/* ============================================================
   mentors-3d.css — 导师 3D 卡片展示
   两种用法：
   1) 独立整页：body.m3-page + .m3-root（pages/mentors.html）
   2) 嵌入长页 section：section.m3-section > .m3-root（about.html）
   换老师只改 js/mentors-3d.js 的 TEACHERS 数组
   ============================================================ */

:root {
  --m3-bg: #050508;
  --m3-ink: #ffffff;
  --m3-ink-dim: rgba(255, 255, 255, 0.55);
  --m3-glow-a: #4f6bff;
  --m3-glow-b: #9b5cff;
  --m3-glow-c: #2fd4ff;
  --m3-card-bg: #0d0d16;
  --m3-card-border: rgba(255, 255, 255, 0.1);
}

html, body { margin: 0; padding: 0; }

/* ---------- 独立整页模式 ---------- */
body.m3-page {
  background: var(--m3-bg);
  color: var(--m3-ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI',
    'PingFang SC', 'Microsoft YaHei', sans-serif;
  overflow: hidden;
  height: 100vh;
}

/* ---------- 嵌入 section 模式 ---------- */
section.m3-section {
  position: relative;
  height: 55vh;
  min-height: 380px;
  overflow-x: clip;
  overflow-y: visible;
  background: var(--m3-bg);
}

/* 底部光晕延伸 — 让导师区紫蓝光晕完整过渡到下方学生区 */
section.m3-section .m3-glow-field {
  bottom: -200px;
  overflow: visible;
}
section.m3-section .m3-glow.g2 {
  bottom: -20vmax;
  opacity: 0.4;
}

/* 所有 3D UI 都装在 .m3-root 里，fixed=整页 / absolute=嵌入 */
.m3-root {
  position: fixed;
  inset: 0;
  overflow: hidden;
  z-index: 1;
}
section.m3-section .m3-root {
  position: absolute;
  z-index: 2;
  overflow: visible;
}

/* 嵌入模式下不需要返回按钮 */
section.m3-section .m3-back { display: none; }

/* ---------- 背景光晕 ---------- */
.m3-glow-field {
  position: absolute;
  inset: 0;
  overflow: visible;
  pointer-events: none;
  z-index: 0;
}

.m3-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.55;
  will-change: transform;
}

.m3-glow.g1 {
  width: 55vmax;
  height: 55vmax;
  left: -15vmax;
  top: -12vmax;
  background: radial-gradient(circle, var(--m3-glow-a) 0%, transparent 65%);
  animation: m3-drift-a 26s ease-in-out infinite alternate;
}

.m3-glow.g2 {
  width: 48vmax;
  height: 48vmax;
  right: -14vmax;
  bottom: -16vmax;
  background: radial-gradient(circle, var(--m3-glow-b) 0%, transparent 65%);
  animation: m3-drift-b 32s ease-in-out infinite alternate;
}

.m3-glow.g3 {
  width: 34vmax;
  height: 34vmax;
  right: 8vw;
  top: -10vmax;
  background: radial-gradient(circle, var(--m3-glow-c) 0%, transparent 65%);
  opacity: 0.35;
  animation: m3-drift-c 22s ease-in-out infinite alternate;
}

@keyframes m3-drift-a {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(9vw, 7vh, 0) scale(1.15); }
}
@keyframes m3-drift-b {
  from { transform: translate3d(0, 0, 0) scale(1.1); }
  to   { transform: translate3d(-8vw, -6vh, 0) scale(0.95); }
}
@keyframes m3-drift-c {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-6vw, 9vh, 0); }
}

/* 光晕随鼠标轻微视差（JS 写 CSS 变量） */
.m3-glow-field {
  transform: translate3d(calc(var(--mx, 0) * 18px), calc(var(--my, 0) * 14px), 0);
  transition: transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

/* 微噪点，避免大面积纯黑的塑料感 */
.m3-grain {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.05;
  background-image: radial-gradient(rgba(255, 255, 255, 0.6) 0.5px, transparent 0.5px);
  background-size: 3px 3px;
}

/* ---------- 嵌入模式：板块标题（沿用站点 section-header） ---------- */
section.m3-section .m3-sec-header {
  position: absolute;
  top: 96px;
  left: 6vw;
  z-index: 25;
}
section.m3-section .m3-sec-header .section-label { color: var(--text-secondary); opacity: 1; font-size: 0.75rem; letter-spacing: 0.3em; font-weight: 500; margin-bottom: 20px; }
section.m3-section .m3-sec-header .section-title { color: var(--text-primary); opacity: 1; font-size: clamp(2rem, 4vw, 3rem); font-weight: 700; margin-bottom: 16px; letter-spacing: normal; }
section.m3-section .m3-sec-header .section-subtitle { color: var(--text-secondary); opacity: 1; font-size: 1.125rem; font-weight: 400; max-width: 600px; }

/* ---------- 顶部返回 / 计数 ---------- */
.m3-back {
  position: absolute;
  top: 28px;
  left: 32px;
  z-index: 30;
  color: var(--m3-ink-dim);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.12em;
  padding: 8px 14px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  backdrop-filter: blur(8px);
  transition: color 0.3s, border-color 0.3s;
}
.m3-back:hover { color: #fff; border-color: rgba(255, 255, 255, 0.5); }

.m3-counter {
  position: absolute;
  top: 32px;
  right: 36px;
  z-index: 30;
  font-family: 'JetBrains Mono', 'SF Mono', Consolas, monospace;
  font-size: 13px;
  color: var(--m3-ink-dim);
  letter-spacing: 0.15em;
}
section.m3-section .m3-counter { top: 96px; }
.m3-counter .cur { color: #fff; font-size: 20px; }

/* ---------- 左侧文字区 ---------- */
.m3-info {
  position: absolute;
  left: 14vw;
  top: 38%;
  transform: translateY(-50%);
  z-index: 20;
  max-width: 34vw;
  pointer-events: none;
}

.m3-info-label {
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--m3-ink-dim);
  text-transform: uppercase;
  margin-bottom: 20px;
  position: relative;
  padding-left: 28px;
}
.m3-info-label::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 20px;
  height: 1px;
  background: linear-gradient(90deg, #4f6bff, #9b5cff);
  opacity: 0.6;
}

.m3-info-name {
  font-family: 'Cormorant Garamond', 'Noto Sans SC', serif;
  font-weight: 600;
  font-size: clamp(32px, 4vw, 46px);
  line-height: 1.1;
  margin: 0 0 14px;
  min-height: 1.1em;
  letter-spacing: 0.04em;
  text-shadow: 0 0 30px rgba(79, 107, 255, 0.15), 0 0 60px rgba(155, 92, 255, 0.08);
}

.m3-info-title {
  font-size: clamp(14px, 1.5vw, 20px);
  font-weight: 500;
  color: var(--m3-ink);
  letter-spacing: 0.05em;
  margin: 0 0 20px;
  min-height: 1.4em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 详情字段 */
.m3-info-details {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 24px;
}
.m3-info-row {
  display: flex;
  align-items: baseline;
  gap: 14px;
}
.m3-info-key {
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.35);
  white-space: nowrap;
  min-width: 56px;
}
.m3-info-val {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.75);
  letter-spacing: 0.02em;
  word-break: break-all;
}
.m3-info-link {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(255, 255, 255, 0.3);
  transition: color 0.3s ease, text-decoration-color 0.3s ease;
  pointer-events: auto;
  cursor: pointer;
  display: inline-block;
  padding: 4px 0;
  margin: -4px 0;
}
.m3-info-link:hover {
  color: #fff;
  text-decoration-color: rgba(255, 255, 255, 0.8);
  opacity: 1;
  text-shadow: 0 0 8px rgba(120, 140, 255, 0.5);
}

.m3-info-hint {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--m3-ink-dim);
  letter-spacing: 0.15em;
}
.m3-info-hint::before {
  content: "";
  width: 34px;
  height: 1px;
  background: rgba(255, 255, 255, 0.35);
}

/* 文字切换动画 */
.m3-fade-swap {
  animation: m3-fade-in 0.55s cubic-bezier(0.22, 1, 0.36, 1) both;
}
@keyframes m3-fade-in {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* 进场动画期间隐藏文字/控件：HTML 直接带 m3-booting 类，
   JS 在卡片收回后移除该类并逐个播放浮现动画。
   visibility 不在 m3-fade-in 关键帧内，可稳定压住元素自带的动画 */
.m3-root.m3-booting .m3-sec-header,
.m3-root.m3-booting .m3-info-label,
.m3-root.m3-booting .m3-info-name,
.m3-root.m3-booting .m3-info-title,
.m3-root.m3-booting .m3-info-details,
.m3-root.m3-booting .m3-info-hint,
.m3-root.m3-booting .m3-counter,
.m3-root.m3-booting .m3-dots,
.m3-root.m3-booting .m3-arrow { opacity: 0; visibility: hidden; }

/* 进场拉尾特效的残影卡（JS 播完自动移除） */
.m3-card.m3-ghost {
  pointer-events: none;
  cursor: default;
  filter: blur(1px);
}

/* ---------- 右侧卡片堆 ---------- */
.m3-stage {
  position: absolute;
  right: 8vw;
  top: 38%;
  transform: translateY(-50%);
  z-index: 10;
  width: min(30vw, 420px);
  aspect-ratio: 3 / 3.8;
}

.m3-stack {
  position: absolute;
  inset: 0;
  transition: transform 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.m3-card {
  position: absolute;
  inset: 0;
  border-radius: 18px;
  background: var(--m3-card-bg);
  border: 1px solid var(--m3-card-border);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.55);
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.65s cubic-bezier(0.22, 1, 0.36, 1),
              opacity 0.65s cubic-bezier(0.22, 1, 0.36, 1),
              box-shadow 0.65s;
  will-change: transform, opacity;
}

/* 堆叠层级位置：pos-0 在最前 */
.m3-card.pos-0 {
  transform: translate3d(0, 0, 0) rotateZ(0deg);
  z-index: 5;
}
.m3-card.pos-1 {
  transform: translate3d(4.5%, -3.5%, -90px) rotateZ(3.5deg);
  z-index: 4;
}
.m3-card.pos-2 {
  transform: translate3d(-4%, -7%, -180px) rotateZ(-2.5deg);
  z-index: 3;
}
.m3-card.pos-3 {
  transform: translate3d(6.5%, 4%, -270px) rotateZ(5deg);
  z-index: 2;
}
.m3-card.pos-back {
  transform: translate3d(-2%, -9%, -340px) rotateZ(-4deg);
  z-index: 1;
}

/* 飞出动画 */
.m3-card.out-next {
  transform: translate3d(38%, 12%, 60px) rotateZ(14deg);
  opacity: 0;
  z-index: 6;
}
.m3-card.out-prev {
  transform: translate3d(-42%, 14%, 60px) rotateZ(-14deg);
  opacity: 0;
  z-index: 6;
}

.m3-card:hover.pos-0 {
  box-shadow: 0 40px 90px rgba(79, 107, 255, 0.25),
              0 30px 60px rgba(0, 0, 0, 0.55);
}

/* 卡片照片 */
.m3-card-photo {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(150deg, #1c1c2e 0%, #10101c 55%, #1a1630 100%);
}

.m3-card-photo .m3-initial {
  font-family: 'Cormorant Garamond', 'Noto Sans SC', serif;
  font-size: clamp(90px, 9vw, 150px);
  color: rgba(255, 255, 255, 0.14);
  user-select: none;
}

.m3-card-photo img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  opacity: 0;
  transition: opacity 0.6s;
}
.m3-card-photo img.loaded { opacity: 1; }

/* 卡片底部小标题条 */
.m3-card-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.75), transparent);
  font-size: 13px;
  letter-spacing: 0.06em;
}
.m3-card-caption .cap-name { font-weight: 600; }
.m3-card-caption .cap-idx {
  font-family: 'JetBrains Mono', 'SF Mono', Consolas, monospace;
  color: var(--m3-ink-dim);
  font-size: 11px;
}

/* 卡片顶部小徽标 */
.m3-card-badge {
  position: absolute;
  top: 18px;
  left: 20px;
  font-size: 10px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  padding: 5px 12px;
  backdrop-filter: blur(6px);
}

/* ---------- 右侧导航点 ---------- */
.m3-dots {
  position: absolute;
  right: 36px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 30;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.m3-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.25);
  cursor: pointer;
  transition: background 0.3s, transform 0.3s, box-shadow 0.3s;
  position: relative;
}
.m3-dot.active {
  background: #fff;
  transform: scale(1.25);
  box-shadow: 0 0 12px rgba(120, 140, 255, 0.9);
}
.m3-dot:hover::after {
  content: attr(data-name);
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.85);
  white-space: nowrap;
  background: rgba(10, 10, 18, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 4px 10px;
  border-radius: 6px;
  pointer-events: none;
}

/* ---------- 底部提示 ---------- */
.m3-scroll-hint {
  position: absolute;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--m3-ink-dim);
  font-size: 11px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
}
.m3-scroll-hint .line {
  width: 1px;
  height: 34px;
  background: linear-gradient(to bottom, transparent, rgba(255, 255, 255, 0.6));
  animation: m3-pulse-line 2s ease-in-out infinite;
}
@keyframes m3-pulse-line {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

/* 左右箭头（桌面端） */
.m3-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 30;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.04);
  color: rgba(255, 255, 255, 0.7);
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  transition: background 0.3s, color 0.3s, border-color 0.3s;
}
.m3-arrow:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}
.m3-arrow.prev { left: 3vw; }
.m3-arrow.next { right: 3vw; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  /* 移动端裁剪光晕溢出，避免水平滚动条 */
  section.m3-section { overflow: hidden; }

  .m3-info {
    left: 50%;
    top: auto;
    bottom: 9vh;
    transform: translateX(-50%);
    max-width: 86vw;
    text-align: center;
  }
  .m3-info-name { font-size: clamp(30px, 8vw, 44px); }
  .m3-info-hint::before { display: none; }
  .m3-info-hint { letter-spacing: 0.08em; }
  .m3-info-title { margin-bottom: 14px; }
  .m3-info-details { gap: 8px; margin-bottom: 18px; }
  .m3-info-key { min-width: 48px; font-size: 10px; }
  .m3-info-val { font-size: 13px; }

  .m3-stage {
    right: 50%;
    top: 42%;
    transform: translate(50%, -50%);
    width: min(64vw, 320px);
  }

  .m3-dots { right: 14px; gap: 14px; }
  .m3-counter { top: auto; bottom: 20px; right: 20px; }
  section.m3-section .m3-counter { top: auto; bottom: 20px; }
  .m3-back { top: 18px; left: 18px; }
  .m3-arrow { display: none; }
  .m3-scroll-hint { display: none; } /* 触屏用户自然滑动，避免与文字区重叠 */
  section.m3-section .m3-sec-header { display: none; } /* 手机端信息块已含 OUR MENTORS */
}

/* 尊重系统减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .m3-glow { animation: none; }
  .m3-card, .m3-stack, .m3-glow-field { transition: none; }
}