.brief-section {
    position: relative;
    height: 300vh;
    background: #08101e;
    
    
}

.brief-section::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 5vw;
    z-index: 10;
    pointer-events: none;
}

.brief-viewport {
    position: sticky;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;       
    z-index: 2;
}

.brief-track {
    position: relative;
    width: 300vw;           
    height: 100vh;
    will-change: transform;
    
}

.brief-bg {
    position: absolute;     
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.brief-bg__spin {
    position: absolute;
    inset: -40%;
    background: conic-gradient(
        from 0deg at 50% 50%,
        transparent         0deg,
        rgba(30,80,180,0.08)   60deg,
        transparent        120deg,
        rgba(255,255,255,0.04) 190deg,
        transparent        250deg,
        rgba(10,40,120,0.06)   320deg,
        transparent        360deg
    );
    animation: briefSpin 40s linear infinite;
    animation-play-state: var(--anim-play, running);
}
@keyframes briefSpin { to { transform: rotate(360deg); } }

.brief-bg__blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(72px);
}
.brief-bg__blob--1 {
    width: 55vw; height: 55vw;
    max-width: 720px; max-height: 720px;
    top: -20%; left: -5%;
    background: radial-gradient(circle, rgba(20,60,160,0.35) 0%, transparent 70%);
    animation: bBlob1 18s ease-in-out infinite alternate;
    animation-play-state: var(--anim-play, running);
}
.brief-bg__blob--2 {
    width: 40vw; height: 40vw;
    max-width: 560px; max-height: 560px;
    bottom: -15%; right: 10%;
    background: radial-gradient(circle, rgba(60,100,200,0.28) 0%, transparent 70%);
    animation: bBlob2 24s ease-in-out infinite alternate;
    animation-play-state: var(--anim-play, running);
}
.brief-bg__blob--3 {
    width: 30vw; height: 30vw;
    max-width: 400px; max-height: 400px;
    top: 30%; left: 50%;
    background: radial-gradient(circle, rgba(255,255,255,0.05) 0%, transparent 70%);
    animation: bBlob3 14s ease-in-out infinite alternate;
    animation-play-state: var(--anim-play, running);
}
@keyframes bBlob1 {
    0%   { transform: translate(0,0)      scale(1.0); }
    50%  { transform: translate(8vw,6vh)  scale(1.12); }
    100% { transform: translate(3vw,12vh) scale(0.92); }
}
@keyframes bBlob2 {
    0%   { transform: translate(0,0)       scale(1.0); }
    60%  { transform: translate(-7vw,-8vh) scale(1.15); }
    100% { transform: translate(-3vw,-4vh) scale(0.88); }
}
@keyframes bBlob3 {
    0%   { transform: translate(0,0)     scale(1.0); opacity:0.4; }
    100% { transform: translate(5vw,8vh) scale(1.3); opacity:0.9; }
}

.brief-bg__grid {
    position: absolute;
    inset: 0;
    width: 100%; height: 100%;
    opacity: 0.6;
}

.brief-bg__particles {
    position: absolute;
    inset: 0;
    width: 100%; height: 100%;
}

.brief-panel {
    position: absolute;
    top: 0;
    width: 100vw;
    height: 100vh;
    display: flex;
    align-items: center;
    padding: 0 6vw;
    box-sizing: border-box;
    
}
.brief-panel--1 { left: 0; }
.brief-panel--2 { left: 100vw; }
.brief-panel--3 { left: 200vw; }

.brief-panel__vline {
    position: absolute;
    left: 3vw;
    top: 8vh; bottom: 8vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
}
.brief-panel__vdot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: rgba(255,255,255,0.6);
    flex-shrink: 0;
}
.brief-panel__vdot--top { box-shadow: 0 0 8px rgba(255,255,255,0.4); }
.brief-panel__vbar {
    flex: 1;
    width: 1px;
    background: linear-gradient(to bottom, rgba(255,255,255,0.5) 0%, rgba(255,255,255,0.08) 100%);
    transform-origin: top;
    animation: vbarGrow 1.2s cubic-bezier(0.16,1,0.3,1) forwards;
}
@keyframes vbarGrow { from { transform: scaleY(0); } to { transform: scaleY(1); } }

.brief-panel__counter {
    position: absolute;
    top: 2.5rem;
    right: 3vw;
    display: flex;
    align-items: baseline;
    gap: 0.3rem;
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.65rem;
    letter-spacing: 0.12em;
    color: rgba(255,255,255,0.25);
}
.brief-panel__counter-cur { color: rgba(255,255,255,0.7); font-size: 0.75rem; }

.brief-panel__content {
    position: relative;
    z-index: 2;
    width: 100%;
}

.brief-p1__label {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.65rem;
    letter-spacing: 0.28em;
    color: rgba(255,255,255,0.35);
    text-transform: uppercase;
    margin-bottom: 1.2rem;
    opacity: 0;
    animation: fadeUp 0.8s ease 0.3s forwards;
}
.brief-p1__title {
    font-family: 'HeroBold', 'Avenir Next World', sans-serif;
    font-size: clamp(4rem, 10vw, 9rem);
    font-weight: 700;
    line-height: 0.92;
    color: #fff;
    margin: 0 0 1.2rem;
    display: flex;
    flex-direction: column;
    opacity: 0;
    animation: fadeUp 0.9s cubic-bezier(0.16,1,0.3,1) 0.5s forwards;
}
.brief-p1__title-accent {
    color: transparent;
    -webkit-text-stroke: 1.5px rgba(255,255,255,0.6);
    letter-spacing: 0.04em;
}
.brief-p1__ruler {
    width: min(400px, 55vw);
    height: 24px;
    margin-bottom: 2rem;
    opacity: 0;
    animation: fadeUp 0.7s ease 0.9s forwards;
}

.brief-p1__quote {
    max-width: 38vw;
    font-family: 'HeroSubtitle', 'Avenir Next World', sans-serif;
    font-size: clamp(0.95rem, 1.5vw, 1.3rem);
    line-height: 1.65;
    color: rgba(255,255,255,0.72);
    margin: 0 0 2.5rem;
    padding: 0;
    border: none;
    position: relative;
    opacity: 0;
    animation: fadeUp 0.8s ease 1.1s forwards;
}
.brief-p1__quote-mark {
    font-size: 2em;
    line-height: 0;
    vertical-align: -0.3em;
    color: rgba(255,255,255,0.2);
    font-family: serif;
}
.brief-p1__quote-mark--close { margin-left: 0.1em; }

.brief-p1__facts {
    display: flex;
    gap: clamp(1.5rem, 4vw, 4rem);
    opacity: 0;
    animation: fadeUp 0.8s ease 1.4s forwards;
}
.brief-p1__fact {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    position: relative;
    padding-top: 1rem;
}
.brief-p1__fact::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 24px; height: 2px;
    background: rgba(255,255,255,0.4);
    animation: factLine 0.6s ease calc(1.6s + var(--fi)*0.15s) forwards;
    transform: scaleX(0);
    transform-origin: left;
}
@keyframes factLine { to { transform: scaleX(1); } }
.brief-p1__fact-num {
    font-family: 'HeroBold', 'Avenir Next World', sans-serif;
    font-size: clamp(1.8rem, 3.5vw, 3rem);
    color: #fff;
    line-height: 1;
    letter-spacing: -0.02em;
}
.brief-p1__fact-label {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.68rem;
    letter-spacing: 0.14em;
    color: rgba(255,255,255,0.40);
    text-transform: uppercase;
}

.brief-panel__scroll-hint {
    position: absolute;
    bottom: 3rem; right: 6vw;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.60rem;
    letter-spacing: 0.22em;
    color: rgba(255,255,255,0.32);
    animation: hintPulse 2.5s ease-in-out 2s infinite;
    animation-play-state: var(--anim-play, running);
}
@keyframes hintPulse {
    0%, 100% { opacity: 0.4; transform: translateX(0); }
    50%       { opacity: 0.9; transform: translateX(5px); }
}

.brief-p2__label {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.62rem;
    letter-spacing: 0.28em;
    color: rgba(255,255,255,0.32);
    text-transform: uppercase;
    margin-bottom: 1.8rem;
}
.brief-p2__layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(2rem, 5vw, 6rem);
    align-items: start;
}

.brief-p2__glass-block {
    background: rgba(255,255,255,0.07);
    backdrop-filter: blur(16px) saturate(1.3);
    -webkit-backdrop-filter: blur(16px) saturate(1.3);
    border: 1px solid rgba(255,255,255,0.15);
    border-bottom-color: rgba(255,255,255,0.06);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.18), 0 8px 28px rgba(0,0,0,0.25);
    padding: 1.6rem 1.8rem;
    margin-bottom: 1.6rem;
}
.brief-p2__glass-block p {
    font-family: 'Avenir Next World', sans-serif;
    font-size: clamp(0.78rem, 0.95vw, 0.9rem);
    line-height: 1.8;
    color: rgba(255,255,255,0.82);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin: 0 0 1rem;
}
.brief-p2__glass-block p:last-child { margin-bottom: 0; }

.brief-p2__info-list { display: flex; flex-direction: column; gap: 0.9rem; }
.brief-p2__info-item {
    display: flex;
    align-items: flex-start;
    gap: 0.9rem;
    opacity: 0;
    transform: translateX(-10px);
    transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.16,1,0.3,1);
}
.brief-panel--2.is-active .brief-p2__info-item { opacity: 1; transform: none; }
.brief-panel--2.is-active .brief-p2__info-item:nth-child(1) { transition-delay: 0.5s; }
.brief-panel--2.is-active .brief-p2__info-item:nth-child(2) { transition-delay: 0.7s; }
.brief-p2__info-icon {
    width: 32px; height: 32px;
    flex-shrink: 0;
    display: flex; align-items: center; justify-content: center;
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 2px;
    color: rgba(255,255,255,0.6);
}
.brief-p2__info-icon svg { width: 16px; height: 16px; }
.brief-p2__info-title {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.78rem;
    color: rgba(255,255,255,0.85);
    letter-spacing: 0.05em;
}
.brief-p2__info-sub {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.65rem;
    color: rgba(255,255,255,0.38);
    letter-spacing: 0.08em;
    margin-top: 0.2rem;
}

.brief-p2__visual-col {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    padding-top: 2rem;
}
.brief-p2__glass-bars {
    display: flex;
    align-items: flex-end;
    gap: 0.8rem;
    height: clamp(180px, 28vh, 320px);
    position: relative;
    padding: 0 0.5rem;
}
.brief-p2__bar {
    width: clamp(36px, 4.5vw, 72px);
    height: var(--bh);
    background: var(--bc);
    border-radius: 3px 3px 0 0;
    border: 1px solid rgba(255,255,255,0.2);
    border-bottom: none;
    position: relative;
    overflow: hidden;
    transform: scaleY(0);
    transform-origin: bottom;
    transition: transform 0.9s cubic-bezier(0.16,1,0.3,1);
    transition-delay: calc(0.3s + var(--bi) * 0.14s);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.25), 0 0 20px rgba(60,100,220,0.25);
}
.brief-panel--2.is-active .brief-p2__bar { transform: scaleY(1); }
@keyframes barGrow { to { transform: scaleY(1); } }

.brief-p2__bar::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 40%;
    background: linear-gradient(to bottom, rgba(255,255,255,0.18), transparent);
    pointer-events: none;
}

.brief-p2__bar { animation: barPulse 4s ease-in-out calc(1.5s + var(--bi)*0.8s) infinite; animation-play-state: var(--anim-play, running); }
@keyframes barPulse {
    0%, 100% { filter: brightness(1) drop-shadow(0 0 0px transparent); }
    50%       { filter: brightness(1.15) drop-shadow(0 0 12px rgba(80,140,255,0.4)); }
}

.brief-p2__visual-label {
    font-family: 'HeroBold', 'Avenir Next World', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 0.22em;
    color: rgba(255,255,255,0.5);
    margin-top: 0.8rem;
    text-align: right;
}
.brief-p2__visual-sub {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.6rem;
    letter-spacing: 0.18em;
    color: rgba(255,255,255,0.25);
    text-align: right;
}

.brief-p3__label {
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.62rem;
    letter-spacing: 0.28em;
    color: rgba(255,255,255,0.32);
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}
.brief-p3__layout {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto 1fr;
    gap: 1.2rem 4vw;
    align-items: start;
}
.brief-p3__heading {
    font-family: 'Avenir Next World', sans-serif;
    font-size: clamp(0.85rem, 1.3vw, 1.1rem);
    line-height: 1.7;
    color: rgba(255,255,255,0.75);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin: 0 0 1.2rem;
    grid-column: 1;
}
.brief-p3__list {
    list-style: none;
    margin: 0; padding: 0;
    grid-column: 1;
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
}
.brief-p3__item {
    display: flex;
    align-items: flex-start;
    gap: 0.7rem;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.45s ease, transform 0.45s cubic-bezier(0.16,1,0.3,1);
    transition-delay: calc(0.15s + var(--pi) * 0.08s);
}
.brief-panel--3.is-active .brief-p3__item { opacity: 1; transform: none; }
.brief-p3__item-icon {
    color: rgba(255,255,255,0.35);
    font-size: 0.55rem;
    margin-top: 0.22rem;
    flex-shrink: 0;
}
.brief-p3__item-text {
    font-family: 'Avenir Next World', sans-serif;
    font-size: clamp(0.72rem, 0.9vw, 0.84rem);
    line-height: 1.5;
    color: rgba(255,255,255,0.78);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.brief-p3__diagram {
    grid-column: 2;
    grid-row: 1 / 3;
    align-self: center;
}
.brief-p3__cycle {
    width: clamp(140px, 18vw, 220px);
    height: auto;
    opacity: 0;
    transition: opacity 0.8s ease 0.6s;
}
.brief-panel--3.is-active .brief-p3__cycle { opacity: 1; }
@keyframes diagramFadeIn { to { opacity: 1; } }
.brief-p3__cycle-ring {
    stroke-dashoffset: 565;
    transition: stroke-dashoffset 2s cubic-bezier(0.16,1,0.3,1) 0.8s;
}
.brief-panel--3.is-active .brief-p3__cycle-ring { stroke-dashoffset: 0; }
@keyframes ringDraw { to { stroke-dashoffset: 0; } }
.brief-p3__cycle-dot {
    opacity: 0;
    transition: opacity 0.35s ease;
    transition-delay: calc(1.8s + var(--di) * 0.1s);
}
.brief-panel--3.is-active .brief-p3__cycle-dot { opacity: 1; }
@keyframes dotPop { to { opacity: 1; } }

.brief-exit-hint {
    position: absolute;
    bottom: 3rem; right: 6vw;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    font-family: 'Avenir Next World', sans-serif;
    font-size: 0.58rem;
    letter-spacing: 0.22em;
    color: rgba(255,255,255,0.3);
    animation: exitPulse 2.5s ease-in-out 1s infinite;
    animation-play-state: var(--anim-play, running);
}
@keyframes exitPulse {
    0%, 100% { opacity: 0.3; transform: translateY(0); }
    50%       { opacity: 0.8; transform: translateY(4px); }
}

.brief-progress {
    position: fixed;
    bottom: 0; left: 0; right: 0;
    height: 2px;
    background: rgba(255,255,255,0.08);
    z-index: 100;
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}
.brief-progress.is-visible { opacity: 1; }
.brief-progress__fill {
    height: 100%;
    background: linear-gradient(90deg, rgba(255,255,255,0.4), rgba(255,255,255,0.8));
    transform-origin: left;
    transform: scaleX(0);
    transition: transform 0.1s linear;
}

.brief-dots {
    position: fixed;
    bottom: 1.8rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 0.6rem;
    z-index: 100;
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}
.brief-dots.is-visible { opacity: 1; pointer-events: auto; }
.brief-dots__dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.4);
    background: transparent;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.3s ease;
    padding: 0;
}
.brief-dots__dot.is-active {
    background: rgba(255,255,255,0.85);
    transform: scale(1.25);
    border-color: transparent;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(14px); }
    to   { opacity: 1; transform: none; }
}

@media (max-width: 64rem) {
    .brief-section { height: auto; }
    .brief-track { position: relative; flex-direction: column; height: auto; transform: none !important; }
    .brief-panel { width: 100%; height: auto; min-height: 100vh; flex: none; }
    .brief-p2__layout, .brief-p3__layout { grid-template-columns: 1fr; }
    .brief-p2__visual-col { display: none; }
    .brief-p3__diagram { display: none; }
    .brief-progress, .brief-dots { display: none; }
}
@media (max-width: 40rem) {
    .brief-panel { padding: 5rem 5vw 3rem 7vw; }
    .brief-p1__title { font-size: clamp(3rem, 14vw, 5rem); }
    .brief-p1__quote { max-width: 100%; }
}