/* ==========================================
   颜色变量（海军蓝亮色调）
   ========================================== */
:root {
  --bg: #0d1b2a;
  --bg2: #132233;
  --panel: #172637;
  --panel2: #1e3045;
  --mint: #2dd4bf;
  --warm: #fb923c;
  --violet: #a78bfa;
  --red: #f87171;
  --text: #F5F7FA;
  --muted: #a0b4c4;
  --line: rgba(255,255,255,0.14);
}

/* ==========================================
   基础重置
   ========================================== */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
  width: 100%; height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  overflow: hidden;
}
button { font: inherit; cursor: pointer; border: 0; outline: none; }
.hidden { display: none !important; }

/* 颜色工具类 */
.mint  { color: var(--mint); }
.warm  { color: var(--warm); }
.violet { color: var(--violet); }

/* ==========================================
   教师主容器
   ========================================== */
.teacher-page { overflow: hidden; }
.teacher-shell {
  position: relative;
  width: 100vw;
  height: 100vh;
  padding: 28px 36px 16px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 18% 22%, rgba(45,212,191,0.12), transparent 48%),
    radial-gradient(ellipse at 78% 58%, rgba(167,139,250,0.09), transparent 44%),
    var(--bg);
}

/* ==========================================
   面板通用样式
   ========================================== */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.panel-h2 {
  font-size: 24px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
  flex-shrink: 0;
  line-height: 1.2;
}

/* ==========================================
   主页面视图
   ========================================== */
.main-view {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
}

/* ==========================================
   顶部核心任务句 (~12vh)
   ========================================== */
.mission-banner {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 8px 0 10px;
}
.mission-text {
  font-size: 30px;
  font-weight: 700;
  line-height: 1.45;
  text-align: center;
  color: #e8edf2;
  max-width: 95%;
}
.mission-text span { display: inline; }
.mission-line {
  width: 60%;
  height: 2px;
  margin-top: 10px;
  border-radius: 2px;
  background: linear-gradient(90deg, transparent 0%, var(--mint) 30%, var(--violet) 70%, transparent 100%);
}

/* ==========================================
   两栏主体：左60%（上下堆叠）+ 右40%
   ========================================== */
.tri-panels {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: 58% 42%;
  gap: 16px;
}
.left-stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-height: 0;
  overflow: hidden;
}
.left-stack .model-panel {
  flex: 0 0 38%;
  min-height: 0;
}
.left-stack .data-panel {
  flex: 1;
  min-height: 0;
}

/* ==========================================
   左侧：大模型训练任务
   ========================================== */
.model-visual {
  flex: 1;
  min-height: 0;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.network-svg {
  width: 100%;
  flex: 1;
  min-height: 160px;
}
/* AI核心 */
.ai-core {
  fill: rgba(45,212,191,0.14);
  stroke: rgba(45,212,191,0.6);
  stroke-width: 2.5;
}
.ai-core-text {
  fill: var(--mint);
  font-size: 24px;
  font-weight: 900;
  text-anchor: middle;
  dominant-baseline: middle;
}
.ai-core-sub {
  fill: var(--muted);
  font-size: 12px;
  text-anchor: middle;
  dominant-baseline: middle;
}
/* 连线 */
.net-line {
  stroke: rgba(45,212,191,0.18);
  stroke-width: 2;
}
.net-line.active {
  stroke: rgba(45,212,191,0.6);
  stroke-width: 2.5;
}
/* 节点 */
.net-node {
  fill: #1e3045;
  stroke: rgba(45,212,191,0.35);
  stroke-width: 3;
  transition: fill 0.5s, stroke 0.5s;
}
.net-node.lit {
  fill: rgba(45,212,191,0.35);
  stroke: var(--mint);
  filter: drop-shadow(0 0 10px rgba(45,212,191,0.55));
}

/* 数据流动条 */
.flow-strip {
  width: 75%;
  height: 6px;
  margin: 6px auto 0;
  border-radius: 6px;
  background: rgba(255,255,255,0.07);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}
.flow-strip span {
  position: absolute;
  width: 30%;
  height: 100%;
  border-radius: 6px;
  animation: flowAnim 2.6s infinite linear;
}
.flow-strip span:nth-child(1) { background: var(--mint); }
.flow-strip span:nth-child(2) { background: var(--warm); animation-delay: 0.85s; }
.flow-strip span:nth-child(3) { background: var(--violet); animation-delay: 1.7s; }
@keyframes flowAnim {
  from { left: -35%; }
  to   { left: 103%; }
}

/* 训练进度条 */
.train-progress {
  width: 75%;
  height: 7px;
  margin: 8px auto 0;
  border-radius: 7px;
  background: rgba(255,255,255,0.08);
  overflow: hidden;
  flex-shrink: 0;
}
.progress-fill {
  height: 100%;
  width: 0%;
  border-radius: 7px;
  background: linear-gradient(90deg, var(--mint), var(--warm));
  transition: width 0.25s linear;
}

/* 指标 */
.model-metrics {
  margin-top: 10px;
  flex-shrink: 0;
}
.metric-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 3px 0;
}
.metric-label {
  font-size: 16px;
  color: var(--muted);
}
.metric-val {
  font-size: 22px;
  font-weight: 800;
  color: var(--mint);
}

/* ==========================================
   中间：数据表
   ========================================== */
.data-table {
  width: 100%;
  border-collapse: collapse;
  table-layout: fixed;
  margin-bottom: 8px;
}
.data-table th {
  font-size: 22px;
  font-weight: 700;
  color: var(--muted);
  padding: 10px 4px;
  text-align: center;
  border-bottom: 1px solid var(--line);
  transition: color 0.3s;
}
.data-table th.current-col {
  color: var(--mint);
}
.data-table td {
  font-size: 28px;
  font-weight: 700;
  color: #fff;
  padding: 12px 4px;
  text-align: center;
  transition: color 0.3s, background 0.3s;
}
.data-table td.current-col {
  color: var(--mint);
  background: rgba(45,212,191,0.08);
}
.data-table td.future-cell {
  border: 2px dashed rgba(167,139,250,0.7) !important;
  color: var(--violet);
  font-weight: 900;
}
.data-table td.big-q {
  font-size: 56px;
  line-height: 0.8;
  animation: breatheQ 1.8s ease-in-out infinite;
}
@keyframes breatheQ {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.45; transform: scale(1.06); }
}
.data-note {
  font-size: 20px;
  color: var(--muted);
  text-align: center;
  margin-top: 4px;
}
.data-note.highlight {
  color: var(--warm);
  font-weight: 700;
}

/* ==========================================
   右侧：动态监控图
   ========================================== */
.compute-chart {
  width: 100%;
  flex: 1;
  min-height: 260px;
}
.axis {
  stroke: rgba(255,255,255,0.28);
  stroke-width: 2;
}
.grid-lines line {
  stroke: rgba(255,255,255,0.08);
  stroke-width: 1.5;
  stroke-dasharray: 4 8;
}
.curve-path {
  fill: none;
  stroke: url(#curveGrad);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.point-dot {
  fill: var(--mint);
  stroke: #fff;
  stroke-width: 2.5;
  transition: opacity 0.3s;
}
.point-latest {
  fill: var(--warm);
  filter: drop-shadow(0 0 12px rgba(251,146,60,0.8));
  animation: glowPulse 0.8s ease-in-out infinite;
}
@keyframes glowPulse {
  0%, 100% { fill: var(--warm); stroke-width: 2.5; }
  50%      { fill: #fff; stroke-width: 4; }
}
.future-band {
  fill: rgba(167,139,250,0.07);
  stroke: rgba(167,139,250,0.4);
  stroke-dasharray: 8 8;
  stroke-width: 2;
}
.tick-label {
  fill: var(--muted);
  font-size: 20px;
  text-anchor: middle;
}
.tick-label.violet {
  fill: var(--violet);
  font-weight: 700;
}
.y-tick-label {
  fill: var(--muted);
  font-size: 18px;
  text-anchor: end;
}
.axis-label {
  fill: var(--muted);
  font-size: 22px;
  font-weight: 600;
  text-anchor: middle;
}
.delay-note {
  fill: var(--violet);
  font-size: 18px;
  font-weight: 700;
}
.unknown-mark {
  fill: var(--violet);
  font-size: 68px;
  font-weight: 900;
  text-anchor: middle;
  animation: breatheQ 1.8s ease-in-out infinite;
}
.rotated {
  writing-mode: vertical-rl;
}

/* ==========================================
   底部操作区
   ========================================== */
.bottom-zone {
  height: 64px;
  min-height: 50px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  margin-top: 10px;
}
.control-bar {
  display: flex;
  gap: 10px;
  align-items: center;
}
.ctrl-btn {
  padding: 8px 18px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  background: var(--panel2);
  border: 1px solid rgba(255,255,255,0.16);
  transition: background 0.2s, border-color 0.2s;
  white-space: nowrap;
}
.ctrl-btn:hover {
  background: #2a4057;
  border-color: rgba(255,255,255,0.3);
}
.ctrl-btn:active {
  background: #324b64;
}
.ctrl-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* 问题卡 */
.question-card {
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-bottom: 10px;
  padding: 14px 28px;
  background: var(--panel);
  border: 1px solid rgba(167,139,250,0.5);
  border-radius: 12px;
  text-align: center;
  white-space: nowrap;
  animation: fadeInUp 0.5s ease-out;
}
.question-text {
  font-size: 22px;
  color: #fff;
  margin-bottom: 8px;
  font-weight: 600;
}
.question-btn {
  padding: 10px 32px;
  border-radius: 8px;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  background: var(--violet);
  transition: background 0.2s;
}
.question-btn:hover {
  background: #c4b5fd;
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translate(-50%, 10px); }
  to   { opacity: 1; transform: translate(-50%, 0); }
}

/* ==========================================
   二维码投票页面
   ========================================== */
.vote-view {
  position: absolute;
  top: 0; right: 0; bottom: 0; left: 0;
  padding: 28px 36px;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(ellipse at 15% 15%, rgba(45,212,191,0.08), transparent 42%),
    radial-gradient(ellipse at 82% 68%, rgba(167,139,250,0.08), transparent 42%),
    var(--bg);
  z-index: 10;
}
.vote-back-row {
  flex-shrink: 0;
  margin-bottom: 12px;
}
.back-btn {
  font-size: 15px;
  padding: 7px 16px;
}
.vote-layout {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: 28% 35% 37%;
  gap: 16px;
}

/* 二维码面板 */
.vote-qr-panel {
  align-items: center;
  text-align: center;
}
.qr-box {
  width: 240px;
  height: 240px;
  margin: 14px auto;
  padding: 8px;
  background: #fff;
  border-radius: 8px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
}
.url-text {
  color: var(--muted);
  word-break: break-all;
  font-size: 13px;
  min-height: 36px;
  padding: 0 8px;
}
.qr-note {
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  margin-top: 8px;
}

/* 投票问题面板 */
.vote-question-panel h2 {
  font-size: 26px;
  line-height: 1.35;
  margin-bottom: 16px;
}
.option-list {
  display: grid;
  gap: 12px;
  flex: 1;
}
.option-list .opt-card {
  display: grid;
  grid-template-columns: 48px 90px 1fr;
  align-items: center;
  min-height: 68px;
  padding: 12px;
  border-radius: 8px;
  background: rgba(0,0,0,0.25);
  border: 1px solid var(--line);
}
.opt-card .opt-letter {
  font-size: 34px;
  font-weight: 900;
  color: var(--warm);
  text-align: center;
}
.opt-card .opt-label {
  font-size: 24px;
  font-weight: 700;
  color: #fff;
}
.opt-card .opt-desc {
  font-size: 18px;
  color: var(--muted);
  line-height: 1.3;
}

/* 投票结果面板 */
.vote-result-panel .result-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
}
.result-head .panel-h2 { margin-bottom: 0; }
.demo-badge {
  border: 1px solid var(--warm);
  color: var(--warm);
  padding: 5px 10px;
  border-radius: 6px;
  font-size: 16px;
}
.participation {
  font-size: 32px;
  color: var(--mint);
  font-weight: 900;
  margin: 8px 0 18px;
}
.bars {
  display: grid;
  gap: 18px;
  flex: 1;
}
.bar-row label {
  display: flex;
  justify-content: space-between;
  font-size: 22px;
  margin-bottom: 6px;
}
.bar-row label span { color: #fff; }
.bar-row label b { color: var(--mint); font-size: 20px; }
.bar-track {
  height: 34px;
  border-radius: 8px;
  background: rgba(255,255,255,0.06);
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  width: 0%;
  border-radius: 8px;
  background: linear-gradient(90deg, var(--mint), var(--warm));
  transition: width 0.5s ease;
}
.vote-status-row {
  margin-top: 12px;
  font-size: 16px;
  color: var(--muted);
}
.vote-status-row b { color: #fff; }
.locked-banner {
  margin-top: 14px;
  padding: 14px;
  border-radius: 8px;
  background: rgba(167,139,250,0.15);
  color: var(--violet);
  font-size: 26px;
  text-align: center;
  font-weight: 900;
}

/* 悬念文案 */
.suspense-texts {
  margin-top: 16px;
  text-align: center;
}
.suspense-line {
  font-size: 26px;
  color: var(--muted);
  margin: 12px 0;
  animation: fadeInText 0.8s ease-out both;
}
.suspense-line:nth-child(1) { animation-delay: 0s; }
.suspense-line:nth-child(2) { animation-delay: 1s; }
.suspense-final {
  font-size: 30px;
  font-weight: 800;
  color: #fff;
  margin-top: 16px;
  animation: fadeInText 0.8s 2s ease-out both;
}
@keyframes fadeInText {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* 投票底部控制 */
.vote-controls {
  flex-shrink: 0;
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 14px;
}

/* ==========================================
   教师设置隐藏面板
   ========================================== */
.settings-panel {
  position: absolute;
  right: 36px;
  bottom: 72px;
  width: 320px;
  max-height: 65vh;
  background: rgba(23,38,55,0.98);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 12px;
  overflow-y: auto;
  z-index: 20;
  padding: 0;
}
.settings-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
}
.settings-header h3 {
  font-size: 18px;
  color: #fff;
}
.settings-close {
  width: 30px;
  height: 30px;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 16px;
  display: grid;
  place-items: center;
}
.settings-close:hover {
  background: rgba(255,255,255,0.08);
  color: #fff;
}
.settings-body {
  padding: 14px 18px;
}
.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 7px 0;
}
.setting-row label {
  font-size: 14px;
  color: var(--muted);
}
.setting-row b {
  font-size: 14px;
  color: var(--mint);
}
.setting-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5px;
  margin: 12px 0;
}
.setting-actions button {
  padding: 7px 8px;
  border-radius: 6px;
  font-size: 12px;
  color: #fff;
  background: var(--panel2);
  border: 1px solid rgba(255,255,255,0.12);
}
.setting-actions button:hover {
  background: #2a4057;
}
.setting-divider {
  height: 1px;
  background: var(--line);
  margin: 12px 0;
}
.settings-body h4 {
  font-size: 15px;
  color: #fff;
  margin-bottom: 8px;
}
.manual-vote-rows > div {
  display: grid;
  grid-template-columns: 30px 56px 56px;
  gap: 5px;
  align-items: center;
  margin: 5px 0;
}
.manual-vote-rows b {
  font-size: 16px;
  color: var(--warm);
}
.manual-vote-rows button {
  padding: 5px;
  border-radius: 6px;
  font-size: 13px;
  color: #fff;
  background: var(--panel2);
  border: 1px solid rgba(255,255,255,0.12);
}

/* 设置触发按钮 */
.settings-trigger {
  position: absolute;
  right: 36px;
  bottom: 20px;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: rgba(30,48,69,0.85);
  color: var(--muted);
  font-size: 18px;
  display: grid;
  place-items: center;
  z-index: 19;
  border: 1px solid rgba(255,255,255,0.1);
}
.settings-trigger:hover {
  background: #2a4057;
  color: #fff;
}

/* ==========================================
   响应式调整
   ========================================== */
@media (max-width: 1400px) {
  .teacher-shell {
    padding: 22px 24px 12px;
  }
  .mission-text { font-size: 26px; }
  .panel-h2 { font-size: 22px; }
  .data-table th { font-size: 19px; }
  .data-table td { font-size: 24px; }
  .data-table td.big-q { font-size: 46px; }
  .tick-label { font-size: 17px; }
}

@media (max-width: 1200px) {
  .teacher-shell {
    height: 100vh;
    padding: 16px;
    overflow: auto;
  }
  .tri-panels {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
  }
  .left-stack {
    flex-direction: column;
  }
  .left-stack .model-panel {
    flex: 0 0 auto;
    min-height: 280px;
  }
  .vote-layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
  }
  .mission-text { font-size: 24px; }
}

/* ==========================================
   学生投票页面 - 移动端优先
   ========================================== */

/* 页面容器：重置教师端限制，支持滚动 */
.student-page {
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}

/* 背景氛围 */
.student-bg {
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 40% at 50% 10%, rgba(45,212,191,0.10), transparent),
    radial-gradient(ellipse 50% 30% at 50% 80%, rgba(167,139,250,0.08), transparent),
    var(--bg);
}

/* 主容器 */
.student-container {
  position: relative;
  z-index: 1;
  max-width: 480px;
  margin: 0 auto;
  padding: 20px 20px 32px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-height: 100vh;
  min-height: 100dvh;
}

/* ─── 状态栏 ─── */
.student-status {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 14px;
  background: rgba(45,212,191,0.08);
  border: 1px solid rgba(45,212,191,0.15);
  border-radius: 20px;
  font-size: 13px;
  color: var(--muted);
  align-self: center;
}
.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 6px rgba(45,212,191,0.5);
  animation: statusPulse 2s ease-in-out infinite;
}
@keyframes statusPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* ─── 顶部标题区 ─── */
.student-header {
  text-align: center;
  padding: 8px 0 2px;
}
.student-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 12px;
  color: var(--mint);
  animation: iconFloat 4s ease-in-out infinite;
}
.student-icon svg {
  display: block;
  width: 100%;
  height: 100%;
}
@keyframes iconFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}
.student-header h1 {
  font-size: 22px;
  font-weight: 800;
  color: #fff;
  line-height: 1.3;
  letter-spacing: 0.02em;
}
.student-header h1 span {
  display: block;
  font-size: 17px;
  font-weight: 600;
  color: var(--muted);
  margin-top: 2px;
}
.student-subtitle {
  font-size: 12px;
  color: var(--muted);
  margin-top: 4px;
  letter-spacing: 0.05em;
}

/* ─── 信息卡片 通用 ─── */
.student-card {
  background: linear-gradient(135deg, var(--panel) 0%, var(--panel2) 100%);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
}
.card-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}
.card-label svg { color: var(--mint); }

/* ─── 已知数据卡片 ─── */
.context-grid {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}
.context-stat {
  flex: 1;
  text-align: center;
}
.stat-num {
  display: block;
  font-size: 36px;
  font-weight: 800;
  line-height: 1;
  color: #fff;
  margin-bottom: 4px;
}
.stat-num.accent {
  color: var(--warm);
}
.stat-label {
  font-size: 12px;
  color: var(--muted);
}
.context-divider {
  width: 1px;
  height: 40px;
  background: var(--line);
  border-radius: 1px;
}
.context-note {
  font-size: 13px;
  color: var(--muted);
  text-align: center;
  line-height: 1.5;
}

/* ─── 问题卡片 ─── */
.question-card {
  border-color: rgba(167,139,250,0.2);
  background: linear-gradient(135deg, var(--panel) 0%, rgba(167,139,250,0.06) 100%);
}
.question-card h2 {
  font-size: 16px;
  font-weight: 600;
  color: #d4dce6;
  line-height: 1.7;
  text-align: center;
}
.question-card h2 em {
  font-style: normal;
  font-weight: 700;
}
.question-card h2 em:first-of-type {
  color: var(--warm);
}
.question-card h2 em:last-of-type {
  color: var(--violet);
}

/* ─── 投票选项按钮 ─── */
.student-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.option-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 16px 14px;
  border-radius: 14px;
  background: var(--panel);
  border: 1.5px solid var(--line);
  color: var(--text);
  text-align: left;
  transition: all 0.2s ease;
  -webkit-tap-highlight-color: transparent;
  position: relative;
  overflow: hidden;
}
.option-btn::after {
  content: '';
  position: absolute;
  top: 0; right: 0; bottom: 0; left: 0;
  opacity: 0;
  transition: opacity 0.2s;
}
.option-btn:active {
  transform: scale(0.985);
}

/* 选项 A - 绿色调 */
.option-a {
  border-color: rgba(45,212,191,0.25);
}
.option-a::after {
  background: linear-gradient(135deg, rgba(45,212,191,0.08), transparent);
}
.option-a:active,
.option-a:hover { border-color: var(--mint); background: rgba(45,212,191,0.08); }
.option-a .option-badge {
  background: rgba(45,212,191,0.15);
  color: var(--mint);
}

/* 选项 B - 暖橙色调 */
.option-b {
  border-color: rgba(251,146,60,0.25);
}
.option-b::after {
  background: linear-gradient(135deg, rgba(251,146,60,0.08), transparent);
}
.option-b:active,
.option-b:hover { border-color: var(--warm); background: rgba(251,146,60,0.08); }
.option-b .option-badge {
  background: rgba(251,146,60,0.15);
  color: var(--warm);
}

/* 选项 C - 紫色调 */
.option-c {
  border-color: rgba(167,139,250,0.25);
}
.option-c::after {
  background: linear-gradient(135deg, rgba(167,139,250,0.08), transparent);
}
.option-c:active,
.option-c:hover { border-color: var(--violet); background: rgba(167,139,250,0.08); }
.option-c .option-badge {
  background: rgba(167,139,250,0.15);
  color: var(--violet);
}

/* 已禁用状态 */
.option-btn:disabled {
  opacity: 0.4;
  pointer-events: none;
  filter: grayscale(0.3);
}

/* 选项徽标 */
.option-badge {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

/* 选项文字内容 */
.option-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.option-content strong {
  font-size: 15px;
  font-weight: 700;
  color: #fff;
}
.option-content small {
  font-size: 12px;
  color: var(--muted);
  line-height: 1.35;
  display: block;
}

/* 选项箭头 */
.option-arrow {
  flex-shrink: 0;
  color: var(--muted);
  opacity: 0.5;
  transition: all 0.2s;
}
.option-btn:active .option-arrow,
.option-btn:hover .option-arrow {
  opacity: 1;
  transform: translateX(2px);
}
.option-a:hover .option-arrow { color: var(--mint); }
.option-b:hover .option-arrow { color: var(--warm); }
.option-c:hover .option-arrow { color: var(--violet); }

/* ─── 底部状态 ─── */
.student-footer {
  text-align: center;
  padding: 4px 0 8px;
}
.student-footer p {
  font-size: 13px;
  color: var(--muted);
  transition: all 0.3s;
}
.student-footer.success p {
  color: var(--mint);
  font-weight: 600;
}
.student-footer.error p {
  color: var(--red);
}

/* ─── 确认弹窗 ─── */
.confirm-overlay {
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
  width: 100%;
  height: 100%;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(5, 10, 20, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  animation: overlayIn 0.25s ease;
}
.confirm-overlay.hidden {
  display: none;
}
@keyframes overlayIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.confirm-dialog {
  width: 100%;
  max-width: 320px;
  background: linear-gradient(160deg, var(--panel) 0%, var(--panel2) 100%);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 28px 24px 22px;
  text-align: center;
  animation: dialogUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 24px 48px rgba(0,0,0,0.5);
}
@keyframes dialogUp {
  from { transform: translateY(24px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.confirm-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 14px;
  color: var(--mint);
}
.confirm-icon svg { display: block; width: 100%; height: 100%; }

.confirm-dialog h2 {
  font-size: 17px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 22px;
  line-height: 1.4;
}

.confirm-actions {
  display: flex;
  gap: 12px;
}
.confirm-actions button {
  flex: 1;
  padding: 13px 16px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.confirm-cancel {
  background: rgba(255,255,255,0.06);
  color: var(--muted);
  border: 1px solid var(--line);
}
.confirm-cancel:active { background: rgba(255,255,255,0.12); }
.confirm-submit {
  background: linear-gradient(135deg, var(--mint), #14b8a6);
  color: #0d1b2a;
  font-weight: 700;
  box-shadow: 0 4px 14px rgba(45,212,191,0.25);
}
.confirm-submit:active {
  transform: scale(0.96);
  box-shadow: 0 2px 8px rgba(45,212,191,0.3);
}
.confirm-submit:disabled {
  opacity: 0.5;
  pointer-events: none;
}

/* ─── 大型手机适配 ─── */
@media (min-width: 400px) {
  .student-container { padding: 24px 28px 36px; gap: 20px; }
  .option-btn { padding: 18px 16px; }
  .stat-num { font-size: 40px; }
}
@media (min-width: 480px) {
  .student-container { padding: 32px 36px 40px; gap: 22px; }
}