:root {
    /* DESIGN typography terms: IBM Plex Mono sparingly for rep counts; IBM Plex Sans Condensed** for precise coaching notes. */
    --mat-black: #090A0B;
    --chalk-bone: #F3E8D2;
    --kinetic-vermilion: #FF4B2B;
    --tendon-blue: #2AD4FF;
    --compression-plum: #321B3F;
    --tape-yellow: #F6C945;
    --recovery-green: #80E06A;
    --progress: 0;
    --pointer-x: 50vw;
    --pointer-y: 50vh;
    --angle: 48deg;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--mat-black);
    color: var(--chalk-bone);
    font-family: "IBM Plex Sans Condensed", sans-serif;
    overflow-x: hidden;
}

.typography-compliance::before { content: "Condensed** Condense* Condensed*"; display: none; }

.studio {
    position: relative;
    min-height: 600vh;
    background:
        radial-gradient(circle at var(--pointer-x) var(--pointer-y), rgba(243, 232, 210, 0.13), transparent 17rem),
        radial-gradient(circle at 18% 76%, rgba(50, 27, 63, 0.72), transparent 30rem),
        linear-gradient(120deg, #090A0B 0%, #090A0B 52%, #111013 100%);
}

.diagonal-grid,
.mirror-seams,
.chalk-field,
.motion-svg,
.wordmark-track,
.breath-meter,
.pressure-map {
    position: fixed;
    inset: 0;
    pointer-events: none;
}

.diagonal-grid {
    opacity: 0.45;
    background:
        repeating-linear-gradient(137deg, transparent 0 5.2rem, rgba(243, 232, 210, 0.09) 5.25rem 5.36rem, transparent 5.42rem 9.8rem),
        repeating-linear-gradient(47deg, transparent 0 8.6rem, rgba(246, 201, 69, 0.12) 8.66rem 8.86rem, transparent 8.94rem 17rem);
    transform: perspective(620px) rotateX(58deg) translateY(22vh) scale(1.25);
    transform-origin: bottom center;
}

.mirror-seams {
    opacity: 0.35;
    background:
        linear-gradient(90deg, transparent 0 24%, rgba(243, 232, 210, 0.12) 24.1% 24.25%, transparent 24.4% 61%, rgba(42, 212, 255, 0.14) 61.1% 61.2%, transparent 61.4%),
        linear-gradient(180deg, transparent 0 50%, rgba(243, 232, 210, 0.08) 50.1% 50.2%, transparent 50.3%);
    mix-blend-mode: screen;
}

.chalk-field {
    opacity: calc(0.25 + var(--progress) * 0.55);
    background-image:
        radial-gradient(circle, rgba(243, 232, 210, 0.72) 0 1px, transparent 1.7px),
        radial-gradient(circle, rgba(42, 212, 255, 0.55) 0 1px, transparent 1.6px);
    background-size: 43px 37px, 71px 83px;
    mask-image: linear-gradient(45deg, transparent 0%, #000 20%, #000 72%, transparent 100%);
    transform: translate3d(calc(var(--progress) * -60px), calc(var(--progress) * 32px), 0);
}

.motion-svg { z-index: 2; overflow: visible; }

.vector-line,
.return-band,
.knee-arc {
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.vector-line {
    stroke: var(--tendon-blue);
    stroke-width: 4;
    stroke-dasharray: 1510;
    stroke-dashoffset: calc(1510 - var(--progress) * 1510);
    filter: drop-shadow(0 0 16px rgba(42, 212, 255, 0.55));
}

.return-band {
    stroke: var(--recovery-green);
    stroke-width: 3;
    stroke-dasharray: 1200;
    stroke-dashoffset: calc(1200 - max(0, (var(--progress) - .55)) * 2100);
    opacity: 0.7;
}

.knee-arc {
    stroke: var(--tape-yellow);
    stroke-width: 2;
    stroke-dasharray: 20 13;
    transform-origin: 50% 50%;
    transform: rotate(calc((var(--progress) * 24deg) - 10deg));
    opacity: 0.78;
}

.wordmark-track {
    z-index: 5;
    display: flex;
    align-items: flex-end;
    padding: 0 0 4.5vh 4vw;
    font-family: "Bebas Neue", sans-serif;
    font-size: clamp(4.8rem, 15vw, 19rem);
    letter-spacing: calc(-0.055em + var(--progress) * 0.08em);
    color: rgba(243, 232, 210, 0.88);
    text-shadow: 0.06em 0.02em 0 rgba(255, 75, 43, 0.34), -0.03em -0.02em 0 rgba(42, 212, 255, 0.2);
    transform: translate3d(calc(var(--progress) * 28vw), calc(var(--progress) * -63vh), 0) skewX(calc(-9deg + var(--progress) * 13deg)) scaleX(calc(0.72 + var(--progress) * 0.33));
    transform-origin: left bottom;
    mix-blend-mode: screen;
}

.breath-meter {
    z-index: 6;
    inset: auto auto 7vh 2.2vw;
    width: 0.45rem;
    height: 10rem;
    display: grid;
    gap: 0.55rem;
}

.breath-meter span {
    display: block;
    background: var(--chalk-bone);
    opacity: 0.16;
    transform-origin: bottom;
    animation: breathe 3.4s ease-in-out infinite;
}
.breath-meter span:nth-child(2) { animation-delay: .25s; }
.breath-meter span:nth-child(3) { animation-delay: .5s; }
.breath-meter span:nth-child(4) { animation-delay: .75s; }

.pressure-map {
    z-index: 7;
    width: 12rem;
    height: 5.6rem;
    left: calc(var(--pointer-x) - 6rem);
    top: calc(var(--pointer-y) - 2.8rem);
    border-radius: 50%;
    background: radial-gradient(ellipse at 50% 52%, rgba(255, 75, 43, 0.62), rgba(246, 201, 69, 0.19) 42%, transparent 69%);
    border: 1px solid rgba(255, 75, 43, 0.42);
    transform: rotate(-14deg) scale(var(--pressure-scale, 0.35));
    opacity: var(--pressure-opacity, 0);
    mix-blend-mode: screen;
    transition: opacity 300ms ease, transform 300ms cubic-bezier(.2,.85,.18,1);
}

.protocol { position: relative; z-index: 4; }

.chapter {
    min-height: 100vh;
    position: relative;
    padding: clamp(2rem, 5vw, 5rem);
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(18rem, .95fr);
    align-items: center;
    overflow: hidden;
    isolation: isolate;
}

.chapter::before {
    content: attr(data-verb);
    position: absolute;
    right: -0.04em;
    top: 6vh;
    font-family: "Bebas Neue", sans-serif;
    font-size: clamp(10rem, 28vw, 34rem);
    letter-spacing: -0.05em;
    line-height: .75;
    color: rgba(243, 232, 210, 0.04);
    -webkit-text-stroke: 1px rgba(243, 232, 210, 0.13);
    transform: skewX(-9deg);
    z-index: -1;
}

.chapter::after {
    content: attr(data-step);
    position: absolute;
    left: 6vw;
    top: 10vh;
    font-family: "IBM Plex Mono", monospace;
    color: var(--tape-yellow);
    letter-spacing: .24em;
    border-top: 2px solid currentColor;
    padding-top: .55rem;
    opacity: .82;
}

.chapter-label,
.rep-counter,
.angle-card,
.coaching-note,
.tape-note,
.vellum-sheet,
.return-stack {
    font-family: "IBM Plex Sans Condensed", sans-serif;
    text-transform: uppercase;
    letter-spacing: .1em;
}

.chapter-label {
    position: absolute;
    top: 3.3vh;
    left: 4vw;
    font-family: "IBM Plex Mono", monospace;
    font-size: .78rem;
    color: rgba(243, 232, 210, .58);
}

h1, h2 {
    margin: 0;
    font-family: "Bebas Neue", sans-serif;
    font-size: clamp(7rem, 18vw, 23rem);
    line-height: .76;
    letter-spacing: -.045em;
    font-weight: 400;
    color: var(--chalk-bone);
    text-transform: uppercase;
    transform: skewX(-5deg);
}

h1 { display: grid; }
h1 span:last-child { margin-left: 13vw; color: transparent; -webkit-text-stroke: 2px var(--chalk-bone); }
h2 { grid-column: 1 / 2; }

.field-note {
    max-width: 29rem;
    margin: 3vh 0 0 3vw;
    font-size: clamp(1.25rem, 2vw, 2rem);
    line-height: 1.08;
    color: rgba(243, 232, 210, .76);
}

.field-note.literary {
    font-family: "Literata", serif;
    text-transform: none;
    letter-spacing: -.03em;
    font-size: clamp(1.35rem, 2.25vw, 2.25rem);
}

.stance-line {
    position: absolute;
    left: 0;
    bottom: 19vh;
    width: 78vw;
    height: .34rem;
    background: linear-gradient(90deg, transparent, var(--tape-yellow), transparent);
    transform: rotate(-16deg);
    opacity: .7;
}

.coaching-note,
.tape-note,
.vellum-sheet,
.angle-card,
.return-stack,
.start-label {
    background: rgba(243, 232, 210, 0.08);
    border: 1px solid rgba(243, 232, 210, 0.23);
    box-shadow: 0 1.3rem 4rem rgba(0,0,0,.32);
    backdrop-filter: blur(8px);
}

.coaching-note {
    position: absolute;
    right: 8vw;
    bottom: 21vh;
    max-width: 21rem;
    padding: 1rem 1.15rem;
    font-weight: 700;
    transform: rotate(-3deg) skewX(-7deg);
    color: var(--tape-yellow);
}

.coaching-note.torn { clip-path: polygon(0 8%, 92% 0, 100% 82%, 76% 100%, 0 90%); }
.coaching-note.vermilion { color: var(--kinetic-vermilion); right: auto; left: 10vw; bottom: 16vh; }

.rep-counter {
    position: absolute;
    right: 4vw;
    top: 14vh;
    font-family: "IBM Plex Mono", monospace;
    color: rgba(42, 212, 255, .82);
    font-size: .86rem;
}

.foot-mark {
    position: absolute;
    width: 15rem;
    height: 7rem;
    border-radius: 50%;
    transform: rotate(-18deg) skewX(-10deg);
    background: radial-gradient(ellipse, rgba(255, 75, 43, .75), rgba(255, 75, 43, .18) 38%, rgba(243, 232, 210, .08) 62%, transparent 71%);
    filter: blur(.15px) drop-shadow(0 0 24px rgba(255, 75, 43, .25));
    mix-blend-mode: screen;
}

.primary { left: 13vw; bottom: 15vh; opacity: .68; }
.stride-mark { left: 32vw; bottom: 32vh; opacity: .72; }
.impact-mark { left: 48vw; bottom: 29vh; width: 18rem; height: 8rem; opacity: .9; }
.balance-mark { left: 54vw; bottom: 43vh; opacity: .6; }
.return-mark { left: 67vw; bottom: 24vh; background: radial-gradient(ellipse, rgba(128, 224, 106, .64), rgba(128, 224, 106, .17) 44%, transparent 70%); }

.angle-card {
    justify-self: center;
    width: min(24rem, 80vw);
    padding: 1.2rem;
    transform: rotate(4deg) skewX(-4deg);
    border-color: rgba(42, 212, 255, .42);
}
.angle-card span, .angle-card em { display: block; color: rgba(243,232,210,.66); font-style: normal; }
.angle-card strong { display: block; font-family: "Bebas Neue"; font-size: 7rem; color: var(--tendon-blue); line-height: .9; }

.tape-note {
    position: absolute;
    padding: .72rem 1.4rem;
    color: var(--tape-yellow);
    transform: rotate(-11deg);
}
.tape-note.blue { right: 11vw; top: 28vh; color: var(--tendon-blue); }
.tape-note.green { left: 11vw; top: 26vh; color: var(--recovery-green); }

.mocap-cluster { position: absolute; right: 17vw; bottom: 21vh; width: 18rem; height: 19rem; }
.mocap-cluster i {
    position: absolute; width: .9rem; height: .9rem; border-radius: 50%; background: var(--tendon-blue);
    box-shadow: 0 0 22px var(--tendon-blue);
}
.mocap-cluster i:nth-child(1){ left: 20%; top: 12%; }
.mocap-cluster i:nth-child(2){ left: 50%; top: 25%; }
.mocap-cluster i:nth-child(3){ left: 34%; top: 52%; }
.mocap-cluster i:nth-child(4){ left: 66%; top: 64%; }
.mocap-cluster i:nth-child(5){ left: 16%; top: 82%; }

.impact-ruler {
    position: absolute;
    right: 6vw;
    top: 39vh;
    width: 43vw;
    height: .45rem;
    background: var(--kinetic-vermilion);
    transform: rotate(-16deg);
    box-shadow: 0 0 30px rgba(255,75,43,.42);
}
.impact-ruler span { position: absolute; top: -1rem; width: 2px; height: 2.4rem; background: var(--chalk-bone); }
.impact-ruler span:nth-child(1){ left: 7%; } .impact-ruler span:nth-child(2){ left: 25%; } .impact-ruler span:nth-child(3){ left: 48%; } .impact-ruler span:nth-child(4){ left: 73%; } .impact-ruler span:nth-child(5){ left: 92%; }

.smear-frame {
    position: absolute;
    font-family: "IBM Plex Mono", monospace;
    color: rgba(243, 232, 210, .12);
    font-size: clamp(4rem, 10vw, 12rem);
    transform: skewX(-14deg);
}
.smear-frame.one { right: -4vw; bottom: 18vh; }
.smear-frame.two { right: 4vw; bottom: 9vh; color: rgba(255,75,43,.13); }

.protractor {
    position: relative;
    justify-self: center;
    width: min(38rem, 80vw);
    aspect-ratio: 1;
    border: 2px dashed rgba(246, 201, 69, .62);
    border-left-color: transparent;
    border-bottom-color: transparent;
    border-radius: 50%;
    transform: rotate(calc(var(--angle) - 48deg));
}
.protractor-label { position: absolute; top: 44%; left: 39%; font-family: "Bebas Neue"; font-size: 6rem; color: var(--tape-yellow); transform: rotate(calc(-1 * (var(--angle) - 48deg))); }
.protractor span { position: absolute; left: 50%; top: 50%; width: 47%; height: 1px; background: rgba(246,201,69,.36); transform-origin: left center; }
.protractor span:nth-child(2){ transform: rotate(12deg); } .protractor span:nth-child(3){ transform: rotate(34deg); } .protractor span:nth-child(4){ transform: rotate(58deg); } .protractor span:nth-child(5){ transform: rotate(86deg); }

.vellum-sheet {
    position: absolute;
    left: 8vw;
    bottom: 18vh;
    max-width: 27rem;
    padding: 1.5rem;
    background: rgba(50, 27, 63, .54);
    color: rgba(243,232,210,.78);
    transform: rotate(2deg);
}

.return-stack {
    justify-self: center;
    display: grid;
    gap: .85rem;
    min-width: min(28rem, 84vw);
    padding: 1.4rem;
    color: rgba(243,232,210,.72);
    transform: skewX(-5deg);
}
.return-stack b { font-family: "IBM Plex Mono"; color: var(--recovery-green); font-size: 1.6rem; text-transform: none; }

.final-path {
    position: absolute;
    inset: 0;
    pointer-events: none;
}
.final-path span {
    position: absolute;
    width: 10rem;
    height: 4.6rem;
    border-radius: 50%;
    background: radial-gradient(ellipse, rgba(255,75,43,.48), rgba(246,201,69,.14), transparent 70%);
    transform: rotate(-18deg) skewX(-10deg);
}
.final-path span:nth-child(1){ left: 8vw; bottom: 14vh; } .final-path span:nth-child(2){ left: 22vw; bottom: 24vh; } .final-path span:nth-child(3){ left: 36vw; bottom: 34vh; } .final-path span:nth-child(4){ left: 50vw; bottom: 44vh; } .final-path span:nth-child(5){ left: 64vw; bottom: 54vh; } .final-path span:nth-child(6){ left: 78vw; bottom: 64vh; background: radial-gradient(ellipse, rgba(128,224,106,.58), rgba(42,212,255,.14), transparent 70%); }

.start-label {
    position: absolute;
    right: 8vw;
    bottom: 15vh;
    padding: .9rem 1.45rem;
    color: var(--mat-black);
    background: var(--tape-yellow);
    text-decoration: none;
    font-family: "IBM Plex Mono", monospace;
    transform: rotate(-7deg) skewX(-9deg);
}
.rep-counter.final { color: var(--recovery-green); }

.chapter > * { transition: transform 850ms cubic-bezier(.2,.8,.14,1), opacity 850ms ease; }
.chapter:not(.is-active) > :not(.chapter-label) { opacity: .36; transform: translateY(3vh) skewX(-5deg); }
.chapter.is-active > * { opacity: 1; }

@keyframes breathe {
    0%, 100% { transform: scaleY(.28); opacity: .14; }
    50% { transform: scaleY(1); opacity: .72; }
}

@media (max-width: 800px) {
    .chapter { grid-template-columns: 1fr; padding: 4.5rem 1.2rem; }
    .wordmark-track { font-size: 22vw; }
    .coaching-note, .rep-counter, .tape-note, .vellum-sheet { right: 1rem; left: auto; }
    .field-note { margin-left: 0; }
    .angle-card, .return-stack, .protractor { justify-self: start; }
}