/* =========================================================
   Base Section
========================================================== */
:root{
  --bg: #0b1220;
  --panel: rgba(255,255,255,0.06);
  --panel2: rgba(255,255,255,0.08);
  --text: rgba(255,255,255,0.92);
  --muted: rgba(255,255,255,0.70);
  --border: rgba(255,255,255,0.12);
  --shadow: 0 10px 24px rgba(0,0,0,0.35);
  --brand: #5dd6ff;
  --good: #30d158;
  --warn: #ffd60a;
  --bad: #ff453a;
  --radius: 14px;
  --radius2: 18px;
  --font: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

[data-theme="light"]{
  --bg: #f6f7fb;
  --panel: rgba(20,28,45,0.05);
  --panel2: rgba(20,28,45,0.08);
  --text: rgba(10,12,18,0.92);
  --muted: rgba(10,12,18,0.68);
  --border: rgba(10,12,18,0.12);
  --shadow: 0 10px 24px rgba(10,12,18,0.12);
  --brand: #0b6bff;
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(1200px 700px at 15% 10%, rgba(93,214,255,0.25), transparent 60%),
              radial-gradient(900px 500px at 85% 20%, rgba(255,214,10,0.10), transparent 55%),
              var(--bg);
  color: var(--text);
}

/* =========================================================
   Utility Section
========================================================== */
.muted{ color: var(--muted); }
.small{ font-size: 0.92rem; }
.sr-only{
  position:absolute; width:1px; height:1px; padding:0; margin:-1px;
  overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
}
code{
  font-family: var(--mono);
  background: var(--panel);
  padding: 0.1rem 0.35rem;
  border-radius: 10px;
  border: 1px solid var(--border);
}

/* =========================================================
   Layout Section
========================================================== */
.app-header{
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 1.1rem;
  border-bottom: 1px solid var(--border);
  background: rgba(0,0,0,0.25);
  backdrop-filter: blur(14px);
}
[data-theme="light"] .app-header{
  background: rgba(255,255,255,0.75);
}

.brand{
  display:flex;
  align-items:center;
  gap:0.75rem;
}
.logo{
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display:flex;
  align-items:center;
  justify-content:center;
  font-weight: 800;
  letter-spacing: 0.5px;
  color: rgba(0,0,0,0.82);
  background: linear-gradient(135deg, rgba(93,214,255,1), rgba(255,214,10,0.95));
  box-shadow: var(--shadow);
}
.brand-title{
  font-weight: 760;
  letter-spacing: 0.2px;
}
.brand-subtitle{
  font-size: 0.92rem;
  color: var(--muted);
}

.header-actions{
  display:flex;
  align-items:center;
  gap:0.5rem;
}

.layout{
  display: grid;
  grid-template-columns: 320px 1fr;
  min-height: calc(100vh - 72px);
}

.sidebar{
  border-right: 1px solid var(--border);
  padding: 1rem;
  display:flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
  background: rgba(0,0,0,0.18);
}
[data-theme="light"] .sidebar{
  background: rgba(255,255,255,0.55);
}
.sidebar-top{ display:flex; flex-direction: column; gap: 0.75rem; }
.sidebar-bottom{ display:flex; flex-direction: column; gap: 0.75rem; }

.main{
  padding: 1.2rem;
  max-width: 1400px;
}

/* =========================================================
   Components Section
========================================================== */
.btn{
  appearance: none;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  padding: 0.55rem 0.75rem;
  border-radius: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}
.btn:hover{ transform: translateY(-1px); background: var(--panel2); border-color: rgba(255,255,255,0.20); }
[data-theme="light"] .btn:hover{ border-color: rgba(10,12,18,0.18); }

.btn:disabled{
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

.btn-primary{
  background: linear-gradient(135deg, rgba(93,214,255,0.9), rgba(11,107,255,0.9));
  border-color: rgba(255,255,255,0.22);
  color: rgba(255,255,255,0.96);
}
[data-theme="light"] .btn-primary{
  border-color: rgba(10,12,18,0.10);
}

.btn-danger{
  background: linear-gradient(135deg, rgba(255,69,58,0.95), rgba(255,214,10,0.35));
  border-color: rgba(255,255,255,0.18);
}

.btn-ghost{
  background: transparent;
}

.icon{ font-size: 1rem; }

.searchbox input{
  width: 100%;
  padding: 0.72rem 0.85rem;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.12);
  color: var(--text);
  outline: none;
}
[data-theme="light"] .searchbox input{ background: rgba(255,255,255,0.70); }
.searchbox input:focus{ border-color: rgba(93,214,255,0.65); }

.nav{
  display:flex;
  flex-direction: column;
  gap: 0.35rem;
}
.nav-item{
  width: 100%;
  text-align: left;
  padding: 0.72rem 0.8rem;
  border-radius: 14px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  display:flex;
  align-items:center;
  gap: 0.55rem;
  font-weight: 650;
}
.nav-item:hover{
  background: var(--panel);
  border-color: var(--border);
}
.nav-item.is-active{
  background: linear-gradient(135deg, rgba(93,214,255,0.22), rgba(11,107,255,0.18));
  border-color: rgba(93,214,255,0.30);
}
.nav-icon{ width: 20px; display:inline-flex; justify-content:center; }

.card{
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: var(--radius2);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.card.mini{ box-shadow: none; }
.card-header{
  padding: 1rem 1.05rem 0.6rem 1.05rem;
  border-bottom: 1px solid var(--border);
}
.card-title{
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0.2px;
}
.card-subtitle{
  margin: 0.3rem 0 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}
.card-body{
  padding: 1rem 1.05rem;
}
.card-footer{
  padding: 0.9rem 1.05rem;
  border-top: 1px solid var(--border);
  display:flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  align-items: center;
}

.route{ display:none; }
.route.is-active{ display:block; }

.route-header h1{
  margin: 0 0 0.35rem 0;
  font-size: 1.55rem;
  letter-spacing: 0.2px;
}
.route-header p{ margin: 0 0 1rem 0; }

.grid.two{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  align-items: start;
}

.chapter-list{
  list-style: none;
  padding: 0;
  margin: 0;
  display:flex;
  flex-direction: column;
  gap: 0.55rem;
}
.chapter-list button{
  width: 100%;
  text-align:left;
  padding: 0.75rem 0.8rem;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  color: var(--text);
  cursor: pointer;
}
[data-theme="light"] .chapter-list button{ background: rgba(255,255,255,0.60); }
.chapter-list button:hover{ background: var(--panel2); }
.chapter-list button.is-active{ border-color: rgba(93,214,255,0.60); }

.reader h2{ margin-top: 0; }
.reader h3{ margin-bottom: 0.25rem; }
.reader ul{ margin-top: 0.45rem; }
.reader .pillrow{ display:flex; flex-wrap: wrap; gap: 0.4rem; margin: 0.7rem 0; }
.pill{
  display:inline-flex;
  align-items:center;
  gap: 0.35rem;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.92rem;
}
[data-theme="light"] .pill{ background: rgba(255,255,255,0.65); }

.field{ display:flex; flex-direction: column; gap: 0.35rem; margin-bottom: 0.75rem; }
.field label{ font-weight: 650; color: var(--muted); }
.field select{
  padding: 0.65rem 0.75rem;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  color: var(--text);
}
[data-theme="light"] .field select{ background: rgba(255,255,255,0.65); }

.field input{
  padding: 0.65rem 0.75rem;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  color: var(--text);
  outline: none;
}
[data-theme="light"] .field input{ background: rgba(255,255,255,0.65); }
.field input:focus{ border-color: rgba(93,214,255,0.65); }



.table-wrap{ width: 100%; overflow-x: auto; }
.table{
  width: 100%;
  border-collapse: collapse;
  min-width: 650px;
}
.table th, .table td{
  text-align: left;
  padding: 0.8rem 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.table th{ color: var(--muted); font-weight: 750; }
.table tr:hover td{ background: rgba(93,214,255,0.06); }

.quiz-area{ display:flex; flex-direction: column; gap: 0.9rem; }
.quiz-q{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 0.85rem;
  background: rgba(0,0,0,0.10);
}
[data-theme="light"] .quiz-q{ background: rgba(255,255,255,0.65); }
.quiz-q .q-title{ font-weight: 780; margin: 0 0 0.6rem 0; }
.quiz-q .q-meta{ color: var(--muted); font-size: 0.92rem; margin-bottom: 0.55rem; }
.choices{ display:flex; flex-direction: column; gap: 0.45rem; }
.choice{
  display:flex;
  gap: 0.55rem;
  align-items: flex-start;
  padding: 0.55rem 0.6rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.06);
}
[data-theme="light"] .choice{ background: rgba(255,255,255,0.75); }
.choice input{ margin-top: 0.15rem; }

.result{
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 0.85rem 0.85rem;
  background: rgba(0,0,0,0.10);
}
.result .score{
  font-size: 1.2rem;
  font-weight: 850;
  margin: 0 0 0.3rem 0;
}
.badge{
  display:inline-flex;
  align-items:center;
  border-radius: 999px;
  border: 1px solid var(--border);
  padding: 0.2rem 0.55rem;
  font-size: 0.9rem;
  color: var(--muted);
}
.badge.good{ color: rgba(48,209,88,0.95); border-color: rgba(48,209,88,0.35); }
.badge.warn{ color: rgba(255,214,10,0.95); border-color: rgba(255,214,10,0.35); }
.badge.bad{ color: rgba(255,69,58,0.95); border-color: rgba(255,69,58,0.35); }

.explain{
  margin-top: 0.65rem;
  padding-top: 0.65rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
}

.checklist{
  list-style: none;
  padding: 0;
  margin: 0;
  display:flex;
  flex-direction: column;
  gap: 0.55rem;
}
.checklist li{
  display:flex;
  align-items:center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: rgba(0,0,0,0.08);
}
[data-theme="light"] .checklist li{ background: rgba(255,255,255,0.65); }
.checklist label{ display:flex; gap: 0.6rem; align-items:center; }

.scores{
  display:flex;
  flex-direction: column;
  gap: 0.55rem;
}
.score-row{
  display:flex;
  align-items:center;
  justify-content: space-between;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: rgba(0,0,0,0.08);
}
[data-theme="light"] .score-row{ background: rgba(255,255,255,0.65); }

.mini-title{ font-weight: 780; margin-bottom: 0.35rem; }
.mini-body{ color: var(--muted); line-height: 1.35; }

.pdf-frame{
  width: 100%;
  height: 520px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow:hidden;
  background: rgba(0,0,0,0.10);
}
[data-theme="light"] .pdf-frame{ background: rgba(255,255,255,0.65); }
.pdf-frame iframe{
  width: 100%;
  height: 100%;
  border: 0;
  display:block;
}

.bullets{ margin: 0; padding-left: 1.1rem; }
.bullets li{ margin: 0.35rem 0; }

.codeblock{
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  overflow:hidden;
}
[data-theme="light"] .codeblock{ background: rgba(255,255,255,0.65); }
.codeblock pre{
  margin: 0;
  padding: 0.85rem 0.85rem;
  font-family: var(--mono);
  font-size: 0.92rem;
  overflow-x: auto;
}

/* =========================================================
   Modal Section
========================================================== */
.modal[hidden]{ display:none; }
.modal{
  position: fixed;
  inset: 0;
  z-index: 50;
  display:flex;
  align-items:center;
  justify-content:center;
  padding: 1.1rem;
}
.modal-backdrop{
  position:absolute;
  inset: 0;
  background: rgba(0,0,0,0.55);
}
.modal-panel{
  position: relative;
  width: min(1000px, 98vw);
  border-radius: 18px;
  border: 1px solid var(--border);
  background: var(--bg);
  box-shadow: var(--shadow);
  overflow:hidden;
}
.modal-header{
  display:flex;
  align-items:center;
  justify-content: space-between;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--border);
}
.modal-title{ font-weight: 800; }
.modal-body{ padding: 1rem; }

/* =========================================================
   Responsive Section
========================================================== */
@media (max-width: 1100px){
  .layout{ grid-template-columns: 280px 1fr; }
  .grid.two{ grid-template-columns: 1fr; }
}

@media (max-width: 820px){
  .layout{ grid-template-columns: 1fr; }
  .sidebar{
    position: sticky;
    top: 72px;
    z-index: 10;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }
  .main{ padding: 1rem; }
  .pdf-frame{ height: 420px; }
}