.3s ease;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--text);
  background-color: var(--bg);
  line-height: 1.8;
  min-height: 100vh;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--secondary);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-title);
  font-weight: 700;
  line-height: 1.4;
  color: var(--text);
}

h1 { font-size: 2.4rem; margin-bottom: 1rem; }
h2 { font-size: 1.8rem; margin-bottom: 0.8rem; }
h3 { font-size: 1.4rem; margin-bottom: 0.6rem; }
h4 { font-size: 1.2rem; margin-bottom: 0.5rem; }

p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 导航栏 */
.site-header {
  background: var(--card);
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
  position: sticky;
  top: 0;
  z-index: 1000;
  padding: 0.8rem 0;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.site-logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.site-logo svg {
  width: 32px;
  height: 32px;
  fill: var(--secondary);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 1.5rem;
  align-items: center;
}

.nav-menu a {
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0;
  border-bottom: 2px solid transparent;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
}

/* Hero区域 */
.hero-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: #fff;
  padding: 4rem 0 3rem;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: rgba(255,255,255,0.05);
  border-radius: 50%;
  animation: heroFloat 8s ease-in-out infinite;
}

@keyframes heroFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(5deg); }
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 2.8rem;
  color: #fff;
  margin-bottom: 1rem;
  text-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.hero-subtitle {
  font-size: 1.2rem;
  opacity: 0.95;
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.hero-stats {
  display: flex;
  gap: 2rem;
  margin-top: 1.5rem;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 800;
  display: block;
}

.stat-label {
  font-size: 0.85rem;
  opacity: 0.9;
}

.hero-right {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.8rem 1.8rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 15px rgba(245,158,11,0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(245,158,11,0.4);
  color: #fff;
  text-decoration: none;
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.8);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.15);
  color: #fff;
  text-decoration: none;
}

/* 卡片 */
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

/* 任务卡 */
.task-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.8rem;
  border-left: 4px solid var(--secondary);
  transition: var(--transition);
}

.task-card:hover {
  transform: translateY(-3px);
  border-left-color: var(--primary);
}

.task-card .task-tag {
  display: inline-block;
  background: rgba(34,197,94,0.1);
  color: var(--secondary);
  padding: 0.2rem 0.8rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
}

.task-card .task-title {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

.task-card .task-desc {
  color: #666;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

/* 里程碑 */
.milestone-track {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2rem 0;
  position: relative;
}

.milestone-track::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 5%;
  right: 5%;
  height: 3px;
  background: linear-gradient(to right, var(--secondary), var(--primary));
  transform: translateY(-50%);
  border-radius: 2px;
}

.milestone-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  z-index: 1;
}

.milestone-icon {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--card);
  border: 3px solid var(--secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
  transition: var(--transition);
}

.milestone-node.active .milestone-icon {
  background: var(--secondary);
  color: #fff;
  box-shadow: 0 0 20px rgba(34,197,94,0.4);
  animation: milestoneGlow 2s ease-in-out infinite;
}

@keyframes milestoneGlow {
  0%, 100% { box-shadow: 0 0 20px rgba(34,197,94,0.4); }
  50% { box-shadow: 0 0 30px rgba(34,197,94,0.6); }
}

.milestone-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text);
  text-align: center;
}

/* 证书样式 */
.certificate-card {
  background: linear-gradient(135deg, #fefce8 0%, #fff 50%, #ecfdf5 100%);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  padding: 2.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.certificate-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(to right, var(--accent), var(--secondary), var(--primary));
}

.certificate-title {
  font-size: 1.6rem;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.certificate-body {
  font-size: 1rem;
  color: var(--text);
  margin: 1rem 0;
}

.certificate-seal {
  width: 60px;
  height: 60px;
  margin: 1rem auto;
  opacity: 0;
  animation: certAppear 1s ease forwards;
}

@keyframes certAppear {
  to { opacity: 1; transform: scale(1); }
  from { opacity: 0; transform: scale(0.8); }
}

/* 影响力计数器 */
.impact-counter {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  padding: 2rem 0;
}

.impact-item {
  background: var(--card);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  box-shadow: var(--shadow);
}

.impact-number {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary);
  display: block;
  margin-bottom: 0.3rem;
}

.impact-label {
  font-size: 0.9rem;
  color: #666;
}

/* 志愿者地图 */
.volunteer-map {
  background: var(--card);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  position: relative;
}

.map-dots {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.map-dot {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  border-radius: 8px;
  background: rgba(14,165,233,0.05);
}

.map-dot::before {
  content: '';
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--primary);
  animation: dotPulse 2s ease-in-out infinite;
}

@keyframes dotPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.5); opacity: 0.5; }
}

/* 栏目区块 */
.section {
  padding: 4rem 0;
}

.section-alt {
  background: rgba(255,255,255,0.6);
}

.section-title {
  text-align: center;
  margin-bottom: 2.5rem;
}

.section-title h2 {
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(to right, var(--primary), var(--secondary));
  border-radius: 2px;
}

.section-title p {
  color: #666;
  margin-top: 1rem;
  font-size: 1rem;
}

/* 网格布局 */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

/* 面包屑 */
.breadcrumb {
  padding: 1rem 0;
  font-size: 0.85rem;
  color: #666;
}

.breadcrumb a {
  color: var(--primary);
}

.breadcrumb span {
  margin: 0 0.5rem;
  color: #999;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--card);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  overflow: hidden;
}

.faq-question {
  padding: 1.2rem 1.5rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
}

.faq-question:hover {
  background: rgba(14,165,233,0.03);
}

.faq-question::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--primary);
  transition: var(--transition);
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 1.5rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
  padding: 0 1.5rem 1.2rem;
  max-height: 500px;
}

/* 页脚 */
.site-footer {
  background: var(--text);
  color: rgba(255,255,255,0.85);
  padding: 3rem 0 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-brand {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.8rem;
}

.footer-desc {
  font-size: 0.9rem;
  opacity: 0.8;
  line-height: 1.7;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  opacity: 0.7;
}

/* 搜索框 */
.search-box {
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 1rem 1.5rem;
  padding-right: 4rem;
  border: 2px solid rgba(14,165,233,0.2);
  border-radius: var(--radius);
  font-size: 1rem;
  outline: none;
  transition: var(--transition);
  background: var(--card);
}

.search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 20px rgba(14,165,233,0.1);
}

.search-box button {
  position: absolute;
  right: 0.5rem;
  top: 50%;
  transform: translateY(-50%);
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 0.6rem 1rem;
  border-radius: 10px;
  cursor: pointer;
  transition: var(--transition);
}

.search-box button:hover {
  background: var(--secondary);
}

/* 搜索结果 */
.search-results {
  margin-top: 2rem;
}

.search-result-item {
  background: var(--card);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.search-result-item h3 {
  color: var(--primary);
  margin-bottom: 0.3rem;
}

.search-result-item .result-path {
  font-size: 0.8rem;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

.search-result-item .result-desc {
  font-size: 0.9rem;
  color: #666;
}

.search-result-item .result-tag {
  display: inline-block;
  background: rgba(14,165,233,0.1);
  color: var(--primary);
  padding: 0.15rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  margin-top: 0.5rem;
}

/* 志愿者故事卡 */
.story-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.story-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  flex-shrink: 0;
}

.story-content {
  flex: 1;
}

.story-name {
  font-weight: 600;
  margin-bottom: 0.3rem;
}

.story-text {
  font-size: 0.9rem;
  color: #666;
  line-height: 1.7;
}

/* 页面头部 */
.page-header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: #fff;
  padding: 3rem 0 2rem;
  text-align: center;
}

.page-header h1 {
  color: #fff;
  font-size: 2.2rem;
}

.page-header p {
  opacity: 0.9;
  max-width: 600px;
  margin: 0.5rem auto 0;
}

/* 内容区 */
.content-section {
  padding: 3rem 0;
}

.content-body {
  max-width: 800px;
  margin: 0 auto;
}

.content-body h2 {
  margin-top: 2rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid rgba(14,165,233,0.1);
}

.content-body ul, .content-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.content-body li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

/* 相关链接 */
.related-links {
  background: rgba(14,165,233,0.03);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-top: 2rem;
}

.related-links h3 {
  margin-bottom: 1rem;
  color: var(--primary);
}

.related-links ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.related-links li a {
  display: inline-block;
  padding: 0.4rem 1rem;
  background: var(--card);
  border-radius: 20px;
  font-size: 0.85rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

/* APP下载页 */
.app-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  padding: 3rem 0;
}

.app-features {
  list-style: none;
}

.app-features li {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 0.8rem 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.app-features li::before {
  content: '✓';
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--secondary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  flex-shrink: 0;
}

/* 响应式 */
@media (max-width: 768px) {
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.4rem; }
  
  .nav-toggle { display: block; }
  
  .nav-menu {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 0;
    padding: 1rem 0;
  }
  
  .nav-menu.active {
    display: flex;
  }
  
  .nav-menu li {
    width: 100%;
  }
  
  .nav-menu a {
    display: block;
    padding: 0.8rem 0;
    border-bottom: 1px solid rgba(0,0,0,0.05);
  }
  
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-title { font-size: 2rem; }
  
  .hero-stats {
    justify-content: center;
  }
  
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .milestone-track {
    flex-direction: column;
    gap: 1.5rem;
  }
  
  .milestone-track::before {
    top: 5%;
    bottom: 5%;
    left: 50%;
    right: auto;
    width: 3px;
    height: 90%;
    transform: translateX(-50%);
  }
  
  .app-showcase {
    grid-template-columns: 1fr;
  }
  
  .impact-counter {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .story-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container { padding: 0 1rem; }
  .hero-section { padding: 2.5rem 0 2rem; }
  .section { padding: 2.5rem 0; }
  .impact-counter { grid-template-columns: 1fr; }
}

/* 动画 */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 隐私说明块 */
.privacy-notice {
  background: rgba(34,197,94,0.05);
  border: 1px solid rgba(34,197,94,0.2);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

.privacy-notice h4 {
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

/* 404页面 */
.error-page {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 3rem;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 6rem;
  font-weight: 800;
  color: var(--primary);
  opacity: 0.3;
}