/* ==========================================================================
   课程界面主题 v1.0
   统一登录、主界面、模块页的视觉规范；加载顺序位于 course.css 与
   course-refinement.css 之后，只覆盖外观，不改变实验功能。
   ========================================================================== */
:root{
 --topbar-h:64px;
 --ink-0:#061219;
 --ink-1:#0a1b26;
 --ink-2:#0f2534;
 --surface:rgba(10,27,39,.84);
 --surface-soft:rgba(255,255,255,.035);
 --surface-hover:rgba(255,255,255,.06);
 --line:rgba(150,192,208,.15);
 --line-strong:rgba(150,192,208,.28);
 --text:#e9f1f4;
 --text-2:#aec2cc;
 --text-3:#7d95a1;
 --accent:#4fc4b6;
 --accent-2:#2f9f93;
 --accent-soft:rgba(79,196,182,.12);
 --amber:#e4b866;
 --radius:10px;
 --radius-sm:6px;
 --shadow:0 18px 48px rgba(0,0,0,.28);
 --page-pad:clamp(20px,4.2vw,72px);
 font-family:"PingFang SC","Microsoft YaHei UI","Microsoft YaHei","Noto Sans CJK SC","Source Han Sans SC",sans-serif;
 color:var(--text);
 background:var(--ink-1);
}
body{background:var(--ink-1);-webkit-font-smoothing:antialiased}

/* ---------- 基础控件 ---------- */
button{border-radius:var(--radius-sm);background:var(--surface-soft);border:1px solid var(--line-strong);color:var(--text);transition:background .15s,border-color .15s,color .15s,transform .15s}
button:hover{background:var(--surface-hover);border-color:rgba(150,192,208,.45)}
.primary{background:linear-gradient(180deg,#45b9ab,#2f9f93);border-color:#5fcfc1;color:#fff;font-weight:500}
.primary:hover{background:linear-gradient(180deg,#52c7b9,#36ab9e);border-color:#7fdcd0}
input,select,textarea{border-radius:var(--radius-sm);background:rgba(3,12,18,.55);border:1px solid var(--line-strong);color:var(--text);transition:border-color .15s,box-shadow .15s}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(79,196,182,.16)}
input::placeholder,textarea::placeholder{color:var(--text-3)}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
.eyebrow{display:flex;align-items:center;gap:10px;margin:0;color:var(--accent);font-size:13px;font-weight:500;letter-spacing:4px}
.eyebrow::before{content:"";width:22px;height:2px;border-radius:2px;background:var(--accent)}
.course-title{margin:0;color:#f4f8f9;font-weight:600;letter-spacing:2px;line-height:1.32}

/* ---------- 页面背景：非实验页使用设计背景，不再显示三维平台截面 ---------- */
.page-backdrop{position:fixed;inset:0;z-index:0;pointer-events:none;background:var(--ink-1) center/cover no-repeat}
.page-backdrop::after{content:"";position:absolute;inset:0}
body[data-page=login] .page-backdrop{background-image:url(assets/bg/bg-login.jpg?v=9);background-position:right center}
body[data-page=login] .page-backdrop::after{background:linear-gradient(90deg,rgba(10,27,38,.88) 0%,rgba(10,27,38,.6) 26%,rgba(10,27,38,0) 42%)}
body[data-page=home] .page-backdrop{background-image:url(assets/bg/bg-home.jpg?v=3);background-position:center 40%}
body[data-page=home] .page-backdrop::after{background:linear-gradient(90deg,rgba(6,18,25,.95) 0%,rgba(6,18,25,.82) 32%,rgba(6,18,25,.28) 62%,rgba(6,18,25,.18) 100%),linear-gradient(0deg,rgba(6,18,25,.96) 0%,rgba(6,18,25,.55) 32%,rgba(6,18,25,.1) 60%,rgba(6,18,25,.25) 100%)}
body[data-page=scenarios] .page-backdrop,body[data-page=learn] .page-backdrop,body[data-page=quiz] .page-backdrop,body[data-page=report] .page-backdrop{background-image:url(assets/bg/bg-inner.jpg?v=2)}
body[data-page=scenarios] .page-backdrop::after,body[data-page=learn] .page-backdrop::after,body[data-page=quiz] .page-backdrop::after,body[data-page=report] .page-backdrop::after{background:linear-gradient(180deg,rgba(6,18,25,.15),rgba(6,18,25,.45))}
body[data-page=lab] .page-backdrop{display:none}
body:not([data-page=lab]) #viewport{visibility:hidden}
.scene-shade{display:none}

/* ---------- 顶部导航 ---------- */
#topbar,body[data-page=home] #topbar{height:var(--topbar-h);padding:0 var(--page-pad);gap:clamp(16px,2.4vw,40px);background:rgba(6,18,25,.82);border-bottom:1px solid var(--line);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
body[data-page=lab] #topbar{padding:0 20px}
body[data-page=home] #topbar nav{display:flex}
.screen{inset:var(--topbar-h) 0 0}
#topbar .identity,body[data-page=home] #topbar .identity{display:flex;align-items:center;gap:14px;min-width:0;flex:0 1 auto}
#topbar .brand-logo{width:118px;height:auto;max-height:none;mix-blend-mode:normal;filter:none;flex:none}
.brand-divider{width:1px;height:28px;background:var(--line-strong);flex:none}
.brand-text{display:flex;flex-direction:column;gap:3px;min-width:0;text-align:left}
#topbar .brand-title,body[data-page=home] #topbar .brand-title{max-width:none;font-size:15px;font-weight:500;line-height:1.25;color:var(--text);text-shadow:none;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.brand-sub{font-size:11px;letter-spacing:3px;color:var(--text-3);line-height:1.2}
#topbar nav{gap:2px;height:100%}
#topbar nav button{position:relative;height:100%;padding:0 14px;font-size:14px;color:var(--text-2);background:none;border:0;border-radius:0}
#topbar nav button::after{content:"";position:absolute;left:50%;bottom:0;width:0;height:2px;border-radius:2px;background:var(--accent);transform:translateX(-50%);transition:width .2s}
#topbar nav button:hover{color:var(--text);background:none}
#topbar nav button.active{color:#fff;background:none;font-weight:500}
#topbar nav button.active::after{width:28px}
.top-actions{gap:10px}
.top-actions svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round;flex:none}
.top-actions button{display:inline-flex;align-items:center;gap:6px;height:36px;padding:0 12px;font-size:13px}
.top-actions .ai-entry{color:#bdeee7;border-color:rgba(79,196,182,.45);background:var(--accent-soft)}
.top-actions .ai-entry:hover{background:rgba(79,196,182,.2);border-color:var(--accent)}
.top-actions .icon-button{width:36px;padding:0;justify-content:center}
.top-actions .user-button{padding:0 10px 0 4px;border-radius:18px}
.user-avatar{display:grid;place-items:center;width:28px;height:28px;border-radius:50%;background:rgba(150,192,208,.16)}
.user-avatar svg{width:16px;height:16px}
.top-actions .logout-mark{width:14px;height:14px;color:var(--text-3)}
.user-button:hover .logout-mark{color:var(--amber)}

/* ---------- 登录页 ---------- */
#page-login{top:0}
.login-layout{position:absolute;inset:0;display:flex;align-items:center;padding:72px var(--page-pad) 96px;overflow:auto}
.login-column{display:flex;flex-direction:column;gap:30px;width:min(440px,100%)}
.login-logo{display:block;width:clamp(190px,15vw,232px);height:auto}
.login-heading{display:flex;flex-direction:column;gap:14px;padding-top:28px;border-top:1px solid var(--line)}
.login-heading .course-title{font-size:clamp(30px,2.6vw,40px)}
.course-title-en{margin:0;font-size:12px;line-height:1.6;letter-spacing:.4px;color:var(--text-3)}
#page-login .login-panel{position:static;inset:auto;width:100%;padding:28px 28px 24px;background:rgba(10,27,39,.78);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
#page-login .login-panel h2{margin:0 0 18px;font-size:17px;font-weight:600}
#page-login .login-panel label{margin:0 0 16px;font-size:13px;color:var(--text-2)}
#page-login .login-panel input{height:44px;margin-top:8px;padding:0 14px;font-size:14px}
#page-login .form-error{min-height:0;margin:0 0 4px;font-size:12px}
#page-login .form-error:empty{display:none}
#page-login .login-panel button{width:100%;height:44px;margin:6px 0 0;padding:0;font-size:15px;letter-spacing:6px}
.login-footer{position:absolute;left:var(--page-pad);right:var(--page-pad);bottom:24px;display:flex;justify-content:space-between;gap:20px;padding-top:16px;border-top:1px solid var(--line);font-size:12px;color:var(--text-3);pointer-events:none}

/* ---------- 主界面 ---------- */
.home-layout{position:absolute;inset:0;display:flex;flex-direction:column;justify-content:space-between;gap:36px;padding:clamp(36px,9vh,110px) var(--page-pad) clamp(24px,4.5vh,44px);overflow:auto}
.home-hero{display:flex;flex-direction:column;gap:18px;max-width:640px}
.home-hero .course-title{font-size:clamp(34px,3.3vw,52px)}
.home-lead{margin:4px 0 0;max-width:560px;font-size:15px;line-height:1.9;color:var(--text-2)}
#page-home .module-menu{position:static;inset:auto;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;padding:0;background:none;border:0;box-shadow:none;backdrop-filter:none;-webkit-backdrop-filter:none}
#page-home .module-menu button{position:relative;display:flex;flex-direction:column;align-items:flex-start;min-height:0;padding:22px 22px 20px;text-align:left;background:rgba(10,27,39,.72);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 12px 32px rgba(0,0,0,.22);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);transition:transform .2s,border-color .2s,background .2s}
#page-home .module-menu button:hover{transform:translateY(-3px);background:rgba(14,37,52,.82);border-color:rgba(79,196,182,.5)}
#page-home .module-card-head{display:flex;align-items:center;justify-content:space-between;width:100%;min-height:0;margin:0 0 18px}
#page-home .module-icon{display:grid;place-items:center;width:42px;height:42px;border-radius:10px;background:var(--accent-soft);color:var(--accent)}
#page-home .module-icon svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
#page-home .module-index{font-size:12px;letter-spacing:2px;color:var(--text-3);margin-bottom:4px}
#page-home .module-menu h2{margin:0 0 8px;font-size:20px;font-weight:600;color:var(--text)}
#page-home .module-menu p{max-width:none;min-height:3.4em;margin:0;font-size:13px;line-height:1.7;color:var(--text-2)}
#page-home .module-go{margin-top:14px;font-size:12px;color:var(--accent);opacity:.75;transition:opacity .2s,transform .2s}
#page-home .module-menu button:hover .module-go{opacity:1;transform:translateX(3px)}

/* 进度标签（主界面与场景卡片共用） */
.progress-state{gap:6px;padding:3px 9px;border-radius:999px;font-size:11px;border:1px solid rgba(150,192,208,.25);background:rgba(6,18,25,.55);color:var(--text-2)}
.progress-state::before{width:6px;height:6px}

/* ---------- 模块页统一框架 ---------- */
.page-frame{position:absolute;inset:0;display:flex;flex-direction:column;padding:28px var(--page-pad) 28px;overflow:auto}
.page-frame>*{width:100%;max-width:1440px;margin-left:auto;margin-right:auto}
.page-frame-narrow>*{max-width:1120px}
.page-frame-fill{overflow:hidden}
.page-frame-fill>.panel{flex:1;min-height:0}
.page-header{display:flex;flex-direction:column;gap:8px;margin-bottom:22px;flex:none}
.page-header h1{margin:0;font-size:28px;font-weight:600;letter-spacing:2px;color:#f4f8f9}
.page-header>p:last-child{margin:0;font-size:13px;line-height:1.6;color:var(--text-2)}

/* 知识学习 */
#page-learn .learning-shell{position:relative;inset:auto;grid-template-columns:272px minmax(0,1fr)}
#page-learn .learning-shell>aside{padding:20px 16px}
#page-learn .learning-shell input{margin:0 0 8px;height:38px}
#page-learn .learning-shell article{padding:36px clamp(28px,3.5vw,56px);background:rgba(255,255,255,.015)}
.chapter-heading{color:var(--accent);letter-spacing:1px}
.lesson-link{border-radius:var(--radius-sm)}
.lesson-link:hover{background:var(--surface-hover);color:var(--text)}
.lesson-link.active{border-left:0;border-radius:var(--radius-sm);background:var(--accent-soft);color:#dff6f2;box-shadow:inset 3px 0 0 var(--accent)}
.learning-shell article h1{font-weight:600;font-size:28px;letter-spacing:1px}
.lesson-diagram{height:auto;padding:18px 22px 12px;border-radius:var(--radius);background:linear-gradient(180deg,rgba(14,38,50,.55),rgba(3,12,18,.45));border-color:var(--line)}
.lesson-diagram svg{display:block;width:100%;height:auto;max-width:960px;margin:0 auto}
.formula{border-radius:0 var(--radius-sm) var(--radius-sm) 0;background:rgba(79,196,182,.09);border-left-color:var(--accent)}
.lesson-task{border-radius:var(--radius);border-color:var(--line);background:var(--surface-soft)}

/* 知识测验 */
#page-quiz .quiz-shell{position:relative;inset:auto;margin:0 auto;max-width:1120px;padding:28px clamp(22px,3.2vw,44px);overflow:auto;background:var(--surface)}
#question-map{margin:0 0 28px}
#question-map button{width:38px;height:34px;padding:0;border-radius:var(--radius-sm)}
#question-map button.current{border-color:var(--accent);color:#fff;box-shadow:0 0 0 2px rgba(79,196,182,.2)}
#question-map button.answered{background:rgba(79,196,182,.24);border-color:rgba(79,196,182,.5)}
.quiz-item legend{font-size:18px;font-weight:500}
.quiz-option{display:flex!important;align-items:center;gap:12px;margin:0 0 10px!important;padding:14px 18px;border-radius:var(--radius-sm);background:var(--surface-soft);border:1px solid var(--line);font-size:14px;line-height:1.6;transition:border-color .15s,background .15s}
.quiz-option:hover{border-color:var(--line-strong);background:var(--surface-hover)}
.quiz-option:has(input:checked){border-color:var(--accent);background:var(--accent-soft)}
.quiz-option input[type=radio]{display:inline-block!important;flex:none;width:16px!important;height:16px;margin:0!important;padding:0;accent-color:var(--accent)}
.quiz-feedback{border-radius:var(--radius-sm)}

/* 实验报告 */
#page-report .report-shell{position:relative;inset:auto;padding:28px clamp(22px,3.2vw,44px);overflow:auto;background:var(--surface)}
#page-report .report-evidence{grid-template-columns:repeat(auto-fit,minmax(180px,1fr));margin:0 0 22px}
#page-report .report-evidence>div{border-radius:var(--radius-sm);background:var(--surface-soft);border:1px solid var(--line)}
#page-report .report-evidence b{font-weight:600}
.submission-summary:empty{display:none}
.report-scene-tabs button.active,.archive-scenes button.active{background:var(--accent-soft);border-color:var(--accent);color:#dff6f2}

/* ---------- 仿真实验：场景选择 ---------- */
#page-scenarios .scenario-menu{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;width:100%;max-width:1440px;margin:0 auto;max-height:none;overflow:visible}
#page-scenarios .scenario-menu button{display:flex;flex-direction:column;padding:0;overflow:hidden;text-align:left;background:rgba(10,27,39,.8);border:1px solid var(--line);border-radius:12px;box-shadow:0 14px 36px rgba(0,0,0,.26);transition:transform .2s,border-color .2s}
#page-scenarios .scenario-menu button:hover{transform:translateY(-3px);border-color:rgba(79,196,182,.55);background:rgba(10,27,39,.86)}
#page-scenarios .scenario-art{position:relative;display:block;min-height:0;height:auto;aspect-ratio:16/10;margin:0;padding:0;overflow:hidden;background:#0d2231;border-bottom:1px solid var(--line)}
#page-scenarios .scenario-art img{display:block;width:100%;height:100%;object-fit:cover;transition:transform .5s ease}
#page-scenarios .scenario-art::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(6,18,25,0) 55%,rgba(6,18,25,.55));pointer-events:none}
#page-scenarios .scenario-menu button:hover .scenario-art img{transform:scale(1.04)}
#page-scenarios .scenario-art .progress-state{position:absolute;top:12px;right:12px;z-index:1;display:inline-flex;backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px)}
#page-scenarios .scenario-copy{display:flex;flex:1;flex-direction:column;justify-content:flex-start;gap:10px;min-height:0;padding:20px 22px 20px}
#page-scenarios .scenario-heading{display:flex;flex-direction:row;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
#page-scenarios .scenario-heading h2{margin:0;font-size:20px;font-weight:600;color:var(--text)}
#page-scenarios .scenario-menu .scenario-meta{display:flex;gap:6px;margin:0}
#page-scenarios .scenario-menu .scenario-meta span{display:inline-block;margin:0;padding:2px 8px;border:1px solid var(--line-strong);border-radius:4px;font-size:11px;line-height:1.6;color:var(--text-2)}
#page-scenarios .scenario-copy p{min-height:3.4em;margin:0;font-size:13px;line-height:1.7;color:var(--text-2)}
#page-scenarios .scenario-menu .scenario-go{display:inline-flex;align-items:center;gap:6px;margin-top:auto;padding-top:4px;font-size:13px;color:var(--accent)}
#page-scenarios .scenario-go i{font-style:normal;transition:transform .2s}
#page-scenarios .scenario-menu button:hover .scenario-go i{transform:translateX(4px)}

/* ---------- 对话框与提示 ---------- */
dialog,#experiment-dialog,.dialog-message{background:#0e2331;border:1px solid var(--line-strong);border-radius:12px;box-shadow:0 30px 80px rgba(0,0,0,.45)}
dialog::backdrop{background:rgba(3,10,15,.7);backdrop-filter:blur(3px)}
.ai-tabs button.active{background:var(--accent-soft);border-color:var(--accent)}
.chat-message{border-radius:var(--radius-sm)}
#toast{border-radius:var(--radius-sm);background:rgba(14,35,49,.96);border-color:var(--line-strong)}

/* ---------- 响应式 ---------- */
@media(max-width:1280px){
 .brand-sub{display:none}
 #topbar nav button{padding:0 11px}
}
@media(max-width:1100px){
 #topbar .brand-divider,#topbar .brand-text{display:none}
 #page-home .module-menu{gap:12px}
 #page-home .module-menu button{padding:18px 16px}
 #page-home .module-menu h2{font-size:18px}
 #page-scenarios .scenario-menu{gap:14px}
 #page-scenarios .scenario-copy{padding:16px}
 #page-scenarios .scenario-heading{flex-direction:column;align-items:flex-start;gap:8px}
}
@media(max-width:960px){
 #page-home .module-menu{grid-template-columns:repeat(2,minmax(0,1fr))}
 #page-home .module-menu p{min-height:0}
 #page-scenarios .scenario-menu{grid-template-columns:1fr;max-width:820px}
 #page-scenarios .scenario-menu button{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:stretch}
 #page-scenarios .scenario-art{aspect-ratio:auto;height:100%;min-height:190px;border-bottom:0;border-right:1px solid var(--line)}
 #page-scenarios .scenario-copy p{min-height:0}
}
@media(max-width:900px){
 body[data-page=login] .page-backdrop{background-position:70% center}
 body[data-page=login] .page-backdrop::after{background:linear-gradient(180deg,rgba(6,18,25,.78),rgba(6,18,25,.92))}
 .login-layout{justify-content:center}
 }
@media(max-width:800px){
 :root{--topbar-h:58px}
 #topbar,body[data-page=home] #topbar{height:var(--topbar-h);padding:0 10px;gap:8px}
 #topbar .identity{display:none!important}
 #topbar nav{overflow-x:auto;flex:1;min-width:0}
 #topbar nav button{padding:0 9px;font-size:13px}
 .screen{top:var(--topbar-h)}
 .top-actions{gap:6px}
 .top-actions .ai-entry{font-size:0;gap:0;width:36px;padding:0;justify-content:center}
 .top-actions .user-button #user-name,.top-actions .logout-mark{display:none}
 .top-actions .user-button{padding:0 3px}
 .page-header h1{font-size:23px}
 .page-header{margin-bottom:16px}
 .page-frame{padding:18px 16px}
 #page-learn .learning-shell{grid-template-columns:150px minmax(0,1fr)}
}
@media(max-width:600px){
 .login-footer span:last-child{display:none}
 .home-layout{gap:24px}
 .home-lead{font-size:13px}
   #page-home .module-menu{gap:10px}
 #page-home .module-menu button{padding:14px}
 #page-home .module-card-head{margin-bottom:10px}
 #page-home .module-icon{width:34px;height:34px}
 #page-home .module-menu h2{font-size:16px}
 #page-home .module-menu p{font-size:11px}
 #page-home .module-go{display:none}
 #page-scenarios .scenario-menu button{grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr)}
 #page-scenarios .scenario-art{min-height:140px}
 #page-scenarios .scenario-copy{padding:12px 14px;gap:6px}
 #page-scenarios .scenario-heading h2{font-size:16px}
 #page-scenarios .scenario-copy p{font-size:11px}
}
@media(max-height:760px) and (min-width:801px){
 .home-layout{padding-top:32px}
 .home-hero{gap:12px}
 .home-hero .course-title{font-size:clamp(28px,2.8vw,40px)}
 .home-lead{font-size:14px;line-height:1.75}
  #page-home .module-menu button{padding:16px 18px}
 #page-home .module-card-head{margin-bottom:12px}
 .login-column{gap:22px}
 .login-heading{padding-top:20px}
}

/* 修正：旧样式 .identity span 的字号会作用到副标题 */
#topbar .identity .brand-sub{font-size:11px;letter-spacing:3px;color:var(--text-3)}
/* 实验页底图为浅色三维场景，面板与顶栏使用更实的底色保证对比 */
body[data-page=lab] #topbar{background:rgba(8,22,31,.96)}
body[data-page=lab] .panel{background:rgba(11,29,41,.94)}