/* ========================================
   恋爱占有欲指数计算器 - 通用样式
   ======================================== */

/* ===== 全局重置 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ===== 全局变量 ===== */
:root {
  /* 主色�?- 粉色�?*/
  --primary-pink: #E91E63;
  --primary-pink-light: #FF4081;
  --primary-pink-dark: #C2185B;

  /* 背景�?*/
  --bg-page: #FFFFFF;
  --bg-section: #FFF5F7;
  --bg-card: #FFFFFF;
  --bg-gray: #F8F9FA;
  --bg-input: #F5F5F5;

  /* 文字�?*/
  --text-primary: #333333;
  --text-secondary: #666666;
  --text-tertiary: #999999;
  --text-white: #FFFFFF;

  /* 边框�?*/
  --border-color: #E0E0E0;
  --border-light: #F0F0F0;

  /* 功能�?*/
  --color-blue: #2196F3;
  --color-blue-light: #E3F2FD;
  --color-green: #4CAF50;
  --color-green-light: #E8F5E9;
  --color-orange: #FF9800;
  --color-orange-light: #FFF3E0;
  --color-red: #F44336;
  --color-red-light: #FFEBEE;

  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-round: 50%;

  /* 阴影 */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
}

/* ===== 全局样式 ===== */
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

a {
  text-decoration: none;
  color: inherit;
  transition: color 0.3s ease;
}

ul {
  list-style: none;
}

/* 按钮通用样式 */
button {
  font-family: inherit;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  outline: none;
}

/* ========================================
   头部导航
   ======================================== */
.header {
  background-color: var(--bg-page);
  border-bottom: 1px solid var(--border-light);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  text-decoration: none;
}

.logo:hover {
  opacity: 0.8;
}

.logo-icon {
  font-size: 28px;
}

.logo-text {
  font-size: 20px;
  font-weight: 600;
  color: var(--primary-pink);
}

.nav {
  display: flex;
  gap: var(--spacing-xs);
}

.nav a {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--text-secondary);
  font-size: 13px;
  padding: 6px 10px;
  border-radius: var(--radius-md);
  transition: all 0.3s ease;
}

.nav a:hover {
  background: var(--bg-section);
  color: var(--primary-pink);
}

.nav-icon {
  font-size: 14px;
}

/* ========================================
   主标题区 (Hero)
   ======================================== */
.hero {
  background: linear-gradient(135deg, var(--bg-section) 0%, var(--bg-page) 100%);
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.hero-title {
  font-size: 52px;
  font-weight: 700;
  color: var(--primary-pink);
  margin-bottom: var(--spacing-sm);
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto var(--spacing-lg);
  line-height: 1.8;
}

.feature-card {
  background: linear-gradient(135deg, #FFF5F7 0%, #FFE8EC 100%);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  max-width: 1300px;
  margin: 0 auto var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  box-shadow: var(--shadow-lg);
  text-align: left;
}

.feature-card-icon {
  font-size: 32px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-card-text h3 {
  font-size: 18px;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.feature-card-text p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.button-group {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
}

.btn {
  padding: 10px 48px;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-xl);
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-pink) 0%, var(--primary-pink-light) 100%);
  color: var(--text-white);
  box-shadow: 0 4px 12px rgba(233, 30, 99, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(233, 30, 99, 0.4);
}

.btn-icon {
  font-size: 18px;
}

.btn-arrow {
  font-size: 18px;
  transition: transform 0.3s ease;
}

.btn:hover .btn-arrow {
  transform: translateX(4px);
}

.btn-secondary {
  background: var(--bg-gray);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--border-color);
}

/* ========================================
   功能介绍�?
   ======================================== */
.features {
  padding: var(--spacing-xl) 0;
  background: var(--bg-section);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
  max-width: 1300px;
  margin: 0 auto;
}

.feature-item {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.feature-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  font-size: 32px;
  margin-bottom: var(--spacing-sm);
}

.feature-number {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary-pink);
  margin-bottom: var(--spacing-xs);
}

.feature-label {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ========================================
   测评选择�?
   ======================================== */
.assessment-selection {
  padding: var(--spacing-xl) 0;
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  text-align: center;
  margin-bottom: var(--spacing-xs);
}

.section-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: var(--spacing-lg);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.selection-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
  max-width: 1100px;
  margin: 0 auto;
}

.selection-card {
  background: var(--bg-gray);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  border: 2px solid transparent;
  transition: all 0.3s ease;
  cursor: pointer;
}

.selection-card:hover {
  border-color: var(--primary-pink);
  box-shadow: var(--shadow-md);
}

.selection-card.selected {
  background: linear-gradient(135deg, #FFF5F7 0%, #FFE8EC 100%);
  color: var(--text-primary);
  border-color: var(--primary-pink);
}

.selection-card.selected .card-header h3,
.selection-card.selected .card-feature-item,
.selection-card.selected .time-info,
.selection-card.selected .question-count {
  color: var(--text-primary);
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  position: relative;
}

.card-icon {
  font-size: 32px;
}

.card-header h3 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
}

.card-badge {
  position: absolute;
  top: -8px;
  right: 0;
  background: var(--color-orange);
  color: var(--text-white);
  font-size: 12px;
  padding: 4px 8px;
  border-radius: var(--radius-round);
}

.card-features {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.card-feature-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 14px;
  color: var(--text-secondary);
}

.check-icon {
  color: var(--color-green);
  font-weight: 700;
}

.card-footer {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.time-info,
.question-count {
  font-size: 12px;
  color: var(--text-tertiary);
}

.btn-card-primary,
.btn-card-secondary {
  width: 100%;
  padding: 12px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
}

.btn-card-primary {
  background: var(--primary-pink);
  color: var(--text-white);
}

.btn-card-primary:hover {
  background: var(--primary-pink-dark);
}

.btn-card-secondary {
  background: var(--primary-pink);
  color: var(--text-white);
}

.btn-card-secondary:hover {
  background: var(--primary-pink-dark);
}

/* ========================================
   科学基础�?
   ======================================== */
.scientific-basis {
  padding: var(--spacing-xl) 0;
  background: var(--bg-gray);
}

.basis-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
  max-width: 1300px;
  margin: var(--spacing-xl) auto 0;
}

.basis-item {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.basis-icon {
  font-size: 36px;
  margin-bottom: var(--spacing-sm);
}

.basis-item h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.basis-item p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ========================================
   隐私声明�?
   ======================================== */
.privacy-section {
  padding: var(--spacing-xl) 0;
}

.privacy-card {
  background: linear-gradient(135deg, #FFF5F7 0%, #FFE8EC 100%);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--text-primary);
}

.privacy-icon {
  font-size: 48px;
  margin-bottom: var(--spacing-md);
}

.privacy-card h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.privacy-card > p {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
  line-height: 1.6;
}

.trust-badges {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.trust-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  background: rgba(233, 30, 99, 0.1);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-round);
  font-size: 14px;
  color: var(--text-secondary);
  white-space: nowrap;
  min-width: 140px;
  height: 40px;
}

.trust-icon {
  font-size: 16px;
}

/* ========================================
   底部CTA�?
   ======================================== */
.cta-section {
  padding: var(--spacing-xl) 0;
  background: var(--bg-section);
  text-align: center;
}

.cta-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.cta-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
}

/* ========================================
   页脚
   ======================================== */
.footer {
  background: var(--bg-gray);
  padding: var(--spacing-xl) 0 var(--spacing-md);
  border-top: 1px solid var(--border-light);
}

.footer-content {
  display: grid;
  grid-template-columns: 450px 1fr 1fr 1fr;
  gap: var(--spacing-lg) 40px;
  margin-bottom: var(--spacing-lg);
  margin-left: 200px;
}

.footer-column h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.footer-column p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-column ul li {
  margin-bottom: 4px;
}

.footer-column ul li a {
  font-size: 13px;
  color: var(--text-secondary);
}

.footer-column ul li a:hover {
  color: var(--primary-pink);
}

.copyright {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

.copyright p {
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ========================================
   FAQ 常见问题�?
   ======================================== */
.faq-section {
  padding: var(--spacing-2xl) 0;
  background: var(--bg-gray);
}

.faq-list {
  max-width: 1300px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s ease;
}

.faq-item:hover {
  box-shadow: var(--shadow-md);
}

.faq-question {
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  user-select: none;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  transition: background-color 0.3s ease;
}

.faq-question:hover {
  background: var(--bg-section);
}

.faq-icon {
  font-size: 12px;
  color: var(--primary-pink);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(90deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  background: var(--bg-section);
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: var(--spacing-md) var(--spacing-lg);
}

.faq-answer p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ========================================
   研究文献�?
   ======================================== */
.research-section {
  padding: var(--spacing-2xl) 0;
}

.research-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.research-item {
  background: var(--bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--primary-pink);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.research-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.research-item h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.research-item p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ========================================
   使用指南�?
   ======================================== */
.guide-section {
  padding: var(--spacing-2xl) 0;
  background: var(--bg-section);
}

.guide-steps {
  max-width: 1300px;
  margin: 0 auto var(--spacing-xl);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
}

.guide-step {
  display: flex;
  gap: var(--spacing-md);
  background: var(--bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease;
}

.guide-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.step-number {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-pink) 0%, var(--primary-pink-light) 100%);
  color: var(--text-white);
  font-size: 20px;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

.step-content h4 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.step-content p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.guide-tips {
  max-width: 1300px;
  margin: 0 auto;
  background: var(--color-blue-light);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
}

.guide-tips h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-blue);
  margin-bottom: var(--spacing-md);
}

.guide-tips ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.guide-tips ul li {
  font-size: 13px;
  color: var(--text-secondary);
  padding-left: 20px;
  position: relative;
  line-height: 1.6;
}

.guide-tips ul li:before {
  content: "�?;
  position: absolute;
  left: 8px;
  color: var(--color-blue);
  font-weight: 700;
}

/* ========================================
   联系我们�?
   ======================================== */
.contact-section {
  padding: var(--spacing-2xl) 0;
}

.contact-content {
  max-width: 1300px;
  margin: 0 auto;
}

.contact-info {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.contact-item {
  background: var(--bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease;
}

.contact-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.contact-icon {
  font-size: 32px;
  margin-bottom: var(--spacing-sm);
}

.contact-item h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.contact-item p {
  font-size: 13px;
  color: var(--text-secondary);
}

.contact-notice {
  background: var(--color-orange-light);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  text-align: center;
}

.contact-notice p {
  font-size: 13px;
  color: var(--color-orange);
  margin-bottom: var(--spacing-xs);
  line-height: 1.6;
}

.contact-notice p:last-child {
  margin-bottom: 0;
}

/* ========================================
   响应式设�?
   ======================================== */
@media (max-width: 768px) {
  .header .container {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .nav {
    gap: var(--spacing-md);
    flex-wrap: wrap;
    justify-content: center;
  }

  .hero-title {
    font-size: 28px;
  }

  .hero-subtitle {
    font-size: 14px;
  }

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

  .selection-cards {
    grid-template-columns: 1fr;
  }

  .button-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    padding: 0 var(--spacing-md);
    margin-left: 0;
  }

  /* 第一列：标题和简介独占一�?*/
  .footer-column:first-child {
    width: 100%;
    text-align: center;
    order: 1;
  }

  .footer-column:first-child h3 {
    font-size: 16px;
    margin-bottom: var(--spacing-sm);
  }

  .footer-column:first-child p {
    font-size: 12px;
    display: block;
  }

  /* 三列导航并排显示在一行，居中 */
  .footer-column:nth-child(2),
  .footer-column:nth-child(3),
  .footer-column:nth-child(4) {
    flex: 0 1 auto;
    text-align: center;
    min-width: 80px;
  }

  .footer-column:nth-child(2) { order: 2; }
  .footer-column:nth-child(3) { order: 3; }
  .footer-column:nth-child(4) { order: 4; }

  .footer-column h3 {
    font-size: 14px;
    margin-bottom: var(--spacing-sm);
  }

  .footer-column ul {
    display: flex;
    flex-direction: column;
    gap: 4px;
    align-items: center;
  }

  .footer-column ul li a {
    font-size: 12px;
  }

  .trust-badges {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
  }

  .trust-badge {
    font-size: 13px;
    padding: var(--spacing-xs) var(--spacing-sm);
  }

  .research-grid,
  .guide-steps {
    grid-template-columns: 1fr;
  }

  .contact-info {
    grid-template-columns: 1fr;
  }

  .copyright {
    margin-left: 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .feature-grid,
  .basis-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    flex-direction: column;
    text-align: center;
  }

  .feature-card-icon {
    align-self: center;
  }

  .hero {
    padding: var(--spacing-xl) 0;
  }

  .hero-title {
    font-size: 24px;
  }

  .guide-steps {
    grid-template-columns: 1fr;
  }

  .guide-step {
    flex-direction: column;
    text-align: center;
  }

  .faq-question {
    font-size: 14px;
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

/* ===== PC端专属样式 ===== */
@media (min-width: 769px) {
  .copyright {
    margin-left: 200px;
  }
}