/* ==================== 常用设置：从这里调整背景 ==================== */
:root {
  --grid-size: 48px; /* 正方形边长，保留 px 单位。 */
  --column-gap: calc(var(--grid-size) / 3); /* 固定列间距，不会忽宽忽窄。 */

  --move-duration: 3s; /* 移动一格的基准时间，数值越小越快。 */

  --paper-color: #faf7ef;
  --grid-color: rgba(143, 96, 77, 0.28);
  --line-width: 1px;
  --phrase-opacity: 0.36; /* 随机文字最深时的不透明度，0～1。 */
  --phrase-color: #716254;
  --title-color: #443d36;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  overflow-x: auto;
  overflow-y: hidden;
  background-color: var(--paper-color);
  animation: page-in 900ms cubic-bezier(.22,.61,.36,1) both;
  overscroll-behavior-x: none;
}

/* 只裁切装饰背景，正文仍可正常滚动和点击。 */
.paper-background {
  position: absolute;
  top: 0;
  left: 0;
  width: calc(100vw + 140px);
  height: 100vh;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  will-change: transform;
}

/* 轨道保持固定，每列以自己的恒定速度独立向上移动。 */
.paper-track {
  position: absolute;
  display: flex;
  gap: var(--column-gap);
  width: max-content;
  left: calc(0px - var(--grid-size) - var(--column-gap));

  /* 上下各预留一格，移动及循环时，窗口边缘始终有图案覆盖。 */
  top: calc(0px - var(--grid-size));
  height: calc(100% + var(--grid-size) * 2);
}

.paper-lane {
  flex: 0 0 var(--grid-size);
  height: 100%;

  /* linear 保证每一列自身匀速；各列系数略有差异，让速度不完全相同。 */
  animation: paper-flow calc(var(--move-duration) * var(--speed-factor)) linear infinite;
}

.paper-column {
  width: 100%;
  height: 100%;
  border-left: var(--line-width) solid var(--grid-color);
  border-right: var(--line-width) solid var(--grid-color);
  background-image: repeating-linear-gradient(
    to bottom,
    var(--grid-color) 0,
    var(--grid-color) var(--line-width),
    transparent var(--line-width),
    transparent var(--grid-size)
  );
}

/* 每次循环恰好向上移动一格，首尾图案一致，无缝衔接。 */
@keyframes paper-flow {
  from { transform: translateY(0); }
  to { transform: translateY(calc(0px - var(--grid-size))); }
}

.page-content {
  position: relative;
  z-index: 1;
  width: calc(100vw + 240px);
  min-height: 100vh;
}

/* 随机短句一字一格，和格子共用边长；外层坐标由脚本对齐。 */
.paper-phrase {
  position: absolute;
  left: 0;
  top: 0;
  width: var(--grid-size);
  color: var(--phrase-color);
  opacity: 0;
  font-family: "Yu Mincho", "YuMincho", "MS Mincho", "Noto Serif CJK JP", serif;
  font-size: calc(var(--grid-size) * 0.51);
  font-weight: 400;
}

.paper-character {
  display: grid;
  place-items: center;
  width: var(--grid-size);
  height: var(--grid-size);
  line-height: 1;
}

/* 右侧竖排标题固定在前景，短句会避开它所在的区域。 */
.site-title {
  position: absolute;
  left: calc(100vw - clamp(70px, 8vw, 130px));
  top: clamp(24px, 5vh, 64px);
  transform: none;
  margin: 0;
  writing-mode: vertical-rl;
  text-orientation: upright;
  color: var(--title-color);
  font-family: "Yu Mincho", "YuMincho", "MS Mincho", "Noto Serif CJK JP", serif;
  font-size: clamp(44px, 5.8vw, 88px);
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.2em;
  text-shadow: 0 0 14px var(--paper-color), 0 0 4px var(--paper-color);
  z-index: 4;
}

.creator-profile {
  position: absolute;
  left: calc(100vw + 12px);
  top: clamp(24px, 5vh, 64px);
  width: 480px;
  min-height: 600px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 42px 46px 38px;
  color: var(--title-color);
  text-decoration: none;
  background: rgba(250, 247, 239, 0.78);
  border: 1px solid rgba(113, 98, 84, 0.34);
  box-shadow: 14px 18px 0 rgba(113, 98, 84, 0.08), 0 18px 38px rgba(68, 61, 54, 0.1);
  opacity: 0;
  transform: translateY(16px);
  animation: profile-in 800ms cubic-bezier(.22,.61,.36,1) 560ms forwards;
  transition: transform 220ms ease, background-color 220ms ease;
  z-index: 4;
}
.creator-profile:hover { transform: translateY(-4px); background: rgba(250, 247, 239, 0.96); }
.profile-mark { display: grid; place-items: center; width: 126px; height: 126px; border-radius: 50%; color: #faf7ef; background: var(--title-color); font: 500 64px/1 "Yu Mincho", "YuMincho", serif; box-shadow: inset 0 0 0 2px rgba(250, 247, 239, 0.35); }
.profile-avatar { width: 100%; height: 100%; border-radius: 50%; object-fit: cover; }
.profile-fallback { display: none; }
.profile-label { color: rgba(113, 98, 84, 0.72); font: 13px/1 ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .22em; }
.creator-profile strong { font: 500 42px/1.2 "Yu Mincho", "YuMincho", "MS Mincho", serif; letter-spacing: .18em; }
.profile-id { color: rgba(113, 98, 84, 0.72); font: 14px/1.3 ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .1em; }
.profile-rule { width: 100%; height: 1px; background: rgba(113, 98, 84, 0.28); }
.profile-note { width: 100%; color: var(--phrase-color); font: 20px/1.8 "Yu Mincho", "YuMincho", "MS Mincho", serif; letter-spacing: .1em; }
.profile-handle { width: 100%; color: rgba(113, 98, 84, 0.68); font: 13px/1.6 ui-monospace, SFMono-Regular, Consolas, monospace; }
.profile-index { align-self: flex-start; margin-top: 10px; color: rgba(113, 98, 84, 0.65); font: 12px/1 ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .18em; }
.profile-quote { width: 100%; margin-top: 8px; color: var(--title-color); font: 19px/1.8 "Yu Mincho", "YuMincho", "MS Mincho", serif; letter-spacing: .1em; }
.profile-link { margin-top: auto; color: var(--title-color); font: 15px/1.2 ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .1em; }
@keyframes profile-in { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }

.video-stage {
  position: absolute;
  top: 50%;
  left: clamp(8vw, 13vw, 16vw);
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-template-rows: repeat(2, auto);
  align-items: center;
  column-gap: clamp(14px, 1.6vw, 26px);
  row-gap: clamp(18px, 2.4vh, 30px);
  width: calc(100vw - 320px);
  max-width: 1200px;
  transform: translateY(-50%);
}

.video-card {
  display: block;
  width: 100%;
  min-width: 0;
  color: var(--title-color);
  text-decoration: none;
  background: rgba(250, 247, 239, 0.82);
  border: 1px solid rgba(113, 98, 84, 0.28);
  box-shadow: 10px 14px 0 rgba(113, 98, 84, 0.09), 0 10px 28px rgba(68, 61, 54, 0.12);
  transform: translateY(calc(var(--card-y, 0px) + 22px)) rotate(var(--card-tilt, 0deg));
  opacity: 0;
  animation: card-in 900ms cubic-bezier(.22,.61,.36,1) var(--card-delay) forwards;
  transition: transform 240ms ease, box-shadow 240ms ease;
}
.video-card:nth-child(1) { --card-y: 0px; --card-tilt: -1deg; }
.video-card:nth-child(2) { --card-y: 10px; --card-tilt: 1.2deg; }
.video-card:nth-child(3) { --card-y: -7px; --card-tilt: -0.8deg; }
.video-card:nth-child(4) { --card-y: 8px; --card-tilt: 1.1deg; }
.video-card:nth-child(5) { --card-y: -8px; --card-tilt: -1.2deg; }
.video-card:nth-child(6) { --card-y: 7px; --card-tilt: 0.9deg; }
.video-card:nth-child(7) { --card-y: -5px; --card-tilt: -1.1deg; }
.video-card:nth-child(8) { --card-y: 9px; --card-tilt: 1deg; }
.video-card:hover { transform: translateY(calc(var(--card-y, 0px) - 8px)) rotate(var(--card-tilt, 0deg)); box-shadow: 14px 20px 0 rgba(113, 98, 84, 0.12), 0 16px 34px rgba(68, 61, 54, 0.18); }
.video-preview { position: relative; aspect-ratio: 16 / 9; overflow: hidden; background: #d9d0c6 var(--cover) center / cover no-repeat; }
.video-cover { position: absolute; inset: 0; z-index: 0; width: 100%; height: 100%; object-fit: cover; opacity: 1; transition: opacity 220ms ease; }
.video-preview iframe { display: block; width: 100%; height: 100%; border: 0; pointer-events: none; opacity: 0; transition: opacity 220ms ease; }
.video-card.is-previewing .video-cover { opacity: 0; }
.video-card.is-previewing .video-preview iframe { opacity: 1; }
.video-duration { position: absolute; right: 8px; bottom: 8px; padding: 3px 6px; color: #faf7ef; background: rgba(68, 61, 54, 0.82); font: 11px/1.2 ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .08em; }
.video-meta { display: grid; gap: 6px; padding: 14px 16px 17px; font-family: "Yu Mincho", "YuMincho", "MS Mincho", "Noto Serif CJK JP", serif; }
.video-meta strong { font-size: 17px; font-weight: 500; line-height: 1.45; }
.video-meta span { color: rgba(113, 98, 84, 0.8); font-size: 12px; letter-spacing: .12em; }
@keyframes page-in { from { opacity: 0; } to { opacity: 1; } }
@keyframes card-in { from { opacity: 0; transform: translateY(calc(var(--card-y, 0px) + 38px)) rotate(var(--card-tilt, 0deg)); } to { opacity: 1; transform: translateY(var(--card-y, 0px)) rotate(var(--card-tilt, 0deg)); } }

@media (max-height: 500px) {
  .site-title { font-size: clamp(30px, 12vh, 60px); letter-spacing: 0.12em; }
}

@media (max-width: 700px) {
  .page-content { width: 430vw; }
  .paper-background { width: 430vw; }
  .site-title { left: calc(390vw - 84px); }
  .creator-profile { left: calc(390vw + 8px); }
  .video-stage { left: 5vw; top: 30vh; width: max-content; max-width: none; display: flex; flex-wrap: nowrap; gap: 24px; transform: none; }
  .video-card { flex: 0 0 72vw; width: auto; }
}

/* 切换标签页时暂停，返回时从原位置继续。 */
.paper-background.is-paused .paper-lane { animation-play-state: paused; }

/* 系统开启“减少动态效果”时显示静态格子。 */
@media (prefers-reduced-motion: reduce) {
  .paper-lane, .video-card, .creator-profile, body { animation: none; }
}