/* ==========================
   CSS3 全局变量 + 深色模式
========================== */
:root {
  --color-primary: #4299e1;
  --color-primary-hover: #3182ce;
  --color-danger: #f56565;
  --color-danger-hover: #e53e3e;
  --color-success: #38b675;
  --color-success-hover: #319f66;
  --color-teal: #38b2ac;
  --color-teal-hover: #319795;
  --color-purple: #9f7aea;
  --color-pink: #ed64a6;
  --color-orange: #f6ad55;

  --color-bg: linear-gradient(180deg, #f7f9fc 0%, #eef2f7 100%);
  --color-text: #333;
  --color-title: #2d3748;
  --color-desc: #718096;
  --color-border: rgba(226, 232, 240, 0.8);
  --color-shadow: rgba(0, 0, 0, 0.06);
  --color-card: #ffffff;
  --color-header-bg: linear-gradient(180deg, #f7f9fc 0.01%, rgba(247,249,252,0.98));
  --color-footer-bg: rgba(247, 249, 252, 0.8);

  --radius-sm: clamp(0.5rem, 1vw, 0.75rem);
  --radius-md: clamp(0.6rem, 2vw, 1rem);
  --radius-lg: clamp(1rem, 3vw, 1.5rem);
  --spacing-xs: clamp(0.4rem, 1vw, 0.6rem);
  --spacing-sm: clamp(0.6rem, 2vw, 0.8rem);
  --spacing-md: clamp(1rem, 2vw, 1.25rem);
  --spacing-lg: clamp(1.5rem, 4vw, 2rem);

  --transition: all 0.3s ease;
  --transition-slow: all 0.4s ease;
  --animation-fade: fadeInUp 0.6s ease forwards;
}
/* ==========================
深夜模式纯黑
html[data-theme="dark"] {
  --color-primary: #63b3ed;
  --color-primary-hover: #4299e1;
  --color-danger: #fc8181;
  --color-danger-hover: #f56565;
  --color-success: #48bb78;
  --color-success-hover: #38b675;
  --color-teal: #4fd1c7;
  --color-teal-hover: #38b2ac;
  --color-purple: #b794f4;
  --color-pink: #f687b3;
  --color-orange: #fbd38d;

  --color-bg: linear-gradient(180deg, #121212 0%, #1a1a1a 100%);
  --color-text: #e0e0e0;
  --color-title: #ffffff;
  --color-desc: #a0aec0;
  --color-border: rgba(255, 255, 255, 0.1);
  --color-shadow: rgba(0, 0, 0, 0.4);
  --color-card: #1e1e1e;
  --color-header-bg: linear-gradient(180deg, #1a1a1a 0.01%, rgba(26,26,26,0.98));
  --color-footer-bg: rgba(26, 26, 26, 0.8);
}
========================== */
html[data-theme="dark"] {
  --color-primary: #63b3ed;
  --color-primary-hover: #4299e1;
  --color-danger: #fc8181;
  --color-danger-hover: #f56565;
  --color-success: #48bb78;
  --color-success-hover: #38b675;
  --color-teal: #4fd1c7;
  --color-teal-hover: #38b2ac;
  --color-purple: #b794f4;
  --color-pink: #f687b3;
  --color-orange: #fbd38d;


  --color-bg: linear-gradient(180deg, #1e293b 0%, #273449 100%);
  --color-text: #e2e8f0;
  --color-title: #f8fafc;
  --color-desc: #94a3b8;
  --color-border: rgba(255, 255, 255, 0.1);
  --color-shadow: rgba(0, 0, 0, 0.2);
  --color-card: #334155;
  --color-header-bg: linear-gradient(180deg, #273449 0.01%, rgba(30, 41, 59, 0.95));
  --color-footer-bg: rgba(30, 41, 59, 0.85);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

html {
  font-size: calc(16px + (18 - 16) * ((100vw - 320px) / (1200 - 320)));
}
@media (max-width: 1024px) {
  html {
    font-size: calc(14px + (16 - 14) * ((100vw - 320px) / (1024 - 320)));
  }
}
@media (max-width: 480px) {
  html {
    font-size: 13px;
  }
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  padding: clamp(1rem, 5vw, 2rem);
  line-height: 1.6;
  min-height: 100vh;
  scroll-behavior: smooth;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(0.5rem, 2vw, 1rem);
  padding-top: clamp(8rem, 15vw, 10rem);
}

a {
  text-decoration: none;
  border: none;
  outline: none;
  color: inherit;
  transition: var(--transition);
}

.btn {
  display: inline-block;
  padding: var(--spacing-sm) clamp(1rem, 3vw, 1.5rem);
  border-radius: var(--radius-md);
  background: var(--color-primary);
  color: #fff;
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(66, 153, 225, 0.15);
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
.btn:hover {
  background: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(66, 153, 225, 0.2);
}
.btn.logout {
  background: var(--color-danger);
  box-shadow: 0 4px 12px rgba(245, 101, 101, 0.15);
}
.btn.logout:hover {
  background: var(--color-danger-hover);
}
.btn.submit {
  width: 100%;
  padding: var(--spacing-md);
  font-size: clamp(0.9375rem, 1.5vw, 1rem);
}

header {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 1200px;
  z-index: 999;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: clamp(1rem, 3vw, 1.5rem);
  padding: clamp(1rem, 5vw, 2rem) clamp(0.5rem, 2vw, 1rem);
  padding-bottom: var(--spacing-md);
  margin-bottom: clamp(2rem, 8vw, 3.5rem);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-header-bg);
  backdrop-filter: blur(8px);
  box-shadow: 0 2px 12px var(--color-shadow);
}
header .left h1 {
  font-size: clamp(1.5rem, 4vw, 1.75rem);
  color: var(--color-title);
  margin-bottom: 0.375rem;
  font-weight: 700;
}
header .left p {
  color: var(--color-desc);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
}

.timeline {
  position: relative;
  width: 100%;
  margin: 0 auto;
  padding: var(--spacing-lg) 0;
}
@media (max-width: 1024px) {
  .timeline {
    display: grid;
    grid-template-columns: 1fr;
    gap: clamp(1.5rem, 5vw, 2rem);
    padding: var(--spacing-md) 0;
  }
}

.timeline::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-purple), var(--color-teal), var(--color-pink), var(--color-orange));
  background-size: 100% 200%;
  transform: translateX(-50%);
  border-radius: 99px;
  box-shadow: 0 0 10px rgba(66, 153, 225, 0.2);
  animation: gradientFlow 15s linear infinite;
  will-change: background-position;
}
@media (max-width: 1024px) {
  .timeline::before {
    display: none;
  }
}

@keyframes gradientFlow {
  0% { background-position: 0 0; }
  100% { background-position: 0 200%; }
}

.timeline-item {
  position: relative;
  width: 50%;
  margin-bottom: clamp(2.5rem, 8vw, 3.75rem);
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  padding-right: clamp(3rem, 8vw, 5rem);
  opacity: 0;
  transform: translateY(20px);
  animation: var(--animation-fade);
  touch-action: pan-y;
}
@media (max-width: 1024px) {
  .timeline-item {
    width: 100%;
    padding: 0;
    margin: 0;
    align-items: stretch;
    left: 0 !important;
    animation-delay: calc(0.1s * var(--item-index, 1));
  }
}

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

.timeline-item.right-card {
  left: 50%;
  align-items: flex-start;
  padding-left: clamp(3rem, 8vw, 5rem);
  padding-right: 0;
}
@media (max-width: 1024px) {
  .timeline-item.right-card {
    left: 0;
    padding: 0;
  }
}

.timeline-dot {
  position: absolute;
  right: -6px;
  top: 2rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-card);
  border: 4px solid var(--color-primary);
  z-index: 3;
  box-shadow: 0 0 10px rgba(66, 153, 225, 0.3);
}
.right-card .timeline-dot {
  right: auto;
  left: -6px;
}
@media (max-width: 1024px) {
  .timeline-dot {
    display: none;
  }
}

.timeline-date {
  position: absolute;
  right: clamp(-8rem, -15vw, -7rem);
  top: clamp(1.5rem, 3vw, 1.75rem);
  color: #fff;
  padding: var(--spacing-sm) clamp(1rem, 2vw, 1.25rem);
  border-radius: 50px;
  font-size: clamp(0.75rem, 1.5vw, 0.875rem);
  font-weight: 600;
  white-space: nowrap;
  z-index: 2;
  transition: var(--transition);
  letter-spacing: 0.5px;
  box-shadow: 0 4px 12px var(--color-shadow);
  cursor: pointer;
}
@media (max-width: 1024px) {
  .timeline-date {
    position: static;
    display: inline-block;
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-xs) clamp(0.8rem, 1.5vw, 1rem);
    font-size: clamp(0.7rem, 1.2vw, 0.8rem);
  }
}

.timeline-item:nth-child(5n+1) .timeline-date { background: var(--color-primary); }
.timeline-item:nth-child(5n+2) .timeline-date { background: var(--color-purple); }
.timeline-item:nth-child(5n+3) .timeline-date { background: var(--color-teal); }
.timeline-item:nth-child(5n+4) .timeline-date { background: var(--color-pink); }
.timeline-item:nth-child(5n+5) .timeline-date { background: var(--color-orange); }

.timeline-date:hover {
  animation: pulse-scale 0.8s infinite ease-in-out;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.18);
  transform: translateY(-2px);
  will-change: transform, box-shadow;
}
@keyframes pulse-scale {
  0% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.15); opacity: 0.9; }
  100% { transform: scale(1); opacity: 1; }
}

.right-card .timeline-date {
  right: auto;
  left: clamp(-8rem, -15vw, -7rem);
}
@media (max-width: 1024px) {
  .right-card .timeline-date {
    left: auto;
    right: auto;
  }
}

.timeline-card {
  width: 100%;
  background: var(--color-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 30px var(--color-shadow);
  transition: var(--transition-slow);
  border: 1px solid rgba(255,255,255,0.05);
  position: relative;
  overflow: hidden;
  will-change: transform, box-shadow;
}
@media (max-width: 1024px) {
  .timeline-card {
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 24px var(--color-shadow);
  }
}

.timeline-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: inherit;
}
.timeline-item:nth-child(5n+1) .timeline-card::before { background: var(--color-primary); }
.timeline-item:nth-child(5n+2) .timeline-card::before { background: var(--color-purple); }
.timeline-item:nth-child(5n+3) .timeline-card::before { background: var(--color-teal); }
.timeline-item:nth-child(5n+4) .timeline-card::before { background: var(--color-pink); }
.timeline-item:nth-child(5n+5) .timeline-card::before { background: var(--color-orange); }

.timeline-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.12);
}
@media (max-width: 1024px) {
  .timeline-card:hover {
    transform: translateY(-4px) scale(1.01);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  }
}

.images {
  display: block;
  width: 100%;
  margin-bottom: var(--spacing-md);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.images img, .images video {
  display: block;
  width: 100%;
  height: clamp(8rem, 20vw, 12rem);
  object-fit: cover;
  border-radius: var(--radius-lg);
  margin-bottom: 0.5rem;
  transition: transform 0.5s ease;
  backface-visibility: hidden;
  image-rendering: auto;
}
@media (max-width: 1024px) {
  .images img, .images video {
    height: clamp(12rem, 45vw, 20rem);
  }
}
@media (max-width: 480px) {
  .images img, .images video {
    height: clamp(10rem, 40vw, 18rem);
  }
}
.images img:hover, .images video:hover {
  transform: scale(1.05);
}

.card-info .title {
  font-size: clamp(1.125rem, 2vw, 1.25rem);
  color: var(--color-title);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}
.card-info .title:hover {
  color: var(--color-primary);
}
.content-preview {
  color: var(--color-desc);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
  line-height: 1.7;
  margin: var(--spacing-sm) 0;
}

.opts {
  display: flex;
  gap: var(--spacing-md);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-border);
}
.opts a {
  color: var(--color-desc);
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0.25rem 0;
}
.opts a:hover {
  color: var(--color-primary);
}
.opts a::before { content: "✏️"; }
.opts a:last-child::before { content: "🗑️"; }

.show-page {
  max-width: clamp(30rem, 80vw, 48.75rem);
  margin: 0 auto;
  padding: 0 clamp(0.5rem, 2vw, 1rem);
}
.show-box {
  background: var(--color-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  line-height: 1.9;
  box-shadow: 0 8px 24px var(--color-shadow);
  overflow-x: hidden;
  word-wrap: break-word;
}
.show-img, .show-video {
  max-width: 100% !important;
  max-height: clamp(20rem, 70vh, 40rem) !important;
  width: auto !important;
  height: auto !important;
  border-radius: var(--radius-lg);
  margin: var(--spacing-md) 0;
  cursor: zoom-in;
  object-fit: contain;
}

.write-form {
  background: var(--color-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  box-shadow: 0 8px 24px var(--color-shadow);
}
.write-form input,
.write-form textarea {
  padding: var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: clamp(0.875rem, 1.5vw, 1rem);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  background: var(--color-card);
  color: var(--color-text);
}
.write-form input:focus,
.write-form textarea:focus {
  border-color: var(--color-primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.1);
}

.upload-row {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}
.upbtn {
  position: relative;
  background: var(--color-success);
  color: #fff;
  padding: var(--spacing-sm) clamp(1rem, 2vw, 1.25rem);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}
.upbtn:hover {
  background: var(--color-success-hover);
  transform: translateY(-2px);
}
.upbtn input {
  position: absolute;
  opacity: 0;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #f7f9fc 0%, #e8f4f8 100%);
  padding: clamp(1rem, 5vw, 2rem);
}
html[data-theme="dark"] .login-body {
  background: linear-gradient(135deg, #121212 0%, #232323 100%);
}
.login-box {
  background: var(--color-card);
  padding: clamp(2rem, 5vw, 3rem);
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 30px var(--color-shadow);
  width: 100%;
  max-width: clamp(20rem, 90vw, 28rem);
  text-align: center;
}
.login-box h2 {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  color: var(--color-title);
  margin-bottom: var(--spacing-lg);
}
.login-box input {
  width: 100%;
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
  background: var(--color-card);
  color: var(--color-text);
}
.login-box .msg.err {
  color: var(--color-danger-hover);
  margin-bottom: var(--spacing-md);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
}

#loadTip, #noMoreTip {
  text-align: center;
  padding: var(--spacing-lg);
  color: var(--color-desc);
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
}

#imgViewer,
#imgViewerIndex {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.95);
  z-index: 9999;
  cursor: zoom-out;
}
#viewerImg,
#imgViewerIndex img {
  max-width: clamp(10rem, 90vw, 60rem);
  max-height: clamp(10rem, 90vh, 40rem);
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  border-radius: var(--radius-sm);
}
.show-img.preview-img {
  transition: opacity 0.3s ease;
}
.show-img.preview-img:hover {
  opacity: 0.9;
}

.year-filter {
  display: flex;
  align-items: center;
  width: 100%;
  margin: 0 0 1.2rem;
  padding: 0;
  background: transparent;
  border: none;
  box-shadow: none;
}
.year-selector {
  flex: 1;
  padding: var(--spacing-sm) clamp(1rem, 3vw, 1.5rem);
  border-radius: var(--radius-md);
  background: var(--color-teal);
  color: #fff;
  font-size: clamp(0.875rem, 1.5vw, 0.9375rem);
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(56, 178, 172, 0.15);
  touch-action: manipulation;
  appearance: none;
  background-image: none;
  -webkit-tap-highlight-color: transparent;
}
.year-selector:hover {
  background: var(--color-teal-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(56, 178, 172, 0.2);
}
.year-selector:focus {
  outline: none;
}
.year-selector option {
  background: var(--color-card);
  color: var(--color-title);
  padding: 12px;
  font-size: 0.9rem;
}

.footer-copyright {
  margin-top: clamp(3rem, 10vw, 5rem);
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-desc);
  font-size: clamp(0.75rem, 1.5vw, 0.875rem);
  width: 100%;
  background: var(--color-footer-bg);
  backdrop-filter: blur(8px);
}
.footer-copyright p {
  margin: 0.3rem 0;
}
.footer-copyright a {
  color: var(--color-primary);
  transition: color 0.3s ease;
}
.footer-copyright a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}
@media (max-width: 1024px) {
  .footer-copyright {
    margin-top: clamp(2rem, 8vw, 3.5rem);
    padding: var(--spacing-md) 0;
  }
}

.back-to-top {
  position: fixed;
  right: clamp(1rem, 3vw, 1.5rem);
  bottom: clamp(1rem, 3vw, 1.5rem);
  width: clamp(2.5rem, 5vw, 3rem);
  height: clamp(2.5rem, 5vw, 3rem);
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: clamp(1rem, 2vw, 1.25rem);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(66, 153, 225, 0.2);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  padding-top: 0.2rem;
  -webkit-tap-highlight-color: transparent;
}
.write-diary-btn {
  bottom: calc(clamp(1rem, 3vw, 1.5rem) + clamp(2.5rem, 5vw, 3rem) + clamp(0.5rem, 1vw, 0.75rem));
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.btn-label {
  font-size: clamp(0.5rem, 1vw, 0.65rem);
  line-height: 1;
  margin-bottom: 0.15rem;
  white-space: nowrap;
}
.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover {
  background: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(66, 153, 225, 0.3);
}

@media (max-width: 1024px) {
  .back-to-top {
    width: clamp(2.25rem, 6vw, 2.75rem);
    height: clamp(2.25rem, 6vw, 2.75rem);
  }
  .write-diary-btn {
    bottom: calc(clamp(1rem, 3vw, 1.5rem) + clamp(2.25rem, 6vw, 2.75rem) + clamp(0.5rem, 1vw, 0.75rem));
  }
  .btn-label {
    font-size: clamp(0.45rem, 1vw, 0.6rem);
    margin-bottom: 0.1rem;
  }
}