/* GchemIB study-notes theme — inspired by clear revision-note layouts */
:root{
  --bg:#f4f7fb;--panel:#ffffff;--panel2:#f8faff;--line:#dfe6f0;
  --text:#18243a;--muted:#61718a;--teal:#167d86;--blue:#2d62cf;
  --purple:#7655c5;--amber:#a86b13;--radius:14px;
  --shadow:0 8px 26px rgba(23,43,77,.07)
}
html{background:var(--bg)}
body{background:var(--bg);color:var(--text);font-size:15px;line-height:1.65}
button,input,select,textarea{color:inherit}
.sidebar{background:#fff;border-right:1px solid #dfe6f0;box-shadow:3px 0 18px rgba(28,49,82,.025)}
.sidebar-topline{color:#738198}
.sidebar-version{background:#eaf0ff;color:#315bc0}
.brand-copy strong{color:#17243b}
.brand-copy small{color:#687892}
.brand-mark{background:#e8efff;color:#2d62cf;box-shadow:none}
.sidebar-course-chip{background:#f4f7fd;border-color:#e0e7f2;color:#24334c}
.sidebar-course-chip small{color:#6d7b91}
.nav-group-label{color:#7d8ba0}
.nav-link{color:#53627a}
.nav-link:hover{background:#f3f6fc;color:#20304a}
.nav-link.active{background:#eaf0ff;border-color:#d5e1ff;color:#214ba7}
.nav-link.active .nav-icon{color:#2d62cf}
.nav-icon{color:#73829a}
.nav-count{background:#edf2fb;color:#586b8a}
.sidebar-journey-card{background:#f7f9fd;border-color:#e1e7f1}
.sidebar-journey-card,.sidebar-journey-card *{color:#53627a}
.sidebar-journey-card .journey-card-head{color:#50617c}
.sidebar-journey-card .sidebar-journey-link{color:#2d62cf}
.sidebar-foot{color:#75839a}
.status-dot,.sidebar-live-dot{background:#1b9a85;box-shadow:none}
.main-area{background:var(--bg)}
.topbar{background:rgba(255,255,255,.94);border-bottom:1px solid #dfe6f0;backdrop-filter:blur(14px)}
.breadcrumbs{color:#7b879a}.breadcrumbs strong{color:#263650}.crumb-slash{color:#c0c9d7}
.global-search,.search-field{background:#f8faff;border-color:#dce4ef;color:#697991}
.global-search input,.search-field input{color:#1d2b43}
.global-search input::placeholder,.search-field input::placeholder{color:#8b98aa}
.global-search kbd{border-color:#d9e1ec;color:#77869a}
.icon-button{background:#fff;border-color:#dce4ef;color:#53637c}
.avatar{background:#e8efff;border-color:#d5e1ff;color:#2d62cf}
.content-wrap{max-width:1540px}
.hero{background:linear-gradient(120deg,#fff 0%,#f1f6ff 62%,#eaf4fa 100%);border-color:#dce6f3;box-shadow:var(--shadow)}
.hero-copy{padding-top:46px}
.eyebrow{color:#5c6e89}.eyebrow-dot{background:#2d62cf;box-shadow:none}
.hero h1,.page-intro h1{color:#17243b;letter-spacing:-1.6px}
.hero h1 span{color:#2d62cf}
.hero-copy>p{color:#596982}
.hero-proof{color:#73829a}
.proof-avatars i{background:#e1eaff;color:#3159ad;border-color:#f5f8ff}
.hero-visual:before{background:radial-gradient(ellipse,#cce5f5 0,transparent 70%)}
.orb{border-color:#77b8d555}
.visual-caption{background:#fff;border-color:#dce6f3;box-shadow:0 8px 24px #183b6410}
.visual-caption strong{color:#24344d}.visual-caption small{color:#71819a}
.floating-chip{background:#fff;border-color:#dce6f3;color:#31415b;box-shadow:0 8px 22px #183b6412}
.floating-chip span{color:#2d62cf}
.btn-primary{background:#2d62cf;color:#fff;box-shadow:0 5px 15px #2d62cf24}
.btn-primary:hover{background:#204fae}
.btn-ghost,.btn-secondary{background:#fff;border-color:#d6e0ed;color:#2d3e59}
.btn-ghost:hover,.btn-secondary:hover{background:#edf3ff}
.section-heading h2{color:#1b2940}
.section-kicker,.feature-meta{color:#74839a}
.feature-card,.panel{background:#fff;border-color:#dfe6f0;box-shadow:0 5px 18px rgba(27,49,80,.035)}
.feature-card:hover{background:#fbfdff;border-color:#a9c1f1;box-shadow:0 10px 25px rgba(37,78,150,.08)}
.feature-card>strong,.panel h3{color:#1b2940}
.feature-card p,.panel p{color:#62718a}
.feature-icon.teal{background:#e3f5f2;color:#167d86}
.feature-icon.blue{background:#e8efff;color:#2d62cf}
.feature-icon.purple{background:#f0eaff;color:#7655c5}
.feature-icon.amber{background:#fff2d9;color:#a86b13}
.card-bottom{border-color:#e6ebf3;color:#7a879b}
.card-bottom b,.subtle-link{color:#2d62cf}
.progress-track,.quiz-progress-track{background:#e5ebf4}
.progress-track span,.quiz-progress-track span{background:#2d62cf}
.tiny-pill{color:#2262bb;background:#edf3ff;border-color:#dce7ff}
.question-preview{background:#f7f9fd;border-color:#e1e7f1;color:#253650}
.daily-options button{background:#fff;border-color:#d8e1ed;color:#41516a}
.daily-options button:hover{border-color:#2d62cf}
.inline-feedback{color:#167d86}
.page-intro p{color:#63728a}
.intro-stat strong{color:#2d62cf}.intro-stat span{color:#7a879b}
.toolbar select{background:#fff;border-color:#dce4ef;color:#34445e}
.topic-button{background:#fff;border-color:#e0e7f0;color:#52627a}
.topic-button.active,.topic-button:hover{border-color:#a8c0f0;background:#edf3ff;color:#244da5}
.topic-index{background:#f0f4fa;color:#60718b}
.topic-button.active .topic-index{background:#dce8ff;color:#2d62cf}
.vn-card,.tq{background:#fff;border-color:#dfe6f0;box-shadow:0 5px 18px rgba(27,49,80,.035)}
.vn-head span{color:#71819a}
.vn-head h2,.vn-card b,.tq-head h3{color:#1b2940}
.vn-head p,.vn-card span,.tq-head span{color:#5f6f87}
.vn-table{background:#fff;border-color:#dfe6f0}
.vn-table th,.vn-table td{border-color:#e4eaf2}
.vn-table thead th{background:#edf3ff;color:#263e69}
.vn-table tbody tr:nth-child(even){background:#f8faff}
.vn-old>summary{color:#65748b;border-color:#d8e1ed}
.tq-opt{border-color:#dfe6f0;color:#293951}
.tq-opt span{background:#edf2fa;color:#4e607a}
.tq-opt:hover:not(:disabled){border-color:#2d62cf}
.tq-why{background:#edf3ff;border-left-color:#2d62cf;color:#293d60}
.language-toggle{background:#fff!important;color:#2d62cf!important;border-color:#d8e1ed!important}
.language-toggle:hover{border-color:#2d62cf!important;color:#204fae!important}
@media(max-width:900px){
 .sidebar{background:#fff;box-shadow:8px 0 30px rgba(20,40,70,.13)}
 .topbar{padding:0 18px}
 .content-wrap{padding:22px 18px}
 .hero{background:linear-gradient(140deg,#fff,#eff5ff)}
}
@media(max-width:560px){
 .hero-copy{padding:28px 22px 20px}
 .hero h1{font-size:36px}
 .hero-visual{min-height:260px}
 .feature-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
 .lower-grid{grid-template-columns:1fr}
}