/* ==========================================================================
   ch6-8.css — 成果展示(6) / 鸣谢终章(7) / 留言墙(8)
   类名严格对应 ch6.js / ch7.js / ch8.js 实际使用的 class
   ========================================================================== */

/* ==========================================================================
   第 6 章 — 成果展示
   ========================================================================== */
.ch6-wrap {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  padding: 5vh 5vw 9vh;
}

.ch6-head { flex: none; text-align: center; margin-bottom: 2.4vh; }

.ch6-kicker {
  font-size: clamp(11px, 1vw, 14px);
  letter-spacing: 0.42em;
  text-indent: 0.42em;
  color: var(--gold);
  opacity: 0.75;
  margin-bottom: 10px;
}

.ch6-title {
  margin: 0;
  font-size: clamp(24px, 3.2vw, 46px);
  font-weight: 800;
  letter-spacing: 0.14em;
  text-indent: 0.14em;
  filter: drop-shadow(0 4px 18px rgba(212, 175, 55, 0.3));
  color: #f0c74a;
  text-shadow:
    0 1px 0 rgba(255, 255, 255, 0.55),
    0 -1px 0 rgba(120, 84, 8, 0.45),
    0 0 22px rgba(255, 200, 70, 0.32);
}

.ch6-rule {
  width: 160px; height: 1px;
  margin: 18px auto 0;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
}

/* 卡片舞台 */
.ch6-stage {
  flex: 1 1 auto;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 0;
}

/* 单个成果卡片（由 JS 动态生成，类名 ch6-card 系列） */
.ch6-card {
  position: absolute;
  width: min(900px, 88vw);
  max-height: 100%;
  display: flex;
  gap: 26px;
  padding: 28px 30px;
  background: linear-gradient(155deg, rgba(22, 26, 36, 0.96), rgba(10, 12, 18, 0.96));
  border: 1px solid rgba(212, 175, 55, 0.3);
  border-radius: 18px;
  box-shadow: 0 26px 70px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.05);
  opacity: 0;
  transform: translateX(60px) scale(0.97);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
  overflow: hidden;
}
.ch6-card.is-in { opacity: 1; transform: none; }
.ch6-card.is-out { opacity: 0; transform: translateX(-60px) scale(0.97); }

/* 卡片左侧编号 */
.ch6-no {
  flex: none;
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: clamp(34px, 4.4vw, 66px);
  font-weight: 800;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1.5px rgba(212, 175, 55, 0.6);
  opacity: 0.85;
}

/* 卡片右侧文本区 */
.ch6-body {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
}

.ch6-heading {
  margin: 0;
  font-size: clamp(20px, 2.3vw, 34px);
  font-weight: 700;
  color: #fff8e2;
  letter-spacing: 0.05em;
  line-height: 1.3;
}

.ch6-desc {
  font-size: clamp(14px, 1.35vw, 20px);
  line-height: 1.85;
  color: #b9bfcc;
  min-height: 1.85em;
}

.ch6-sig {
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: 0.28em;
  color: rgba(212, 175, 55, 0.55);
}

/* 打字机光标 */
.ch6-caret::after {
  content: '▍';
  color: var(--gold);
  animation: ch6blink 0.9s step-end infinite;
}
@keyframes ch6blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }

/* 媒体区 */
.ch6-media {
  position: relative;
  flex: 0 0 42%;
  min-width: 0;
  border-radius: 12px;
  overflow: hidden;
  background: #06070b;
  border: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
}
.ch6-img, .ch6-video {
  width: 100%;
  height: 100%;
  max-height: 46vh;
  object-fit: contain;
  display: block;
}

/* 无媒体时的图标占位 */
.ch6-media--icon {
  position: relative;
  min-height: 180px;
  background:
    radial-gradient(circle at 50% 45%, rgba(212, 175, 55, 0.14), transparent 62%),
    #080a10;
}
.ch6-icon-ring {
  position: absolute;
  width: 150px; height: 150px;
  border: 1px solid rgba(212, 175, 55, 0.35);
  border-radius: 50%;
  animation: ch6ring 2.6s ease-in-out infinite;
}
@keyframes ch6ring {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50%      { transform: scale(1.1); opacity: 0.95; }
}
.ch6-icon {
  font-size: 56px;
  filter: drop-shadow(0 0 18px rgba(212, 175, 55, 0.55));
  animation: ch6glow 2.4s ease-in-out infinite;
}
@keyframes ch6glow {
  0%, 100% { filter: drop-shadow(0 0 10px rgba(212, 175, 55, 0.35)); }
  50%      { filter: drop-shadow(0 0 26px rgba(212, 175, 55, 0.9)); }
}
.ch6-icon-star { font-size: 62px; }
.ch6-icon-ph { font-size: 46px; opacity: 0.85; }
.ch6-icon-txt {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--text-dim);
}

/* 加载/错误状态 */
.ch6-state {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 14px;
  color: var(--text-dim);
  font-size: 15px;
  letter-spacing: 0.1em;
}
.ch6-spin {
  width: 32px; height: 32px;
  border: 2px solid rgba(212, 175, 55, 0.25);
  border-top-color: var(--gold);
  border-radius: 50%;
  animation: ch6spin 0.9s linear infinite;
}
@keyframes ch6spin { to { transform: rotate(360deg); } }
.ch6-err-ico { font-size: 34px; }

/* 底部：指示点 + 跳过 */
.ch6-foot {
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding-top: 2vh;
  min-height: 44px;
}

.ch6-dots { display: flex; gap: 9px; align-items: center; }
.ch6-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
  transition: all 0.4s ease;
}
.ch6-dot.is-on {
  background: var(--gold);
  box-shadow: 0 0 12px rgba(212, 175, 55, 0.85);
  transform: scale(1.35);
}

.ch6-skip { position: absolute; right: 28px; bottom: 58px; }

/* 通用隐藏（本篇章内用） */
.ch6-wrap .is-hidden { display: none !important; }
.ch6-media.is-muted { opacity: 0.4; }

/* 视频手动播放/重试按钮：自动播放被拦或加载失败时的最后通道 */
.ch6-video-play {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 5;
  padding: 12px 22px;
  border: 1px solid rgba(212, 175, 55, .7);
  border-radius: 999px;
  background: rgba(12, 10, 6, .82);
  color: #f2d98a;
  font: 600 15px/1.2 system-ui, -apple-system, "Microsoft YaHei", sans-serif;
  letter-spacing: .08em;
  cursor: pointer;
  backdrop-filter: blur(6px);
}
.ch6-video-play:hover { background: rgba(40, 32, 12, .92); }

/* ==========================================================================
   第 7 章 — 鸣谢终章（电影片尾字幕）
   ========================================================================== */
.ch7-wrap {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: #000;
  overflow: hidden;
}

/* 星空/粒子背景 */
.ch7-stars {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-image:
    radial-gradient(1px 1px at 12% 18%, rgba(255, 255, 255, 0.55), transparent),
    radial-gradient(1px 1px at 78% 32%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(1.5px 1.5px at 42% 72%, rgba(212, 175, 55, 0.5), transparent),
    radial-gradient(1px 1px at 88% 82%, rgba(255, 255, 255, 0.35), transparent),
    radial-gradient(1px 1px at 26% 52%, rgba(212, 175, 55, 0.35), transparent),
    radial-gradient(1.2px 1.2px at 62% 12%, rgba(255, 255, 255, 0.3), transparent);
  opacity: 0.7;
  animation: ch7twinkle 6s ease-in-out infinite;
}
@keyframes ch7twinkle {
  0%, 100% { opacity: 0.45; }
  50%      { opacity: 0.85; }
}

/* 上下遮幅（电影感） */
/* 上下遮幅已删除：第 7 章改成「打字机居中」之后不再需要电影黑边，
   而这两条黑边正是用户看到的「底部往上黑了一块长条」。
   保留选择器但彻底不显示 —— 老缓存里头的 HTML 还带着这两个空壳，直接不显示最稳。 */
.ch7-mask { display: none !important; }

/* ============ 打字机舞台：一行一行居中打出来（ch7.js 逐行写入 .ch7-stroke） ============
   为什么不用「滚动字幕」：滚动会一直动、读不完、看着像卡住。
   现在是每一行都在画面正中，打完一行再长下一行，全部出现在正中这叠里。 */
.ch7-stage {
  position: absolute;
  top: 12vh; right: 0; bottom: 12vh; left: 0;   /* 躲开上下遮幅，字不会钻到黑边里 */
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;      /* 整叠字永远垂直居中：2 行和 12 行都在正中间 */
  padding: 0 6vw;
  overflow: hidden;
}

.ch7-con {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  text-align: center;
}

/* 每一行鸣谢（JS 动态生成 ch7-line + 内层 ch7-stroke） */
.ch7-line {
  margin: 0 0 clamp(10px, 1.7vh, 20px);
  line-height: 1.42;
  letter-spacing: 0.14em;
  /* 打字机是从「空」长到「满」，初始高度为 0 会让整叠字抖动；
     用 min-height 按字号撑住一行，打完之前就占好位置，画面不跳。 */
  min-height: 1.42em;
  opacity: 0;
  transition: opacity .5s ease;
  text-shadow: 0 2px 22px rgba(0, 0, 0, .92);
  word-break: break-word;
}
.ch7-line.is-done { opacity: 1; }
.ch7-line.is-in { opacity: 1; }
/* 正在打字的那一行：后面跟一根闪动的光标，像真的在写 */
.ch7-line.is-typing { opacity: 1; }
.ch7-line.is-typing .ch7-stroke::after {
  content: '';
  display: inline-block;
  width: 2px;
  height: .92em;
  margin-left: .1em;
  vertical-align: -.08em;
  background: currentColor;
  box-shadow: 0 0 10px currentColor;
  animation: ch7Caret .72s steps(1, end) infinite;
}
@keyframes ch7Caret { 0%, 49% { opacity: 1; } 50%, 100% { opacity: .06; } }

/* 全部打完之后：留一点金线分隔的收束感，别让最后一行孤零零飘着 */
.ch7-con.is-all .ch7-line:last-child {
  margin-bottom: 0;
  padding-bottom: clamp(6px, 1.2vh, 14px);
}

/* 底部小提示：只在全部显示完之后浮出来 */
.ch7-tip {
  position: absolute;
  left: 0; right: 0;
  bottom: max(14px, 3.2vh);
  z-index: 7;
  text-align: center;
  font-size: 13px;
  letter-spacing: .18em;
  color: rgba(232, 217, 160, .62);
  opacity: 0;
  transition: opacity .5s ease;
  pointer-events: none;
}
.ch7-tip.on { opacity: 1; animation: ch7tipIn .6s ease both; }
@keyframes ch7tipIn { from { transform: translateY(8px); } to { transform: none; } }

.ch7-state {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-dim);
  font-size: 15px;
  letter-spacing: 0.14em;
  background: #000;
}

/* ==========================================================================
   第 8 章 — 留言墙（核心篇章）
   ========================================================================== */
.ch8-wrap {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(circle at 18% 12%, rgba(212, 175, 55, 0.09), transparent 52%),
    radial-gradient(circle at 82% 78%, rgba(120, 90, 200, 0.1), transparent 55%),
    linear-gradient(165deg, #0a0d16 0%, #0d1020 48%, #07090f 100%);
  overflow: hidden;
}

/* 极光流动背景 */
.ch8-aurora {
  position: absolute;
  top: -25%;
  right: -25%;
  bottom: -25%;
  left: -25%;
  z-index: 0;
  background:
    radial-gradient(closest-side, rgba(212, 175, 55, 0.14), transparent 70%) 22% 30%/46% 46% no-repeat,
    radial-gradient(closest-side, rgba(110, 140, 255, 0.12), transparent 70%) 76% 64%/50% 50% no-repeat,
    radial-gradient(closest-side, rgba(220, 120, 190, 0.09), transparent 70%) 50% 88%/42% 42% no-repeat;
  filter: blur(22px);
  animation: ch8aurora 22s ease-in-out infinite alternate;
  pointer-events: none;
}
@keyframes ch8aurora {
  0%   { transform: translate3d(-3%, -2%, 0) scale(1); }
  50%  { transform: translate3d(3%, 2%, 0) scale(1.08); }
  100% { transform: translate3d(-2%, 3%, 0) scale(1.03); }
}

/* 头部 */
.ch8-head {
  position: relative;
  z-index: 3;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 2.6vh 4vw 1.4vh;
}

.ch8-title {
  margin: 0;
  font-size: clamp(22px, 2.9vw, 42px);
  font-weight: 800;
  letter-spacing: 0.12em;
  filter: drop-shadow(0 3px 16px rgba(212, 175, 55, 0.3));
  color: #f0c74a;
  text-shadow:
    0 1px 0 rgba(255, 255, 255, 0.55),
    0 -1px 0 rgba(120, 84, 8, 0.45),
    0 0 22px rgba(255, 200, 70, 0.32);
}

.ch8-sub {
  margin: 6px 0 0;
  font-size: clamp(12px, 1.1vw, 15px);
  letter-spacing: 0.2em;
  color: var(--text-dim);
}

/* 计数徽章 */
.ch8-count, .ch8-count2 {
  flex: none;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 18px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold-lt);
  background: rgba(212, 175, 55, 0.1);
  border: 1px solid rgba(212, 175, 55, 0.34);
  border-radius: 999px;
  white-space: nowrap;
}
/* 白纸里的字数计数器要深色，不然看不见 */
.ch8-count2 { color: #9c7a12; background: rgba(212, 175, 55, 0.16); border-color: rgba(212, 175, 55, 0.45); }
.ch8-count2 b { color: #7a5c00; }
.ch8-count b, .ch8-count2 b {
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: 18px;
  color: #fff8dc;
}

/* 便签墙 */
.ch8-wall {
  position: relative;
  z-index: 2;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 1.4vh 4vw 12vh;
}
.ch8-wall-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-content: flex-start;
}

/* 单张便签（JS 生成 .ch8-note）
   以前这里没有 background，JS 算好的 --ch8-bg 也没人用 ——
   便签是透明的，深色字直接压在深色墙上，用户反馈「内容错乱，根本看不了一点」。
   现在把底色、轻微倾斜、文字样式全部接上，便签才真的是「便签」。 */
.ch8-note {
  position: relative;
  width: 200px;
  min-height: 130px;
  padding: 16px 16px 14px;
  border-radius: 3px;
  background: var(--ch8-bg, #FFF9C4);
  color: #2b2b2b;
  transform: rotate(var(--ch8-rot, 0deg));
  transform-origin: center top;
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.42), 0 1px 0 rgba(255, 255, 255, 0.5) inset;
  transition: transform 0.28s cubic-bezier(0.22, 1, 0.36, 1), box-shadow 0.28s;
}
.ch8-note:hover {
  transform: rotate(0deg) scale(1.05) !important;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.55);
  z-index: 5;
}
/* 头部：姓名 + 学生/老师标签 */
.ch8-note-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 7px;
  padding-bottom: 6px;
  border-bottom: 1px dashed rgba(0, 0, 0, 0.18);
}

/* 图钉 */
.ch8-note::before {
  content: '';
  position: absolute;
  top: -5px; left: 50%;
  width: 11px; height: 11px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: radial-gradient(circle at 35% 32%, #fff2b8, #c9a227 65%, #7d6414);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.45);
}
.ch8-note-name {
  font-size: 13px;
  font-weight: 700;
  color: #1f1f1f;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
/* 学生 / 老师标签（JS 用的是 .ch8-note-tag，原来这里写的是 .ch8-note-role，压根没生效） */
.ch8-note-tag {
  flex: none;
  font-size: 10.5px;
  font-weight: 400;
  padding: 1px 7px;
  border-radius: 20px;
  background: rgba(0, 0, 0, 0.1);
  color: #444;
}
.ch8-note-tag.is-teacher { background: rgba(180, 130, 20, 0.22); color: #6b4c00; }
.ch8-note-text {
  font-size: 14.5px;
  line-height: 1.7;
  word-break: break-word;
  white-space: pre-wrap;
  color: #2b2b2b;
}
.ch8-note-foot {
  margin-top: 9px;
  font-size: 10.5px;
  text-align: right;
  color: rgba(0, 0, 0, 0.42);
}

/* 依次「啪」地贴上去（结束帧保留便签自身的倾斜，别把贴纸转正） */
.ch8-note-stick { animation: ch8stick 0.62s cubic-bezier(0.34, 1.45, 0.5, 1) both; }
@keyframes ch8stick {
  0%   { transform: scale(1.32) rotate(calc(var(--ch8-rot, 0deg) - 7deg)); }
  45%  { transform: scale(0.93) rotate(calc(var(--ch8-rot, 0deg) + 2deg)); }
  70%  { transform: scale(1.05) rotate(calc(var(--ch8-rot, 0deg) - 1deg)); }
  100% { transform: rotate(var(--ch8-rot, 0deg)); }
}
.ch8-note.is-pop { animation: ch8stick 0.62s cubic-bezier(0.34, 1.45, 0.5, 1) both; }

/* 弹幕层 */
.ch8-dm-layer {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 4;
  pointer-events: none;
  overflow: hidden;
}
.ch8-dm {
  position: absolute;
  left: 100%;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 16px;
  font-size: clamp(15px, 1.5vw, 22px);
  font-weight: 600;
  /* 文字颜色由 ch8.js 注入（便签是浅色 → 弹幕底也是亮色 → 必须用深色字） */
  color: var(--ch8-dm-tx, #fff);
  white-space: nowrap;
  border-radius: 999px;
  /* 弹幕配色 = 对应那条留言便利贴的配色。
     ch8.js 把浅色便签「提纯」成鲜艳色再注入：
       --ch8-dm-bg   = 便签同色相的鲜艳底色（不透明）
       --ch8-dm-bd   = 同色相但更亮一档 → 这就是「外面那一圈颜色」
       --ch8-dm-chip = 名字胶囊的浅色底
     这样便利贴是黄色，飞过去的那条弹幕就是一圈黄。 */
  /* 实心彩色底 + 同色系亮边（颜色由 ch8.js 内联写入，这里是兜底）
     —— 不再有任何半透明 / 毛玻璃，避免看起来"没颜色" */
  background: var(--ch8-dm-bg, #d9c25f);
  border: 3px solid var(--ch8-dm-bd, #f0d97a);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
  text-shadow: none;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  will-change: transform;
}
.ch8-dm-name {
  font-size: 0.78em;
  padding: 1px 9px;
  border-radius: 20px;
  /* 名字小胶囊 = 便签同色系的更浅一档（--ch8-dm-chip 由 JS 注入） */
  background: var(--ch8-dm-chip, rgba(212, 175, 55, 0.28));
  color: #1b2230;
  font-weight: 800;
  border: 1px solid rgba(0, 0, 0, 0.18);
}
/* 老师弹幕：颜色照样跟便利贴走（内联样式优先级更高），
   这里只把描边再加粗一点，让老师的话在满屏弹幕里更突出 */
.ch8-dm--teacher { border-width: 3.5px; }
.ch8-dm--teacher .ch8-dm-name { background: var(--ch8-dm-chip, rgba(255, 214, 92, 0.3)); }

/* 空状态 */
/* 空状态（「还没有人留言」）：以前这里没有 display 规则，
   JS 加的 .is-on 完全不起作用 → 这句话永远显示，跟留言便签叠在一起。
   现在默认隐藏，只有真的没有留言时（JS 加 .is-on）才出现。 */
.ch8-empty {
  display: none;
  width: 100%;
  padding: 8vh 20px;
  text-align: center;
  color: var(--text-dim);
}
.ch8-empty.is-on { display: block; }
.ch8-empty-ico { font-size: 44px; opacity: 0.55; display: block; margin-bottom: 14px; }
.ch8-empty p { margin: 0; font-size: 15px; letter-spacing: 0.12em; line-height: 2; }

/* 「我也要留言」按钮（位置由 .ch8-bar 统一居中） */
.ch8-write {
  position: static;
  z-index: 40;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: clamp(14px, 1.2vw, 17px);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: #14100a;
  background: linear-gradient(135deg, var(--gold-lt), var(--gold));
  border: none;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 10px 30px rgba(212, 175, 55, 0.36);
  transition: transform 0.22s, box-shadow 0.22s, filter 0.22s;
  font-family: inherit;
}
.ch8-write:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 40px rgba(212, 175, 55, 0.55);
  filter: brightness(1.06);
}
.ch8-write:active { transform: translateY(0) scale(0.98); }
.ch8-write-ico { font-size: 1.15em; }

/* 「继续下一章」按钮（位置由 .ch8-bar 统一居中）
   以前它没有任何样式，用的是浏览器默认灰按钮，又小又土，还显得没居中 → 改成和金按钮同尺寸的描边样式 */
.ch8-next {
  position: static;
  z-index: 40;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: clamp(14px, 1.2vw, 17px);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--gold-lt);
  background: rgba(20, 16, 10, 0.55);
  border: 1.5px solid rgba(212, 175, 55, 0.75);
  border-radius: 999px;
  cursor: pointer;
  white-space: nowrap;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.42);
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.22, 1, 0.36, 1),
              box-shadow 0.25s ease, background 0.25s ease;
}
.ch8-next.is-on { opacity: 1; transform: none; pointer-events: auto; }
.ch8-next:hover { transform: translateY(-3px); background: rgba(212, 175, 55, 0.18); box-shadow: 0 16px 40px rgba(212, 175, 55, 0.42); }
.ch8-next:active { transform: translateY(0) scale(0.98); }

/* 底部按钮条：两个按钮居中并排（需求：别再一个贴左一个贴右） */
.ch8-bar {
  position: absolute;
  left: 50%;
  bottom: 52px;
  transform: translateX(-50%);
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  width: max-content;
  max-width: 94vw;
  padding: 0;
  background: none;
  border: none;
  backdrop-filter: none;
  white-space: normal;
}
.ch8-tip { color: #9c7a12; }

/* ---------------- 留言弹窗 ---------------- */
/* 以前漏了 .ch8-modal 这一层的样式（JS 给 .ch8-modal 加 is-on，CSS 却在等 .ch8-mask.is-on），
   结果弹窗根本不是浮层，而是被插进页面流里：一点「我也要留言」就把墙上半截顶出浏览器窗口，
   底下的按钮也被顶到屏幕外，关掉还收不回来 —— 用户反馈的「最后停留有部分跑到窗口之外」就是它。
   这里补齐外层：默认不占位，打开时铺满整屏并把对话框居中。 */
.ch8-modal {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 300;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.ch8-modal.is-on { display: flex; }

.ch8-mask {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 0;
  background: rgba(3, 4, 8, 0.8);
  backdrop-filter: blur(6px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.32s, visibility 0.32s;
}
.ch8-modal.is-on .ch8-mask { opacity: 1; visibility: visible; }
.ch8-mask.is-on { opacity: 1; visibility: visible; }

.ch8-dialog {
  position: relative;
  z-index: 1;
  width: min(560px, 93vw);
  max-height: 90vh;
  overflow: auto;
  padding: 26px 28px 22px;
  /* 用户要求：屏幕中间那张留言纸原来是暗色的，改成浅色（白纸） */
  background: linear-gradient(168deg, #fffdf7, #fff6e4);
  color: #2b2b2b;
  border: 1px solid rgba(212, 175, 55, 0.5);
  border-radius: 18px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.75);
  transform: translateY(20px) scale(0.97);
  transition: transform 0.36s cubic-bezier(0.22, 1, 0.36, 1);
}
.ch8-mask.is-on .ch8-dialog,
.ch8-modal.is-on .ch8-dialog { transform: none; }

.ch8-dlg-head { text-align: center; margin-bottom: 20px; }
.ch8-dlg-head h3 {
  margin: 0;
  font-size: 21px;
  letter-spacing: 0.1em;
  color: #9c7a12;
}
.ch8-dlg-head p {
  margin: 8px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: rgba(60, 50, 30, 0.62);
}

.ch8-field { margin-bottom: 16px; }
.ch8-label {
  display: block;
  margin-bottom: 7px;
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: rgba(60, 50, 30, 0.72);
}

/* 身份切换（学生 / 老师） */
.ch8-seg {
  display: flex;
  gap: 10px;
  padding: 4px;
  background: rgba(0, 0, 0, 0.045);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: 11px;
}
.ch8-seg-btn {
  flex: 1;
  padding: 11px 8px;
  font-size: 14.5px;
  font-weight: 600;
  color: #6b6250;
  background: transparent;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.22s;
  font-family: inherit;
}
.ch8-seg-btn:hover { color: #2b2b2b; background: rgba(0, 0, 0, 0.055); }
.ch8-seg-btn.is-on {
  color: #14100a;
  background: linear-gradient(135deg, var(--gold-lt), var(--gold));
  box-shadow: 0 4px 16px rgba(212, 175, 55, 0.34);
}

/* 姓名下拉 / 输入 */
.ch8-namebox { position: relative; }
.ch8-select, .ch8-input {
  width: 100%;
  padding: 11px 14px;
  font-size: 15px;
  color: #2b2b2b;
  background: #fff;
  border: 1px solid rgba(0, 0, 0, 0.16);
  border-radius: 10px;
  outline: none;
  font-family: inherit;
  transition: border-color 0.22s, box-shadow 0.22s;
}
.ch8-select:focus, .ch8-input:focus {
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.15);
}
.ch8-select option, .ch8-select optgroup {
  background: #fff;
  color: #2b2b2b;
}
.ch8-select--wait {
  display: flex;
  align-items: center;
  gap: 10px;
  color: rgba(60, 50, 30, 0.6);
  font-size: 14px;
}
.ch8-select--wait::before {
  content: '';
  width: 14px; height: 14px;
  border: 2px solid rgba(212, 175, 55, 0.3);
  border-top-color: var(--gold);
  border-radius: 50%;
  animation: ch6spin 0.9s linear infinite;
}

/* 留言输入框 */
.ch8-textarea {
  width: 100%;
  min-height: 108px;
  padding: 12px 14px;
  font-size: 15px;
  line-height: 1.7;
  color: #2b2b2b;
  background: #fff;
  border: 1px solid rgba(0, 0, 0, 0.16);
  border-radius: 10px;
  outline: none;
  resize: vertical;
  font-family: inherit;
  transition: border-color 0.22s, box-shadow 0.22s;
}
.ch8-textarea:focus {
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.15);
}
.ch8-textarea.is-low { border-color: rgba(224, 90, 90, 0.6); }
.ch8-textarea::placeholder { color: rgba(0, 0, 0, 0.34); }

.ch8-dlg-foot {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  margin-top: 20px;
}
/* 关闭按钮：原来只有 20px 高、又被文字样式带偏，手机上几乎点不中 → 做成 34px 圆钮 */
.ch8-x {
  margin-right: auto;
  width: 34px;
  height: 34px;
  min-width: 34px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  line-height: 1;
  font-weight: 700;
  color: #6b6250;
  background: rgba(0, 0, 0, 0.05);
  border: 1px solid rgba(0, 0, 0, 0.13);
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}
.ch8-x:hover {
  color: #2b2b2b;
  background: rgba(0, 0, 0, 0.1);
  border-color: rgba(212, 175, 55, 0.7);
}
.ch8-x:active { transform: scale(0.94); }

.ch8-btn {
  padding: 11px 24px;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.08em;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.22s;
  font-family: inherit;
  border: 1px solid transparent;
  white-space: nowrap;
}
.ch8-btn-main {
  color: #14100a;
  background: linear-gradient(135deg, var(--gold-lt), var(--gold));
  border-color: var(--gold);
  box-shadow: 0 6px 20px rgba(212, 175, 55, 0.3);
}
.ch8-btn-main:hover { filter: brightness(1.07); box-shadow: 0 10px 28px rgba(212, 175, 55, 0.5); }
.ch8-btn-main.is-busy { opacity: 0.6; cursor: wait; }
.ch8-btn-ghost {
  color: #6b6250;
  background: rgba(0, 0, 0, 0.045);
  border-color: rgba(0, 0, 0, 0.15);
}
.ch8-btn-ghost:hover { color: #2b2b2b; background: rgba(0, 0, 0, 0.09); }

/* 小屏适配 */
@media (max-width: 900px) {
  .ch6-card { flex-direction: column; gap: 16px; padding: 20px; }
  .ch6-media { flex: 0 0 auto; width: 100%; }
  .ch6-no { font-size: 30px; }
  .ch8-note { width: calc(50% - 8px); }
  /* 小屏：两个按钮依旧居中，改成上下排，别被裁掉 */
  .ch8-bar {
    flex-direction: column;
    gap: 10px;
    bottom: 34px;
    width: 92vw;
  }
  .ch8-write, .ch8-next { width: 100%; justify-content: center; padding: 12px 18px; }
}

/* ==================================================================
   留言墙姓名选择：自己画的可点选名字网格。
   原来用原生 <select>，在微信 / QQ / iOS 的带 transform 动画弹层里点不开，
   用户反馈「名单加载不出来 / 选择不了」就是这个原因，改成普通按钮后全平台可点。
   ================================================================== */
.ch8-namegrid {
  max-height: 32vh;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding-right: 4px;
}
.ch8-namegroup + .ch8-namegroup { margin-top: 10px; }
.ch8-namelab {
  margin: 2px 0 6px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: rgba(60, 50, 30, 0.75);
}
.ch8-namelist {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(74px, 1fr));
  gap: 6px;
}
.ch8-namechip {
  min-height: 40px;
  padding: 6px 8px;
  border-radius: 10px;
  border: 1px solid rgba(0, 0, 0, 0.14);
  background: #fff;
  color: #2b2b2b;
  font-size: 14px;
  line-height: 1.2;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  -webkit-appearance: none;
  appearance: none;
}
.ch8-namechip:hover { background: #fff8e3; border-color: rgba(212, 175, 55, 0.65); }
.ch8-namechip.is-on {
  background: linear-gradient(135deg, rgba(255, 208, 120, 0.9), rgba(255, 168, 90, 0.9));
  border-color: rgba(255, 226, 168, 0.95);
  color: #3a2400;
  font-weight: 700;
  box-shadow: 0 4px 14px rgba(255, 180, 90, 0.35);
}
.ch8-picked {
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(60, 50, 30, 0.78);
}
.ch8-namefail { display: flex; flex-direction: column; gap: 8px; }
.ch8-namefail-txt { margin: 0; font-size: 13px; color: rgba(60, 50, 30, 0.8); }
.ch8-retry {
  align-self: flex-start;
  min-height: 38px;
  padding: 6px 14px;
  border-radius: 10px;
  border: 1px solid rgba(212, 175, 55, 0.6);
  background: rgba(255, 208, 120, 0.32);
  color: #7a5c00;
  font-size: 13px;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}
@media (max-width: 640px) {
  .ch8-namelist { grid-template-columns: repeat(auto-fill, minmax(66px, 1fr)); }
  .ch8-namegrid { max-height: 36vh; }
}

/* ============================================================ 鸣谢名单 · 标题
   用户反馈「鸣谢名单那里没有『鸣谢名单』这几个字」——
   滚动名单上方固定一行金色标题，z-index 高于遮幅与滚动内容，任何情况下都不会被顶出屏幕 */
.ch7-head {
  position: absolute;
  top: max(22px, 4vh);
  left: 0; right: 0;
  z-index: 6;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 0 18px;
  pointer-events: none;
  animation: ch7headIn 1.1s cubic-bezier(0.22, 1, 0.36, 1) both;
}
.ch7-head b {
  font-size: clamp(15px, 2.4vw, 22px);
  font-weight: 500;
  letter-spacing: 0.34em;
  text-indent: 0.34em;
  color: var(--gold-lt, #e8d9a0);
  text-shadow: 0 0 18px rgba(212, 175, 55, 0.45);
  white-space: nowrap;
}
.ch7-head-line {
  flex: 0 1 96px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(212, 175, 55, 0.75), transparent);
}
@keyframes ch7headIn {
  from { opacity: 0; transform: translateY(-14px); }
  to   { opacity: 1; transform: none; }
}
@media (max-width: 640px) {
  .ch7-head { top: 3.4vh; gap: 10px; }
  .ch7-head b { font-size: 15px; letter-spacing: 0.26em; }
  .ch7-head-line { flex-basis: 54px; }
}

/* ============================================================ 成果展示 · 音频卡片
   音频没有画面，用一排跳动的音柱 + 标题撑住版面，
   跟图片 / 视频卡片的视觉重量保持一致，不会看起来「空了一块」。 */
.ch6-media--audio { display: flex; }

.ch6-audioart {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(12px, 2vh, 26px);
  width: 100%;
  height: 100%;
  padding: 18px;
}

.ch6-audioart-bars {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(4px, 0.5vw, 9px);
  height: clamp(56px, 12vh, 130px);
}
.ch6-audioart-bars i {
  display: block;
  width: clamp(5px, 0.55vw, 10px);
  height: 100%;
  border-radius: 99px;
  background: linear-gradient(180deg, #f5d76e, #d4af37 55%, rgba(212, 175, 55, 0.25));
  transform-origin: center;
  animation: ch6AudioBar 1.5s ease-in-out infinite;
  animation-delay: var(--dl, 0s);
  opacity: 0.92;
  box-shadow: 0 0 14px rgba(240, 199, 74, 0.28);
}
@keyframes ch6AudioBar {
  0%, 100% { transform: scaleY(0.26); }
  50%      { transform: scaleY(var(--d, 0.8)); }
}

.ch6-audioart-lbl {
  font-size: clamp(12px, 1.2vw, 19px);
  font-weight: 600;
  letter-spacing: 0.06em;
  color: rgba(240, 199, 74, 0.92);
  text-align: center;
  text-shadow: 0 0 18px rgba(240, 199, 74, 0.28);
  max-width: 92%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 音频元素本身不占版面（只用来出声） */
.ch6-audio { display: none !important; }

/* 窄屏收紧 */
@media (max-width: 760px) {
  .ch6-audioart { gap: 10px; padding: 10px; }
  .ch6-audioart-bars { height: 56px; gap: 4px; }
  .ch6-audioart-bars i { width: 4px; }
}