:root {
  --bg: #0d1220;
  --panel: #141b2d;
  --panel-2: #1a2338;
  --border: #26324d;
  --text: #e8eefb;
  --dim: #93a3bf;
  --accent: #4f8cff;
  --accent-2: #22d3ee;
  --green: #34d399;
  --red: #ff6b6b;
  --orange: #ffb86c;
  --font: 15px;
  --mono: "Consolas", "JetBrains Mono", "Cascadia Code", "Microsoft YaHei", monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
  font-size: var(--font);
  overflow: hidden;
}

button {
  font-family: inherit;
}

/* ---------- 顶栏 ---------- */

.topbar {
  display: flex;
  align-items: center;
  gap: 18px;
  height: 54px;
  padding: 0 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
}

.brand .logo {
  font-size: 20px;
}

.brand .title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 1px;
}

.brand .sub {
  color: var(--dim);
  font-size: 13px;
}

.tabs {
  display: flex;
  gap: 4px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3px;
}

.tab {
  border: none;
  background: transparent;
  color: var(--dim);
  padding: 6px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.15s;
}

.tab:hover {
  color: var(--text);
}

.tab.active {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}

.actions {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}

select {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 7px 10px;
  font-size: 13px;
  max-width: 260px;
  cursor: pointer;
}

.btn {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 7px 14px;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s;
}

.btn:hover {
  border-color: var(--accent);
  color: #fff;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent), #6f5cff);
  border-color: transparent;
  color: #fff;
  font-weight: 600;
}

.btn.accent {
  background: linear-gradient(135deg, #0ea5a6, #22d3ee);
  border-color: transparent;
  color: #062022;
  font-weight: 600;
}

.btn.sm {
  padding: 6px 9px;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.divider {
  width: 1px;
  height: 24px;
  background: var(--border);
  margin: 0 4px;
}

/* ---------- 视图 ---------- */

.view {
  display: none;
  height: calc(100vh - 54px);
}

.view.active {
  display: block;
}

/* ---------- 演示台 ---------- */

.demo-grid {
  display: grid;
  grid-template-columns: minmax(380px, 44%) 1fr;
  height: calc(100% - 46px);
}

.editor-pane,
.output-pane {
  display: flex;
  flex-direction: column;
  min-height: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
}

.pane-head {
  height: 40px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--dim);
  border-bottom: 1px solid var(--border);
  background: var(--panel-2);
  flex-shrink: 0;
}

.hint {
  color: var(--dim);
  font-weight: 400;
  font-size: 12px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#editor-wrap {
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.CodeMirror {
  height: 100% !important;
  font-family: var(--mono);
  font-size: var(--font);
  line-height: 1.55;
  background: #101728;
  color: #d8e1f0;
}

.CodeMirror-gutters {
  background: #101728;
  border-right: 1px solid #1d2942;
  color: #55617a;
}

.CodeMirror-linenumber {
  color: #55617a;
}

.CodeMirror-cursor {
  border-left: 2px solid var(--accent-2);
}

.CodeMirror-selected {
  background: rgba(79, 140, 255, 0.25) !important;
}

.cm-s-teach-dark .cm-keyword {
  color: #c792ea;
  font-weight: 600;
}

.cm-s-teach-dark .cm-string,
.cm-s-teach-dark .cm-string-2 {
  color: #a5e075;
}

.cm-s-teach-dark .cm-number {
  color: #f78c6c;
}

.cm-s-teach-dark .cm-comment {
  color: #64748b;
  font-style: italic;
}

.cm-s-teach-dark .cm-builtin {
  color: #82aaff;
}

.cm-s-teach-dark .cm-def {
  color: #ffcb6b;
}

.cm-s-teach-dark .cm-operator {
  color: #89ddff;
}

.cm-s-teach-dark .cm-variable {
  color: #d8e1f0;
}

.cm-s-teach-dark .cm-variable-2 {
  color: #d8e1f0;
}

.cm-s-teach-dark .cm-attribute {
  color: #f78c6c;
}

.cm-s-teach-dark .cm-tag {
  color: #f07178;
}

.editor-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 34px;
  padding: 0 14px;
  font-size: 12px;
  color: var(--dim);
  border-top: 1px solid var(--border);
  background: var(--panel-2);
  flex-shrink: 0;
}

#status-text.running::after {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-left: 6px;
  border: 2px solid var(--accent-2);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: -1px;
}

#status-text.ok {
  color: var(--green);
}

#status-text.err {
  color: var(--red);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ---------- 输出区 ---------- */

.output-body {
  flex: 1;
  display: grid;
  grid-template-rows: minmax(120px, 42%) 1fr;
  min-height: 0;
}

.console-area {
  overflow: auto;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  background: #0e1424;
}

.console {
  font-family: var(--mono);
  font-size: calc(var(--font) * 0.96);
  white-space: pre-wrap;
  word-break: break-word;
  color: #d5e2f8;
  min-height: 1em;
}

.console.error {
  color: #ff9d9d;
}

.console:empty {
  display: none;
}

#meta {
  margin-top: 8px;
  font-size: 12px;
  color: var(--dim);
}

.result-area {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 0;
}

.figures-pane,
.vars-pane {
  overflow: auto;
  padding: 10px 14px;
  min-height: 0;
}

.figures-pane {
  border-right: 1px solid var(--border);
}

h4 {
  font-size: 13px;
  color: var(--dim);
  font-weight: 600;
  margin-bottom: 8px;
}

.badge {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1px 8px;
  font-size: 11px;
  color: var(--text);
}

.figures {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.figures img {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}

.vars table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.vars th,
.vars td {
  text-align: left;
  padding: 5px 8px;
  border-bottom: 1px solid #1d2942;
  vertical-align: top;
  word-break: break-all;
}

.vars th {
  color: var(--dim);
  font-weight: 600;
  position: sticky;
  top: 0;
  background: var(--panel);
}

.vars td.name {
  color: var(--accent-2);
  font-family: var(--mono);
  font-weight: 600;
  white-space: nowrap;
}

.vars td.type {
  color: var(--orange);
  font-family: var(--mono);
  font-size: 12px;
  white-space: nowrap;
}

.vars td.value {
  font-family: var(--mono);
  font-size: 12px;
  color: #c9d6ec;
}

.vars tr.changed td {
  background: rgba(52, 211, 153, 0.09);
}

.vars tr.added td {
  background: rgba(79, 140, 255, 0.1);
}

.vars .empty,
.figures .empty {
  color: var(--dim);
  font-size: 13px;
  padding: 18px 0;
}

/* ---------- 逐步执行条 ---------- */

.stepbar {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 46px;
  padding: 0 16px;
  background: var(--panel);
  border-top: 1px solid var(--border);
}

.stepbar.hidden {
  display: none;
}

#step-slider {
  flex: 1;
  accent-color: var(--accent-2);
  cursor: pointer;
}

#step-info {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--accent-2);
  white-space: nowrap;
}

.cm-line-active {
  background: rgba(34, 211, 238, 0.14) !important;
}

.cm-line-active::before {
  content: "▶";
  color: var(--accent-2);
  margin-right: 6px;
  font-size: 11px;
}

/* ---------- 讲义 ---------- */

.lesson-layout {
  display: grid;
  grid-template-columns: 230px 1fr;
  height: 100%;
}

.lesson-list {
  border-right: 1px solid var(--border);
  background: var(--panel);
  overflow: auto;
  padding: 14px 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.lesson-item {
  text-align: left;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
  transition: all 0.15s;
}

.lesson-item:hover {
  border-color: var(--accent);
}

.lesson-item.active {
  border-color: var(--accent);
  background: rgba(79, 140, 255, 0.12);
}

.lesson-item .t {
  font-size: 14px;
  font-weight: 600;
}

.lesson-item .d {
  font-size: 12px;
  color: var(--dim);
  margin-top: 4px;
  line-height: 1.45;
}

.lesson-add {
  border-style: dashed;
  text-align: center;
}

.lesson-item-actions {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

.lesson-item-actions .btn {
  padding: 3px 10px;
  font-size: 12px;
}

.btn.danger {
  color: var(--red);
  border-color: rgba(255, 107, 107, 0.4);
}

.example-mgr-list {
  overflow: auto;
  padding: 14px 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
  min-height: 0;
}

.example-mgr-list .lesson-item {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: default;
}

.example-mgr-list .lesson-item .d {
  flex: 1;
  margin-top: 0;
}

.example-mgr-list .lesson-item .sub {
  font-size: 12px;
  color: var(--dim);
  margin-top: 4px;
  line-height: 1.45;
}

.example-manager {
  display: flex;
  flex-direction: column;
  width: min(680px, 94vw);
  max-height: 82vh;
}

.code-preview {
  background: var(--panel);
}

/* ============ 代码工作台 ============ */

.ws-layout {
  display: flex;
  height: calc(100vh - var(--topbar-h, 54px));
  min-height: 0;
}

.ws-side {
  width: 230px;
  min-width: 190px;
  border-right: 1px solid var(--border);
  background: var(--panel);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.ws-side-head {
  padding: 10px 10px 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
}

.ws-title {
  font-weight: 600;
  font-size: 14px;
  white-space: nowrap;
}

.ws-side-actions {
  display: flex;
  gap: 4px;
}

.ws-side-actions .btn {
  padding: 3px 8px;
  font-size: 12px;
  white-space: nowrap;
}

.ws-pathbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
  padding: 4px 10px 8px;
  font-size: 12px;
  border-bottom: 1px solid var(--border);
}

.ws-crumb {
  background: none;
  border: none;
  color: var(--dim);
  cursor: pointer;
  padding: 2px 5px;
  border-radius: 4px;
  font-size: 12px;
}

.ws-crumb:hover {
  color: var(--accent);
  background: rgba(79, 140, 255, 0.1);
}

.ws-sep {
  color: var(--dim);
  opacity: 0.6;
}

.ws-file-list {
  flex: 1;
  overflow: auto;
  padding: 0 8px 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-height: 0;
}

.ws-file-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 7px 9px;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.12s;
}

.ws-file-item:hover {
  border-color: var(--accent);
}

.ws-file-item.active {
  border-color: var(--accent);
  background: rgba(79, 140, 255, 0.13);
}

.ws-file-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}

.ws-file-size {
  color: var(--dim);
  font-size: 11px;
  flex-shrink: 0;
}

.ws-dir {
  color: var(--accent);
  font-weight: 500;
}

.ws-del {
  background: none;
  border: none;
  color: var(--dim);
  cursor: pointer;
  padding: 1px 4px;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.12s;
  flex-shrink: 0;
}

.ws-file-item:hover .ws-del {
  opacity: 1;
}

.ws-del:hover {
  color: var(--red);
}

.ws-tip {
  margin: 8px;
  padding: 8px;
  font-size: 11.5px;
  line-height: 1.55;
  color: var(--dim);
  background: var(--panel-2);
  border: 1px dashed var(--border);
  border-radius: 6px;
}

.ws-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.ws-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.ws-toolbar input[type="text"] {
  flex: 1;
  min-width: 160px;
  max-width: 320px;
}

.ws-spacer {
  flex: 1;
}

.ws-editor-wrap {
  flex: 1;
  min-height: 160px;
  border-bottom: 1px solid var(--border);
  overflow: hidden;
}

.ws-editor-wrap .CodeMirror {
  height: 100%;
}

.ws-output {
  height: 38%;
  min-height: 150px;
  display: flex;
  flex-direction: column;
  background: var(--panel);
}

.ws-output-head {
  padding: 6px 12px;
  font-size: 12px;
  color: var(--dim);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}

.ws-output-body {
  flex: 1;
  overflow: auto;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
}

.ws-output-body .console {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.ws-stepbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
}

.ws-status.ok {
  color: #4ade80;
}

.ws-status.err {
  color: var(--red);
}

.ws-status.running {
  color: var(--accent);
}

.ws-vars {
  border-top: 1px dashed var(--border);
  padding-top: 6px;
}

.ws-vars-title {
  margin: 4px 0;
  font-size: 12px;
  color: var(--dim);
}

.ws-var-item {
  display: flex;
  gap: 8px;
  align-items: baseline;
  font-size: 12.5px;
  padding: 2px 0;
}

.ws-var-item .vname {
  color: var(--accent);
  min-width: 90px;
}

.ws-var-item .vtype {
  color: #c084fc;
  font-size: 11px;
  min-width: 70px;
}

.ws-var-item code {
  background: var(--panel-2);
  padding: 1px 6px;
  border-radius: 4px;
  word-break: break-all;
}

/* ============ 文件中转站 ============ */

.transfer-box {
  max-width: 900px;
  margin: 22px auto;
  padding: 0 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.transfer-head h2 {
  margin: 0 0 6px;
}

.transfer-upload {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding: 14px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.transfer-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.transfer-table th,
.transfer-table td {
  padding: 9px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  font-size: 13px;
}

.transfer-table th {
  background: var(--panel-2);
  color: var(--dim);
  font-weight: 600;
}

.tf-name {
  max-width: 380px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.tf-size {
  color: var(--dim);
  white-space: nowrap;
}

.tf-ops {
  display: flex;
  gap: 6px;
  white-space: nowrap;
}

.tf-status.running {
  color: var(--accent);
}

.log-content {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.log-day {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.log-day-title {
  padding: 8px 12px;
  background: var(--panel-2);
  font-size: 13px;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
}

.log-pre {
  margin: 0;
  max-height: 420px;
  overflow: auto;
  font-size: 12px;
  line-height: 1.55;
  padding: 10px 12px;
  white-space: pre-wrap;
  word-break: break-word;
}

.dataset-panel {
  width: min(860px, 94vw);
  max-height: 84vh;
  display: flex;
  flex-direction: column;
}

.ds-body {
  display: flex;
  gap: 14px;
  padding: 12px;
  overflow: auto;
  min-height: 0;
}

.ds-col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ds-col h3 {
  margin: 0;
  font-size: 13px;
  color: var(--dim);
  font-weight: 600;
}

.ds-list {
  border: 1px solid var(--border);
  border-radius: 8px;
  min-height: 120px;
  max-height: 320px;
  overflow: auto;
  padding: 6px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: var(--panel);
}

.ds-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 6px;
  font-size: 13px;
  background: var(--panel-2);
}

.ds-item .ds-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ds-item .ds-size {
  color: var(--dim);
  font-size: 11px;
}

.ds-item:hover .ws-del {
  opacity: 1;
}

.ds-tip {
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--dim);
  background: var(--panel-2);
  border: 1px dashed var(--border);
  border-radius: 6px;
  padding: 8px 10px;
}

.ds-tip code {
  color: var(--accent);
  word-break: break-all;
}

/* ============ 实验工作台（学生 · PyCharm Darcula 配色） ============ */

.cm-s-pycharm-dark.CodeMirror {
  background: #2b2b2b;
  color: #a9b7c6;
}

.cm-s-pycharm-dark .CodeMirror-gutters {
  background: #313335;
  border-right: 1px solid #323232;
}

.cm-s-pycharm-dark .CodeMirror-linenumber {
  color: #606366;
}

.cm-s-pycharm-dark .CodeMirror-cursor {
  border-left: 1px solid #bbbbbb;
}

.cm-s-pycharm-dark .CodeMirror-selected {
  background: #214283;
}

.cm-s-pycharm-dark .CodeMirror-activeline-background {
  background: #323232;
}

.cm-s-pycharm-dark .cm-keyword {
  color: #cc7832;
  font-weight: 600;
}

.cm-s-pycharm-dark .cm-string,
.cm-s-pycharm-dark .cm-string-2 {
  color: #6a8759;
}

.cm-s-pycharm-dark .cm-number {
  color: #6897bb;
}

.cm-s-pycharm-dark .cm-comment {
  color: #808080;
  font-style: italic;
}

.cm-s-pycharm-dark .cm-builtin {
  color: #8888c6;
}

.cm-s-pycharm-dark .cm-def {
  color: #ffc66d;
}

.cm-s-pycharm-dark .cm-operator {
  color: #a9b7c6;
}

.cm-s-pycharm-dark .cm-variable,
.cm-s-pycharm-dark .cm-variable-2 {
  color: #a9b7c6;
}

.cm-s-pycharm-dark .cm-attribute {
  color: #bababa;
}

.cm-s-pycharm-dark .cm-tag {
  color: #e8bf6a;
}

.pycharm {
  background: #2b2b2b;
}

.lab-layout {
  display: flex;
  height: calc(100vh - var(--topbar-h, 54px));
  min-height: 0;
  background: #2b2b2b;
}

.lab-side {
  width: 220px;
  min-width: 180px;
  background: #3c3f41;
  border-right: 1px solid #323232;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.lab-side-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 10px;
  background: #3c3f41;
  border-bottom: 1px solid #323232;
  color: #bbbbbb;
  font-size: 12px;
  font-weight: 600;
}

.lab-icon-btn {
  background: #4c5052;
  color: #bbbbbb;
  border: 1px solid #5a5e60;
  border-radius: 3px;
  width: 20px;
  height: 20px;
  line-height: 1;
  cursor: pointer;
  font-size: 12px;
}

.lab-icon-btn:hover {
  background: #5a5e60;
  color: #ffffff;
}

.lab-file-list {
  flex: 1;
  overflow: auto;
  padding: 6px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-height: 0;
}

.lab-file-list .empty {
  color: #808080;
  font-size: 12px;
  padding: 10px;
  line-height: 1.6;
}

.lab-file {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  border-radius: 3px;
  cursor: pointer;
  font-size: 13px;
  color: #a9b7c6;
}

.lab-file:hover {
  background: #4c5052;
}

.lab-file.active {
  background: #214283;
  color: #ffffff;
}

.lab-file-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lab-del {
  background: none;
  border: none;
  color: #808080;
  cursor: pointer;
  font-size: 12px;
  opacity: 0;
}

.lab-file:hover .lab-del {
  opacity: 1;
}

.lab-del:hover {
  color: #ff6b68;
}

.lab-side-tip {
  padding: 8px 10px;
  font-size: 11px;
  line-height: 1.5;
  color: #808080;
  border-top: 1px solid #323232;
}

.lab-side-tip a {
  color: #589df6;
  text-decoration: none;
}

.lab-side-tip a:hover {
  text-decoration: underline;
}

.lab-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.lab-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  background: #3c3f41;
  border-bottom: 1px solid #323232;
}

.lab-btn {
  background: #4c5052;
  color: #bbbbbb;
  border: 1px solid #5a5e60;
  border-radius: 3px;
  padding: 4px 12px;
  font-size: 12.5px;
  cursor: pointer;
  transition: background 0.12s;
}

.lab-btn:hover {
  background: #5a5e60;
  color: #ffffff;
}

.lab-btn:disabled {
  opacity: 0.45;
  cursor: default;
}

.lab-run-btn {
  background: #499c54;
  border-color: #499c54;
  color: #ffffff;
  font-weight: 600;
}

.lab-run-btn:hover {
  background: #3e8547;
}

.lab-debug-btn {
  background: #629755;
  border-color: #629755;
  color: #ffffff;
}

.lab-debug-btn:hover {
  background: #548048;
}

.lab-status {
  font-size: 12px;
  color: #808080;
}

.lab-status.ok {
  color: #6a8759;
}

.lab-status.err {
  color: #ff6b68;
}

.lab-status.running {
  color: #6897bb;
}

.lab-editor-wrap {
  flex: 1;
  min-height: 140px;
  overflow: hidden;
  border-bottom: 1px solid #323232;
}

.lab-editor-wrap .CodeMirror {
  height: 100%;
}

.lab-run-panel {
  height: 40%;
  min-height: 150px;
  display: flex;
  flex-direction: column;
  background: #2b2b2b;
}

.lab-run-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 4px 12px;
  background: #3c3f41;
  border-bottom: 1px solid #323232;
  font-size: 12px;
  color: #bbbbbb;
}

.lab-run-title {
  font-weight: 600;
  border-bottom: 2px solid #4c5052;
  padding-bottom: 2px;
}

.lab-run-info {
  color: #808080;
  font-size: 11.5px;
}

.lab-run-body {
  flex: 1;
  overflow: auto;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
  font-family: Consolas, "Courier New", monospace;
  font-size: 13px;
  color: #a9b7c6;
}

.lab-run-body pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.lab-run-body pre.err {
  color: #ff6b68;
}

.lab-stepbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 4px;
  border-top: 1px solid #323232;
}

.lab-vars-title {
  color: #808080;
  font-size: 11.5px;
  margin-bottom: 4px;
}

.lab-var {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 12.5px;
  padding: 2px 0;
}

.lab-var .n {
  color: #a9b7c6;
  min-width: 80px;
  font-weight: 600;
}

.lab-var .t {
  color: #8888c6;
  font-size: 11px;
  min-width: 60px;
}

.lab-var code {
  background: #3c3f41;
  color: #6a8759;
  padding: 1px 6px;
  border-radius: 3px;
  word-break: break-all;
}

.pycharm .figures img {
  background: #ffffff;
  border: 1px solid #323232;
}

.btn.danger:hover {
  border-color: var(--red);
  background: rgba(255, 107, 107, 0.1);
}

.lesson-content {
  overflow: auto;
  padding: 28px 36px 60px;
  line-height: 1.75;
}

.markdown-body h1 {
  font-size: 26px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.markdown-body h2 {
  font-size: 20px;
  margin: 26px 0 10px;
  color: var(--accent-2);
}

.markdown-body h3 {
  font-size: 16px;
  margin: 20px 0 8px;
  color: #c9d6ec;
}

.markdown-body p,
.markdown-body li {
  font-size: 15px;
  margin: 8px 0;
}

.markdown-body ul,
.markdown-body ol {
  padding-left: 24px;
}

.markdown-body blockquote {
  border-left: 3px solid var(--accent);
  padding: 6px 14px;
  background: rgba(79, 140, 255, 0.07);
  border-radius: 0 8px 8px 0;
  color: #c3d0e8;
  margin: 12px 0;
}

.markdown-body table {
  border-collapse: collapse;
  margin: 12px 0;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 6px 12px;
  font-size: 14px;
}

.markdown-body th {
  background: var(--panel-2);
}

.codebox {
  margin: 14px 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: #101728;
}

.codebox-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  background: var(--panel-2);
  border-bottom: 1px solid var(--border);
}

.codebox-bar .lang {
  font-size: 12px;
  color: var(--accent-2);
  font-weight: 600;
  margin-right: auto;
}

.codebox-bar .btn {
  padding: 3px 10px;
  font-size: 12px;
}

.codebox pre {
  margin: 0;
  padding: 12px 14px;
  overflow: auto;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  color: #d8e1f0;
}

.tok-comment {
  color: #64748b;
  font-style: italic;
}

.tok-string {
  color: #a5e075;
}

.tok-number {
  color: #f78c6c;
}

.tok-keyword {
  color: #c792ea;
  font-weight: 600;
}

.tok-builtin {
  color: #82aaff;
}

.tok-decorator {
  color: #ffcb6b;
}

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  bottom: 70px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--panel-2);
  border: 1px solid var(--accent);
  color: var(--text);
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  opacity: 0;
  pointer-events: none;
  transition: all 0.25s;
  z-index: 99;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- 登录遮罩 ---------- */

.login-overlay {
  position: fixed;
  inset: 0;
  background: rgba(8, 12, 22, 0.88);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}

.login-overlay.hidden {
  display: none;
}

.login-box {
  width: min(420px, 90vw);
  background: var(--panel);
  border: 1px solid var(--accent);
  border-radius: 14px;
  padding: 30px 32px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.login-box h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.login-box .dim {
  color: var(--dim);
  font-size: 13px;
  margin-bottom: 18px;
  line-height: 1.5;
}

.login-box input {
  width: 100%;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 11px 14px;
  font-size: 15px;
  margin-bottom: 14px;
}

.login-box input:focus {
  outline: none;
  border-color: var(--accent);
}

.login-btn {
  width: 100%;
  padding: 11px;
  font-size: 15px;
}

.login-error {
  color: var(--red);
  font-size: 13px;
  margin-top: 12px;
  min-height: 1em;
}

/* ---------- 课件编辑器（教师） ---------- */

.lesson-editor {
  width: min(1120px, 94vw);
  height: min(86vh, 820px);
  background: var(--panel);
  border: 1px solid var(--accent);
  border-radius: 14px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.le-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  background: var(--panel-2);
  border-bottom: 1px solid var(--border);
}

.le-head h2 {
  font-size: 17px;
}

.le-meta {
  display: flex;
  gap: 10px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--border);
}

.le-meta input {
  flex: 1;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 9px 12px;
  font-size: 14px;
}

.le-meta input:focus,
.le-md:focus {
  outline: none;
  border-color: var(--accent);
}

.le-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.le-spacer {
  flex: 1;
}

.le-body {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 0;
}

.le-md {
  width: 100%;
  height: 100%;
  resize: none;
  border: none;
  background: #0e1424;
  color: #d8e1f0;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.65;
  padding: 14px 16px;
  outline: none;
}

.le-preview {
  overflow: auto;
  padding: 16px 20px;
  border-left: 1px solid var(--border);
}

.le-preview pre {
  background: #101728;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  overflow: auto;
  font-size: 12px;
}

.le-preview img {
  max-width: 100%;
  border-radius: 8px;
  border: 1px solid var(--border);
}

/* ---------- 环境配置 ---------- */

.env-layout {
  display: grid;
  grid-template-columns: minmax(380px, 44%) 1fr;
  height: 100%;
}

.env-install,
.env-pkgs {
  padding: 22px 26px;
  overflow: auto;
  min-height: 0;
}

.env-install {
  border-right: 1px solid var(--border);
}

.env-install h3,
.env-pkgs h3 {
  font-size: 16px;
  margin-bottom: 10px;
}

.env-install .dim {
  color: var(--dim);
  font-size: 13px;
  margin-bottom: 14px;
  line-height: 1.6;
}

.env-row {
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.env-row input {
  flex: 1;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
  font-family: var(--mono);
  width: 100%;
}

.env-row input:focus {
  outline: none;
  border-color: var(--accent);
}

.env-log {
  margin-top: 8px;
  max-height: 300px;
  overflow: auto;
  background: #0e1424;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  min-height: 2em;
}

.env-filter {
  width: 100%;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 9px 12px;
  font-size: 13px;
  margin-bottom: 12px;
}

.pkg-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.pkg-item {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 6px 10px;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 13px;
  border-bottom: 1px solid #1d2942;
}

.pkg-item:hover {
  background: var(--panel-2);
}

.pkg-item .pname {
  color: var(--accent-2);
  word-break: break-all;
}

.pkg-item .pver {
  color: var(--dim);
  white-space: nowrap;
}

/* ---------- 全屏 / 小屏适配 ---------- */

body:fullscreen .topbar {
  height: 58px;
}

@media (max-width: 1100px) {
  .demo-grid {
    grid-template-columns: 40% 60%;
  }
  .env-layout {
    grid-template-columns: 1fr;
  }
  .env-install {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .result-area {
    grid-template-columns: 1fr;
  }
  .figures-pane {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .brand .sub {
    display: none;
  }
}

/* ============ 演示代码（教师讲解 / 学生查看） ============ */

.dc-layout {
  display: flex;
  height: calc(100vh - var(--topbar-h, 54px));
  min-height: 0;
}

.dc-side {
  width: 250px;
  min-width: 200px;
  border-right: 1px solid var(--border);
  background: var(--panel);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.dc-side-head {
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
}

.dc-list {
  flex: 1;
  overflow: auto;
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
}

.dc-item {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  background: var(--panel-2);
  transition: all 0.12s;
}

.dc-item:hover {
  border-color: var(--accent);
}

.dc-item.active {
  border-color: var(--accent);
  background: rgba(79, 140, 255, 0.12);
}

.dc-item-title {
  display: block;
  font-size: 13px;
  font-weight: 600;
}

.dc-item-file {
  display: block;
  font-size: 11px;
  color: var(--dim);
  margin-top: 2px;
}

.dc-side-tip {
  padding: 8px 12px;
  font-size: 11px;
  line-height: 1.5;
  color: var(--dim);
  border-top: 1px solid var(--border);
}

.dc-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.dc-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.dc-title {
  font-size: 13px;
  font-weight: 600;
}

.dc-spacer {
  flex: 1;
}

.dc-editor-wrap {
  flex: 1;
  min-height: 160px;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}

.dc-editor-wrap .CodeMirror {
  height: 100%;
}

.dc-output {
  height: 38%;
  min-height: 150px;
  display: flex;
  flex-direction: column;
  background: var(--panel);
}

.dc-output-head {
  padding: 6px 12px;
  font-size: 12px;
  color: var(--dim);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}

.dc-output-body {
  flex: 1;
  overflow: auto;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
}

.dc-output-body pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.dc-status.ok {
  color: #4ade80;
}

.dc-status.err {
  color: var(--red);
}

.dc-status.running {
  color: var(--accent);
}

/* ============ 手机端适配 v2（覆盖式：允许整页滚动 + 明确编辑器高度） ============ */

@media (max-width: 900px) {
  /* 关键修复：手机端允许整页纵向滚动（原来 body overflow:hidden 会裁掉内容） */
  html,
  body {
    height: auto !important;
    overflow: auto !important;
    -webkit-text-size-adjust: 100%;
  }

  .topbar {
    height: auto;
    min-height: 44px;
    flex-wrap: wrap;
    gap: 4px;
    padding: 4px 8px;
    /* 手机上不再固定顶栏，避免遮挡内容区 */
    position: static;
  }

  .brand {
    flex: 0 0 auto;
  }

  .brand .title {
    font-size: 14px;
  }

  .tabs {
    order: 2;
    flex: 1 1 120px;
    width: auto;
    min-width: 0;
    display: flex;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: 4px;
    padding-bottom: 2px;
  }

  .tabs .tab {
    flex: 0 0 auto;
    padding: 6px 10px;
    min-height: 34px;
    font-size: 12.5px;
    white-space: nowrap;
  }

  .actions {
    order: 3;
    width: 100%;
    display: flex;
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: 6px;
    padding-bottom: 2px;
  }

  .actions .btn {
    flex: 0 0 auto;
    min-height: 34px;
    padding: 6px 10px;
    font-size: 12.5px;
  }

  .actions select {
    flex: 0 0 auto;
    max-width: 50vw;
    min-height: 36px;
  }

  .divider {
    display: none;
  }

  main {
    height: auto !important;
    overflow: visible !important;
  }

  .view {
    height: auto !important;
    min-height: 0;
  }

  /* ---- 演示台：编辑器 / 输出上下排列 ---- */
  .demo-grid {
    display: flex !important;
    flex-direction: column;
    height: auto !important;
  }

  .editor-pane {
    height: 58vh;
    min-height: 320px;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .output-pane {
    height: auto;
    min-height: 52vh;
  }

  .result-area {
    grid-template-columns: 1fr !important;
  }

  .figures-pane {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .stepbar {
    flex-wrap: wrap;
    gap: 6px;
    padding: 8px 10px;
  }

  .stepbar input[type="range"] {
    width: 100%;
  }

  /* ---- 演示代码 / 代码工作台 / 实验工作台：纵向排列 ---- */
  .dc-layout,
  .ws-layout,
  .lab-layout {
    flex-direction: column !important;
    height: auto !important;
  }

  .dc-side,
  .ws-side,
  .lab-side {
    width: 100% !important;
    min-width: 0 !important;
    max-height: 34vh;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .dc-editor-wrap,
  .ws-editor-wrap,
  .lab-editor-wrap {
    height: 58vh;
    min-height: 320px;
    flex: none;
  }

  .dc-output,
  .ws-output,
  .lab-run-panel {
    height: auto !important;
    min-height: 42vh;
  }

  .dc-toolbar,
  .ws-toolbar,
  .lab-toolbar {
    flex-wrap: wrap;
    gap: 6px;
    padding: 8px 10px;
  }

  .dc-toolbar .btn,
  .ws-toolbar .btn,
  .lab-toolbar .btn {
    min-height: 36px;
    padding: 8px 12px;
  }

  .dc-title {
    flex: 1 1 100%;
  }

  /* ---- 讲义课件 ---- */
  .lesson-layout {
    /* 原来是 grid: 230px 1fr，手机上改为单列纵向排列 */
    display: block !important;
    height: auto !important;
  }

  .lesson-list {
    width: 100% !important;
    min-width: 0 !important;
    max-height: 34vh;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .lesson-content {
    width: 100% !important;
    min-width: 0 !important;
    padding: 14px !important;
    height: auto !important;
    overflow: visible !important;
    word-break: break-word;
  }

  /* 讲义里的代码块和表格在窄屏可横向滚动，避免撑破页面 */
  .lesson-content pre,
  .lesson-content table,
  .markdown-body pre,
  .markdown-body table {
    max-width: 100%;
    overflow-x: auto;
    display: block;
  }

  /* ---- 环境配置 ---- */
  .env-layout {
    display: block !important;
    height: auto !important;
  }

  .env-install,
  .env-pkgs {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .pkg-list {
    max-height: 40vh;
  }

  /* ---- 弹层与表单 ---- */
  .login-box {
    width: 92vw;
    max-width: 420px;
  }

  .lesson-editor {
    width: 96vw !important;
    height: 90vh !important;
  }

  .le-body {
    flex-direction: column;
  }

  .le-md,
  .le-preview {
    width: 100%;
    min-height: 32vh;
  }

  .ds-body {
    flex-direction: column;
  }

  .ds-list {
    max-height: 30vh;
  }

  .transfer-box {
    padding: 0 10px;
    margin: 14px auto;
  }

  .transfer-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }

  /* ---- 触摸友好：输入框 ≥16px 防止 iOS 自动放大 ---- */
  input,
  select,
  textarea {
    font-size: 16px !important;
  }

  .console,
  pre,
  .CodeMirror {
    font-size: 13px;
  }

  /* 手机上代码区支持惯性触摸滚动 */
  .CodeMirror-scroll,
  .dc-list,
  .ws-file-list,
  .lab-file-list,
  .dc-output-body,
  .ws-output-body,
  .lab-run-body {
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 480px) {
  .brand .title {
    font-size: 15px;
  }

  .editor-pane,
  .dc-editor-wrap,
  .ws-editor-wrap,
  .lab-editor-wrap {
    height: 62vh;
  }

  .topbar {
    padding: 6px 8px;
  }
}