/* Shared visual language: soft objects, precise research, one orange accent. */
:root{--surface:#fff;--warm:#fff0e7;--radius-card:24px;--muted:#5e6d6c}
.site-header{border-bottom-color:#17232b0d;background:#f0f3f1f2}
.site-header nav>a{display:inline-flex;align-items:center;gap:7px;min-height:40px}
.nav-notebook-icon{width:22px;height:22px;flex:none}
.nav-idea{min-height:38px;align-items:center;padding-inline:18px;box-shadow:0 3px 8px #17232b0a}
.button{min-height:46px;letter-spacing:.01em}
.button-dark,.nav-idea{background:#17232b}
.button-orange{box-shadow:0 4px 12px #f05a3812}
.button:active{transform:translateY(1px)}
.direction-card,.idea-entry,.stats-summary>article,.counting-note,.tread-numbers>article,.engineering-note,.origin-proof,.document-card,.tread-card,.submit-card{border-radius:var(--radius-card)}
.direction-card,.idea-entry,.stats-summary>article,.tread-numbers>article,.document-card,.tread-card{border-color:#17232b10;box-shadow:0 4px 18px #17232b03}
.feature-card{border-radius:28px;overflow:hidden}
.submit-card{background:var(--warm);border:1px solid #f05a3814}
.submit-card h3{font-size:clamp(28px,3vw,40px);line-height:1.4}
.note-dialog{border-radius:28px;border:1px solid #17232b0d;padding:32px;box-shadow:0 24px 90px #17232b30}
.note-dialog::backdrop{background:#17232b66;backdrop-filter:blur(7px)}
.note-dialog input:not([type=range]),.note-dialog textarea,.note-dialog select{border-color:#cfd8d3;border-radius:13px;background:#fafcfb;line-height:1.6}
.submission-guide{background:#f4f7f4;border-color:#17232b0b;border-radius:16px}
.dialog-close{background:#f0f3f1;color:var(--ink);width:36px;height:36px}
.document-preview{background:#edf1ed}
.document-actions{font-size:12px}
.film-frame,.tread-hero>img,.tread-wide img{border-radius:24px}
.collection-intro{padding-block:56px 42px}
.collection-intro>.eyebrow{display:flex;align-items:center;gap:12px;color:#596764;letter-spacing:.14em;margin-bottom:24px}
.notebook-badge{display:inline-flex;width:42px;height:42px;border-radius:14px;align-items:center;justify-content:center;background:#fff;border:1px solid #17232b09;transform:rotate(-5deg)}
.collection-intro h1{font-size:clamp(34px,4.1vw,58px);line-height:1.3;letter-spacing:-.04em}
.collection-intro p:not(.eyebrow){font-size:14px;line-height:1.9}
.contribution-steps{background:#e6ece7;border:0;border-radius:18px;padding:19px 24px;gap:32px;margin-top:36px;justify-content:space-between}
.contribution-steps b{display:inline-flex;align-items:center;justify-content:center;border-radius:50%;background:#fff;width:24px;height:24px;font-size:10px;margin-right:9px;color:#b33e24}
.active-studies{padding-block:14px 72px}
.active-studies .materials-heading{margin-bottom:28px}
.active-studies .materials-heading h2{font-size:clamp(28px,3.2vw,42px);line-height:1.4;letter-spacing:-.035em}
.active-studies .materials-heading .eyebrow{font-size:10px;letter-spacing:.13em;margin-bottom:16px;color:#62716c}
.active-studies .materials-heading>p{font-size:12px;line-height:1.95;max-width:360px}
.chapter-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;background:transparent;border:0;padding:0}
.chapter-row{display:flex;flex-direction:column;min-width:0;overflow:hidden;background:#fff;border:1px solid #17232b10;border-radius:24px;box-shadow:0 5px 20px #17232b04;transition:transform .25s,box-shadow .25s}
.chapter-visual{position:relative;overflow:hidden;aspect-ratio:1.65;background:#17232b}
.chapter-visual>img{width:100%;height:100%;object-fit:cover;transition:transform .5s}
.chapter-row:first-child .chapter-visual>img{object-position:65% center}
.study-status{position:absolute;left:16px;bottom:14px;display:inline-flex;align-items:center;gap:6px;background:#fffef7ee;color:#25332e;border-radius:999px;padding:6px 10px;font-size:10px;line-height:1.4;backdrop-filter:blur(10px)}
.study-status i{width:5px;height:5px;background:#f05a38;border-radius:50%}
.chapter-copy{padding:26px;display:flex;flex-direction:column;flex:1;min-width:0}
.chapter-number{font-size:10px;letter-spacing:.06em;color:var(--muted);display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 0 16px}
.chapter-number>span{font-size:9px;letter-spacing:.09em}
.chapter-copy h3{display:flex;align-items:center;justify-content:space-between;font-size:32px;line-height:1.3;letter-spacing:-.03em;margin:0}
.chapter-copy h3 .project-arrow{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border:1px solid #dbe2dd;border-radius:50%;font-size:20px;font-weight:400;color:#42544d}
.chapter-tagline{font-size:17px;line-height:1.65;font-weight:600;margin-top:17px;min-height:56px;text-wrap:balance}
.chapter-subtitle{font-size:12px;line-height:1.8;color:var(--muted);margin-top:8px}
.chapter-evidence{display:flex;gap:6px;flex-wrap:wrap;margin-block:19px 24px}
.chapter-evidence span{font-size:10px;background:#f1f5f1;padding:5px 9px;border-radius:8px;color:#4c5c54;line-height:1.4}
.chapter-action{display:flex;align-items:center;justify-content:space-between;border-top:1px solid #e9eee9;padding-top:16px;margin-top:auto;font-size:11px;color:#44594e}
.chapter-action>span{color:var(--link);font-size:18px}
.chapter-row:hover{transform:translateY(-4px);box-shadow:0 12px 28px #17232b0b}
.chapter-row:hover .chapter-visual>img{transform:scale(1.035)}
.chapter-invite{display:flex;flex-direction:column;min-width:0;background:var(--warm);border:1px solid #f05a381a;border-radius:24px;padding:28px;color:var(--ink)}
.invite-top{display:flex;align-items:center;justify-content:space-between;gap:12px}
.invite-number{font-size:10px;letter-spacing:.08em;color:#8b4937;margin:0}
.invite-sticker{font-size:27px;line-height:1;color:#c84425;transform:rotate(12deg)}
.invite-face{width:100px;height:92px;border-radius:28px;background:#f05a38;color:#fff;display:flex;align-items:center;justify-content:center;margin-block:27px 25px;transform:rotate(-7deg);box-shadow:4px 6px 0 #f05a381a}
.invite-face svg{width:78px;height:66px;transform:rotate(7deg)}
.chapter-invite h3{font-size:30px;line-height:1.4;letter-spacing:-.035em}
.chapter-invite h3>span{color:#bd3d20}
.invite-description{font-size:12px;line-height:1.95;color:#785548;margin-top:19px}
.invite-prompts{display:flex;gap:7px;flex-wrap:wrap;margin-top:17px}
.invite-prompts>span{font-size:10px;border:1px solid #d5a18a66;padding:5px 9px;border-radius:8px;color:#805342}
.invite-bottom{margin-top:auto;padding-top:26px}
.invite-bottom .button{display:flex;justify-content:space-between;width:100%;font-size:13px;padding:14px 20px;min-height:48px}
.invite-bottom>p{font-size:10px;text-align:center;color:#805342;margin-top:12px}
.direction-grid{gap:20px}
.direction-card{padding:28px;transition:border-color .2s,box-shadow .2s}
.direction-card:hover{border-color:#bfcfc3;box-shadow:0 6px 20px #17232b06}
.direction-card h3{font-size:28px;letter-spacing:-.025em}
.direction-card>p{font-size:13px;line-height:1.9}
.direction-card>.direction-scene{min-height:72px}
.direction-question{border-left:0;border-radius:12px;padding:13px 15px;background:#f4f7f3;font-size:12px;line-height:1.85;margin-block:22px 8px}
.direction-card>details{font-size:12px}
.direction-card>details p{font-size:12px;line-height:1.9}
.category-filters button{border-color:#d8e1d8;background:#f9fbf8;padding:9px 16px;min-height:38px;font-size:11px}
.category-filters button[aria-checked=true]{background:#17232b;color:#fff;box-shadow:0 3px 8px #17232b10}
.board-empty{background:#f7faf6;border:1px dashed #b5c6b7;border-radius:20px;padding:40px 28px;line-height:1.95}
.research-method article{background:#fff;border:1px solid #17232b0b;padding:26px;border-radius:20px}
.research-method article>span{font-size:18px}
.research-method article>p{font-size:13px;line-height:1.9}
@media(min-width:1400px){.chapter-copy{padding:28px 30px}.chapter-invite{padding:30px}.chapter-invite h3{font-size:32px}}
@media(min-width:768px) and (max-width:1099px){.chapter-list{grid-template-columns:repeat(2,minmax(0,1fr))}.chapter-invite{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;gap:0 36px;padding:30px 34px}.invite-top{grid-column:1/-1;margin-bottom:20px}.invite-face{grid-row:2/5;grid-column:1;width:90px;height:82px;margin:4px 0;align-self:start}.chapter-invite h3{grid-column:1;grid-row:2/5;margin-left:114px;font-size:26px}.invite-description{grid-column:2;grid-row:2;margin-top:0}.invite-prompts{grid-column:2;grid-row:3;margin-top:15px}.invite-bottom{grid-column:2;padding-top:20px}.chapter-tagline{font-size:17px}.chapter-copy{padding:24px}}
@media(max-width:767px){.site-header nav>a{min-height:36px;gap:5px}.nav-notebook-icon{width:19px;height:19px}.nav-idea{padding-inline:13px;gap:10px}.collection-intro{padding-block:35px 30px}.collection-intro>.eyebrow{font-size:9px;gap:10px;margin-bottom:22px}.notebook-badge{width:36px;height:36px;border-radius:12px}.notebook-badge img{width:28px;height:28px}.collection-intro h1{font-size:34px}.collection-intro p:not(.eyebrow){font-size:13px}.contribution-steps{padding:18px 16px;gap:16px 8px;font-size:10px;margin-top:26px}.contribution-steps b{width:22px;height:22px;font-size:9px;margin-right:5px}.chapter-list{grid-template-columns:1fr;gap:18px}.chapter-row,.chapter-invite{border-radius:22px}.chapter-copy{padding:24px}.chapter-visual{aspect-ratio:1.8}.chapter-tagline{min-height:0;font-size:18px}.chapter-invite{padding:28px}.invite-face{width:86px;height:78px;margin-block:22px}.chapter-invite h3{font-size:30px}.active-studies{padding-bottom:48px}.active-studies .materials-heading h2{font-size:29px}.active-studies .materials-heading>p{font-size:12px}.direction-card{padding:25px}.direction-card>.direction-scene{min-height:0}.direction-card>p{font-size:13px}.note-dialog{padding:24px}.film-frame,.tread-hero>img,.tread-wide img{border-radius:18px}.research-method article{padding:24px}.document-actions{font-size:11px}}
@media(max-width:380px){.collection-intro h1{font-size:29px}.chapter-copy{padding:21px}.chapter-copy h3{font-size:30px}.chapter-number{font-size:9px}.chapter-number>span{font-size:8px}.chapter-invite{padding:24px}.chapter-invite h3{font-size:29px}.contribution-steps{padding-inline:12px;font-size:9px}.contribution-steps b{width:19px;height:19px}.nav-notebook-icon{width:17px;height:17px}}
@media(prefers-reduced-motion:reduce){.chapter-row,.chapter-visual>img,.direction-card{transition:none}.chapter-row:hover,.chapter-row:hover .chapter-visual>img{transform:none}}
/* Keep compact headers horizontal even at the smallest supported phone size. */
.site-header nav>a,.nav-idea{white-space:nowrap;flex-shrink:0}
@media(max-width:767px){.site-header{gap:12px}.site-header nav{gap:12px;flex-shrink:0}}
@media(max-width:380px){.site-header .brand-logo{width:108px}.site-header{gap:10px}.site-header nav{gap:10px}.nav-idea{font-size:10px;gap:8px;padding-inline:10px}.collection-intro h1{font-size:27px}.active-studies .materials-heading h2{font-size:25px}}