/* =====================================================
   我的健康之旅 — 样式表
   颜色和字体变量在 :root 中集中管理，修改一处即可全局生效
====================================================== */

/* ——— 全局重置 ——— */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ——— 设计变量（主题色可在此统一修改） ——— */
:root {
  /* 主色调：米白 + 暖色 */
  --bg:           #f9f6f1;
  --bg-alt:       #f2ede5;
  --white:        #ffffff;

  /* 强调色：柔和鼠尾草绿 */
  --green:        #7ba68a;
  --green-light:  #e8f0eb;
  --green-dark:   #5a8a6e;

  /* 文字 */
  --text:         #3a3530;
  --text-muted:   #6b6560;
  --border:       #e5e0d8;

  /* 蒙版 */
  --overlay:      rgba(35, 30, 25, 0.48);

  /* 字体栈 */
  --serif: 'Noto Serif SC', 'STSong', 'SimSun', Georgia, serif;
  --sans:  'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  /* 间距 */
  --sec-pad:   90px 0;
  --max-w:     1100px;

  /* 圆角 */
  --r-sm:  6px;
  --r-md:  12px;
  --r-lg:  22px;

  /* 阴影 */
  --sh-sm:    0 2px 10px rgba(0,0,0,0.07);
  --sh-md:    0 4px 22px rgba(0,0,0,0.10);
  --sh-hover: 0 10px 36px rgba(0,0,0,0.14);

  /* 过渡 */
  --t: 0.3s ease;
}

/* ——— 基础 ——— */
html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

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

a {
  text-decoration: none;
  color: inherit;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ——— 通用标题 ——— */
.section-title {
  font-family: var(--serif);
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  font-weight: 500;
  color: var(--text);
  text-align: center;
  margin-bottom: 10px;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 52px;
  letter-spacing: 0.02em;
}


/* =====================================================
   导航栏
====================================================== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(249, 246, 241, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t), box-shadow var(--t);
}

.navbar.scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--sh-sm);
}

.nav-container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}

.nav-logo {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  letter-spacing: 0.04em;
}

.nav-menu {
  list-style: none;
  display: flex;
  gap: 36px;
}

.nav-link {
  font-size: 0.92rem;
  color: var(--text-muted);
  position: relative;
  padding-bottom: 3px;
  transition: color var(--t);
}

/* 下划线动画 */
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1.5px;
  background: var(--green);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--t);
}

.nav-link:hover {
  color: var(--text);
}

.nav-link:hover::after {
  transform: scaleX(1);
}

/* 汉堡按钮（移动端显示） */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--t), opacity var(--t);
}


/* =====================================================
   Hero 首屏
====================================================== */
.hero {
  position: relative;
  height: 100vh;
  min-height: 620px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
}

.hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  /* 图片加载时的背景色兜底 */
  background: #c8d4cc;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: var(--overlay);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  color: #fff;
  padding: 0 24px;
  animation: fadeUp 0.9s ease both;
}

.hero-title {
  font-family: var(--serif);
  font-size: clamp(2.2rem, 6vw, 4.2rem);
  font-weight: 500;
  letter-spacing: 0.08em;
  margin-bottom: 18px;
  text-shadow: 0 2px 16px rgba(0,0,0,0.3);
}

.hero-subtitle {
  font-size: clamp(0.95rem, 2.5vw, 1.2rem);
  font-weight: 300;
  letter-spacing: 0.04em;
  margin-bottom: 42px;
  opacity: 0.9;
}

.btn-primary {
  display: inline-block;
  padding: 14px 38px;
  background: var(--green);
  color: #fff;
  border-radius: 50px;
  font-size: 1rem;
  letter-spacing: 0.06em;
  transition: background var(--t), transform var(--t), box-shadow var(--t);
  box-shadow: 0 4px 20px rgba(91,138,110,0.35);
}

.btn-primary:hover {
  background: var(--green-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(91,138,110,0.45);
}

/* 向下箭头 */
.hero-arrow {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  color: rgba(255,255,255,0.7);
  animation: bounce 2s infinite;
  transition: color var(--t);
}

.hero-arrow:hover {
  color: #fff;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(8px); }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}


/* =====================================================
   简短介绍区
====================================================== */
.intro {
  padding: var(--sec-pad);
  background: var(--white);
}

.intro-content {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.intro-decor {
  font-size: 1.4rem;
  color: var(--green);
  margin-bottom: 18px;
  letter-spacing: 0.3em;
}

.intro-text {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 2;
  margin-bottom: 18px;
}

/* 统计数字行 */
.intro-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  padding-top: 44px;
  border-top: 1px solid var(--border);
}

.stat-item {
  text-align: center;
  padding: 0 52px;
}

.stat-divider {
  width: 1px;
  height: 48px;
  background: var(--border);
  flex-shrink: 0;
}

.stat-number {
  display: block;
  font-family: var(--serif);
  font-size: 2.6rem;
  color: var(--green);
  font-weight: 500;
  line-height: 1;
  margin-bottom: 6px;
}

.stat-label {
  display: block;
  font-size: 0.88rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}


/* =====================================================
   照片展示区（瀑布流网格）
====================================================== */
.photos {
  padding: var(--sec-pad);
  background: var(--bg);
}

/* CSS columns 瀑布流 */
.photo-grid {
  columns: 3;
  column-gap: 20px;
}

.photo-card {
  break-inside: avoid;
  margin-bottom: 20px;
  background: var(--white);
  border-radius: var(--r-md);
  overflow: hidden;
  box-shadow: var(--sh-sm);
  cursor: pointer;
  /* 入场动画初始状态 */
  opacity: 0;
  transform: translateY(22px);
  transition:
    opacity 0.55s ease,
    transform 0.55s ease,
    box-shadow var(--t);
}

/* JS 添加 .visible 后显示 */
.photo-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.photo-card:hover {
  box-shadow: var(--sh-hover);
}

.photo-img-wrap {
  overflow: hidden;
  line-height: 0; /* 消除底部空隙 */
}

.photo-img-wrap img {
  width: 100%;
  height: auto;
  transition: transform 0.5s ease;
}

.photo-card:hover .photo-img-wrap img {
  transform: scale(1.045);
}

.photo-info {
  padding: 16px 20px 20px;
}

.photo-title {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 5px;
}

.photo-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}


/* =====================================================
   健康故事区
====================================================== */
.stories {
  padding: var(--sec-pad);
  background: var(--bg-alt);
}

.stories-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.story-card {
  background: var(--white);
  border-radius: var(--r-md);
  padding: 32px 28px;
  box-shadow: var(--sh-sm);
  display: flex;
  flex-direction: column;
  /* 入场动画 */
  opacity: 0;
  transform: translateY(22px);
  transition:
    opacity 0.55s ease,
    transform 0.55s ease,
    box-shadow var(--t);
}

.story-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.story-card:hover {
  box-shadow: var(--sh-hover);
}

.story-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.story-tag {
  display: inline-block;
  padding: 3px 12px;
  background: var(--green-light);
  color: var(--green-dark);
  border-radius: 50px;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.story-date {
  font-size: 0.83rem;
  color: var(--text-muted);
}

.story-title {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.55;
  margin-bottom: 14px;
}

.story-excerpt {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.9;
  flex: 1;
  margin-bottom: 22px;
}

.story-link {
  font-size: 0.88rem;
  color: var(--green-dark);
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: color var(--t), letter-spacing var(--t);
}

.story-link:hover {
  color: var(--green);
  letter-spacing: 0.06em;
}


/* =====================================================
   关于我区域
====================================================== */
.about {
  padding: var(--sec-pad);
  background: var(--white);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about-title {
  text-align: left;
  margin-bottom: 24px;
}

.about-desc {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 2;
  margin-bottom: 18px;
}

.about-img-wrap {
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: var(--sh-md);
  /* 入场动画 */
  opacity: 0;
  transform: translateX(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.about-img-wrap.visible {
  opacity: 1;
  transform: translateX(0);
}

.about-img {
  width: 100%;
  height: 420px;
  object-fit: cover;
  display: block;
}


/* =====================================================
   Lightbox 全屏查看
====================================================== */
#lightbox {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.92);
  z-index: 9999;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  animation: lbFadeIn 0.2s ease;
}

#lightbox.open {
  display: flex;
}

#lightbox img {
  max-width: 90vw;
  max-height: 88vh;
  object-fit: contain;
  border-radius: var(--r-sm);
  pointer-events: none;
  box-shadow: 0 0 60px rgba(0,0,0,0.5);
}

#lightbox-close {
  position: absolute;
  top: 20px; right: 24px;
  color: rgba(255,255,255,0.7);
  font-size: 2rem;
  line-height: 1;
  cursor: pointer;
  transition: color var(--t), transform var(--t);
  background: none;
  border: none;
  pointer-events: all;
}

#lightbox-close:hover {
  color: #fff;
  transform: rotate(90deg);
}

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


/* =====================================================
   页脚
====================================================== */
.footer {
  background: #2e2a26;
  color: rgba(255,255,255,0.6);
  padding: 48px 0 36px;
  text-align: center;
}

.footer-logo {
  font-family: var(--serif);
  font-size: 1.2rem;
  color: rgba(255,255,255,0.85);
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.footer-copy {
  font-size: 0.9rem;
  margin-bottom: 6px;
  color: rgba(255,255,255,0.75);
}

.footer-tagline {
  font-size: 0.85rem;
  font-family: var(--serif);
  letter-spacing: 0.08em;
  margin-bottom: 18px;
  color: rgba(255,255,255,0.45);
}

.footer-icp a {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.3);
  transition: color var(--t);
}

.footer-icp a:hover {
  color: rgba(255,255,255,0.6);
}


/* =====================================================
   响应式 — 平板（≤ 900px）
====================================================== */
@media (max-width: 900px) {
  :root {
    --sec-pad: 72px 0;
  }

  .photo-grid {
    columns: 2;
  }

  .stories-grid {
    grid-template-columns: 1fr;
    max-width: 560px;
    margin: 0 auto;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .about-img {
    height: 300px;
  }

  .about-img-wrap {
    transform: none;
  }

  .stat-item {
    padding: 0 32px;
  }
}


/* =====================================================
   响应式 — 手机（≤ 600px）
====================================================== */
@media (max-width: 600px) {
  :root {
    --sec-pad: 56px 0;
  }

  /* 显示汉堡按钮 */
  .nav-toggle {
    display: flex;
  }

  /* 移动端菜单：固定在导航栏下方 */
  .nav-menu {
    display: none;
    position: fixed;
    top: 66px; left: 0; right: 0;
    background: rgba(249, 246, 241, 0.97);
    backdrop-filter: blur(14px);
    flex-direction: column;
    gap: 0;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--sh-md);
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-menu li {
    border-bottom: 1px solid var(--border);
  }

  .nav-link {
    display: block;
    padding: 16px 24px;
    font-size: 1rem;
    color: var(--text);
  }

  .nav-link::after {
    display: none;
  }

  /* 汉堡动画 */
  .nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }
  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }
  .nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* 单列照片 */
  .photo-grid {
    columns: 1;
  }

  .stat-item {
    padding: 0 20px;
  }

  .stat-number {
    font-size: 2rem;
  }

  .intro-text {
    font-size: 0.97rem;
  }

  .about-img {
    height: 240px;
  }
}