:root{--ink:#17213d;--ink-soft:#4d5a78;--muted:#7e8aa3;--line:#dfe5ef;--canvas:#f4f6fa;--surface:#fff;--surface-soft:#f9fafe;--teal:#117e76;--teal-soft:#dff4ee;--blue:#3c6fe8;--blue-soft:#e8efff;--coral:#e55a4f;--amber:#c77b16;--green:#1c9557;--yellow:#fff2bd;--shadow:0 18px 45px rgba(35,53,88,.10);--ease:cubic-bezier(.2,.8,.2,1);font-family:ui-rounded,"SF Pro Rounded","SF Pro Display",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--canvas)}
*{box-sizing:border-box}body{min-width:320px;margin:0;background:var(--canvas)}button,input,select{font:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid rgba(60,111,232,.3);outline-offset:3px}svg{width:1.2rem;height:1.2rem;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.app-shell{height:100vh;min-height:100vh;display:grid;grid-template-rows:76px minmax(0,1fr) 98px}.topbar{z-index:4;display:flex;align-items:center;gap:14px;padding:0 24px;border-bottom:1px solid rgba(217,224,235,.85);background:rgba(255,255,255,.92);box-shadow:0 4px 18px rgba(34,51,82,.035)}.mobile-brand{display:none}.home-button,.shuffle-button{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:42px;padding:0 14px;border:1px solid var(--line);border-radius:15px;color:var(--ink-soft);font-size:.8rem;font-weight:780;background:var(--surface);transition:transform .22s var(--ease),box-shadow .22s var(--ease),border-color .22s var(--ease),color .22s var(--ease)}.home-button:hover,.shuffle-button:hover{border-color:#bdcbe1;color:var(--blue);box-shadow:0 8px 16px rgba(53,87,145,.10);transform:translateY(-1px) scale(1.01)}.home-button svg,.shuffle-button svg{width:18px}.search-control{display:flex;align-items:center;width:min(330px,32vw);height:42px;gap:9px;padding:0 14px;border:1px solid var(--line);border-radius:15px;color:#79869f;background:#f7f9fd;transition:border-color .22s var(--ease),box-shadow .22s var(--ease),background .22s var(--ease)}.search-control:focus-within{border-color:#aabce1;background:#fff;box-shadow:0 0 0 4px rgba(60,111,232,.10)}.search-control svg{width:19px}.search-control input{width:100%;border:0;outline:0;color:var(--ink);font-size:.83rem;background:transparent}.search-control input::placeholder{color:#97a2b8}.due-summary{display:grid;justify-items:center;min-width:80px;margin-left:auto;line-height:1.05}.due-summary span{font-size:.64rem;font-weight:760;color:var(--muted);text-transform:uppercase;letter-spacing:.06em}.due-summary b{margin-top:2px;color:var(--teal);font-size:1.42rem;font-variant-numeric:tabular-nums}.top-level{display:grid;min-width:94px;gap:3px;padding:4px 0 4px 14px;border-left:1px solid var(--line);font-size:.7rem;font-weight:770;color:var(--ink-soft)}.top-level strong{color:var(--blue);font-size:.72rem;font-variant-numeric:tabular-nums}
.workspace{display:grid;grid-template-columns:246px minmax(0,1fr) 304px;min-height:0}.book-rail,.progress-rail{min-height:0;overflow-y:auto;background:rgba(255,255,255,.75)}.book-rail{padding:12px;border-right:1px solid var(--line)}.rail-brand{display:flex;align-items:center;gap:10px;min-height:58px;padding:0 10px;font-size:1.02rem;font-weight:830}.brand-mark{display:grid;width:36px;height:36px;place-items:center;border-radius:13px;color:#fff;background:#243b72;box-shadow:inset 0 0 0 1px rgba(255,255,255,.25),0 5px 12px rgba(29,52,105,.16)}.mobile-home{border:0;padding:0}.brand-mark svg{width:22px;height:22px}.book-list{display:grid;gap:5px;padding:10px 0}.book-item{position:relative;display:grid;grid-template-columns:42px minmax(0,1fr) auto;align-items:center;width:100%;min-height:69px;gap:10px;padding:10px;border:0;border-radius:18px;text-align:left;color:var(--ink);background:transparent;transition:transform .24s var(--ease),background .24s var(--ease),box-shadow .24s var(--ease)}.book-item:hover{background:#fff;box-shadow:0 8px 18px rgba(40,58,90,.07);transform:translateX(3px)}.book-item.is-selected{background:color-mix(in srgb,var(--book-accent),white 89%);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--book-accent),white 70%)}.book-icon{display:grid;width:39px;height:39px;place-items:center;border-radius:14px;color:#fff;background:var(--book-accent);box-shadow:inset 0 0 0 1px rgba(255,255,255,.28)}.book-icon svg{width:20px;height:20px}.book-copy{display:grid;min-width:0;gap:3px}.book-copy strong{font-size:.8rem;line-height:1}.book-copy small{overflow:hidden;color:var(--muted);font-size:.67rem;line-height:1.2;text-overflow:ellipsis;white-space:nowrap}.book-count{display:grid;justify-items:end;gap:1px;color:var(--book-accent);font-variant-numeric:tabular-nums}.book-count b{font-size:.82rem}.book-count small{font-size:.58rem;color:var(--muted)}.book-meter{position:absolute;right:10px;bottom:7px;overflow:hidden;width:calc(100% - 70px);height:3px;border-radius:99px;background:rgba(160,173,195,.23)}.book-meter i{display:block;height:100%;border-radius:inherit;background:var(--book-accent);transition:width .42s var(--ease)}.rail-footer{display:flex;align-items:center;gap:8px;margin:9px 9px 0;padding:15px 2px;border-top:1px solid var(--line);color:var(--muted);font-size:.7rem}.rail-footer svg{width:17px}.rail-footer strong{margin-left:auto;color:var(--ink);font-variant-numeric:tabular-nums}
.study-main,.home-main{min-width:0;min-height:0;background:var(--canvas)}.study-main{display:grid;grid-template-rows:auto minmax(0,1fr);padding:24px clamp(28px,4.4vw,68px) 24px}.study-toolbar{display:flex;align-items:flex-start;justify-content:space-between;min-height:76px;gap:15px}.study-title{display:flex;align-items:center;gap:10px;margin-bottom:11px;color:var(--ink-soft);font-size:.8rem;font-weight:730}.book-tag{display:inline-flex;align-items:center;height:25px;padding:0 9px;border-radius:99px;color:var(--book-accent);font-size:.63rem;font-weight:840;letter-spacing:.075em;text-transform:uppercase;background:color-mix(in srgb,var(--book-accent),white 90%)}.mode-switch{display:inline-flex;gap:4px;padding:4px;border:1px solid var(--line);border-radius:14px;background:#fff;box-shadow:0 4px 10px rgba(40,58,90,.035)}.mode-button{display:inline-flex;align-items:center;min-width:70px;height:29px;gap:5px;padding:0 9px;border:0;border-radius:10px;color:var(--muted);font-size:.68rem;font-weight:790;background:transparent;transition:background .22s var(--ease),color .22s var(--ease),transform .22s var(--ease)}.mode-button svg{width:14px;height:14px}.mode-button b{margin-left:auto;font-size:.62rem;font-variant-numeric:tabular-nums}.mode-button:hover{color:var(--ink);background:#f1f4fa}.mode-button.is-active{color:var(--teal);background:var(--teal-soft)}.study-actions{display:flex;align-items:center;gap:8px}.topic-select select{height:34px;max-width:190px;padding:0 31px 0 11px;border:1px solid var(--line);border-radius:12px;color:var(--ink-soft);font-size:.71rem;background:#fff}.card-position{color:var(--muted);font-size:.72rem;font-variant-numeric:tabular-nums}.icon-button,.mini-icon{display:inline-grid;width:36px;height:36px;place-items:center;padding:0;border:1px solid transparent;border-radius:13px;color:var(--ink-soft);background:transparent;transition:transform .22s var(--ease),background .22s var(--ease),box-shadow .22s var(--ease),color .22s var(--ease)}.icon-button:hover,.mini-icon:hover{color:var(--blue);background:#fff;box-shadow:0 7px 13px rgba(40,58,90,.08);transform:translateY(-1px)}.icon-button.is-saved{color:var(--coral);background:#fff1ef}
.flashcard{position:relative;align-self:center;display:grid;width:min(100%,820px);height:min(100%,574px);min-height:0;max-height:100%;margin:8px auto 0;padding:clamp(31px,4.3vw,54px) clamp(24px,6.4vw,74px) 28px;overflow-y:auto;border:1px solid rgba(208,218,233,.95);border-radius:30px;color:var(--ink);text-align:left;background:#fff;box-shadow:var(--shadow);transition:border-color .3s var(--ease),box-shadow .3s var(--ease),transform .3s var(--ease)}.flashcard::before{position:absolute;top:17px;right:21px;width:38px;height:7px;border-radius:99px;content:"";background:var(--teal-soft)}.flashcard:hover{border-color:#c7d8ed;box-shadow:0 22px 50px rgba(35,53,88,.13);transform:translateY(-3px)}.flashcard.is-revealed{border-color:#b5ddd5}.flashcard.is-entering{animation:cardIn .48s var(--ease) both}.flashcard.is-revealing .card-content.answer,.flashcard.is-revealing .card-visual{animation:revealUp .42s var(--ease) both}.card-topline{display:flex;align-items:center;justify-content:space-between;gap:12px}.card-side-label{display:inline-flex;align-items:center;height:23px;padding:0 9px;border-radius:99px;color:var(--teal);font-size:.64rem;font-weight:850;letter-spacing:.08em;text-transform:uppercase;background:var(--teal-soft)}.card-topic{color:var(--muted);font-size:.7rem;font-weight:760}.card-content{align-self:center;display:block;max-width:690px;margin:27px 0;font-size:clamp(1.45rem,2.4vw,2.2rem);font-weight:680;line-height:1.3;letter-spacing:0}.card-content.answer{font-size:clamp(1rem,1.25vw,1.14rem);font-weight:480;line-height:1.65}.key-term{padding:0 .08em;border-radius:5px;color:#0c685f;font-weight:800;background:#e4f5ef}.question .key-term{color:inherit;background:#edf1ff}.reveal-hint{justify-self:center;display:flex;align-items:center;gap:7px;margin-top:13px;color:#7d8aa3;font-size:.73rem;font-weight:760}.reveal-hint svg{width:17px;height:17px;color:var(--teal)}.card-visual{display:grid;width:min(100%,450px);margin:0 auto 14px;padding:10px 10px 7px;border:1px solid #e2e8f0;border-radius:18px;color:#0c6b64;background:#fbfdfd}.card-visual svg{display:block;width:100%;height:auto;max-height:186px}.source-visual{overflow:hidden;padding:7px;background:#fff}.source-visual img{display:block;width:100%;max-height:235px;object-fit:contain;border-radius:12px}.card-visual figcaption{padding:7px 7px 0;color:#64728a;font-size:.65rem;line-height:1.38;text-align:center}.card-visual text{fill:#33445f;font-family:inherit;font-size:11px;stroke:none}.axis{stroke:#3d4f6b;stroke-width:1.35}.graph-line,.ray,.field,.lens,.circuit,.stationary{stroke:#08756d;stroke-width:2.4}.graph-dash{stroke:#9ab2b1;stroke-dasharray:4 4}.graph-fill{fill:#c9ebe5;stroke:none}.graph-dot,.node{fill:#08756d;stroke:none}.boundary,.plate{stroke:#334e7f;stroke-width:5}.positive{stroke:#d64b3d}.negative{stroke:#2c659a}.angle{stroke:#c97b11}.particle circle{fill:#08756d;stroke:none}.orbit{stroke:#b3c4cc;stroke-width:2;stroke-dasharray:5 5}.secondary{opacity:.45}.resistor{stroke:#c66d13;stroke-width:2.1}.meter{fill:#f0f7ff;stroke:#1669d8;stroke-width:2}
.progress-rail{padding:12px;border-left:1px solid var(--line)}.xp-section,.calendar-section,.retention-section{padding:15px;border:1px solid #e4e9f1;border-radius:20px;background:#fff;box-shadow:0 5px 13px rgba(40,58,90,.04)}.calendar-section,.retention-section{margin-top:9px}.xp-heading,.section-heading{display:flex;align-items:center;justify-content:space-between;gap:8px}.xp-heading span,.section-heading>span:first-child{font-size:.77rem;font-weight:830}.xp-heading small,.section-heading small{color:var(--muted);font-size:.64rem;font-weight:730}.xp-track{overflow:hidden;height:8px;margin-top:10px;border-radius:99px;background:#e5ebf4}.xp-track i{display:block;height:100%;border-radius:inherit;background:var(--blue);transition:width .55s var(--ease)}.xp-section p{margin:7px 0 0;color:var(--muted);font-size:.65rem}.calendar-nav{display:flex;align-items:center;gap:3px}.calendar-nav strong{min-width:93px;text-align:center;font-size:.69rem}.mini-icon{width:23px;height:23px;border-radius:9px}.mini-icon svg{width:14px;height:14px}.calendar-weekdays,.calendar-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:4px}.calendar-weekdays{margin:10px 0 4px;color:#8994aa;font-size:.55rem;font-weight:780;text-align:center}.calendar-grid{grid-auto-rows:25px}.calendar-day{position:relative;display:grid;place-items:center;min-width:0;border:1px solid #e0e6ef;border-radius:8px;color:#59667c;font-size:.6rem;background:#fbfcfe}.calendar-day b{font-weight:720}.calendar-day em{position:absolute;right:2px;bottom:1px;color:inherit;font-size:.5rem;font-style:normal;font-weight:800}.calendar-day.is-today{outline:2px solid #99b8ff;outline-offset:1px}.calendar-day.is-blank{border-color:transparent;background:transparent}.heat-0{background:#fbfcfe}.heat-1{border-color:#c9e8df!important;background:#e9f7f3!important;color:#137167!important}.heat-2{border-color:#92d4c2!important;background:#cceee4!important;color:#075f57!important}.heat-3{border-color:#54b49d!important;background:#91d7c5!important;color:#064e47!important}.heat-4{border-color:#117e76!important;background:#117e76!important;color:#fff!important}.calendar-key{display:flex;align-items:center;gap:4px;margin-top:8px;color:var(--muted);font-size:.58rem}.calendar-key i{display:block;width:9px;height:9px;border:1px solid #dce5e8;border-radius:3px}.calendar-key span{margin-left:4px}.retention-numbers{display:grid;grid-template-columns:repeat(3,1fr);gap:7px;margin-top:11px}.retention-numbers div{display:grid;gap:3px}.retention-numbers b{font-size:1.05rem;font-variant-numeric:tabular-nums}.retention-numbers span{color:var(--muted);font-size:.59rem}.stat-foot{display:flex;justify-content:space-between;margin-top:10px;color:var(--muted);font-size:.62rem}.stat-foot span{display:inline-flex;align-items:center;gap:4px}.stat-foot svg{width:14px;height:14px;color:var(--teal)}.companion-panel{position:relative;min-height:140px;margin-top:9px;overflow:hidden;padding:15px;border:1px solid #f2d986;border-radius:21px;background:var(--yellow)}.companion-panel>div{position:relative;z-index:1;width:55%}.companion-label{color:#946c0e;font-size:.57rem;font-weight:850;letter-spacing:.09em;text-transform:uppercase}.companion-panel h2{margin:7px 0 4px;font-size:.98rem;letter-spacing:0}.companion-panel p{margin:0;color:#5a5960;font-size:.68rem;line-height:1.42}.companion-panel img{position:absolute;right:-8px;bottom:-11px;width:61%;max-height:136px;object-fit:contain;object-position:right bottom;image-rendering:pixelated;animation:companionFloat 4s var(--ease) infinite}
.review-bar{z-index:3;display:grid;grid-template-columns:auto repeat(4,minmax(132px,1fr));min-height:98px;padding:0 24px;border-top:1px solid var(--line);background:rgba(255,255,255,.96);box-shadow:0 -8px 24px rgba(35,53,88,.045)}.review-bar.is-empty{min-height:0}.review-nav{display:flex;align-items:center;gap:4px;padding-right:16px}.rate-button{display:grid;grid-template-columns:35px auto;grid-template-rows:1fr 1fr;align-content:center;column-gap:10px;min-height:65px;padding:0 18px;border:0;border-left:1px solid #edf0f5;text-align:left;background:transparent;transition:transform .22s var(--ease),background .22s var(--ease)}.rate-button:hover{background:#f9fbfe;transform:translateY(-3px)}.rate-button span{grid-row:1/span 2;display:grid;width:32px;height:32px;place-items:center;border:1.5px solid currentColor;border-radius:12px}.rate-button span svg{width:17px;height:17px}.rate-button strong{align-self:end;font-size:.86rem}.rate-button small{align-self:start;margin-top:2px;color:var(--muted);font-size:.66rem}.rate-button.again{color:var(--coral)}.rate-button.hard{color:var(--amber)}.rate-button.good{color:var(--green)}.rate-button.easy{color:var(--blue)}.reveal-bar{grid-template-columns:auto 1fr}.reveal-button{justify-self:center;align-self:center;display:flex;align-items:center;justify-content:center;min-width:276px;height:48px;gap:9px;padding:0 18px;border:0;border-radius:16px;color:#fff;background:var(--teal);box-shadow:0 10px 20px rgba(17,126,118,.20);transition:transform .22s var(--ease),box-shadow .22s var(--ease),background .22s var(--ease)}.reveal-button:hover{background:#0c6d66;box-shadow:0 13px 25px rgba(17,126,118,.25);transform:translateY(-2px) scale(1.01)}.reveal-button svg{width:18px}.reveal-button strong{font-size:.83rem}.reveal-button kbd{padding:3px 6px;border:1px solid rgba(255,255,255,.35);border-radius:6px;font:inherit;font-size:.63rem;color:#d8fffa}.empty-state{align-self:center;justify-self:center;max-width:520px;padding:36px;text-align:center}.empty-icon{display:grid;width:54px;height:54px;place-items:center;margin:0 auto 13px;border-radius:19px;color:var(--teal);background:var(--teal-soft)}.completion-chip{display:inline-flex;margin-bottom:8px;padding:5px 9px;border-radius:99px;color:#24726c;font-size:.64rem;font-weight:820;background:#e7f7f2}.empty-state h1{margin:0;font-size:1.55rem;letter-spacing:0}.empty-state p{margin:10px 0 20px;color:var(--muted);font-size:.87rem;line-height:1.55}.empty-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:8px}.text-button{height:37px;padding:0 13px;border:1px solid var(--line);border-radius:13px;color:var(--ink-soft);font-size:.72rem;font-weight:780;background:#fff;transition:transform .22s var(--ease),box-shadow .22s var(--ease),border-color .22s var(--ease)}.text-button:hover{border-color:#bdcbe1;color:var(--blue);box-shadow:0 7px 14px rgba(40,58,90,.08);transform:translateY(-1px)}.mobile-menu,.mobile-close{display:none}
.home-main{padding:clamp(24px,4vw,54px);overflow-y:auto}.home-hero{display:grid;grid-template-columns:minmax(0,1fr) 260px;height:clamp(250px,34vh,330px);min-height:250px;overflow:hidden;border:1px solid #cedcf8;border-radius:30px;background:#edf3ff;box-shadow:var(--shadow)}.hero-copy{align-self:center;max-width:630px;padding:clamp(28px,4.5vw,56px)}.eyebrow{display:block;color:#5674b8;font-size:.65rem;font-weight:850;letter-spacing:.1em;text-transform:uppercase}.hero-copy h1{max-width:560px;margin:9px 0 10px;font-size:clamp(2rem,3.8vw,3.35rem);line-height:1.02;letter-spacing:0}.hero-copy p{max-width:550px;margin:0;color:#5d6d8d;font-size:.94rem;line-height:1.55}.hero-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:21px}.primary-action,.secondary-action{display:inline-flex;align-items:center;gap:9px;min-height:43px;padding:0 14px;border-radius:15px;font-size:.76rem;font-weight:800;transition:transform .24s var(--ease),box-shadow .24s var(--ease)}.primary-action{border:0;color:#fff;background:#3567d4;box-shadow:0 10px 20px rgba(53,103,212,.20)}.primary-action b{padding-left:9px;border-left:1px solid rgba(255,255,255,.32);font-size:.67rem}.secondary-action{border:1px solid #c8d5ee;color:#5570ac;background:#fff}.primary-action:hover,.secondary-action:hover{box-shadow:0 12px 22px rgba(53,87,145,.17);transform:translateY(-2px) scale(1.01)}.home-orbit{position:relative;min-height:0;background:#e1ebff}.home-orbit img{position:absolute;right:6px;bottom:0;width:100%;height:220px;object-fit:contain;object-position:right bottom;image-rendering:pixelated;animation:companionFloat 4s var(--ease) infinite}.orbit-ring{position:absolute;top:43px;right:42px;width:164px;height:164px;border:16px solid #cadbfd;border-radius:50%}.orbit-card{position:absolute;z-index:1;display:grid;width:50px;height:50px;place-items:center;border:1px solid rgba(255,255,255,.75);border-radius:17px;color:#3567d4;font-size:.73rem;font-weight:850;background:#fff;box-shadow:0 9px 18px rgba(53,87,145,.12)}.orbit-card-one{top:34px;left:21px}.orbit-card-two{right:18px;bottom:37px}.home-summary{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin-top:15px}.home-summary>div{display:grid;gap:5px;padding:15px 17px;border:1px solid #e1e6ef;border-radius:18px;background:#fff}.home-summary span{color:var(--muted);font-size:.65rem;font-weight:720}.home-summary strong{font-size:1.26rem;font-variant-numeric:tabular-nums}.home-books{margin-top:25px}.home-section-heading{display:flex;align-items:end;justify-content:space-between;margin-bottom:12px}.home-section-heading h2{margin:5px 0 0;font-size:1.22rem}.home-section-heading>span{color:var(--muted);font-size:.7rem}.home-book-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.home-book-card{position:relative;display:grid;grid-template-columns:44px minmax(0,1fr) auto;align-items:center;min-height:84px;gap:11px;padding:13px;border:1px solid #e0e6ef;border-radius:21px;text-align:left;color:var(--ink);background:#fff;box-shadow:0 5px 13px rgba(40,58,90,.035);transition:transform .24s var(--ease),box-shadow .24s var(--ease),border-color .24s var(--ease)}.home-book-card:hover{border-color:color-mix(in srgb,var(--book-accent),white 55%);box-shadow:0 13px 25px rgba(40,58,90,.09);transform:translateY(-3px)}.home-book-icon{display:grid;width:43px;height:43px;place-items:center;border-radius:15px;color:#fff;background:var(--book-accent)}.home-book-icon svg{width:22px;height:22px}.home-book-copy{display:grid;min-width:0;gap:4px}.home-book-copy strong{font-size:.82rem}.home-book-copy small{overflow:hidden;color:var(--muted);font-size:.68rem;text-overflow:ellipsis;white-space:nowrap}.home-book-metrics{display:grid;justify-items:end;gap:4px}.home-book-metrics b{color:var(--book-accent);font-size:.71rem}.home-book-metrics small{color:var(--muted);font-size:.6rem}.home-book-progress{position:absolute;right:13px;bottom:9px;left:68px;overflow:hidden;height:3px;border-radius:99px;background:#e9edf4}.home-book-progress i{display:block;height:100%;border-radius:inherit;background:var(--book-accent);transition:width .5s var(--ease)}.home-footer{display:flex;align-items:center;justify-content:space-between;padding:0 36px;color:var(--muted);font-size:.74rem}.footer-focus{height:38px;padding:0 14px;border:0;border-radius:14px;color:#fff;font-size:.74rem;font-weight:800;background:var(--teal);box-shadow:0 7px 15px rgba(17,126,118,.16);transition:transform .22s var(--ease)}.footer-focus:hover{transform:translateY(-2px)}
@keyframes cardIn{from{opacity:0;transform:translateY(17px) scale(.985)}to{opacity:1;transform:translateY(0) scale(1)}}@keyframes revealUp{from{opacity:0;transform:translateY(10px) scale(.99)}to{opacity:1;transform:translateY(0) scale(1)}}@keyframes companionFloat{0%,100%{transform:translateY(0)}50%{transform:translateY(-6px)}}
@media(max-width:1160px){.workspace{grid-template-columns:220px minmax(0,1fr) 276px}.study-main{padding-inline:30px}.home-main{padding:28px}.home-hero{grid-template-columns:minmax(0,1fr) 215px}.home-orbit{min-height:0}.review-bar{padding-inline:16px}.rate-button{padding-inline:12px}.home-button span{display:none}.home-button{width:42px;padding:0}}
@media(min-width:901px) and (max-width:1160px){.home-hero{height:320px}.hero-copy{padding:27px}.hero-copy h1{font-size:2rem;line-height:1.05}.hero-copy p{font-size:.82rem;line-height:1.45}.hero-actions{margin-top:15px;gap:7px}.primary-action,.secondary-action{min-height:39px;padding:0 11px;font-size:.68rem}.home-orbit img{width:235px;height:210px;right:-24px}}
@media(min-width:901px) and (max-height:800px){.xp-section,.calendar-section,.retention-section{padding:11px}.calendar-weekdays{margin:6px 0 3px}.calendar-grid{grid-auto-rows:21px}.calendar-key{margin-top:5px}.retention-numbers{margin-top:8px}.stat-foot{margin-top:7px}.companion-panel{min-height:118px;padding:12px}.companion-panel h2{margin:5px 0 2px}.companion-panel img{max-height:117px}}
@media(max-width:900px){.app-shell{height:auto;min-height:100vh;grid-template-rows:64px auto auto}.topbar{gap:9px;padding:0 15px}.mobile-brand{display:flex;align-items:center;gap:8px}.mobile-menu{display:inline-grid}.mobile-brand .brand-mark{width:33px;height:33px;border-radius:12px}.home-button{display:none}.topbar>.search-control{flex:1;width:auto}.top-level{display:none}.due-summary{display:none}.shuffle-button{width:38px;padding:0;border-radius:13px}.shuffle-button span{display:none}.workspace{display:block}.book-rail{position:fixed;z-index:10;top:0;bottom:0;left:0;width:min(310px,87vw);transform:translateX(-104%);box-shadow:18px 0 35px rgba(20,37,61,.18);transition:transform .32s var(--ease)}.book-rail.is-open{transform:translateX(0)}.mobile-close{display:inline-grid;margin-left:auto}.study-main{min-height:calc(100vh - 64px - 86px);padding:20px 18px 24px}.progress-rail{display:grid;grid-template-columns:1fr 1.25fr;gap:9px;padding:14px;border-top:1px solid var(--line);border-left:0}.xp-section{grid-column:1}.calendar-section{grid-column:2;grid-row:1/span 2;margin:0}.retention-section{grid-column:1;margin:0}.companion-panel{grid-column:1/span 2;margin:0;min-height:166px}.flashcard{height:auto;min-height:min(57vh,560px);max-height:none;border-radius:25px}.review-bar{position:sticky;bottom:0;grid-template-columns:repeat(4,1fr);min-height:86px;padding:0}.review-nav{display:none}.rate-button{grid-template-columns:1fr;grid-template-rows:auto auto;justify-items:center;gap:3px;min-width:0;padding:9px 4px;text-align:center}.rate-button span{width:28px;height:28px;border-radius:10px}.rate-button strong{align-self:auto;font-size:.77rem}.rate-button small{display:none}.reveal-bar{grid-template-columns:1fr}.reveal-button{width:100%;min-width:0;height:53px;border-radius:0}.home-main{padding:20px 18px 28px}.home-hero{grid-template-columns:1fr;height:auto;min-height:0}.hero-copy{padding:30px}.home-orbit{min-height:185px}.home-orbit img{height:175px;width:260px}.orbit-ring{top:24px;right:50px;width:130px;height:130px}.home-summary{grid-template-columns:repeat(2,1fr)}.home-book-grid{grid-template-columns:1fr}.home-footer{position:static;min-height:76px;padding:0 16px}.home-footer span{display:none}.footer-focus{width:100%}}
@media(max-width:590px){.study-toolbar{min-height:114px;flex-direction:column;align-items:stretch}.study-actions{justify-content:space-between;width:100%}.topic-select{flex:1}.topic-select select{width:100%;max-width:none}.mode-switch{width:100%}.mode-button{flex:1;justify-content:center}.mode-button b{margin-left:3px}.flashcard{min-height:51vh;padding:27px 20px}.card-content{margin:23px 0;font-size:1.4rem}.card-content.answer{font-size:.97rem;line-height:1.58}.card-visual{max-height:250px}.source-visual img{max-height:220px}.calendar-grid{grid-auto-rows:28px}.progress-rail{display:block}.xp-section,.retention-section,.calendar-section{margin-bottom:9px}.companion-panel{min-height:178px}.search-control{height:38px}.card-position{white-space:nowrap}.home-hero{border-radius:25px}.hero-copy h1{font-size:2.18rem}.hero-actions{display:grid}.primary-action,.secondary-action{justify-content:center}.home-summary>div{padding:13px}.home-book-card{min-height:78px}.empty-state{padding:26px 6px}.empty-actions{display:grid}.text-button{width:100%}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}}

/* Progress companions use a consistent level-specific icon, tint and reward name. */
.top-level>span,.xp-level-title{display:flex;align-items:center;gap:6px}.level-companion-icon{display:inline-grid;flex:0 0 auto;width:20px;height:20px;place-items:center;border-radius:7px;color:var(--companion-accent,#3567d4);font-size:.9rem;font-style:normal;line-height:1;background:var(--companion-soft,#e8efff)}.xp-level-title{min-width:0}.xp-level-title em{overflow:hidden;max-width:88px;color:var(--companion-accent,#3567d4);font-size:.62rem;font-style:normal;font-weight:820;text-overflow:ellipsis;white-space:nowrap}.xp-section{border-color:color-mix(in srgb,var(--companion-accent,#3567d4),white 78%)}.xp-section .xp-track i{background:var(--companion-accent,#3567d4)}.companion-panel{border-color:color-mix(in srgb,var(--companion-accent,#8a5c09),white 68%);background:var(--companion-soft,#fff2bd)}.companion-panel h2{display:flex;align-items:center;gap:7px}.companion-panel h2 .level-companion-icon{width:24px;height:24px;border-radius:8px;font-size:1rem}.companion-label{color:var(--companion-accent,#946c0e)}.home-orbit{background:var(--companion-soft,#e1ebff)}.home-orbit .orbit-ring{border-color:color-mix(in srgb,var(--companion-accent,#3567d4),white 78%)}.orbit-card-two{color:var(--companion-accent,#3567d4);font-size:1.12rem;background:var(--companion-soft,#fff)}.flux-line{fill:none;stroke:#0f766e;stroke-width:2.6}.emf-line{fill:none;stroke:#d15b28;stroke-width:2.6}.core{fill:#eff5f6;stroke:#5c7180;stroke-width:3}.transformer-coil{fill:none;stroke:#7c3aed;stroke-width:2.6}

.diagram-panel{fill:#fff;stroke:#d9e5ea;stroke-width:1.5}.coil-plane{fill:none;stroke:#7c3aed;stroke-width:2.6}
@media(max-width:900px){.xp-level-title em{max-width:112px}.top-level>span{gap:0}.top-level .level-companion-icon{display:none}}

@media(min-width:901px) and (max-height:800px){.study-main{padding-top:16px;padding-bottom:14px}.study-toolbar{min-height:64px}.flashcard{margin-top:2px;padding:28px clamp(24px,5vw,58px) 20px}.card-content{margin:18px 0}.card-content.answer{line-height:1.52}.card-visual:not(.source-visual){width:min(100%,410px);margin-bottom:8px;padding:8px 8px 6px}.card-visual:not(.source-visual) svg{max-height:164px}.card-visual figcaption{padding:5px 5px 0}}

/* Supplied campus line art is softened into the app's light mint study palette. */
.home-hero{position:relative;display:block;isolation:isolate;border-color:#c5dfd8;background:#eaf5f2}.home-hero::before{position:absolute;z-index:3;right:10px;bottom:-4px;width:174px;height:174px;pointer-events:none;content:"";background:url("assets/mascot/physics-study-companion.png") center/contain no-repeat;filter:saturate(.78) drop-shadow(0 12px 14px rgba(18,80,71,.17));image-rendering:pixelated}.home-hero::after{position:absolute;z-index:1;inset:0;pointer-events:none;content:"";background:rgba(246,251,249,.56)}.campus-hero-art{position:absolute;z-index:0;inset:0;width:100%;height:100%;object-fit:cover;object-position:center;opacity:.54;filter:brightness(1.32) saturate(.56)}.hero-copy{position:relative;z-index:2;display:flex;height:100%;max-width:540px;flex-direction:column;justify-content:center}.hero-copy .eyebrow{color:#28776e}.hero-copy h1{color:#193f40}.hero-copy p{color:#476e6a}.primary-action{color:#fff;background:#176f6b;box-shadow:0 10px 20px rgba(23,111,107,.2)}.primary-action b{border-color:rgba(255,255,255,.34)}.secondary-action{border-color:#b7d8d1;color:#1e7068;background:rgba(255,255,255,.74)}.primary-action:hover{color:#fff;background:#105f5a;box-shadow:0 12px 22px rgba(23,111,107,.26)}.secondary-action:hover{box-shadow:0 12px 22px rgba(23,111,107,.14)}
@media(max-width:900px){.home-hero{display:block;height:auto;min-height:0}.home-hero::before{right:12px;bottom:10px;width:104px;height:104px}.campus-hero-art{object-position:63% center;opacity:.46}.hero-copy{height:auto;min-height:474px;padding:30px 30px 126px;justify-content:flex-start}}

/* A quiet credit for the department that maintains the study deck. */
.footer-meta{display:grid;gap:3px}.footer-meta small{color:#9aa5b5;font-size:.59rem;font-weight:650;letter-spacing:.02em}@media(max-width:900px){.home-footer .footer-meta{display:none}}