/* ====================================================
   🌟 当人类群星闪耀时 - 优化版主页CSS
   专为提升转化率与用户体验设计
   版本: 2.0 | 日期: 2023-10-15
==================================================== */


/* ====================
   1. 基础重置与全局设置
==================== */

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

html {
  scroll-behavior: smooth;
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
  background: #c1c1c1;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #a1a1a1;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.2s ease;
}

img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: 1rem;
  outline: none;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* ====================
   2. 设计变量（CSS Variables）
==================== */

:root {
  --primary: #165DFF;
  --secondary: #FF7D00;
  --dark: #1D2939;
  --light: #F9FAFB;
  --primary-light: #E8F3FF;
  --secondary-light: #FFF3E0;
}

/* 卡片悬停效果 */
.card-hover {
  transition: all 0.3s ease;
}
.card-hover:hover {
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  transform: translateY(-4px);
}

/* 响应式标题 */
.responsive-title {
  font-size: clamp(1.5rem, 3vw, 2.5rem);
}

/* 按钮悬停效果 */
.btn-hover {
  transition: all 0.2s ease;
}

/* 星空背景 */
.star-pattern {
  background-image: radial-gradient(circle, rgba(255,255,255,0.1) 1px, transparent 1px);
  background-size: 30px 30px;
}

/* 输入框聚焦效果 */
.input-focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(22, 93, 255, 0.25);
}
.input-focus:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.3);
  border-color: var(--primary);
}

/* 卡片悬停效果 */
.card-hover {
  transition: all 0.3s ease;
}
.card-hover:hover {
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  transform: translateY(-4px);
}

/* 渐变背景 */
.gradient-bg {
  background: linear-gradient(135deg, #165DFF 0%, #0A2463 100%);
}

/* 标签悬停效果 */
.badge-hover {
  transition: all 0.2s ease;
}
.badge-hover:hover {
  background-color: var(--primary);
  color: white;
}

/* 星级评分动画 */
.star-rating .fa-star,
.star-rating .fa-star-half-o,
.star-rating .fa-star-o {
  transition: transform 0.2s ease;
}

.star-rating:hover .fa-star,
.star-rating:hover .fa-star-half-o,
.star-rating:hover .fa-star-o {
  transform: scale(1.1);
}

/* 平滑滚动 */
html {
  scroll-behavior: smooth;
}

/* 基础动画 */
.fade-in {
  animation: fadeIn 0.5s ease-in;
}

/* 加载动画样式 */
.loading-spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid #f3f3f3;
  border-top: 2px solid var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-right: 8px;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* 错误消息样式 */
.error-message {
  background-color: #f8d7da;
  color: #721c24;
  padding: 10px;
  border-radius: 4px;
  margin-bottom: 15px;
  border: 1px solid #f5c6cb;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* 滚动渐显动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease forwards;
}

/* 响应式标题 */
.responsive-title {
  font-size: clamp(1.5rem, 3vw, 2.5rem);
}

/* 文字阴影 */
.text-shadow {
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* 卡片分隔线 */
.card-divider {
  border-top: 1px solid rgba(0, 0, 0, 0.05);
  margin: 1rem 0;
}

/* 渐变背景 */
.gradient-bg {
  background: linear-gradient(135deg, #165DFF 0%, #0A2463 100%);
}

/* 滚动渐显动画 */
@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.animate-fade-in {
  animation: fadeIn 0.6s ease forwards;
}

/* 任务卡片的行限制 */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}


/* ====================
   3. 字体与排版系统
==================== */

h1 {
  font-size: 3.2rem;
  line-height: 1.2;
  font-weight: 800;
  margin-bottom: 1.5rem;
  letter-spacing: -0.5px;
}

h2 {
  font-size: 2.2rem;
  line-height: 1.3;
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--dark);
}

h3 {
  font-size: 1.5rem;
  line-height: 1.4;
  font-weight: 600;
  margin-bottom: 0.8rem;
  color: var(--dark);
}

p {
  margin-bottom: 1.2rem;
  color: #555;
  font-size: 1.05rem;
}

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

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }
.mb-4 { margin-bottom: 4rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.pt-2 { padding-top: 2rem; }
.pt-3 { padding-top: 3rem; }
.pt-4 { padding-top: 4rem; }
.pb-2 { padding-bottom: 2rem; }
.pb-3 { padding-bottom: 3rem; }
.pb-4 { padding-bottom: 4rem; }

/* ====================
   4. 头部导航栏 (优化版)
==================== */

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem 0;
  background-color: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  transition: var(--transition);
}

.header.scrolled {
  padding: 0.8rem 0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

#navbar a:first-child {
  font-size: 1.8rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 8px;
  /* 移除固定颜色，允许HTML中的渐变效果 */
}

/* 修复logo动画 */
@keyframes twinkle {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.05); }
}

#navbar .fa-star-o {
  animation: twinkle 3s infinite ease-in-out;
}

.nav-links {
  display: flex;
  gap: 2.2rem;
}

.nav-links a {
  font-weight: 500;
  color: var(--dark);
  position: relative;
  padding-bottom: 4px;
  font-size: 1.05rem;
}

.nav-links a:hover {
  color: var(--secondary);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

.auth-buttons {
  display: flex;
  gap: 1rem;
  align-items: center;
}

/* ====================
   5. 首页 Banner 区域 (全面优化)
==================== */

.hero {
  height: 100vh;
  min-height: 700px;
  display: flex;
  align-items: center;
  text-align: center;
  padding-top: 80px;
  background: linear-gradient(135deg, rgba(44, 62, 80, 0.85), rgba(142, 68, 173, 0.85)), 
              url('https://picsum.photos/id/1036/1600/1000') no-repeat center center;
  background-size: cover;
  color: white;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at center, transparent 0%, rgba(0, 0, 0, 0.7) 100%);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 20px;
}

.hero h1 {
  color: white;
  max-width: 800px;
  margin: 0 auto 1.5rem;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero p {
  font-size: 1.4rem;
  max-width: 700px;
  margin: 0 auto 2.5rem;
  opacity: 0.9;
  font-weight: 300;
}

.search-container {
  max-width: 700px;
  margin: 0 auto 2.5rem;
  position: relative;
}

.search-bar {
  width: 100%;
  padding: 1.3rem 1.8rem;
  border: none;
  border-radius: 50px;
  font-size: 1.1rem;
  box-shadow: var(--shadow-xl);
  transition: var(--transition);
  font-weight: 500;
}

.search-bar:focus {
  outline: none;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

.tags {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.tags span {
  background: rgba(255, 255, 255, 0.15);
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 1.05rem;
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: var(--transition);
  cursor: pointer;
  font-weight: 500;
}

.tags span:hover {
  transform: translateY(-3px);
  background: rgba(255, 255, 255, 0.25);
  border-color: rgba(255, 255, 255, 0.3);
}

/* ====================
   6. 数据统计模块 (全新设计)
==================== */

.stats {
  padding: 4rem 0;
  background: white;
  position: relative;
  z-index: 5;
  margin-top: -50px;
}

.stats::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

.stats h2 {
  text-align: center;
  margin-bottom: 3rem;
  font-size: 2.5rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.stat-card {
  text-align: center;
  padding: 2rem 1.5rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.stat-card:hover {
  transform: translateY(-8px);
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

.stat-card strong {
  font-size: 3.5rem;
  display: block;
  margin-bottom: 0.8rem;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-weight: 800;
  line-height: 1.1;
}

.stat-card p {
  font-size: 1.25rem;
  color: var(--gray);
  font-weight: 500;
  margin: 0;
}

/* ====================
   7. 推荐任务卡片 (全面重构)
==================== */

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  font-size: 2.3rem;
  position: relative;
  display: inline-block;
  padding-bottom: 15px;
}

.section-header h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.section-header p {
  max-width: 700px;
  margin: 0 auto;
  color: var(--gray);
  font-size: 1.15rem;
}

.recommended-tasks {
  padding: 4.5rem 0;
  background: #fafbfc;
}

.filters {
  display: flex;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
  justify-content: center;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.filters select {
  padding: 0.9rem 1.3rem;
  border: 1px solid #e0e6ed;
  border-radius: var(--radius-md);
  min-width: 180px;
  font-size: 1rem;
  background-color: white;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.filters select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.filter-button {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  border: none;
  padding: 0.9rem 1.8rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-size: 1.05rem;
}

.filter-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.task-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.task-card {
  background: white;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  position: relative;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.task-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-hover);
}

.task-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transform: scaleX(0);
  transform-origin: left;
  transition: var(--transition);
}

.task-card:hover::before {
  transform: scaleX(1);
}

.category {
  background: var(--accent);
  color: white;
  display: inline-block;
  padding: 6px 16px;
  border-radius: 20px;
  margin: 1.5rem 1.5rem 0;
  font-weight: 600;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.task-card h3 {
  margin: 0.8rem 1.5rem 0.5rem;
  font-size: 1.35rem;
  line-height: 1.4;
  min-height: 2.8em;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.task-card p {
  padding: 0 1.5rem;
  color: #666;
  font-size: 0.98rem;
  margin-bottom: 1.2rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 3.6em;
}

.meta {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 1.5rem 0.8rem;
  font-size: 0.92rem;
  color: var(--gray);
}

.meta img {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--light);
}

.price {
  font-weight: 700;
  color: var(--primary);
  margin: 0.5rem 1.5rem;
  font-size: 1.25rem;
  font-size: 1.3rem;
}

.apply-btn {
  display: block;
  width: 92%;
  margin: 0.8rem auto 1.5rem;
  text-align: center;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 0.95rem 0;
  border-radius: 30px;
  font-weight: 600;
  transition: var(--transition);
  font-size: 1.05rem;
  box-shadow: 0 4px 15px rgba(44, 62, 80, 0.2);
  border: none;
  cursor: pointer;
}

.apply-btn:hover {
  background: linear-gradient(135deg, #1a2530, #6a3085);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(44, 62, 80, 0.25);
}

/* ====================
   8. 平台介绍区域 (全新设计)
==================== */

.platform-intro {
  padding: 5rem 0;
  background: white;
}

.platform-intro .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.platform-intro h2 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.platform-intro p {
  font-size: 1.15rem;
  margin-bottom: 2rem;
  color: var(--gray);
}

.platform-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  position: relative;
  height: 400px;
}

.platform-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.platform-image:hover img {
  transform: scale(1.05);
}

.cta-buttons {
  display: flex;
  gap: 1.5rem;
  margin-top: 2rem;
}

.cta-buttons a {
  flex: 1;
  padding: 1.2rem;
  text-align: center;
  font-size: 1.15rem;
  font-weight: 600;
  border-radius: var(--radius-md);
}

.cta-buttons a:first-child {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
}

.cta-buttons a:last-child {
  border: 2px solid var(--primary);
  color: var(--primary);
  background: white;
}

.cta-buttons a:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* ====================
   9. 页脚 Footer (优化版)
==================== */

.footer {
  text-align: center;
  padding: 4rem 1rem 2rem;
  background-color: var(--dark);
  color: rgba(255, 255, 255, 0.8);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 4rem;
}

.footer .container {
  max-width: 1100px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2.5rem;
}

.footer-logo {
  grid-column: 1 / -1;
  text-align: center;
  margin-bottom: 2rem;
}

.footer-logo h3 {
  font-size: 1.8rem;
  color: white;
  margin-top: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.footer-logo h3::after {
  content: '✨';
  animation: twinkle 3s infinite ease-in-out;
}

.footer-links h4 {
  color: white;
  font-size: 1.2rem;
  margin-bottom: 1.2rem;
  font-weight: 600;
}

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

.footer-links ul li {
  margin-bottom: 0.8rem;
}

.footer-links ul li a {
  color: rgba(255, 255, 255, 0.7);
  transition: var(--transition);
}

.footer-links ul li a:hover {
  color: white;
  padding-left: 4px;
}

.footer .links {
  font-size: 0.95rem;
  margin: 2rem 0;
  display: flex;
  justify-content: center;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.footer .links a {
  color: rgba(255, 255, 255, 0.7);
  transition: var(--transition);
}

.footer .links a:hover {
  color: white;
}

.footer address {
  font-style: normal;
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 1.5rem;
  line-height: 1.7;
}

.footer-bottom {
  grid-column: 1 / -1;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
  margin: 0;
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.9rem;
}

/* ====================
   10. 表单页面通用样式（登录 / 注册）
==================== */

.auth-page {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  min-height: 100vh;
  color: white;
  text-align: center;
  padding: 4rem 1rem;
}

.auth-container {
  background: white;
  color: #333;
  border-radius: var(--radius-xl);
  padding: 3rem;
  max-width: 450px;
  margin: 0 auto;
  box-shadow: var(--shadow-xl);
  transform: translateY(20px);
  opacity: 0;
  animation: fadeInUp 0.6s ease forwards;
}

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

.auth-container h1 {
  margin-bottom: 2rem;
  color: var(--dark);
  font-size: 1.9rem;
  font-weight: 700;
}

.auth-container label {
  display: block;
  text-align: left;
  margin: 1.2rem 0 0.5rem;
  font-weight: 600;
  color: var(--dark);
  font-size: 1.05rem;
}

.auth-container input[type="text"],
.auth-container input[type="email"],
.auth-container input[type="password"],
.auth-container select {
  width: 100%;
  padding: 0.9rem 1.2rem;
  border: 1px solid #ddd;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  transition: var(--transition);
}

.auth-container input[type="text"]:focus,
.auth-container input[type="email"]:focus,
.auth-container input[type="password"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.auth-container button[type="submit"] {
  width: 100%;
  margin-top: 1.5rem;
  padding: 0.95rem;
  font-size: 1.1rem;
  border: none;
  border-radius: var(--radius-sm);
}

.forgot-link {
  float: right;
  font-size: 0.95rem;
  color: var(--accent);
  margin-top: -0.5rem;
  text-decoration: none;
  transition: var(--transition);
}

.forgot-link:hover {
  color: #2980b9;
  text-decoration: underline;
}

.third-party {
  margin: 2.2rem 0;
}

.third-party p {
  margin-bottom: 1.2rem;
  color: var(--gray);
  font-size: 1.05rem;
}

.social-login {
  display: flex;
  gap: 1.2rem;
  margin-top: 1rem;
}

.social-login button {
  flex: 1;
  padding: 0.9rem;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.wechat {
  background: #2ecc71;
  color: white;
}

.qq {
  background: #3498db;
  color: white;
}

.wechat:hover, .qq:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.switch {
  margin-top: 1.8rem;
  color: var(--gray);
  font-size: 1.05rem;
}

.switch a {
  color: var(--accent);
  font-weight: 600;
  transition: var(--transition);
}

.switch a:hover {
  color: #2980b9;
  text-decoration: underline;
}

/* ====================
   11. 响应式设计（移动端适配）
==================== */

@media (max-width: 1024px) {
  h1 {
    font-size: 2.8rem;
  }
  
  h2 {
    font-size: 2rem;
  }
  
  .platform-intro .container {
    grid-template-columns: 1fr;
  }
  
  .platform-image {
    height: 300px;
  }
}

@media (max-width: 768px) {
  .header {
    padding: 1rem 0;
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav-links {
    gap: 1.2rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .hero {
    min-height: 600px;
    padding-top: 100px;
  }
  
  .hero h1 {
    font-size: 2.4rem;
  }
  
  .hero p {
    font-size: 1.2rem;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .filters {
    flex-direction: column;
  }
  
  .filters select, .filter-button {
    width: 100%;
  }
  
  .task-cards {
    grid-template-columns: 1fr;
  }
  
  .footer .container {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.7rem;
  }
  
  h3 {
    font-size: 1.3rem;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .hero p {
    font-size: 1.1rem;
  }
  
  .search-bar {
    padding: 1rem 1.2rem;
    font-size: 1rem;
  }
  
  .tags span {
    padding: 8px 14px;
    font-size: 0.95rem;
  }
  
  .auth-container {
    padding: 2rem 1.5rem;
  }
  
  .auth-container h1 {
    font-size: 1.7rem;
  }
  
  .apply-btn, .btn-primary {
    font-size: 1rem;
    padding: 0.8rem 0;
  }
}

/* ====================
   12. 小动效与点缀
==================== */

@keyframes twinkle {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.1); }
}

.twinkle {
  animation: twinkle 3s infinite ease-in-out;
  display: inline-block;
}

/* 添加页面加载动画 */
body {
  opacity: 0;
  animation: fadeIn 0.6s ease forwards;
}

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

/* 添加滚动渐显效果 */
.scroll-fade {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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