/*
 * 智瞰AI高中信息技术教学平台学生端 · 课程引擎与业务组件样式
 * 全局设计令牌与通用控件见 /assets/css/globals.css
 */

/* app/ui.js 等动态注入的确认按钮基类（与 Tailwind 工具类组合使用） */
.ctrl-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    font-size: var(--cs-text-sm);
    font-weight: 600;
    border-radius: var(--cs-radius-md);
    background: rgba(0, 0, 0, 0.02);
    border: 1px solid var(--cs-border-default);
    color: var(--cs-text-tertiary);
    transition:
        background var(--cs-duration-normal) var(--cs-ease-spring),
        color var(--cs-duration-normal) var(--cs-ease-spring),
        border-color var(--cs-duration-normal) var(--cs-ease-spring),
        transform var(--cs-duration-fast) var(--cs-ease-spring);
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(0, 60, 136, 0.08);
    cursor: pointer;
}
.ctrl-btn:hover {
    background: rgba(0, 0, 0, 0.04);
    color: var(--cs-text-secondary);
}
.ctrl-btn:active {
    transform: scale(0.97);
}

/* 兼容历史命名：课程模块广泛使用 */
:root {
    --xmu-blue: var(--cs-brand);
    --jiageng-red: #D7422A;
    --ease-apple: var(--cs-ease-spring);
}

/* ── 字体（018）：Inter 变量字体（vendor 自带）打头——latin 字母/数字更精密；
      中文回落系统苹方/雅黑，仅学生端应用（globals 三端共用，不动）。 ── */
@font-face {
    font-family: 'Inter';
    src:
        url('/vendor/fonts/apple/InterVariable.woff2') format('woff2-variations'),
        url('/vendor/fonts/apple/InterVariable.woff2') format('woff2');
    font-weight: 100 900;
    font-style: normal;
    font-display: swap;
}

body {
    font-family:
        'Inter',
        -apple-system, BlinkMacSystemFont,
        "PingFang SC", "Microsoft YaHei", "Noto Sans SC",
        "Helvetica Neue", Arial, sans-serif;
}

/* 色彩降噪（018b 小毅：蓝紫 AI 感重）：学生端把紫 orb 覆写为极淡冷青，
   场景只剩「蓝 + 淡青 + 暖白」一族冷调；globals 共享 orb 类不动（教师端不受影响）。 */
.cs-orb-violet {
    background: radial-gradient(circle, rgba(148, 198, 208, 0.26) 0%, transparent 70%);
}

/* 全幅细噪点（018 环境场景）：无 blur 的静态纹理，给玻璃拟态一层「底片颗粒」 */
.cs-scene-noise {
    position: absolute;
    inset: 0;
    opacity: 0.07;
    mix-blend-mode: soft-light;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.82' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* 学生端 body 由 index 与 globals 共同约束；此处仅补充课程区习惯 */

/* 学生端悬浮式侧边栏 */
#app-sidebar.cs-app-sidebar {
    min-height: auto;
    /* #5/#9：抽屉玻璃——比纯白略透(再透一点)、但不渐隐(原 .cs-glass-panel 0.50→0.28 底部太透)，配强模糊保证暗背景也看得清；阴影对齐胶囊。 */
    background: rgba(255, 255, 255, 0.70);
    backdrop-filter: blur(24px) saturate(1.4);
    -webkit-backdrop-filter: blur(24px) saturate(1.4);
    transform: translateX(calc(-100% - 1.25rem));
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition:
        transform 280ms var(--cs-ease-spring),
        opacity 180ms var(--cs-ease-out),
        visibility 0s linear 280ms,
        box-shadow 280ms var(--cs-ease-spring);
    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.82),
        0 18px 42px rgba(15, 23, 42, 0.08);
}

body.cs-sidebar-open #app-sidebar.cs-app-sidebar {
    transform: translateX(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transition:
        transform 280ms var(--cs-ease-spring),
        opacity 180ms var(--cs-ease-out),
        visibility 0s linear 0s,
        box-shadow 280ms var(--cs-ease-spring);
}

#app-sidebar.cs-app-sidebar::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    pointer-events: none;
    background: linear-gradient(180deg, rgba(255,255,255,0.22), rgba(255,255,255,0.02));
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    -webkit-mask-composite: xor;
    padding: 1px;
}

#course-entry-anchor {
    transform: translateX(0);
}

body.cs-sidebar-open #course-entry-anchor {
    transform: translateX(18.75rem);
}

#learning-canvas {
    transition: padding-top 280ms var(--cs-ease-spring);
}

body.cs-page-landing #learning-canvas {
    /* 统一顶栏：品牌 logo 行（左）与 fixed 个人胶囊（右）横向分列、同高连成一条，
       故顶部只留与胶囊 top 对齐的小边距（不再整体下压一行）。 */
    padding-top: 1.5rem;
    /* launch：大厅改纵向滚动（4 板块随内容增高）——放开旧「一屏固定」的 overflow:hidden */
    padding-bottom: 2.5rem;
    overflow-y: auto;
}

body.cs-page-course #learning-canvas {
    padding-top: 2.35rem;
}

.cs-side-topic-shell {
    padding: 0.25rem 0.75rem 1rem;
    margin: 0 0.25rem 0.75rem;
    border-bottom: 1px solid rgba(15, 23, 42, 0.06);
}

.cs-side-topic-kicker {
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: rgba(148, 163, 184, 0.96);
}

.cs-side-topic-title {
    margin: 0.55rem 0 0;
    font-size: 1.2rem;
    line-height: 1.3;
    font-weight: 800;
    color: rgba(15, 23, 42, 0.92);
    letter-spacing: -0.02em;
}

.cs-side-topic-subtitle {
    margin: 0.45rem 0 0;
    font-size: 12px;
    line-height: 1.8;
    color: rgba(100, 116, 139, 0.94);
    font-weight: 600;
}

.cs-side-chapter-label {
    padding: 0 0.9rem 0.55rem;
    font-size: 11px;
    font-weight: 800;
    color: rgba(148, 163, 184, 0.96);
    letter-spacing: 0.16em;
}

.cs-side-nav-btn {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    padding: 0.8rem 0.9rem;
    border-radius: 1.05rem;
    color: rgba(71, 85, 105, 0.96);
    transition:
        background var(--cs-duration-normal) var(--cs-ease-spring),
        color var(--cs-duration-normal) var(--cs-ease-spring),
        transform var(--cs-duration-fast) var(--cs-ease-spring),
        box-shadow var(--cs-duration-normal) var(--cs-ease-spring);
}

.cs-side-nav-btn:hover {
    background: rgba(255, 255, 255, 0.5);
    color: rgba(15, 23, 42, 0.92);
}

.cs-side-nav-btn:active {
    transform: scale(0.985);
}

.cs-side-nav-btn.is-active {
    background: linear-gradient(180deg, rgba(255,255,255,0.78), rgba(255,255,255,0.54));
    color: rgba(15, 23, 42, 0.96);
    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.86),
        0 10px 22px rgba(15, 23, 42, 0.05);
}

.cs-side-nav-title {
    display: block;
    font-size: 13px;
    font-weight: 700;
    line-height: 1.45;
    color: inherit;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.cs-side-nav-tail {
    flex: 0 0 auto;
    width: 7px;
    height: 7px;
    border-radius: 9999px;
    background: rgba(203, 213, 225, 0.9);
    transition:
        background var(--cs-duration-normal) var(--cs-ease-spring),
        transform var(--cs-duration-normal) var(--cs-ease-spring),
        box-shadow var(--cs-duration-normal) var(--cs-ease-spring);
}

.cs-side-nav-btn.is-active .cs-side-nav-tail {
    background: var(--cs-brand);
    transform: scale(1.08);
    box-shadow: 0 0 0 4px rgba(0, 60, 136, 0.08);
}

/* 课序号（018）：等宽小号，激活时随主色点亮 */
.cs-side-nav-num {
    flex: 0 0 auto;
    font-family: ui-monospace, "SF Mono", Menlo, monospace;
    font-size: 10.5px;
    font-weight: 800;
    letter-spacing: 0.04em;
    color: rgba(148, 163, 184, 0.85);
    transition: color var(--cs-duration-normal) var(--cs-ease-spring);
}
.cs-side-nav-btn.is-active .cs-side-nav-num { color: var(--cs-brand); }

/* 返回课程大厅（018）：从素描边按钮升级为玻璃浮起行 */
.cs-side-home {
    display: flex;
    width: 100%;
    align-items: center;
    justify-content: space-between;
    border-radius: 18px;
    padding: 10px 12px 10px 10px;
    font-size: 12.5px;
    font-weight: 700;
    color: var(--cs-text-secondary);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.55), rgba(255, 255, 255, 0.30));
    border: 1px solid rgba(255, 255, 255, 0.70);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.85), 0 4px 14px rgba(15, 23, 42, 0.04);
    cursor: pointer;
    transition:
        color var(--cs-duration-normal) var(--cs-ease-spring),
        transform var(--cs-duration-fast) var(--cs-ease-spring),
        box-shadow var(--cs-duration-normal) var(--cs-ease-spring);
}
.cs-side-home:hover {
    color: var(--cs-brand);
    transform: translateY(-1px);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 8px 20px rgba(15, 23, 42, 0.07);
}
.cs-side-home:active { transform: scale(0.985); }
.cs-side-home:focus-visible {
    outline: 2px solid var(--cs-primary-400);
    outline-offset: 2px;
}
.cs-side-home-ic {
    width: 28px;
    height: 28px;
    border-radius: 10px;
    display: grid;
    place-items: center;
    color: var(--cs-primary-600);
    background: rgba(0, 98, 214, 0.09);
    border: 1px solid rgba(0, 98, 214, 0.14);
}

/* 用户菜单身份块（018）：打开时由 app/ui.js 懒渲染；无身份数据则整块隐藏 */
.cs-menu-id {
    display: none;
    align-items: center;
    gap: 11px;
    padding: 11px 12px 12px;
    margin-bottom: 6px;
    border-bottom: 1px solid rgba(15, 23, 42, 0.06);
}
.cs-menu-id.has-id { display: flex; }
.cs-menu-id-avatar {
    width: 38px;
    height: 38px;
    border-radius: 13px;
    flex: none;
    display: grid;
    place-items: center;
    color: #fff;
    font-size: 15px;
    font-weight: 800;
    background: linear-gradient(140deg, var(--cs-primary-500), var(--cs-brand));
    box-shadow: 0 8px 18px rgba(0, 98, 214, 0.22), inset 0 1px 0 rgba(255, 255, 255, 0.35);
}
.cs-menu-id-name {
    font-size: 14px;
    font-weight: 800;
    color: var(--cs-text-primary);
    line-height: 1.2;
}
.cs-menu-id-sub {
    margin-top: 2px;
    font-size: 11px;
    font-weight: 600;
    color: var(--cs-text-muted);
    letter-spacing: 0.02em;
}

@media (max-width: 899px) {
    body.cs-sidebar-open #course-entry-anchor {
        transform: translateX(0);
    }

    body.cs-page-course #learning-canvas {
        padding-top: 2rem;
    }
}

.no-scrollbar::-webkit-scrollbar { display: none; }
.no-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }

.animate-fade-in { animation: fadeIn 0.5s var(--cs-ease-spring) forwards; }
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* AI 面板发送：方形图标按钮 */
.student-ai-send-btn {
    width: 2.25rem;
    height: 2.25rem;
    min-width: 2.25rem;
    padding: 0 !important;
    border-radius: var(--cs-radius-md) !important;
}

/* Chat bubbles */
.chat-bubble-user { background-color: var(--cs-brand); color: white; border-radius: 18px 18px 4px 18px; }
.chat-bubble-ai { background-color: #F1F1F4; color: var(--cs-text-primary); border-radius: 18px 18px 18px 4px; }

/* Progress Bar Glow */
.progress-glow {
    box-shadow: 0 0 15px rgba(0, 60, 136, 0.4);
}

.step-pulse {
    animation: stepPulse 2.5s ease-in-out infinite;
}
@keyframes stepPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(0, 60, 136, 0.3); }
    50% { box-shadow: 0 0 0 8px rgba(0, 60, 136, 0); }
}

/* DNS Sandbox Dot Grid */
.dot-grid-bg {
    background-image: radial-gradient(circle, #d1d5db 0.8px, transparent 0.8px);
    background-size: 24px 24px;
}

/* Tracking Packet (Red Glow) */
.comet-packet {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: radial-gradient(circle at 40% 40%, #ff6b6b, #D7422A);
    box-shadow: 0 0 10px rgba(215, 66, 42, 0.6), 0 0 25px rgba(215, 66, 42, 0.25);
    position: absolute;
    z-index: 40;
}

/* Input Focus Glow（课程内联表单 — 与 globals 品牌焦点环一致） */
.input-glow:focus,
.input-glow:focus-visible {
    border-color: var(--cs-input-focus-border) !important;
    box-shadow: var(--cs-input-focus-shadow) !important;
    background: var(--cs-bg-elevated) !important;
}

/* AI Widget Spring Animation */
.ai-panel-spring {
    animation: springBounce 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}
@keyframes springBounce {
    0% { opacity: 0; transform: scale(0.6) translateY(20px); }
    60% { opacity: 1; transform: scale(1.03) translateY(-3px); }
    100% { opacity: 1; transform: scale(1) translateY(0); }
}

.ai-panel-close {
    animation: springClose 0.25s ease-in forwards;
}
@keyframes springClose {
    to { opacity: 0; transform: scale(0.9) translateY(10px); }
}

/* 小信非画布入口 FAB 已移除（027 P6）：画布唯一课型，入口统一为顶栏 #cs-ai-entry；大厅无课无上下文、不放入口。 */

/* AI Thinking Ring */
.ai-thinking-ring {
    animation: thinkingRing 1.5s linear infinite;
}
@keyframes thinkingRing {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* AI Chat Typography */
#ai-chat-panel .prose {
    font-size: 13px !important;
    line-height: 1.65 !important;
}
#ai-chat-panel .prose :where(p, li, blockquote, code, pre, strong, em, a, span) {
    font-size: inherit !important;
    line-height: inherit !important;
}
#ai-chat-panel .prose :where(h1, h2, h3) {
    font-size: 14px !important;
    line-height: 1.4 !important;
    margin: 0.35rem 0 0.25rem !important;
}
#ai-chat-panel .prose :where(ul, ol) {
    margin: 0.35rem 0 0.35rem 1.05rem !important;
}
#ai-chat-panel .prose :where(p) {
    margin: 0.25rem 0 !important;
}

/* DNS Node Glow */
.dns-node-glass {
    background: rgba(15, 23, 42, 0.75);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}
.dns-node-glass.active {
    border-color: rgba(239, 68, 68, 0.5);
    box-shadow: 0 0 20px rgba(239, 68, 68, 0.2), 0 4px 15px rgba(0, 0, 0, 0.3);
}

/* Star Rating Widget */
.star-btn { cursor: pointer; background: none; border: none; padding: 0 1px; }
.star-btn.star-lit { color: #f59e0b !important; filter: drop-shadow(0 0 4px rgba(245,158,11,0.35)); }
.star-btn.star-hover { color: #fbbf24 !important; }
.sec-feedback.rated .star-label { color: #f59e0b; }
@keyframes starPop { 0% { transform: scale(1); } 50% { transform: scale(1.35); } 100% { transform: scale(1); } }
.star-pop { animation: starPop 0.3s var(--cs-ease-spring); }

/* Gate Reveal Animation */
.gate-reveal {
    animation: gateSlideIn 0.6s var(--cs-ease-spring) forwards;
}
@keyframes gateSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Locked Step */
.nav-step-locked {
    opacity: 0.35;
    cursor: not-allowed !important;
    position: relative;
}

/* ════ 登录（018 沉浸式重绘）：玻璃幕 + 品牌网格背景 + 弹性入场卡 ════
   auth.js 契约不动：#auth-overlay 切 opacity-0/pointer-events-none/hidden、#auth-card 切 scale-95、
   #auth-error 切 hidden、#auth-submit-btn innerHTML 会被替换为 spinner 再还原。 */

.cs-auth-backdrop {
    background: linear-gradient(180deg, rgba(244, 247, 251, 0.68), rgba(237, 242, 248, 0.62));
    backdrop-filter: blur(26px) saturate(1.3);
    -webkit-backdrop-filter: blur(26px) saturate(1.3);
}
.cs-auth-backdrop::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(0, 60, 136, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 60, 136, 0.05) 1px, transparent 1px);
    background-size: 36px 36px;
    -webkit-mask-image: radial-gradient(circle at 50% 42%, #000 0%, transparent 74%);
    mask-image: radial-gradient(circle at 50% 42%, #000 0%, transparent 74%);
}

.cs-auth-card {
    border-radius: 32px;
    padding: 38px 34px 26px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.80), rgba(255, 255, 255, 0.54));
    backdrop-filter: blur(30px) saturate(1.4);
    -webkit-backdrop-filter: blur(30px) saturate(1.4);
    border: 1px solid rgba(255, 255, 255, 0.80);
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.92),
        0 28px 70px -18px rgba(0, 42, 94, 0.20),
        0 6px 22px rgba(15, 23, 42, 0.05);
    /* fill 用 backwards：动画结束后回到常规样式，不压住 auth.js 切的 scale-95 */
    animation: csAuthIn 640ms var(--cs-ease-spring) backwards;
}
@keyframes csAuthIn {
    from { opacity: 0; transform: translateY(20px) scale(0.96); }
    to   { opacity: 1; transform: translateY(0) scale(1); }
}

.cs-auth-logo {
    width: 60px;
    height: 60px;
    border-radius: 19px;
    overflow: hidden;
    margin-bottom: 16px;
    box-shadow: 0 14px 30px rgba(0, 98, 214, 0.24), inset 0 1px 0 rgba(255, 255, 255, 0.4);
}
.cs-auth-logo img {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
}

.cs-auth-wordmark {
    font-size: 10.5px;
    font-weight: 800;
    letter-spacing: 0.22em;
    color: var(--cs-primary-600);
}
.cs-auth-wordmark i {
    font-style: normal;
    opacity: 0.4;
    margin: 0 3px;
}

.cs-auth-title {
    margin: 10px 0 0;
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--cs-text-primary);
}

.cs-auth-sub {
    margin: 7px 0 0;
    font-size: 13px;
    font-weight: 500;
    color: var(--cs-text-muted);
}

/* 字段：语义图标 + 输入框（图标 focus 时点亮品牌蓝） */
.cs-auth-field { position: relative; }
.cs-auth-field .cs-auth-ic {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    width: 17px;
    height: 17px;
    color: var(--cs-text-muted);
    pointer-events: none;
    z-index: 1;
    transition: color 200ms var(--cs-ease-out);
}
.cs-auth-field .cs-input-auth { padding-left: 42px; }
.cs-auth-field:focus-within .cs-auth-ic { color: var(--cs-primary-600); }

/* 提交：品牌渐变大按钮（spinner 替换 innerHTML 时白色可见） */
.cs-auth-submit {
    width: 100%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 50px;
    border: none;
    border-radius: 16px;
    cursor: pointer;
    font-family: inherit;
    font-size: 15px;
    font-weight: 800;
    letter-spacing: 0.02em;
    color: #fff;
    background: linear-gradient(135deg, var(--cs-primary-500), var(--cs-brand));
    box-shadow: 0 14px 30px -10px rgba(0, 80, 181, 0.45), inset 0 1px 0 rgba(255, 255, 255, 0.32);
    transition:
        transform 180ms var(--cs-ease-spring),
        box-shadow 240ms var(--cs-ease-out),
        filter 240ms var(--cs-ease-out);
}
.cs-auth-submit:hover {
    transform: translateY(-1px);
    filter: brightness(1.05);
    box-shadow: 0 18px 38px -10px rgba(0, 80, 181, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.32);
}
.cs-auth-submit:active { transform: translateY(0) scale(0.98); }
.cs-auth-submit:disabled { opacity: 0.6; pointer-events: none; }
.cs-auth-submit:focus-visible {
    outline: 2px solid var(--cs-primary-400);
    outline-offset: 2px;
}

.cs-auth-error {
    margin-top: 14px;
    padding: 9px 12px;
    text-align: center;
    font-size: 12px;
    font-weight: 700;
    color: var(--cs-danger-600);
    background: var(--cs-danger-50);
    border: 1px solid var(--cs-danger-100);
    border-radius: 12px;
    animation: csAuthShake 360ms var(--cs-ease-out);
}
@keyframes csAuthShake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-4px); }
    60% { transform: translateX(3px); }
}

.cs-auth-foot {
    margin-top: 22px;
    text-align: center;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.06em;
    color: var(--cs-text-ghost);
}

/* 017 倒计时锁屏：最后 10 秒四周红边脉冲预警。
   强度由 --cs-warn(0~1) 驱动——剩余越少越强、脉冲越急；z-index 在浮条(9998)/锁屏(9999)之下，pointer-events:none 不遮挡。 */
@keyframes cs-warn-pulse {
    0%, 100% { opacity: calc(0.45 + 0.55 * var(--cs-warn, 0)); }
    50%      { opacity: calc(0.12 + 0.30 * var(--cs-warn, 0)); }
}
body.cs-countdown-warn::after {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9997;
    border: solid rgba(225, 29, 72, calc(0.6 + 0.4 * var(--cs-warn, 0)));
    border-width: calc(4px + 8px * var(--cs-warn, 0));
    box-shadow: inset 0 0 calc(24px + 64px * var(--cs-warn, 0)) calc(2px + 10px * var(--cs-warn, 0)) rgba(244, 63, 94, 0.78);
    animation: cs-warn-pulse calc(1.2s - 0.7s * var(--cs-warn, 0)) ease-in-out infinite;
}

/* ════ 画布模式（ADR-0015 草案 · 固定 1280×800 逻辑画布 + 等比缩放 + 永不滚动）════
   课程 course.json 根级 layout:"canvas" 时引擎置 body.cs-canvas-mode：
   - #learning-canvas 不滚动、清 padding；小节渲进 .cs-canvas-board（逻辑尺寸固定，transform scale 适配）
   - 顶栏 #cs-topnav 小节条（✓/当前/锁）；小信展开 = body.cs-ai-docked 整高停靠，画布让位重缩放 */

body.cs-canvas-mode #learning-canvas { padding: 0 !important; overflow: hidden !important; }
body.cs-canvas-mode #main-content-area { max-width: none !important; height: 100%; }
body.cs-canvas-mode .module-content { padding-bottom: 0 !important; height: 100%; }
body.cs-canvas-mode #cs-section-root { position: relative; flex: 1 1 auto; min-height: 0; }

.cs-canvas-stage { position: absolute; inset: 0; overflow: hidden; }
/* 画板入场 = 原地轻淡入（小毅否决左下角飞入）：首帧定位由引擎免过渡直接落点，.ready 只补一段 opacity */
.cs-canvas-board {
    position: absolute;
    transform-origin: center;
    will-change: transform;
    border-radius: 28px;
    /* 统一画布外框弧度（系统规范）：画板自己裁剪 → 所有小节恒为 28px 圆角，
       与 fragment 根是否写 border-radius:inherit 无关（修 riso/pixel/minimal 等铺满直角背景盖住圆角）。
       外阴影不受 overflow:hidden 影响，照常浮起。 */
    overflow: hidden;
    opacity: 0;
    /* 画布阴影与小信入口同质感：顶边亮线 + 浅外阴影，浮起不抢内容 */
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.72),
        0 16px 48px -16px rgba(15, 23, 42, 0.10),
        0 4px 14px -6px rgba(15, 23, 42, 0.06);
    transition:
        opacity 180ms ease,
        transform 380ms var(--cs-ease-spring),
        left 380ms var(--cs-ease-spring),
        top 380ms var(--cs-ease-spring);
}
.cs-canvas-board.ready { opacity: 1; }

/* ── 顶栏小节条（玻璃胶囊 · 系统蓝 #003C88 一族 · 小信停靠时不移动）──
   信息量：每个小节恒显「状态 + 短标题」，hover 出全名+副题（title attr）——
   学生任意时刻可见 共几节 / 各讲什么 / 进行到哪。 */
#cs-topnav {
    position: fixed;
    top: 1.05rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 60;
    display: none;
    pointer-events: none;
}
body.cs-canvas-mode #cs-topnav { display: block; }
.cs-tn-pill {
    pointer-events: auto;
    display: flex; align-items: center; gap: 4px;
    background: var(--cs-glass-bg-header, rgba(255, 255, 255, 0.52));
    backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    -webkit-backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    border: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.74));
    box-shadow: inset 0 1px 0 rgba(255,255,255,.88), 0 10px 28px rgba(15, 23, 42, 0.07);
    border-radius: 999px;
    padding: 4px 9px;
    height: 38px;
    max-width: min(900px, calc(100vw - 460px));   /* 给右簇「小信入口 + 用户菜单」留位 */
}
.cs-tn-step {
    display: inline-flex; align-items: center; justify-content: center; gap: 5px;
    height: 30px; min-width: 30px; padding: 0 13px;
    border: none; border-radius: 999px; cursor: pointer;
    font-size: 12px; font-weight: 700; color: var(--cs-text-tertiary, #64748b); background: transparent;
    transition: transform 200ms var(--cs-ease-spring), background 200ms, color 200ms, box-shadow 200ms;
    white-space: nowrap;
}
.cs-tn-step:hover { transform: translateY(-1px); background: rgba(255, 255, 255, 0.65); }
.cs-tn-step .cs-tn-ic { display: inline-grid; place-items: center; }
.cs-tn-step .cs-tn-title { font-size: 12px; max-width: 8em; overflow: hidden; text-overflow: ellipsis; }
.cs-tn-step.done { color: var(--cs-course-accent, var(--cs-brand, #003C88)); }
.cs-tn-step.done .cs-tn-ic { width: 16px; height: 16px; border-radius: 50%; background: var(--cs-course-accent, var(--cs-brand, #003C88)); color: #fff; }
.cs-tn-step.done svg { width: 10px; height: 10px; }
.cs-tn-step.open .cs-tn-ic { font-family: ui-monospace, Menlo, monospace; font-weight: 800; color: #94a3b8; }
.cs-tn-step.lock { color: #a4afc4; }
.cs-tn-step.lock svg { width: 11px; height: 11px; opacity: .75; }
/* 选中态走轻浅底（小毅：深色渐变太硬太沉、抢镜）——浅底深字，融进玻璃语言；
   主色吸收当前小节 --cs-course-accent（引擎注入），无声明时回落系统蓝 */
.cs-tn-step.cur {
    color: var(--cs-course-accent, var(--cs-brand, #003C88));
    background: color-mix(in srgb, var(--cs-course-accent, var(--cs-primary-500, #0062D6)) 13%, #ffffff);
    box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--cs-course-accent, var(--cs-primary-500, #0062D6)) 26%, transparent);
    padding: 0 16px;
    font-weight: 800;
}
.cs-tn-step.cur .cs-tn-num { font-family: ui-monospace, Menlo, monospace; font-size: 12px; font-weight: 900; opacity: .65; }
.cs-tn-step.cur .cs-tn-title { max-width: 12em; font-weight: 800; }

/* 顶部左右胶囊：画布模式下收窄，与小节条同高同线（38px @ top 1.05rem） */
body.cs-canvas-mode #course-entry-anchor,
body.cs-canvas-mode #student-user-menu { top: 1.05rem !important; }
/* 课程入口胶囊覆盖在小节条(#cs-topnav z-60)之上，不被抽屉遮挡。
   注：胶囊原在 <main>(z-10 层叠上下文)内，此 z-62 仅在引擎把它升到 body 级后才生效（course-engine.js 画布模式）。 */
body.cs-canvas-mode #course-entry-anchor { z-index: 62; }
body.cs-canvas-mode #btn-toggle-sidebar,
body.cs-canvas-mode #btn-user-menu-trigger { height: 38px !important; border-radius: 999px; }
/* 加宽一点点（小毅：顶部元素有点小）——只横向，高度不动 */
body.cs-canvas-mode #btn-toggle-sidebar { padding-left: 17px; padding-right: 19px; }
body.cs-canvas-mode #btn-user-menu-trigger { padding-left: 19px; padding-right: 17px; }
body.cs-canvas-mode #btn-toggle-sidebar > span:first-child { height: 26px; width: 26px; border-radius: 9px; }
body.cs-canvas-mode #btn-toggle-sidebar > span:first-child svg { width: 14px; height: 14px; }

/* ── 小信入口（画布模式）：入口 = 顶栏右簇胶囊（成熟 AI 产品形态：工具栏入口 + 侧栏面板）──
   呈现（小毅 2026-06-11 二轮）：胶囊不自带「饱和蓝渐变」风格——任何自带风格的涂法都会跟
   某种画布美学打架。改走「系统层制服」：壳 = 顶栏同款玻璃（已被五种画布验证的公约数材质），
   小信的标志蓝收敛成两个词：呼吸的「信号点」+ 蓝墨文字。黑/白/玻璃 + 纯色圆点是所有美学共有的词汇。
   存在感不靠饱和度、靠行为：信号点常年呼吸。 */
#cs-ai-entry { position: fixed; top: 1.05rem; right: var(--cs-ai-entry-right, 190px); z-index: 61; display: none; }
body.cs-canvas-mode #cs-ai-entry { display: flex; align-items: center; gap: 8px; }
/* 老师关 AI（cmd_ai_disable → body.cs-ai-off）：画布模式入口随之退场 */
body.cs-ai-off #cs-ai-entry { display: none !important; }
#cs-ai-entry button:not(.cs-fs-btn) {
    display: inline-flex; align-items: center; gap: 8px;
    height: 38px; padding: 0 16px;
    border: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.74));
    border-radius: 999px; cursor: pointer;
    background: var(--cs-glass-bg-header, rgba(255, 255, 255, 0.52));
    backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    -webkit-backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    /* 小信=固定系统蓝（小毅 2026-06-11：身份色不随课变）——蓝在这里是「墨」不是「漆」 */
    font-size: 13px; font-weight: 800; color: var(--cs-brand, #003C88);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.88), 0 10px 28px rgba(15, 23, 42, 0.07);
    transition: transform 200ms var(--cs-ease-spring), box-shadow 200ms, background 200ms, color 200ms;
}
#cs-ai-entry button:not(.cs-fs-btn):hover {
    transform: translateY(-1px);
    border-color: rgba(0, 98, 214, 0.30);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.88), 0 12px 30px rgba(15, 23, 42, 0.10);
}
#cs-ai-entry button:not(.cs-fs-btn):focus-visible {
    outline: 2px solid var(--cs-primary-400, #338EEB);
    outline-offset: 2px;
}
/* 在岗态 = 反转成实心蓝（用 primary-500 中蓝，brand 深海蓝太重） */
#cs-ai-entry button.on {
    background: var(--cs-primary-500, #0062D6);
    color: #fff;
    border-color: transparent;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.26), 0 10px 26px -10px rgba(0, 98, 214, 0.36);
}
#cs-ai-entry button.on .cs-ai-dot { background: #fff; animation: none; box-shadow: 0 0 0 3px rgba(255,255,255,.20); }

/* ── 小信信号点 `.cs-ai-dot`：身份标记，用于画布模式入口胶囊「问小信」──
   实心系统蓝正圆 + 雷达式呼吸光环——“活着、在线、可以叫”。（面板头装饰点、搭话气泡已移除，信号点现仅入口一处） */
.cs-ai-dot {
    flex: none;
    width: 9px; height: 9px;
    border-radius: 50%;
    background: var(--cs-primary-500, #0062D6);
    animation: csAiDotPing 2.6s ease-in-out infinite;
}
.cs-ai-dot-md { width: 11px; height: 11px; }
@keyframes csAiDotPing {
    0%, 100% { box-shadow: 0 0 0 0 rgba(0, 98, 214, 0.36); }
    55%      { box-shadow: 0 0 0 6px rgba(0, 98, 214, 0); }
}

/* ── 凑近对话气泡 .cs-ai-nudge（027 P6·方向一，升级自 ADR-0016 连错救援）──
   从顶栏小信入口下方探出。「凑近说话」气质：玻璃卡片 + tail 指入口（=这话是小信说的）+ 信号点锚（小信人格）
   + 「小信」署名 + 一句含糊不点破的引导。点主体=进对话（预填不自动发）；角落 ×=一键忽略。老师关 AI 随入口一并退场。
   连错≥2 自动触发 / 老师派小信（T5）共用此气泡。 */
.cs-ai-nudge {
    position: fixed; z-index: 9990;   /* 小信主动开口要最显眼：盖住课堂内容/面板，仅让位锁屏(9999)与倒计时浮条(9998) */
    width: 300px; max-width: calc(100vw - 24px);
    display: flex; align-items: flex-start; gap: 11px;
    padding: 13px 14px; border-radius: 16px;
    background: rgba(255, 255, 255, 0.74);
    backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    -webkit-backdrop-filter: blur(var(--cs-glass-blur, 20px)) saturate(var(--cs-glass-saturate, 1.5));
    border: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.82));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 14px 34px rgba(15, 23, 42, 0.14);
    cursor: pointer;
    opacity: 0; transform: translateY(-6px) scale(0.98);
    transition: opacity 300ms var(--cs-ease-out, ease), transform 300ms var(--cs-ease-spring, ease), box-shadow 200ms;
}
.cs-ai-nudge.show { opacity: 1; transform: none; }
.cs-ai-nudge:hover { box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 18px 40px rgba(0, 60, 136, 0.16); }
.cs-ai-nudge-tail {
    position: absolute; top: -5px; right: 34px;
    width: 11px; height: 11px;
    background: rgba(255, 255, 255, 0.74);
    border-left: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.82));
    border-top: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.82));
    transform: rotate(45deg);
}
.cs-ai-nudge-anchor {
    flex: none; width: 30px; height: 30px; border-radius: 50%;
    background: rgba(0, 98, 214, 0.10);
    display: flex; align-items: center; justify-content: center;
}
.cs-ai-nudge-anchor .cs-ai-dot { width: 10px; height: 10px; }
.cs-ai-nudge-body { display: flex; flex-direction: column; padding-right: 14px; }
.cs-ai-nudge-name { font-size: 11px; font-weight: 700; color: var(--cs-brand, #003C88); letter-spacing: 0.02em; }
.cs-ai-nudge-text { margin-top: 3px; font-size: 13px; font-weight: 500; color: var(--cs-text-primary, #26324A); line-height: 1.5; }
.cs-ai-nudge-close {
    position: absolute; top: 8px; right: 9px;
    width: 18px; height: 18px; padding: 0;
    border: none; background: transparent; cursor: pointer;
    color: var(--cs-text-muted, #9AA7BD);
    display: inline-flex; align-items: center; justify-content: center;
    transition: color 160ms var(--cs-ease-out, ease);
}
.cs-ai-nudge-close svg { width: 13px; height: 13px; }
.cs-ai-nudge-close:hover { color: var(--cs-brand); }
body.cs-ai-off .cs-ai-nudge { display: none !important; }


/* ── 全屏按钮（018b）：裸图标贴在背景上，无容器；hover 才微显底。
      全屏后由 ui.js 加 hidden 整体隐藏——课堂里不引导学生自己退出全屏。 ── */
.cs-fs-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    padding: 0;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    background: transparent;
    color: rgba(100, 116, 139, 0.52);
    transition: color 200ms var(--cs-ease-out), background 200ms var(--cs-ease-out);
}
.cs-fs-btn:hover {
    color: var(--cs-brand);
    background: rgba(255, 255, 255, 0.55);
}
.cs-fs-btn:focus-visible {
    outline: 2px solid var(--cs-primary-400);
    outline-offset: 2px;
}

/* ── 目录抽屉（画布模式）：顶对齐课程入口胶囊、底距视口底 1.25rem ──
   小毅 2026-06-12：顶 1.05rem / 底 1.25rem 都是抽屉自己的固定边距，与画布缩放脱钩（不再跟 --cs-board-h 变）、高度随视口撑开。
   两个值独立成立、不绑定任何其它元素（底边距此刻恰与左下聚焦浮条视觉同高，但二者无依赖——聚焦浮条日后若改，这里不必跟）。 */
body.cs-canvas-mode #app-sidebar {
    top: 1.05rem !important;
    bottom: 1.25rem !important;
    height: auto !important;
}


/* ── 小信老师停靠（画布模式展开 = 与画布同顶同高的液态玻璃侧栏，不喧宾夺主）── */
body.cs-canvas-mode.cs-ai-docked #ai-chat-panel {
    position: fixed !important;
    top: var(--cs-board-top, 76px);
    height: var(--cs-board-h, 600px) !important;
    bottom: auto !important;
    right: 16px;
    width: 420px !important;
    margin: 0 !important;
    z-index: 80;
    border-radius: 28px;   /* 与 .cs-canvas-board 同圆角：停靠栏和画布是一对版面同伴 */
    background: linear-gradient(168deg, rgba(255, 255, 255, 0.56), rgba(255, 255, 255, 0.30)) !important;
    backdrop-filter: blur(30px) saturate(1.8) !important;
    -webkit-backdrop-filter: blur(30px) saturate(1.8) !important;
    border: var(--cs-glass-border, 1px solid rgba(255, 255, 255, 0.74)) !important;
    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.92),
        inset 0 -1px 0 rgba(255, 255, 255, 0.30),
        inset 1px 0 0 rgba(255, 255, 255, 0.45),
        0 24px 60px -30px rgba(15, 23, 42, 0.32) !important;
    transition: top 380ms var(--cs-ease-spring), height 380ms var(--cs-ease-spring);
}
/* 停靠面板头部紧凑化（56px）；身份 = 信号点 + 名字，消息流无头像（成熟侧栏形态，靠气泡左右/配色区分角色） */
body.cs-canvas-mode.cs-ai-docked #ai-drag-handle { cursor: default; height: 56px; background: linear-gradient(180deg, rgba(255,255,255,.5), rgba(255,255,255,0)); }

/* 停靠态出入场：从右缘滑入/滑出，跟画布让位（380ms 弹性）同一个呼吸——
   浮窗用的 scale 弹跳（springBounce）不适合整高侧栏，停靠时覆写掉 */
body.cs-canvas-mode.cs-ai-docked #ai-chat-panel.ai-panel-spring {
    animation: csDockIn 420ms var(--cs-ease-spring) both;
}
body.cs-canvas-mode.cs-ai-docked #ai-chat-panel.ai-panel-close {
    animation: csDockOut 220ms ease-in both;
}
@keyframes csDockIn {
    from { opacity: 0; transform: translateX(56px); }
    to   { opacity: 1; transform: none; }
}
@keyframes csDockOut {
    from { opacity: 1; transform: none; }
    to   { opacity: 0; transform: translateX(48px); }
}

@media (prefers-reduced-motion: reduce) {
    .cs-canvas-board, #cs-topnav { transition: none !important; }
    #cs-ai-entry button, .cs-ai-dot { animation: none !important; }
    .cs-auth-card, .cs-auth-error { animation: none !important; }
    .cs-side-home, .cs-auth-submit { transition: none !important; }
}