/* ========================================
   青春的故事 - 公共组件
   ======================================== */

/* 导航栏 */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1rem 2rem;
  background: linear-gradient(to bottom, var(--paper-cream), transparent);
  transition: all 0.3s ease;
}

.nav.scrolled {
  background: var(--paper-cream);
  box-shadow: 0 2px 10px var(--shadow-warm);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
}

.nav-logo {
  font-family: var(--font-title);
  font-size: 1.5rem;
  color: var(--ink-brown);
  letter-spacing: 0.1em;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--ink-brown);
  position: relative;
  padding-bottom: 0.3rem;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gold);
  transition: width 0.3s ease;
}

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

/* 移动端导航 */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 25px;
  height: 2px;
  background: var(--ink-brown);
  transition: all 0.3s ease;
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  
  .nav-links {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--paper-cream);
    padding: 1rem;
    gap: 1rem;
    transform: translateY(-100%);
    opacity: 0;
    transition: all 0.3s ease;
    box-shadow: 0 4px 10px var(--shadow-warm);
  }
  
  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
  }
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 0.8rem 2rem;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--ink-brown);
  background: transparent;
  border: 2px solid var(--ink-brown);
  border-radius: 255px 15px 225px 15px / 15px 225px 15px 255px;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: var(--paper-aged);
  transition: left 0.3s ease;
  z-index: -1;
}

.btn:hover::before {
  left: 0;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--shadow-warm);
}

/* 卡片 */
.card {
  background: var(--paper-white);
  padding: 2rem;
  border-radius: 255px 15px 225px 15px / 15px 225px 15px 255px;
  box-shadow: 0 4px 15px var(--shadow-warm);
  position: relative;
  transition: all 0.3s ease;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border: 1px solid var(--paper-sepia);
  border-radius: inherit;
  pointer-events: none;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px var(--shadow-deep);
}

/* 便签纸 */
.note {
  background: linear-gradient(135deg, #fff9c4 0%, #fff59d 100%);
  padding: 1.5rem;
  box-shadow: 2px 4px 8px var(--shadow-warm);
  position: relative;
  font-family: var(--font-body);
  line-height: 1.8;
}

.note::before {
  content: '';
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 16px;
  background: rgba(255, 255, 255, 0.8);
  box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
}

/* 老照片效果 */
.vintage-photo {
  position: relative;
  overflow: hidden;
  border-radius: 2px;
}

.vintage-photo img {
  width: 100%;
  height: auto;
  filter: sepia(30%) contrast(90%) brightness(105%);
  transition: all 0.3s ease;
}

.vintage-photo::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, rgba(139, 119, 101, 0.1) 0%, transparent 50%, rgba(139, 119, 101, 0.1) 100%);
  pointer-events: none;
  z-index: 1;
}

.vintage-photo::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  box-shadow: inset 0 0 60px rgba(139, 119, 101, 0.3);
  pointer-events: none;
  z-index: 2;
}

.vintage-photo:hover img {
  filter: sepia(20%) contrast(95%) brightness(110%);
}

/* 信纸样式 */
.letter-paper {
  background: var(--paper-white);
  padding: 3rem;
  position: relative;
  box-shadow: 0 4px 15px var(--shadow-warm);
}

.letter-paper::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 8px;
  background: repeating-linear-gradient(90deg, var(--accent-rose) 0, var(--accent-rose) 2px, transparent 2px, transparent 20px);
}

.letter-lines {
  background-image: repeating-linear-gradient(transparent, transparent 31px, var(--paper-sepia) 31px, var(--paper-sepia) 32px);
  background-position: 0 20px;
  min-height: 200px;
}

/* 时间轴 */
.timeline {
  position: relative;
  padding: 2rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, transparent, var(--ink-faded) 10%, var(--ink-faded) 90%, transparent);
}

.timeline-item {
  position: relative;
  width: 50%;
  padding: 2rem;
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.timeline-item.visible {
  opacity: 1;
  transform: translateY(0);
}

.timeline-item:nth-child(odd) {
  left: 0;
  padding-right: 4rem;
  text-align: right;
}

.timeline-item:nth-child(even) {
  left: 50%;
  padding-left: 4rem;
  text-align: left;
}

.timeline-dot {
  position: absolute;
  width: 16px;
  height: 16px;
  background: var(--accent-rose);
  border: 3px solid var(--paper-cream);
  border-radius: 50%;
  top: 2.5rem;
}

.timeline-item:nth-child(odd) .timeline-dot {
  right: -8px;
}

.timeline-item:nth-child(even) .timeline-dot {
  left: -8px;
}

@media (max-width: 768px) {
  .timeline::before {
    left: 20px;
  }
  
  .timeline-item {
    width: 100%;
    left: 0 !important;
    padding-left: 4rem !important;
    padding-right: 1rem !important;
    text-align: left !important;
  }
  
  .timeline-dot {
    left: 12px !important;
    right: auto !important;
  }
}

/* 手绘边框 */
.hand-drawn {
  border: 2px solid var(--ink-brown);
  border-radius: 255px 15px 225px 15px / 15px 225px 15px 255px;
}

.hand-drawn-light {
  border: 1px solid var(--ink-faded);
  border-radius: 255px 15px 225px 15px / 15px 225px 15px 255px;
}

/* 页脚 */
.footer {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--ink-faded);
  font-size: 0.9rem;
}

.footer-divider {
  width: 100px;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--ink-faded), transparent);
  margin: 1rem auto;
}

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

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

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: all 0.6s ease;
}

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

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: all 0.6s ease;
}

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