/* Paper white is the default. Dark colors exist only inside the browser preference query. */
:root{color-scheme:light dark;--bg:#fffdf8;--surface:#fff;--ink:#3b3732;--muted:#80776e;--line:#e9e2d8;--soft:#f4f0e9;--inverse:#fffdf8;--accent:#8b775f;--shadow:#705d4512;--warm-light:#e5dacc;--warm-glow:#f7f1e6;--tap-color:#b5a18a50;--chapter-ink:#a9998129;--river-hint:#b6c6bc14}
@media(prefers-color-scheme:dark){:root{--bg:#211f1d;--surface:#2c2926;--ink:#f3eee7;--muted:#b5aaa0;--line:#49413a;--soft:#332e29;--inverse:#211f1d;--accent:#ccbba4;--shadow:#0004;--warm-light:#a58d7140;--warm-glow:#a58d710d;--tap-color:#dbc6aa40;--chapter-ink:#c4af931a;--river-hint:#9cb6a909}}
body{background:var(--bg);background-image:radial-gradient(ellipse at 78% 37%,var(--warm-glow),transparent 58%);background-attachment:fixed}
.site-header{height:85px;border-bottom:0;gap:16px}.site-header .home-link{font-size:11px;color:var(--muted);padding:10px 0}.site-header:has(+main .hero) .home-link{visibility:hidden}.site-header nav{gap:22px}.site-header nav button[data-action=gallery]{display:block}.site-footer{border-top-color:var(--line);font-size:10px;letter-spacing:.02em;min-height:72px}.competition-note{font-size:10px;white-space:nowrap;letter-spacing:.015em}.footer-center{font-family:SimSun,serif;color:var(--muted);font-size:11px;letter-spacing:.15em}
.hero{min-height:calc(100svh - 157px);padding-top:40px;padding-bottom:40px}.hero-copy>.eyebrow{letter-spacing:.25em}.hero .eyebrow::before{content:'来信';font:10px SimSun,serif;border:0;border-radius:20px;padding:6px 10px;background:var(--soft);color:var(--accent);margin-right:14px}.hero h1{letter-spacing:.035em}.hero .lede{font-size:13px;line-height:2.2}.hero-actions{margin-top:30px}.hero-art{perspective:1300px}.envelope{transform:rotateX(var(--tilt-x,0deg)) rotateY(var(--tilt-y,0deg)) rotateZ(-3deg);transform-style:preserve-3d;border-radius:20px;cursor:grab;touch-action:pan-y;will-change:transform;box-shadow:0 28px 55px var(--shadow),0 4px 12px #4855380a;background:linear-gradient(116deg,#fffdf8,#f1f0e5 30%,#e0e3d8 70%,#faf9f2);border-color:#c9cebe;outline-offset:15px}.envelope.is-dragging{cursor:grabbing;touch-action:none}.envelope::before,.envelope::after{opacity:.4;border-color:#a0aa92}.envelope .paper-shine{position:absolute;inset:0;border-radius:inherit;pointer-events:none;background:radial-gradient(circle at var(--shine-x,50%) var(--shine-y,45%),#ffffffa0,transparent 65%);mix-blend-mode:soft-light}.envelope-title{color:#506046;letter-spacing:.24em;font-family:SimSun,serif}.envelope-foot{font-family:SimSun,serif;letter-spacing:.2em}.envelope-label{letter-spacing:.12em;font-size:9px;color:#738167}.art-frame{border-radius:40% 40% 12px 12px;border-color:#89957c50;overflow:hidden}.art-frame::before{border-radius:inherit;border-color:#89957c40}.landscape{color:#7d8d6b}.orbit{border-color:var(--line);opacity:.65}.orbit::after{border-style:dashed;opacity:.45}.art-note{font-family:SimSun,serif;color:var(--accent);font-size:11px}.art-number{font-family:SimSun,serif;line-height:1.7;font-size:10px;letter-spacing:.15em}.drag-invitation{position:absolute;left:0;right:0;bottom:0;text-align:center;font-size:10px;color:var(--muted);letter-spacing:.1em;pointer-events:none}.hero-art::after{content:'';width:7px;height:7px;border:1px solid var(--accent);border-radius:50%;position:absolute;left:3%;top:35%;opacity:.45;box-shadow:14px 25px 0 -1px var(--line)}
.button,.action{border-radius:999px;box-shadow:0 4px 13px var(--shadow);transition:transform .2s,box-shadow .2s,background .2s,border-color .2s}.button{background:#796850;border-color:#796850;color:#fffef7;min-height:49px;padding-left:25px;padding-right:23px}.button:hover{background:#88765c;border-color:#88765c;box-shadow:0 8px 20px var(--shadow);transform:translateY(-2px)}.button.secondary{color:var(--ink);background:var(--surface);border-color:var(--line)}.button.secondary:hover{background:var(--soft)}button:active,.button:active{transform:scale(.965)}.icon-btn{background:var(--surface);border-color:var(--line)}button:focus-visible,a:focus-visible,input:focus-visible{outline-color:var(--accent)}.remember input{accent-color:#8c785f}.remember{line-height:1.9}.meta-strip{border:0;gap:38px;padding-top:25px;margin-top:22px}.meta-strip div{position:relative}.meta-strip div+div::before{content:'';width:1px;height:25px;background:var(--line);position:absolute;left:-19px;top:9px}.meta-strip b{color:var(--accent)}
.journey{min-height:calc(100svh - 157px);padding-top:25px}.journey-top{font-size:11px;letter-spacing:.07em}.progress-track{height:4px;border-radius:9px;background:var(--soft)}.progress-track span{height:4px;border-radius:9px;background:linear-gradient(90deg,#d6c8b6,#9e896c);box-shadow:0 0 15px var(--warm-light)}.chapters span.active{color:var(--accent)}.chapters span.active::after{content:'·';margin-left:7px;color:var(--accent)}.scene-text h1{color:var(--ink)}.bridge{border:0;background:var(--soft);border-radius:0 18px 18px 18px;padding:15px 18px;position:relative;font-size:12px}.bridge::before{content:'来路';display:block;font-family:SimSun,serif;font-size:10px;color:var(--accent);margin-bottom:6px;letter-spacing:.18em}.memory-note{border:0;background:var(--surface);border-radius:14px;padding:12px 15px;box-shadow:0 2px 15px var(--shadow)}.memory-note>span:first-child{color:var(--accent)}.choices{gap:13px}.choice{background:var(--surface);border-color:var(--line);border-radius:20px;min-height:88px;padding:19px 20px;box-shadow:0 2px 12px var(--shadow);transition:background .2s,border-color .2s,box-shadow .2s,transform .2s}.choice:hover{background:var(--soft);border-color:#b9a58c;transform:translateY(-2px);box-shadow:0 7px 20px var(--shadow)}.choice .letter{border:0;background:var(--soft);font-family:SimSun,serif;color:var(--muted);width:30px;height:30px}.choice[aria-checked=true]{border-color:#ac9475;background:var(--soft);box-shadow:0 0 0 2px #b69c7b18,0 5px 17px var(--shadow)}.choice[aria-checked=true] .letter{background:#958065;color:#fff}.choice .mark{color:var(--accent)}.choice.just-chosen{animation:choice-settle .45s ease}.choice-reflection{font-size:10px;line-height:1.7;margin:16px 0 -7px;color:var(--muted);min-height:17px;transition:color .2s}.choice-reflection.noted{color:var(--accent)}.save-state{margin-top:16px;font-size:10px}.scene-note{opacity:.9}.chapter-caption{text-align:left;font-style:normal;font-family:SimSun,serif}.result-toolbar{background:var(--bg);border:0;height:55px}.result-frame{height:calc(100svh - 55px)}.result-toolbar>span{font-size:10px}.result-toolbar .music-toggle{padding:6px}.result-loading{background:var(--bg);inset:55px 0 0}
.music-toggle{display:inline-flex;align-items:center;gap:8px;font-size:10px;color:var(--muted);border-radius:999px;padding:9px 12px;white-space:nowrap;background:var(--soft)}.music-bars{height:14px;display:flex;gap:3px;align-items:center}.music-bars i{display:block;width:2px;height:4px;border-radius:4px;background:currentColor;transform-origin:center}.music-bars i:nth-child(2){height:10px}.music-bars i:nth-child(3){height:6px}[data-music-state=playing] .music-bars i{animation:music-breathe 1.8s ease-in-out infinite alternate}[data-music-state=playing] .music-bars i:nth-child(2){animation-delay:-.7s}[data-music-state=playing] .music-bars i:nth-child(3){animation-delay:-1.2s}.music-toggle[aria-pressed=true]{color:var(--accent)}
.gallery-card{border-radius:20px;padding:9px;box-shadow:0 3px 15px var(--shadow);overflow:hidden}.gallery-card img{border-radius:13px;filter:saturate(.55)}.gallery-card .card-copy{padding:17px 13px}.gallery-card h2{font-size:22px}.gallery-card .eyebrow{letter-spacing:.12em;font-family:SimSun,serif;font-size:10px}.filter{border-radius:999px;background:var(--surface);padding:10px 16px}.filter.active{background:#8e785c;border-color:#8e785c;color:#fff}.page-title h1{font-size:38px}dialog{border-radius:25px;box-shadow:0 28px 100px var(--shadow);border-color:var(--line);padding:28px 30px}dialog::backdrop{background:#3b302536;backdrop-filter:blur(10px)}.dialog-head .eyebrow{font-family:SimSun,serif;letter-spacing:.15em}.dialog-actions{gap:12px}.toast{border-radius:18px;background:var(--surface);color:var(--ink);border:1px solid var(--line);box-shadow:0 10px 35px var(--shadow)}.editor input,.editor textarea,.editor select{border-radius:12px}.editor .page-title h1{font-size:32px}
.touch-ripple{position:fixed;z-index:1000;width:36px;height:36px;margin:-18px;border:1px solid var(--tap-color);background:radial-gradient(circle,var(--tap-color),transparent 70%);border-radius:50%;pointer-events:none;animation:tap-ripple .6s ease-out forwards}@keyframes tap-ripple{from{transform:scale(.4);opacity:.9}to{transform:scale(2.2);opacity:0}}@keyframes choice-settle{0%{transform:scale(.98)}60%{transform:scale(1.012)}100%{transform:scale(1)}}@keyframes music-breathe{to{transform:scaleY(.45)}}
/* Result module shares the same paper, gestures and quiet visual language. */
.experience{background:radial-gradient(ellipse at 50% 45%,var(--surface),var(--bg) 70%)}.experience .header .brand{display:none}.experience .header{justify-content:flex-end}.experience .header-rule{opacity:.45}.experience .pack-shell{border-radius:17px;box-shadow:0 20px 45px var(--shadow)}.experience .pack-mainlabel{font-family:SimSun,serif;letter-spacing:.2em}.experience .pack-kicker,.experience .pack-smalllabel{font-family:SimSun,serif;letter-spacing:.12em}.experience .pack-frame,.experience .pack-frame::before{border-radius:35% 35% 9px 9px}.experience .card,.experience .card-face{border-radius:18px}.experience .card-title{letter-spacing:.04em}.experience .card-kind,.experience .card-mark,.experience .card-serial{font-family:SimSun,serif;letter-spacing:.08em}.experience .card-en{font-family:SimSun,serif;font-style:normal;letter-spacing:.1em}.experience .card-footer{padding-top:10px}.experience .en{font-family:SimSun,serif;font-style:normal}.experience .sheet{border-radius:25px;padding:34px;box-shadow:0 20px 80px var(--shadow)}.experience .sheet-overlay{background:var(--veil)}.experience .action{border-radius:999px}.experience .action.primary{background:#8b7559;border-color:#8b7559;color:#fff}.experience .trait{border-radius:999px;padding:6px 10px}.experience .dossier-meter{height:3px;border-radius:9px}.experience .dossier-meter span{background:#b9a080}.experience .footer>.foot-label{font-family:inherit;letter-spacing:.02em;font-size:9px}.experience .footer>.foot-label::before{content:none}.experience #soundButton{display:none}.experience .geometry{opacity:.4}.experience .card-serial span{font-size:8px;letter-spacing:.03em}
@media(max-width:700px){.site-header{height:70px;margin:0 7vw}.site-header nav{gap:13px}.site-header nav button[data-action=gallery]{font-size:10px}.site-header .home-link{font-size:10px}.music-label{font-size:9px}.music-toggle{padding:8px 10px;gap:6px}.hero{padding:20px 8vw 28px;min-height:0}.hero-art{min-height:278px;margin-bottom:27px}.envelope{width:161px;max-width:161px;border-radius:14px}.envelope-label{font-size:6px}.envelope-title{font-size:19px}.envelope-foot{font-size:6px}.art-frame{border-radius:45% 45% 10px 10px}.art-note{font-size:9px}.art-number{font-size:8px;bottom:28px}.drag-invitation{bottom:-8px;font-size:9px}.hero-copy>.eyebrow{font-size:10px}.hero h1{font-size:40px;margin-top:19px}.hero .lede{font-size:12px;line-height:2.15}.hero-actions{margin-top:24px}.button{min-height:46px}.remember{font-size:9px}.meta-strip{margin-top:18px;padding-top:22px;gap:40px}.meta-strip div+div::before{left:-20px}.site-footer{margin:0 7vw;min-height:70px;gap:10px}.competition-note{font-size:8px;white-space:normal;max-width:75%}.site-footer button{font-size:9px}.journey{padding:21px 7vw 30px;min-height:calc(100svh - 140px)}.journey-top{font-size:10px}.chapters{margin-bottom:27px}.chapters span{font-size:8px}.choice{border-radius:17px;padding:16px;min-height:78px}.choices{gap:11px}.choice-reflection{font-size:9px}.scene-grid{gap:25px}.scene-note{font-size:9px}.save-state{font-size:9px}.bridge{font-size:11px;padding:12px 15px;border-radius:0 16px 16px 16px}.memory-note{font-size:10px}.result-toolbar{height:51px;padding:0 5vw}.result-frame{height:calc(100svh - 51px)}.result-toolbar>span{display:none}.result-toolbar>div{gap:14px}.result-toolbar .music-label{display:inline}.result-loading{inset:51px 0 0}.gallery-card{border-radius:16px;padding:6px}.gallery-card img{border-radius:10px}.gallery-card h2{font-size:17px}.gallery-card .eyebrow{font-size:8px}.gallery-card .card-copy{padding:12px 8px}.filter{padding:8px 12px}.page-title h1{font-size:30px}.experience .sheet{border-radius:25px 25px 0 0;padding:32px 24px}.experience .footer>.foot-label{font-size:8px}.experience .card-serial span{font-size:6px}dialog{padding:23px;border-radius:23px}}
@media(prefers-reduced-motion:reduce){.touch-ripple{display:none}.envelope{will-change:auto}.music-bars i{animation:none!important}*,*::before,*::after{animation:none!important;transition:none!important}}

/* The complete letter is an image: no text selection, native drag ghost or text hit targets. */
.envelope{padding:0;overflow:hidden;background:#f3ecdf;border-color:#cdbfae;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}.envelope::before,.envelope::after{display:none}.home-card-image{display:block;width:100%;height:100%;position:absolute;inset:0;object-fit:fill;border-radius:inherit;pointer-events:none;user-select:none;-webkit-user-select:none;-webkit-user-drag:none}.gallery-card img{filter:none}
/* Five restrained paper landscapes; river green appears only as a faint wash during the journey. */
body:has(.journey){background-image:radial-gradient(ellipse at 82% 70%,var(--river-hint),transparent 52%),radial-gradient(ellipse at 16% 90%,var(--warm-glow),transparent 62%)}.journey{isolation:isolate}.journey::before{content:"";position:fixed;inset:22% -5% 0 26%;z-index:-1;pointer-events:none;background:var(--chapter-ink);mask:var(--chapter-art) right bottom/contain no-repeat;-webkit-mask:var(--chapter-art) right bottom/contain no-repeat}.journey[data-chapter="0"]{--chapter-art:url("https://www.imgos.cn/i/2026/10/28/6ae1fec44648f.png")}.journey[data-chapter="1"]{--chapter-art:url("https://www.imgos.cn/i/2026/10/28/6ae1fec84a721.png")}.journey[data-chapter="2"]{--chapter-art:url("https://www.imgos.cn/i/2026/10/28/6ae1fecc4c19b.png")}.journey[data-chapter="3"]{--chapter-art:url("https://www.imgos.cn/i/2026/10/28/6ae1fed11ba1f.png")}.journey[data-chapter="4"]{--chapter-art:url("https://www.imgos.cn/i/2026/10/28/6ae1fed42a2fb.png")}@media(max-width:700px){.journey::before{inset:48% -28% 2% -10%}.envelope{padding:0}}