:root {
  --bg: #0f1220; --panel: rgba(255,255,255,.06); --border: rgba(255,255,255,.12);
  --text: #e8eaf2; --muted: #9aa1b5; --accent: #6c8cff; --ok: #35c48d; --warn: #f5b74e; --bad: #f06a6a;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: "Pretendard Variable", Pretendard, sans-serif; background: var(--bg); color: var(--text); }
.app-container { display: flex; height: 100vh; gap: 16px; padding: 16px; }
.glass-panel { background: var(--panel); border: 1px solid var(--border); border-radius: 16px; backdrop-filter: blur(12px); }
.sidebar { width: 300px; display: flex; flex-direction: column; overflow: hidden; }
.sidebar-header { padding: 20px 16px 12px; border-bottom: 1px solid var(--border); }
.sidebar-header h2 { font-size: 18px; } .sidebar-header p { font-size: 12px; color: var(--muted); margin: 2px 0 10px; }
.mode-tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-bottom: 10px; }
.mode-tab { padding: 8px 6px; font-size: 12px; border: 1px solid var(--border); background: transparent; color: var(--muted); border-radius: 8px; cursor: pointer; }
.mode-tab.active { background: var(--accent); color: #fff; border-color: transparent; }
.course-tabs { display: flex; gap: 6px; }
.course-tab { flex: 1; padding: 8px; font-size: 12px; border: 1px solid var(--border); background: transparent; color: var(--muted); border-radius: 8px; cursor: pointer; }
.course-tab.active { background: rgba(108,140,255,.2); color: var(--text); border-color: var(--accent); }
.file-list { flex: 1; overflow-y: auto; padding: 10px; }
.file-item { display: block; width: 100%; text-align: left; padding: 10px 12px; margin-bottom: 4px; font-size: 13px; color: var(--muted); background: transparent; border: none; border-radius: 8px; cursor: pointer; }
.file-item:hover { background: rgba(255,255,255,.06); color: var(--text); }
.file-item.active { background: rgba(108,140,255,.18); color: var(--text); }
.group-label { font-size: 11px; color: var(--muted); padding: 10px 12px 4px; text-transform: uppercase; letter-spacing: .06em; }
.loading-text { color: var(--muted); font-size: 13px; padding: 16px; }
.main-content { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.content-header { display: flex; justify-content: space-between; align-items: center; padding: 18px 24px; border-bottom: 1px solid var(--border); }
.content-header h1 { font-size: 20px; }
.status-badge { font-size: 11px; color: var(--ok); border: 1px solid var(--ok); padding: 4px 10px; border-radius: 999px; }
.markdown-body { flex: 1; overflow-y: auto; padding: 28px 32px; line-height: 1.75; font-size: 15px; }
.markdown-body h1,.markdown-body h2,.markdown-body h3 { margin: 1.2em 0 .5em; }
.markdown-body p,.markdown-body li { color: #cfd4e4; }
.markdown-body ul,.markdown-body ol { padding-left: 1.4em; }
.markdown-body code { background: rgba(255,255,255,.09); padding: 2px 6px; border-radius: 6px; font-size: 13px; }
.markdown-body pre { background: #0b0e1a; border: 1px solid var(--border); border-radius: 12px; padding: 16px; overflow-x: auto; margin: 1em 0; }
.markdown-body pre code { background: none; padding: 0; }
.markdown-body table { border-collapse: collapse; margin: 1em 0; width: 100%; }
.markdown-body th,.markdown-body td { border: 1px solid var(--border); padding: 8px 12px; font-size: 13px; }
.welcome-screen { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; color: var(--muted); }
/* 코드 추적 */
.trace-wrap { display: grid; grid-template-columns: 1.2fr 1fr; gap: 16px; height: 100%; }
.trace-code { background: #0b0e1a; border: 1px solid var(--border); border-radius: 12px; padding: 12px; overflow: auto; font-family: Consolas, monospace; font-size: 13px; }
.trace-code .ln { display: flex; gap: 12px; padding: 2px 8px; border-radius: 6px; white-space: pre; }
.trace-code .ln .no { color: var(--muted); width: 2em; text-align: right; user-select: none; flex-shrink: 0; }
.trace-code .ln.hl { background: rgba(108,140,255,.25); }
.trace-side { display: flex; flex-direction: column; gap: 12px; overflow: auto; }
.trace-desc { padding: 14px; border: 1px solid var(--border); border-radius: 12px; font-size: 14px; }
.trace-vars { padding: 14px; border: 1px solid var(--border); border-radius: 12px; font-size: 13px; }
.trace-vars table { width: 100%; border-collapse: collapse; }
.trace-vars td,.trace-vars th { border-bottom: 1px solid var(--border); padding: 6px 8px; text-align: left; }
.trace-controls { display: flex; gap: 8px; align-items: center; }
.btn { padding: 9px 16px; border-radius: 10px; border: 1px solid var(--border); background: rgba(255,255,255,.07); color: var(--text); cursor: pointer; font-size: 13px; }
.btn:hover { background: rgba(255,255,255,.14); }
.btn.primary { background: var(--accent); border-color: transparent; }
.btn:disabled { opacity: .4; cursor: default; }
.step-indicator { color: var(--muted); font-size: 12px; margin-left: auto; }
/* 기출 풀이 */
.quiz-setup { display: flex; flex-wrap: wrap; gap: 10px; align-items: end; padding: 16px; border: 1px solid var(--border); border-radius: 12px; margin-bottom: 18px; }
.quiz-setup label { font-size: 12px; color: var(--muted); display: flex; flex-direction: column; gap: 4px; }
.quiz-setup select { background: #0b0e1a; color: var(--text); border: 1px solid var(--border); border-radius: 8px; padding: 8px; font-size: 13px; }
.quiz-setup .chk { flex-direction: row; align-items: center; gap: 6px; }
.quiz-card { border: 1px solid var(--border); border-radius: 14px; padding: 22px; }
.quiz-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; font-size: 11px; }
.tag { padding: 3px 9px; border-radius: 999px; border: 1px solid var(--border); color: var(--muted); }
.tag.review { color: var(--warn); border-color: var(--warn); }
.quiz-q { white-space: pre-wrap; font-size: 15px; line-height: 1.8; margin-bottom: 18px; }
.quiz-q pre { background: #0b0e1a; border: 1px solid var(--border); border-radius: 10px; padding: 14px; font-family: Consolas, monospace; font-size: 13px; overflow-x: auto; white-space: pre; }
.quiz-q table { border-collapse: collapse; margin: .6em 0; }
.quiz-q th,.quiz-q td { border: 1px solid var(--border); padding: 6px 12px; font-size: 13px; }
.quiz-input { width: 100%; min-height: 70px; background: #0b0e1a; color: var(--text); border: 1px solid var(--border); border-radius: 10px; padding: 12px; font-size: 14px; font-family: inherit; margin-bottom: 14px; }
.quiz-answer { border-top: 1px dashed var(--border); margin-top: 16px; padding-top: 16px; }
.quiz-answer .a { color: var(--ok); font-weight: 600; white-space: pre-wrap; }
.quiz-answer .e { color: var(--muted); font-size: 13px; margin-top: 8px; white-space: pre-wrap; }
.mark-btns { display: flex; gap: 8px; margin-top: 16px; }
.mark-btns .btn.o { border-color: var(--ok); } .mark-btns .btn.tri { border-color: var(--warn); } .mark-btns .btn.x { border-color: var(--bad); }
.quiz-progress { color: var(--muted); font-size: 12px; margin-bottom: 12px; }
.quiz-summary { text-align: center; padding: 40px 0; }
.quiz-summary .big { font-size: 40px; font-weight: 700; margin: 10px 0; }
/* 대시보드 */
.dash-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; }
.dash-card { border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.dash-card h3 { font-size: 13px; margin-bottom: 10px; }
.bar { height: 8px; border-radius: 999px; background: rgba(255,255,255,.08); overflow: hidden; margin: 8px 0; }
.bar > i { display: block; height: 100%; background: var(--accent); }
.dash-nums { display: flex; justify-content: space-between; font-size: 12px; color: var(--muted); }
.dash-actions { margin: 0 0 16px; display: flex; gap: 10px; }