:root{--bg:#f8fafc;--surface:#fff;--surface-muted:#f1f5f9;--line:#dbe3ef;--text:#0f172a;--text-muted:#475569;--text-soft:#64748b;--primary:#2563eb;--primary-strong:#1d4ed8;--success:#15803d;--warning:#b45309;--danger:#b91c1c;--shadow:0 16px 40px #0f172a14;--radius-sm:12px;--radius-md:18px;--radius-lg:24px;--container:760px;--safe-bottom:env(safe-area-inset-bottom,0px)}*,:before,:after{box-sizing:border-box}html{background:var(--bg);color:var(--text);scroll-behavior:smooth}body{color:var(--text);background:linear-gradient(#f8fafc 0%,#f1f5f9 100%);margin:0;font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,Apple SD Gothic Neo,Noto Sans KR,Segoe UI,sans-serif}a{color:inherit;text-decoration:none}button,input,select,textarea{font:inherit}button{cursor:pointer}textarea{resize:none}img{max-width:100%}.container{width:min(100%, var(--container));margin:0 auto;padding:0 20px}.page-shell{min-height:100dvh;padding-bottom:calc(88px + var(--safe-bottom))}.page-content{width:min(100%, var(--container));margin:0 auto;padding:20px}.page-header{z-index:20;-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#f8fafce0;border-bottom:1px solid #dbe3efb3;position:sticky;top:0}.page-header-inner{width:min(100%, var(--container));align-items:center;gap:12px;min-height:64px;margin:0 auto;padding:0 20px;display:flex}.page-header h1{margin:0;font-size:1.05rem}.page-header .subtitle{color:var(--text-soft);margin-top:2px;font-size:.88rem}.page-grid{gap:16px;display:grid}.page-grid-lg{gap:20px;display:grid}.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-md);box-shadow:var(--shadow);padding:18px}.card.elevated{border-color:#2563eb33}.card.narrow{max-width:420px;margin:0 auto}.card-header{justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:12px;display:flex}.card-title{margin:0;font-size:1rem}.card-subtitle,.muted{color:var(--text-muted)}.muted.small{font-size:.88rem}.hero-copy{color:#d9e2f5;max-width:720px;margin:0;line-height:1.7}.landing-shell{min-height:100dvh;padding:0 0 40px}.landing-hero{color:#fff;isolation:isolate;padding-top:48px;padding-bottom:32px;position:relative}.landing-hero:before{content:"";z-index:0;pointer-events:none;background:radial-gradient(circle at 100% 0,#60a5fa42,#0000 34%),radial-gradient(circle at 0 100%,#2563eb3d,#0000 42%),linear-gradient(#0f172aeb,#111827d1);border-radius:36px;position:absolute;inset:24px 20px 0;box-shadow:0 24px 80px #0f172a38}.landing-shell{background:radial-gradient(circle at 100% 0,#3b82f638,#0000 28%),radial-gradient(circle at 0 0,#0f172a47,#0000 32%),linear-gradient(#0b1120 0%,#111827 36%,#dbeafe 74%,#f8fafc 100%)}.landing-hero-panel{z-index:1;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:linear-gradient(#0f172ab3,#0f172a6b);border:1px solid #ffffff1a;border-radius:32px;gap:20px;padding:40px 28px 36px;display:grid;position:relative}.landing-hero h1{max-width:760px;margin:0;font-size:clamp(2rem,6vw,3.4rem);line-height:1.1}.hero-badge,.inline-badge,.badge{border:1px solid var(--line);background:var(--surface-muted);min-height:28px;color:var(--text);border-radius:999px;align-items:center;gap:6px;padding:0 12px;font-size:.82rem;font-weight:700;display:inline-flex}.hero-badge{color:#c7d6f7;background:#ffffff14;border-color:#ffffff24;margin-bottom:14px}.badge.primary{color:var(--primary-strong);background:#2563eb14;border-color:#2563eb38}.badge.success{color:var(--success);background:#15803d14;border-color:#15803d33}.badge.warning{color:var(--warning);background:#b453091a;border-color:#b4530938}.badge.danger{color:var(--danger);background:#b91c1c14;border-color:#b91c1c2e}.badge.grade-a{color:var(--success);background:#15803d1a;border-color:#15803d40}.badge.grade-b{color:var(--warning);background:#b453091a;border-color:#b453093d}.badge.grade-c{color:var(--danger);background:#b91c1c1a;border-color:#b91c1c3d}.hero-actions,.action-row,.inline-actions{flex-wrap:wrap;gap:12px;display:flex}.hero-footnote{color:#d9e2f5cc;margin:0;font-size:.95rem}.action-row.sticky{bottom:calc(12px + var(--safe-bottom));z-index:30;padding-top:8px;position:sticky}.btn{border:1px solid #0000;border-radius:14px;justify-content:center;align-items:center;gap:8px;min-height:48px;padding:0 16px;font-weight:700;transition:transform .12s,background-color .12s,border-color .12s;display:inline-flex}.btn:hover:not(:disabled){transform:translateY(-1px)}.btn:disabled{cursor:not-allowed;opacity:.6}.btn.btn-lg{min-height:54px;padding-inline:20px}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--primary-strong)}.btn-secondary{color:var(--text);background:#ffffffeb;border-color:#ffffff73}.btn-ghost{color:var(--text-muted);background:0 0;border-color:#0000;min-height:40px}.btn-danger{color:var(--danger);background:#b91c1c1a;border-color:#b91c1c33}.btn-full{width:100%}.stack-sm>*+*,.stack-md>*+*,.stack-lg>*+*{margin-top:12px}.stack-md>*+*{margin-top:16px}.stack-lg>*+*{margin-top:20px}.field{gap:8px;display:grid}.field-label{font-size:.92rem;font-weight:700}.field-hint,.field-error{font-size:.82rem}.field-hint{color:var(--text-soft)}.field-error{color:var(--danger)}.input,.select,.textarea{border:1px solid var(--line);background:var(--surface);width:100%;color:var(--text);border-radius:14px;min-height:48px;padding:12px 14px}.textarea{min-height:120px;line-height:1.5}.input:focus,.select:focus,.textarea:focus{border-color:#2563eb73;outline:2px solid #2563eb33}.input-row{align-items:stretch;gap:10px;display:flex}.metric-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;display:grid}.metric{background:var(--surface-muted);border:1px solid var(--line);border-radius:16px;padding:14px}.metric-value{margin-top:4px;font-size:1.32rem;font-weight:800}.metric-label{color:var(--text-soft);font-size:.84rem}.progress-track{background:#e2e8f0;border-radius:999px;height:12px;position:relative;overflow:hidden}.progress-bar{border-radius:inherit;background:linear-gradient(90deg,#2563eb,#60a5fa);height:100%}.tabs{gap:8px;padding-bottom:4px;display:flex;overflow-x:auto}.tab-btn{border:1px solid var(--line);background:var(--surface);min-height:40px;color:var(--text-muted);border-radius:999px;flex:none;padding:0 14px;font-weight:700}.tab-btn.active{color:var(--primary-strong);background:#2563eb14;border-color:#2563eb38}.bottom-nav{z-index:50;width:min(100% - 24px,720px);padding:8px;padding-bottom:calc(8px + var(--safe-bottom));-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);background:#ffffffeb;border:1px solid #dbe3efd9;border-radius:22px;position:fixed;bottom:12px;left:50%;transform:translate(-50%);box-shadow:0 18px 40px #0f172a29}.bottom-nav-list{grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;display:grid}.bottom-nav-link{min-height:54px;color:var(--text-soft);text-align:center;border-radius:16px;align-content:center;justify-items:center;gap:4px;padding:8px;font-size:.78rem;font-weight:700;display:grid}.bottom-nav-link.active{color:var(--primary-strong);background:#2563eb14}.icon-label{font-size:1.05rem;line-height:1}.centered-page{place-items:center;min-height:100dvh;padding:24px;display:grid}.spinner{border:3px solid #2563eb26;border-top-color:var(--primary);border-radius:999px;width:40px;height:40px;animation:.8s linear infinite spin}.spinner.inline{border-width:2px;width:18px;height:18px}@keyframes spin{to{transform:rotate(360deg)}}.skeleton{background:linear-gradient(90deg,#eef2f7 25%,#f8fafc 50%,#eef2f7 75%) 0 0/200% 100%;border-radius:12px;animation:1.3s linear infinite shimmer}@keyframes shimmer{0%{background-position:200% 0}to{background-position:-200% 0}}.empty-state,.error-state{text-align:center;justify-items:center;gap:10px;padding:20px;display:grid}.empty-state h3,.error-state h3{margin:0}.feature-grid{gap:16px;padding-bottom:24px;display:grid}.course-card{gap:14px;display:grid}.course-card-top,.list-row,.split-row{justify-content:space-between;align-items:flex-start;gap:12px;display:flex}.list-row{border-bottom:1px solid #dbe3efb3;padding:12px 0}.list-row:last-child{border-bottom:none;padding-bottom:0}.kpi-row{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;display:grid}.kpi-tile{background:var(--surface-muted);border:1px solid var(--line);border-radius:14px;padding:12px}.kpi-label{color:var(--text-soft);font-size:.78rem}.kpi-value{margin-top:6px;font-weight:800}.answer-box,.feedback-box,.result-box{border:1px solid var(--line);background:var(--surface-muted);border-radius:16px;padding:14px}.source-sentence{font-size:1.08rem;font-weight:700;line-height:1.7}.session-layout{gap:16px;display:grid}.session-meta{flex-wrap:wrap;gap:8px;display:flex}.feedback-card details{margin-top:12px}.feedback-card summary{cursor:pointer;color:var(--primary-strong);font-weight:700}.word-chip-list{flex-wrap:wrap;gap:8px;display:flex}.word-chip{color:var(--primary-strong);background:#2563eb0f;border:1px solid #2563eb29;border-radius:999px;align-items:center;gap:6px;padding:8px 10px;font-size:.86rem;display:inline-flex}.word-chip button{color:inherit;cursor:pointer;background:0 0;border:none;padding:0;font-weight:700}.timer{min-height:36px;color:var(--danger);background:#b91c1c14;border:1px solid #b91c1c2e;border-radius:999px;align-items:center;gap:8px;padding:0 12px;font-weight:800;display:inline-flex}.timer.warning{color:var(--warning);background:#b453091a;border-color:#b453092e}.timer.safe{color:var(--success);background:#15803d14;border-color:#15803d29}table{border-collapse:collapse;width:100%}th,td{text-align:left;vertical-align:top;border-bottom:1px solid #dbe3efb3;padding:12px 8px;font-size:.92rem}th{color:var(--text-soft);font-weight:700}.table-wrap{overflow-x:auto}.modal-backdrop{z-index:120;background:#0f172a75;place-items:end center;padding:16px;display:grid;position:fixed;inset:0}.modal-sheet{background:var(--surface);border:1px solid var(--line);border-radius:24px 24px 18px 18px;width:min(100%,720px);max-height:min(90dvh,860px);padding:18px;overflow:auto;box-shadow:0 24px 56px #0f172a42}.toast-region{z-index:140;pointer-events:none;justify-items:center;gap:10px;display:grid;position:fixed;inset:16px 16px auto}.toast{pointer-events:auto;background:var(--surface);border:1px solid var(--line);border-radius:16px;width:min(100%,520px);padding:14px 16px;box-shadow:0 18px 36px #0f172a2e}.toast.success{border-color:#15803d38}.toast.error{border-color:#b91c1c38}.sr-only{clip-path:inset(50%);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}@media (min-width:768px){.feature-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.metric-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.landing-hero{padding-top:64px;padding-bottom:48px}.landing-hero-panel{padding:56px 48px 44px}}.stack-xs>*+*{margin-top:8px}.inline-flex-row{align-items:center;gap:8px;display:inline-flex}.wrap-gap{flex-wrap:wrap}.align-end{align-items:flex-end}.center-text{text-align:center}.inline-top-gap{margin-top:12px}.smallish{font-size:.92rem}.text-link{color:var(--primary-strong);font-weight:700}.auth-shell{background:radial-gradient(circle at 100% 0,#2563eb33,#0000 28%),linear-gradient(#0f172a,#111827 38%,#eff6ff 38%,#f8fafc 100%);align-items:center;min-height:100dvh;display:grid}.auth-content{padding-top:48px;padding-bottom:48px}.auth-card{-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px)}.auth-badge{margin-inline:auto}.auth-title{margin:0;font-size:clamp(1.7rem,5vw,2.2rem)}.auth-helper-row{justify-content:center;align-items:center;gap:8px;display:flex}.app-loading-screen{place-items:center;min-height:100dvh;padding:20px;display:grid}.app-topbar{z-index:40;-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);background:#f8fafce6;border-bottom:1px solid #dbe3efcc;position:sticky;top:0}.app-topbar-inner{align-items:center;gap:12px;min-height:64px;display:flex}.app-brand{color:var(--text);font-size:1.1rem;font-weight:800}.topbar-user-meta{flex:1;min-width:0}.topbar-user-name{font-weight:700}.bottom-nav-inner,.bottom-nav-list{grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;display:grid}.filters-row{flex-wrap:wrap;align-items:center;gap:12px;display:flex}.two-col-grid{gap:12px;display:grid}.level-pill{min-height:44px;color:var(--primary-strong);background:#2563eb14;border-radius:999px;justify-content:center;align-items:center;padding:0 14px;font-weight:800;display:inline-flex}.info-list{color:var(--text-muted);margin:0;padding-left:20px;line-height:1.7}.word-chip.neutral{color:var(--text);background:#0f172a0a;border-color:#64748b33}.action-row.compact,.compact{gap:8px}@media (min-width:768px){.two-col-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}