:root{--black:#111;--lime:#c6f46e;--amber:#ffd95a;--amber-dark:#ffb547;--white:#fff;--line:#1111111a;--muted:#11111194;--r-sm:12px;--r-md:18px;--r-lg:24px;color:var(--black);background:var(--white);font-synthesis:none;-webkit-font-smoothing:antialiased;font-family:Pretendard,system-ui,-apple-system,Segoe UI,sans-serif}*{box-sizing:border-box}body{background:var(--white);min-width:0;margin:0;line-height:1.6}h1,h2{letter-spacing:-.03em;line-height:1.3}button,input,select{font:inherit;color:inherit}button{cursor:pointer;touch-action:manipulation;background:0 0;border:0}button:disabled{cursor:not-allowed;opacity:.45}a{color:var(--black);text-underline-offset:4px}:focus-visible{outline:3px solid var(--black);outline-offset:2px}.primary{background:var(--lime);width:100%;color:var(--black);border-radius:var(--r-md);text-align:center;margin-top:8px;padding:15px 20px;font-weight:700;text-decoration:none;transition:transform .12s;display:block}.primary:active:not(:disabled){transform:scale(.98)}.danger-button{border:1px solid var(--line);border-radius:var(--r-md);width:100%;margin-top:10px;padding:14px;font-weight:600;display:block}.danger-button:last-of-type{color:var(--black);background:var(--amber-dark);border-color:#0000}.text-button{padding:8px;font-size:14px;font-weight:600}.page>button:not([class]),.center>button:not([class]){color:var(--muted);margin:14px auto 0;padding:10px;font-size:14px;font-weight:600;display:block}.panel{background:var(--white);border:1px solid var(--line);border-radius:var(--r-lg);overflow-wrap:anywhere;margin:14px 0;padding:20px 22px}.panel h2{margin:0 0 10px;font-size:16px}.panel p{margin:6px 0}.center{place-content:center;justify-items:center;gap:12px;min-height:100dvh;padding:20px;display:grid}.loading-panel{color:var(--muted);justify-items:center;gap:14px;padding:40px 20px;display:grid}.loading-panel p{margin:0;font-size:14px}.spinner{border:3px solid var(--lime);border-top-color:var(--black);border-radius:50%;width:28px;height:28px;animation:.8s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.error-panel{background:var(--amber);border-radius:var(--r-md);margin:14px 0;padding:16px 18px}.error-panel p{margin:0 0 8px}.error-panel button:not(.primary){border-radius:var(--r-sm);background:var(--white);margin:4px 4px 0 0;padding:10px 14px;font-weight:600}.error{border-radius:var(--r-sm);background:var(--amber);margin:0;padding:10px 12px;font-size:14px}.mock-banner{text-align:center;background:var(--amber);margin:0;padding:6px;font-size:12px;font-weight:600}.logo{flex:none;display:block}label{color:var(--muted);gap:6px;font-size:13px;font-weight:600;display:grid}input,select{border:1px solid var(--line);border-radius:var(--r-sm);background:var(--white);width:100%;min-width:0;color:var(--black);padding:13px 14px;font-size:16px;font-weight:500}input:focus,select:focus{border-color:var(--black);outline:none}fieldset{border:0;margin:0;padding:0}legend{color:var(--muted);margin-bottom:8px;padding:0;font-size:13px;font-weight:600}.setup-form{gap:16px;display:grid}.form-row{grid-template-columns:1fr 1fr;gap:12px;display:grid}.chip-grid{flex-wrap:wrap;gap:8px;display:flex}.chip{border:1px solid var(--line);border-radius:999px;padding:9px 16px;font-size:14px;font-weight:600}.chip.selected{background:var(--black);color:var(--lime);border-color:var(--black)}.auth-page{place-content:center;justify-items:center;gap:4px;min-height:100dvh;padding:32px 20px;display:grid}.auth-page h1{letter-spacing:-.05em;margin:18px 0 0;font-size:32px}.auth-copy{color:var(--muted);margin:0 0 24px}.auth-card{gap:14px;width:min(100vw - 40px,380px);display:grid}.auth-card h2{margin:0;font-size:18px}.auth-card a{text-align:center;color:var(--muted);font-size:13px}.google{border:1px solid var(--line);border-radius:var(--r-md);width:100%;padding:14px;font-weight:600}.auth-page>p:last-child{color:var(--muted);font-size:12px}.app-shell{max-width:640px;min-height:100dvh;padding-bottom:calc(84px + env(safe-area-inset-bottom,0px));margin:auto}.page{overflow-wrap:anywhere;padding:32px 20px}.page>h1{margin:0 0 20px;font-size:28px}.bottom-nav{left:50%;bottom:calc(12px + env(safe-area-inset-bottom,0px));background:var(--black);z-index:10;border-radius:999px;justify-content:space-around;width:min(100vw - 24px,440px);padding:6px;display:flex;position:fixed;transform:translate(-50%)}.bottom-nav a{text-align:center;color:#ffffff9e;border-radius:999px;flex:1;padding:11px 4px;font-size:14px;font-weight:600;text-decoration:none}.bottom-nav a.active{background:var(--lime);color:var(--black)}.stat-grid{grid-template-columns:repeat(3,1fr);gap:10px;margin:14px 0;display:grid}.stat-grid>div{border-radius:var(--r-md);background:var(--lime);gap:2px;padding:16px 14px;display:grid}.stat-grid~.stat-grid>div{background:var(--amber)}.stat-grid strong{letter-spacing:-.03em;font-size:24px;line-height:1.2}.stat-grid span{color:var(--muted);font-size:12px;font-weight:600}.week-chart{text-align:center;grid-template-columns:repeat(7,1fr);align-items:end;gap:6px;display:grid}.week-chart>div{justify-items:center;gap:4px;display:grid}.week-chart strong{font-size:13px}.week-chart i{background:var(--black);border-radius:6px;width:100%;max-width:28px;min-height:4px;display:block}.week-chart>div:last-child i{background:var(--amber-dark)}.week-chart span{color:var(--muted);font-size:11px}.week-chart small{color:var(--muted);font-size:10px}progress{appearance:none;background:var(--line);border:0;border-radius:99px;width:100%;height:8px;overflow:hidden}progress::-webkit-progress-bar{background:var(--line)}progress::-webkit-progress-value{background:var(--black);border-radius:99px}progress::-moz-progress-bar{background:var(--black);border-radius:99px}ol.panel{padding:6px 0;list-style:none}.rank{grid-template-columns:36px 1fr auto;align-items:center;gap:10px;padding:12px 20px;display:grid}.rank+.rank{border-top:1px solid var(--line)}.rank strong{background:var(--line);border-radius:50%;place-items:center;width:28px;height:28px;font-size:13px;display:grid}.rank:first-child strong{background:var(--lime)}.rank:nth-child(2) strong{background:var(--amber)}.rank:nth-child(3) strong{background:var(--amber-dark)}.rank b{font-size:14px}.table-scroll{max-width:100%;overflow:auto}.intro-screen{text-align:center;place-content:center;justify-items:center;gap:8px;min-height:100dvh;padding:32px 20px;display:grid}.intro-screen h1{margin:20px 0 0;font-size:30px}.intro-screen p{color:var(--muted);margin:0 0 20px}.intro-screen .primary{width:min(100vw - 40px,320px)}.app-shell:has(.study-stage){max-width:none;padding:0}.app-shell:has(.study-stage)>.bottom-nav{display:none}body:has(.study-stage){overflow:hidden}.study-stage{touch-action:pan-y;max-width:760px;height:100dvh;margin:auto;overflow:hidden}.stage-card{flex-direction:column;height:100%;min-height:0;display:flex}.stage-head{justify-content:space-between;align-items:flex-start;gap:16px;padding:28px 24px 0;display:flex}.stage-head span{color:var(--muted);font-size:13px;font-weight:600;display:block}.stage-head h1{letter-spacing:-.06em;margin:4px 0 0;font-size:clamp(36px,9vw,64px);line-height:1.05}.stage-head a{background:var(--black);color:var(--white);border-radius:999px;flex:none;padding:8px 14px;font-size:13px;font-weight:600;text-decoration:none}.stage-body{overscroll-behavior:contain;flex:1;min-height:0;padding:20px 24px;overflow:auto}.stage-kicker{background:var(--lime);border-radius:999px;margin-bottom:12px;padding:4px 10px;font-size:12px;font-weight:700;display:inline-block}.stage-question h2,.stage-concept h2,.stage-generating h2{white-space:pre-wrap;overflow-wrap:anywhere;margin:0 0 20px;font-size:clamp(20px,3.4vw,30px)}.stage-material{border-left:3px solid var(--amber);white-space:pre-wrap;margin:0 0 18px;padding:14px 16px}.stage-concept p,.stage-concept li{font-size:17px;line-height:1.75}.stage-concept ul{padding-left:20px}.stage-concept table{border-collapse:collapse;font-size:14px}.stage-concept th,.stage-concept td{border-bottom:1px solid var(--line);text-align:left;padding:9px 12px}.stage-concept th{background:var(--lime)}.stage-choices{gap:10px;display:grid}.stage-choices button{border:1.5px solid var(--line);border-radius:var(--r-md);text-align:left;align-items:center;gap:14px;width:100%;min-height:56px;padding:10px 14px;font-size:16px;font-weight:500;transition:border-color .12s;display:flex}.stage-choices button b{background:var(--line);border-radius:50%;flex:none;place-items:center;width:30px;height:30px;font-size:14px;display:grid}.stage-choices button:hover:not(:disabled){border-color:var(--black)}.stage-choices button:disabled{opacity:1;cursor:default}.stage-choices button.selected{border-color:var(--black);background:var(--amber)}.stage-choices button.selected b{background:var(--black);color:var(--amber)}.stage-solution{border-radius:var(--r-lg);background:var(--lime);padding:20px 22px}.stage-solution.wrong{background:var(--amber-dark)}.stage-solution strong{letter-spacing:-.03em;font-size:22px;display:block}.stage-solution p{white-space:pre-wrap;margin:10px 0;font-size:16px}.stage-solution small{color:var(--muted);font-size:13px}.stage-checked{color:var(--muted);margin:14px 0 0;font-size:13px;font-weight:600}.stage-generating{flex-direction:column;justify-content:center;min-height:100%;display:flex}.live-pill{background:var(--amber);border-radius:999px;align-self:flex-start;margin-bottom:16px;padding:6px 12px;font-size:13px;font-weight:700;animation:1.4s ease-in-out infinite blink}@keyframes blink{50%{opacity:.55}}.stage-report{color:var(--muted);margin-top:22px;padding:4px 0;font-size:12px;display:block}.stage-report-form{flex-wrap:wrap;gap:8px;margin-top:16px;display:flex}.stage-report-form select{flex:1;width:auto;padding:9px;font-size:14px}.stage-report-form button{border:1px solid var(--line);border-radius:var(--r-sm);padding:9px 14px;font-size:14px;font-weight:600}.stage-footer{padding:12px 24px calc(20px + env(safe-area-inset-bottom,0px));border-top:1px solid var(--line);color:var(--muted);justify-content:space-between;align-items:center;gap:12px;font-size:13px;font-weight:600;display:flex}.stage-footer>button{background:var(--lime);width:48px;height:48px;color:var(--black);border-radius:50%;flex:none;font-size:22px;font-weight:700}.stage-footer .error-panel{flex:1;max-height:120px;margin:0;overflow:auto}@media (height<=700px){.stage-head{padding:14px 18px 0}.stage-head h1{font-size:clamp(30px,7vw,46px)}.stage-body{padding:10px 18px}.stage-kicker{margin-bottom:6px}.stage-question h2{margin-bottom:10px;font-size:clamp(18px,3vw,24px)}.stage-choices{gap:6px}.stage-choices button{gap:10px;min-height:42px;padding:6px 10px;font-size:15px}.stage-choices button b{width:24px;height:24px;font-size:12px}.stage-report{margin-top:8px}.stage-footer{padding:8px 18px calc(10px + env(safe-area-inset-bottom,0px))}}@media (pointer:coarse) and (width<=699px){.app-shell{padding-bottom:calc(84px + max(48px, env(safe-area-inset-bottom,0px)))}.bottom-nav{bottom:max(48px, env(safe-area-inset-bottom,0px))}.app-shell:has(.study-stage){padding-bottom:0}.stage-footer{padding-bottom:calc(16px + max(48px, env(safe-area-inset-bottom,0px)))}}@media (width<=400px){.page{padding:24px 16px}.stat-grid{gap:6px}.stat-grid>div{padding:12px 10px}.stat-grid strong{font-size:19px}.stage-head,.stage-body,.stage-footer{padding-left:16px;padding-right:16px}}@media (prefers-reduced-motion:reduce){*,:before,:after{transition:none!important;animation:none!important}}