@layer properties{@supports (((-webkit-hyphens:none)) and (not (margin-trim:inline))) or ((-moz-orient:inline) and (not (color:rgb(from red r g b)))){*,:before,:after,::backdrop{--tw-blur:initial;--tw-brightness:initial;--tw-contrast:initial;--tw-grayscale:initial;--tw-hue-rotate:initial;--tw-invert:initial;--tw-opacity:initial;--tw-saturate:initial;--tw-sepia:initial;--tw-drop-shadow:initial;--tw-drop-shadow-color:initial;--tw-drop-shadow-alpha:100%;--tw-drop-shadow-size:initial}}}@layer theme{:root,:host{--font-sans:ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";--font-mono:ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;--spacing:.25rem;--default-font-family:var(--font-sans);--default-mono-font-family:var(--font-mono)}}@layer base{*,:after,:before,::backdrop{box-sizing:border-box;border:0 solid;margin:0;padding:0}::file-selector-button{box-sizing:border-box;border:0 solid;margin:0;padding:0}html,:host{-webkit-text-size-adjust:100%;tab-size:4;line-height:1.5;font-family:var(--default-font-family,ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji");font-feature-settings:var(--default-font-feature-settings,normal);font-variation-settings:var(--default-font-variation-settings,normal);-webkit-tap-highlight-color:transparent}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:var(--default-mono-font-family,ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace);font-feature-settings:var(--default-mono-font-feature-settings,normal);font-variation-settings:var(--default-mono-font-variation-settings,normal);font-size:1em}small{font-size:80%}sub,sup{vertical-align:baseline;font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}:-moz-focusring{outline:auto}progress{vertical-align:baseline}summary{display:list-item}ol,ul,menu{list-style:none}img,svg,video,canvas,audio,iframe,embed,object{vertical-align:middle;display:block}img,video{max-width:100%;height:auto}button,input,select,optgroup,textarea{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}::file-selector-button{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}:where(select:is([multiple],[size])) optgroup{font-weight:bolder}:where(select:is([multiple],[size])) optgroup option{padding-inline-start:20px}::file-selector-button{margin-inline-end:4px}::placeholder{opacity:1}@supports (not ((-webkit-appearance:-apple-pay-button))) or (contain-intrinsic-size:1px){::placeholder{color:currentColor}@supports (color:color-mix(in lab, red, red)){::placeholder{color:color-mix(in oklab, currentcolor 50%, transparent)}}}textarea{resize:vertical}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-date-and-time-value{min-height:1lh;text-align:inherit}::-webkit-datetime-edit{display:inline-flex}::-webkit-datetime-edit-fields-wrapper{padding:0}::-webkit-datetime-edit{padding-block:0}::-webkit-datetime-edit-year-field{padding-block:0}::-webkit-datetime-edit-month-field{padding-block:0}::-webkit-datetime-edit-day-field{padding-block:0}::-webkit-datetime-edit-hour-field{padding-block:0}::-webkit-datetime-edit-minute-field{padding-block:0}::-webkit-datetime-edit-second-field{padding-block:0}::-webkit-datetime-edit-millisecond-field{padding-block:0}::-webkit-datetime-edit-meridiem-field{padding-block:0}::-webkit-calendar-picker-indicator{line-height:1}:-moz-ui-invalid{box-shadow:none}button,input:where([type=button],[type=reset],[type=submit]){appearance:button}::file-selector-button{appearance:button}::-webkit-inner-spin-button{height:auto}::-webkit-outer-spin-button{height:auto}[hidden]:where(:not([hidden=until-found])){display:none!important}}@layer components;@layer utilities{.relative{position:relative}.start{inset-inline-start:var(--spacing)}.table{display:table}.filter{filter:var(--tw-blur,) var(--tw-brightness,) var(--tw-contrast,) var(--tw-grayscale,) var(--tw-hue-rotate,) var(--tw-invert,) var(--tw-saturate,) var(--tw-sepia,) var(--tw-drop-shadow,)}}:root{--teal:#476c77;--teal-dark:#34525b;--teal-light:#d0e2e6;--background:#d4dee2;--background-dark:#c4d3d8;--text:#313d41;--muted:#5a6e74;--black:#1a1a1a;--white:#fff;--card:#e4edf0;--line:#c3d0d4;--orange:#efb071;--orange-deep:#c2703d;--orange-light:#fae7d2;--heading:"Dapifer", Georgia, "Times New Roman", serif;--body:"Sanchez", Georgia, "Times New Roman", serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{background:var(--background);color:var(--text);font-family:var(--body);-webkit-font-smoothing:antialiased;margin:0;line-height:1.6}button,input,select{font:inherit}a{color:inherit}h1,h2,h3{color:var(--teal);font-family:var(--heading);letter-spacing:-.01em;font-weight:700;line-height:1.12}.site-header{min-height:188px;color:var(--teal);justify-content:space-between;align-items:flex-start;gap:42px;padding:54px clamp(28px,4.2vw,66px);display:flex}.brand{border:3px solid var(--orange);background:linear-gradient(160deg, var(--teal-dark), var(--teal));border-radius:50%;flex:none;place-items:center;width:96px;height:96px;padding:11px;text-decoration:none;display:grid}.brand img{object-fit:contain;width:100%;height:100%;display:block}.site-header nav{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:11px 28px;max-width:760px;font-size:16px;display:flex}.site-header nav a{border-bottom:1px solid #0000;text-decoration:none}.site-header nav a:hover{border-bottom-color:var(--teal)}.site-header .book-link{color:#fff;background:var(--black);border:0;border-radius:300px;padding:15px 28px}.site-header .book-link:hover{background:#000;border:0}.hero{max-width:1120px;min-height:auto;color:var(--text);grid-template-columns:1.05fr .95fr;align-items:center;gap:40px;margin:0 auto;padding:34px 22px 78px;display:grid}.hero:after{display:none}.eyebrow,.kicker{color:var(--orange-deep);font-family:var(--body);text-transform:uppercase;letter-spacing:.18em;font-size:.78rem;font-weight:400;display:inline-block}.eyebrow{background:var(--orange-light);border-radius:300px;padding:8px 18px}.eyebrow span{color:inherit}.hero h1{max-width:590px;color:var(--teal);margin:18px 0 22px;font-size:clamp(44px,4.2vw,62px);line-height:1.28}.hero h1 em{background:var(--orange);color:var(--text);-webkit-box-decoration-break:clone;box-decoration-break:clone;border-radius:5px;padding:.05em .18em;font-style:normal;display:inline}.hero-copy>p{max-width:520px;color:var(--text);margin:0 0 28px;font-size:1.18rem;line-height:1.6}.hero-button{background:var(--black);color:#fff;box-shadow:none;border-radius:300px;padding:17px 32px;font-weight:400;text-decoration:none;transition:all .15s;display:inline-block}.hero-button:hover{background:#000;transform:translateY(-1px)}.hero-button span{margin-left:10px}.hero-art{place-items:center;min-height:405px;display:grid;position:relative}.hero-art:before,.orbit{display:none}.mini-card{border:5px solid var(--orange);background:linear-gradient(160deg, var(--teal-dark), var(--teal));color:#fff;z-index:1;border-radius:22px;width:100%;min-height:340px;padding:36px 36px 32px;position:relative;transform:none;box-shadow:0 18px 40px -20px #34525b99,0 0 0 1px #c2703d2e}.mini-label{color:#ffffffb8;text-transform:uppercase;letter-spacing:.16em;font-size:.74rem;font-weight:400}.mini-equation{color:#fff;font:700 50px/1.1 var(--heading);text-align:center;margin:55px 0 38px}.mini-line{background:#fff3;height:1px}.mini-answer{color:#ffffffe6;font:400 18px/1.5 var(--body);margin-top:24px}.featured-section,.archive-section{max-width:1120px;margin:0 auto;padding:0 22px 74px}.archive-section{background:var(--background-dark);max-width:none;padding-top:72px;padding-bottom:80px}.archive-section>*{max-width:1120px;margin-left:auto;margin-right:auto}.section-heading,.archive-heading{justify-content:space-between;align-items:end;gap:30px;margin-bottom:34px;display:flex}.section-heading h2,.archive-heading h2,.cta-section h2{color:var(--teal);margin:14px 0 0;font-size:clamp(34px,3.2vw,46px)}.daily-badge{color:var(--teal);text-transform:uppercase;letter-spacing:.14em;align-items:center;gap:11px;font-size:.78rem;font-weight:400;display:flex}.daily-badge img{object-fit:cover;border-radius:50%;width:44px;height:44px}.problem-card{border:1px solid var(--line);background:var(--card);box-shadow:none;border-radius:14px;padding:clamp(26px,4vw,44px)}.featured-card{border-top:4px solid var(--orange);padding:clamp(30px,4.5vw,50px)}.problem-topline{justify-content:space-between;align-items:center;gap:20px;margin-bottom:30px;display:flex}.problem-number{color:var(--orange-deep);text-transform:uppercase;letter-spacing:.16em;font-size:.76rem;font-weight:400}.tags{flex-wrap:wrap;justify-content:flex-end;gap:8px;display:flex}.tags span{background:var(--teal-light);color:var(--teal-dark);border-radius:300px;padding:7px 12px;font-size:.72rem;font-weight:400}.tags .difficulty{background:var(--orange-light);color:var(--orange-deep)}.tags .section-tag{background:var(--teal-dark);color:#fff}.prompt{max-width:950px;color:var(--text);font-family:var(--body);font-size:clamp(19px,2vw,25px);line-height:1.62}.prompt p{margin:0 0 1.25em}.prompt p:last-child{margin-bottom:0}.prompt ul{margin:0 0 1.35em;padding-left:1.35em}.prompt li{margin:.35em 0}.equation{color:var(--teal-dark);font:700 clamp(22px, 2.3vw, 30px)/1.7 var(--heading);text-align:center;margin:8px 0 28px}.data-table{border-collapse:collapse;text-align:center;margin:4px 0 24px;font-size:1.05em}.data-table th,.data-table td{border:1px solid var(--text);min-width:86px;padding:10px 18px}.problem-media{border:1px solid var(--line);object-fit:contain;background:#fff;border-radius:10px;width:100%;height:auto;margin:0 0 28px;display:block}.frac{vertical-align:middle;text-align:center;grid-template-rows:auto auto;margin:0 .1em;font-size:.76em;line-height:1;display:inline-grid}.frac span:first-child{border-bottom:1px solid;padding:0 .14em .07em}.frac span:last-child{padding-top:.07em}.answer-form{border-top:1px solid var(--line);margin-top:36px;padding-top:26px}.answer-label{color:var(--teal);text-transform:uppercase;letter-spacing:.16em;margin-bottom:10px;font-size:.74rem;font-weight:400;display:block}.answer-row{gap:10px;max-width:500px;display:flex}.answer-row input{min-width:0;color:var(--text);background:#fff;border:1px solid #abbcc1;border-radius:300px;flex:1;padding:13px 16px}.answer-row input:focus,.filter select:focus{border-color:var(--orange-deep);outline:3px solid #c2703d2e}.check-button{background:var(--black);color:#fff;cursor:pointer;border:2px solid #0000;border-radius:300px;margin-top:14px;padding:13px 22px;font-weight:400;transition:all .15s}.check-button:hover{background:#000;transform:translateY(-1px)}.check-button:disabled{cursor:not-allowed;opacity:.45;transform:none}.choice-list{gap:10px;max-width:960px;display:grid}.choice{cursor:pointer;background:#ffffff94;border:1px solid #aebfc4;border-radius:12px;grid-template-columns:34px 1fr;align-items:start;gap:12px;padding:14px 16px;transition:border-color .15s,background .15s;display:grid}.choice:hover{border-color:var(--teal);background:#ffffffd1}.choice.selected{border-color:var(--orange-deep);background:var(--orange-light)}.choice input{opacity:0;pointer-events:none;position:absolute}.choice-key{background:var(--teal-light);width:30px;height:30px;color:var(--teal-dark);border-radius:50%;place-items:center;font-weight:700;display:grid}.choice.selected .choice-key{background:var(--orange);color:var(--text)}.feedback{min-height:22px;margin-top:10px;font-size:.9rem}.feedback.correct{color:#277055}.feedback.incorrect{color:#9b4b35}.solution-toggle{border:0;border-top:1px solid var(--line);width:100%;color:var(--teal);text-align:left;cursor:pointer;background:0 0;justify-content:space-between;align-items:center;margin-top:10px;padding:18px 0 0;font-weight:400;display:flex}.solution-toggle span{color:var(--orange-deep);font-size:24px}.solution{border-left:4px solid var(--orange);background:var(--orange-light);border-radius:4px 12px 12px 4px;margin-top:20px;padding:24px}.solution-label{color:var(--orange-deep);text-transform:uppercase;letter-spacing:.16em;font-size:.72rem}.solution p{margin:10px 0 18px;line-height:1.65}.final-answer{color:var(--teal-dark);font-weight:700}.archive-heading p{color:var(--muted);margin:12px 0 0;font-size:1.05rem}.filter span{color:var(--teal);text-transform:uppercase;letter-spacing:.16em;margin-bottom:8px;font-size:.72rem;display:block}.filter select{background:var(--card);min-width:210px;color:var(--text);border:1px solid #aebfc4;border-radius:300px;padding:12px 38px 12px 15px}.section-tabs{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;max-width:1120px;margin:0 auto 26px;display:grid}.section-tabs button{background:var(--card);color:var(--teal);text-align:left;cursor:pointer;border:1px solid #aebfc4;border-radius:14px;justify-content:space-between;align-items:center;gap:14px;padding:17px 20px;display:flex}.section-tabs button span{font:700 1.18rem/1.2 var(--heading)}.section-tabs button small{color:var(--muted)}.section-tabs button.active{border-color:var(--teal);background:linear-gradient(160deg, var(--teal-dark), var(--teal));color:#fff}.section-tabs button.active small{color:#ffffffbf}.problem-grid{grid-template-columns:repeat(2,minmax(0,1fr));align-items:start;gap:22px;display:grid}.problem-grid .problem-card:first-child{grid-column:span 2}.problem-grid .problem-card:not(:first-child){height:100%}.problem-grid .problem-card:not(:first-child) .prompt{font-size:19px}.problem-grid.verbal-grid{grid-template-columns:1fr}.problem-grid.verbal-grid .problem-card:first-child{grid-column:auto}.verbal-card .prompt{max-width:none;font-size:18px}.cta-section{background:var(--background-dark);max-width:1076px;color:var(--text);border-radius:18px;justify-content:space-between;align-items:center;gap:30px;margin:72px auto;padding:54px 46px;display:flex}.cta-section .kicker{color:var(--orange-deep)}.cta-section h2{max-width:680px;color:var(--teal)}.cta-section a{background:var(--black);color:#fff;border-radius:300px;flex:none;padding:17px 30px;font-weight:400;text-decoration:none}.cta-section a:hover{background:#000}footer{background:var(--teal-dark);color:#ffffffc7;align-items:flex-start;gap:32px;min-height:250px;padding:58px clamp(28px,6vw,90px);display:flex}footer img{filter:brightness(0)invert();opacity:.92;width:180px}footer p{margin:0 auto 0 0}footer a{color:#fff;text-decoration:none}@media (max-width:900px){.site-header{min-height:130px}.site-header nav a:not(.book-link){display:none}.hero{grid-template-columns:1fr;padding-top:10px}.hero-art{min-height:350px}.problem-grid{grid-template-columns:1fr}.problem-grid .problem-card:first-child{grid-column:auto}.cta-section{margin-inline:22px}}@media (max-width:620px){.site-header{align-items:center;min-height:104px;padding:30px 20px}.brand{width:74px;height:74px;padding:8px}.site-header .book-link{padding:11px 16px;font-size:.82rem}.hero{padding:10px 20px 58px}.hero h1{font-size:2.6rem}.hero-art{min-height:300px}.mini-card{min-height:275px;padding:30px 26px}.mini-equation{margin:42px 0 30px;font-size:40px}.featured-section,.archive-section{padding-left:18px;padding-right:18px}.section-heading,.archive-heading,.problem-topline{flex-direction:column;align-items:flex-start}.tags{justify-content:flex-start}.answer-row{flex-direction:column}.section-tabs{grid-template-columns:1fr}.section-tabs button{flex-direction:column;align-items:flex-start}.check-button{width:100%}.cta-section{flex-direction:column;align-items:flex-start;padding:40px 26px}footer{flex-direction:column;min-height:280px}footer p{margin:0}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@property --tw-blur{syntax:"*";inherits:false}@property --tw-brightness{syntax:"*";inherits:false}@property --tw-contrast{syntax:"*";inherits:false}@property --tw-grayscale{syntax:"*";inherits:false}@property --tw-hue-rotate{syntax:"*";inherits:false}@property --tw-invert{syntax:"*";inherits:false}@property --tw-opacity{syntax:"*";inherits:false}@property --tw-saturate{syntax:"*";inherits:false}@property --tw-sepia{syntax:"*";inherits:false}@property --tw-drop-shadow{syntax:"*";inherits:false}@property --tw-drop-shadow-color{syntax:"*";inherits:false}@property --tw-drop-shadow-alpha{syntax:"<percentage>";inherits:false;initial-value:100%}@property --tw-drop-shadow-size{syntax:"*";inherits:false}