/* ============================================================
   信件世界：书架 + 信封 + 信纸 + 惊喜（自 v2.0 style.css 迁移）
   ============================================================ */

/* ---------- 书架页面 ---------- */
#galleryView{
  overflow-y:auto;
  z-index:10;
}
.gallery-header{
  text-align:center;
  padding:clamp(40px,8vh,72px) 20px clamp(20px,4vh,36px);
  position:relative;
}
.gallery-title{
  font-family:"Songti SC","STSong","Noto Serif SC",serif;
  font-size:clamp(28px,5vw,42px);
  font-weight:600;
  color:var(--rose-deep);
  letter-spacing:.12em;
  margin-bottom:8px;
}
.gallery-subtitle{
  font-size:14px;
  color:var(--ink-soft);
  letter-spacing:.2em;
}
.gallery-count{
  display:inline-block;
  margin-top:14px;
  padding:4px 16px;
  border-radius:999px;
  background:rgba(255,255,255,.6);
  font-size:13px;
  color:var(--ink-soft);
  letter-spacing:.08em;
}

.gallery-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill, minmax(260px, 1fr));
  gap:clamp(16px,3vw,28px);
  padding:clamp(20px,4vw,40px);
  max-width:1100px;
  margin:0 auto;
}

.letter-card{
  position:relative;
  background:rgba(255,255,255,.7);
  -webkit-backdrop-filter:blur(8px);
  backdrop-filter:blur(8px);
  border-radius:18px;
  padding:28px 24px 22px;
  cursor:pointer;
  transition:transform .3s cubic-bezier(.25,.7,.3,1), box-shadow .3s ease;
  border:1px solid rgba(255,255,255,.6);
  overflow:hidden;
}
.letter-card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:4px;
  background:var(--card-accent,var(--rose));
}
.letter-card:hover{
  transform:translateY(-6px);
  box-shadow:0 20px 40px -12px rgba(var(--shadow-rgba),.3);
}
.letter-card:active{
  transform:translateY(-2px) scale(.98);
}
.letter-card:focus-visible{
  outline:2px dashed var(--rose);outline-offset:4px;
}

.card-icon{
  width:52px;height:52px;border-radius:14px;
  background:var(--card-accent,var(--rose));
  display:grid;place-items:center;
  margin-bottom:16px;
  box-shadow:0 6px 16px rgba(var(--shadow-rgba),.2);
}
.card-icon svg{width:26px;height:26px}

.card-title{
  font-family:"Songti SC","STSong","Noto Serif SC",serif;
  font-size:19px;
  font-weight:600;
  color:var(--ink);
  margin-bottom:6px;
  letter-spacing:.04em;
}
.card-date{
  font-size:12.5px;
  color:var(--ink-soft);
  letter-spacing:.06em;
  margin-bottom:12px;
}
.card-summary{
  font-size:14px;
  color:var(--ink-soft);
  line-height:1.7;
  display:-webkit-box;
  -webkit-line-clamp:3;
  -webkit-box-orient:vertical;
  overflow:hidden;
}
.card-hint{
  margin-top:16px;
  display:flex;align-items:center;gap:6px;
  font-size:12px;
  color:var(--rose);
  letter-spacing:.1em;
  opacity:0;
  transform:translateY(6px);
  transition:opacity .3s, transform .3s;
}
.letter-card:hover .card-hint{
  opacity:1;transform:translateY(0);
}
.card-hint svg{width:14px;height:14px}

.gallery-footer{
  text-align:center;
  padding:32px 20px 48px;
  font-size:12px;
  color:var(--ink-soft);
  opacity:.6;
  letter-spacing:.1em;
}

@media (max-width:600px){
  .gallery-grid{
    grid-template-columns:1fr;
    padding:16px;
    gap:14px;
  }
  .letter-card{padding:22px 20px 18px}
}

/* ---------- 信封页面 ---------- */
#envelopeView{
  overflow:hidden;
}

/* 返回按钮（信封→书架 / 书架→星系 共用样式） */
.back-btn{
  position:fixed;z-index:10;
  top:max(16px, env(safe-area-inset-top));
  left:max(16px, env(safe-area-inset-left));
  width:44px;height:44px;border-radius:50%;
  border:1px solid rgba(194,80,120,.35);
  background:rgba(255,255,255,.62);
  -webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);
  color:#b05576;cursor:pointer;
  display:grid;place-items:center;
  box-shadow:0 6px 16px rgba(var(--shadow-rgba),.18);
  transition:background .25s, transform .15s;
  -webkit-tap-highlight-color:transparent;
}
.back-btn:hover{background:#fff;color:#c2476f}
.back-btn:active{transform:scale(.94)}
.back-btn:focus-visible{outline:2px dashed var(--rose);outline-offset:3px}
.back-btn svg{width:20px;height:20px}

/* 花瓣画布 */
#petals{position:fixed;inset:0;width:100%;height:100%;z-index:1;pointer-events:none}

/* ---------- 信封舞台 ---------- */
.stage{
  position:fixed;inset:0;z-index:2;
  display:flex;align-items:center;justify-content:center;
}
.envelope-wrap{
  position:relative;border:0;background:none;padding:0;cursor:pointer;
  -webkit-tap-highlight-color:transparent;
  display:flex;flex-direction:column;align-items:center;gap:30px;
  width:min(430px,82vw,90dvh*1.55);
  transition:opacity .7s ease, transform .7s cubic-bezier(.5,0,.3,1);
}
.envelope-wrap.is-leaving{opacity:0;transform:scale(.55) translateY(90px);pointer-events:none}
.envelope-wrap:focus-visible{outline:2px dashed var(--rose);outline-offset:16px;border-radius:18px}

.shadow{
  position:absolute;left:50%;bottom:-36px;width:86%;height:44px;
  transform:translateX(-50%);
  background:radial-gradient(50% 50% at 50% 50%, rgba(var(--shadow-rgba),.30), rgba(var(--shadow-rgba),0) 72%);
  border-radius:50%;filter:blur(5px);
  animation:shadowBreathe 4s ease-in-out infinite;
}
@keyframes shadowBreathe{
  0%,100%{transform:translateX(-50%) scaleX(1)}
  50%{transform:translateX(-50%) scaleX(.94)}
}

.envelope-scene{
  width:100%;aspect-ratio:155/100;
  perspective:1300px;
}
.envelope{
  position:absolute;inset:0;
  transform-style:preserve-3d;
  transform:rotateX(7deg) rotateZ(-2.5deg);
  transition:transform .6s cubic-bezier(.2,.9,.3,1);
}
.envelope-wrap:not(.is-leaving):hover .envelope{transform:rotateX(3deg) rotateZ(-1deg) translateY(-8px)}
.envelope-wrap:not(.is-leaving):active .envelope{transform:translateY(2px) scale(.985)}

.env-back{
  position:absolute;inset:0;z-index:1;
  background:linear-gradient(150deg,var(--env-cream) 0%,var(--env-cream-deep) 100%);
  border-radius:16px;
  box-shadow:
    0 30px 60px -20px rgba(var(--shadow-rgba),.45),
    0 8px 18px -8px rgba(var(--shadow-rgba),.25);
}

.letter-mini{
  position:absolute;left:4.5%;right:4.5%;top:5%;bottom:7%;z-index:2;
  background:var(--paper);border-radius:9px;
  box-shadow:0 6px 16px rgba(var(--shadow-rgba),.16);
  display:flex;flex-direction:column;align-items:center;justify-content:flex-start;
  padding-top:8%;
  transition:transform 1.55s cubic-bezier(.33,0,.21,1) .5s;
  background-image:repeating-linear-gradient(transparent,transparent 22px,rgba(233,190,208,.22) 23px);
}
.letter-mini svg{width:22px;height:22px;opacity:.55}
.letter-mini .mini-word{
  margin-top:7px;font-size:13px;letter-spacing:.22em;color:var(--ink-soft);opacity:.7;
  font-family:"Songti SC","STSong","Noto Serif SC",serif;
}
.envelope.is-open .letter-mini{transform:translateY(-46%)}

.flap{
  position:absolute;top:0;left:0;width:100%;height:56%;z-index:3;
  background:linear-gradient(180deg,var(--flap-top) 0%,var(--flap-bottom) 100%);
  clip-path:polygon(0 0,100% 0,50% 100%);
  border-radius:16px 16px 0 0;
  transform-origin:top center;
  backface-visibility:hidden;
  box-shadow:0 5px 12px rgba(var(--shadow-rgba),.12);
  transition:transform 1.7s cubic-bezier(.42,.05,.25,1);
}
.envelope.is-open .flap{transform:rotateX(-180deg)}

.pocket{
  position:absolute;left:0;right:0;bottom:0;height:62%;z-index:4;
  background:linear-gradient(180deg,var(--env-cream) 0%,var(--env-cream-deep) 100%);
  clip-path:polygon(0 0,50% 34%,100% 0,100% 100%,0 100%);
  border-radius:0 0 16px 16px;
  box-shadow:inset 0 -10px 18px rgba(var(--shadow-rgba),.10);
}
.pocket::before,.pocket::after{
  content:"";position:absolute;bottom:0;width:50%;height:100%;opacity:.42;
}
.pocket::before{left:0;clip-path:polygon(0 0,100% 68%,0 100%);background:linear-gradient(100deg,rgba(255,255,255,.75),transparent 60%)}
.pocket::after{right:0;clip-path:polygon(0 68%,100% 0,100% 100%);background:linear-gradient(-100deg,rgba(255,255,255,.75),transparent 60%)}

.seal{
  position:absolute;top:calc(56% - 34px);left:50%;z-index:6;
  width:68px;height:68px;transform:translateX(-50%) rotate(-7deg);
  background:radial-gradient(circle at 32% 28%,var(--seal-hi) 0%,var(--rose) 46%,var(--rose-deep) 80%,#a93a5d 100%);
  border-radius:46% 54% 50% 50% / 55% 46% 54% 45%;
  display:grid;place-items:center;
  box-shadow:
    0 9px 20px rgba(var(--shadow-rgba),.38),
    inset 0 2px 3px rgba(255,255,255,.5),
    inset 0 -4px 7px rgba(110,25,55,.38);
  animation:sealBreathe 3.4s ease-in-out infinite;
}
.seal svg{width:30px;height:30px;filter:drop-shadow(0 1px 1px rgba(120,30,60,.4))}
@keyframes sealBreathe{
  0%,100%{transform:translateX(-50%) rotate(-7deg) scale(1);box-shadow:0 9px 20px rgba(var(--shadow-rgba),.38),inset 0 2px 3px rgba(255,255,255,.5),inset 0 -4px 7px rgba(110,25,55,.38)}
  50%{transform:translateX(-50%) rotate(-7deg) scale(1.045);box-shadow:0 13px 26px rgba(var(--shadow-rgba),.5),inset 0 2px 3px rgba(255,255,255,.5),inset 0 -4px 7px rgba(110,25,55,.38)}
}
.seal.seal-pop{animation:sealPop .7s cubic-bezier(.4,0,.5,1) forwards}
@keyframes sealPop{
  0%{opacity:1;transform:translateX(-50%) rotate(-7deg) scale(1)}
  35%{transform:translateX(-50%) rotate(-7deg) scale(1.08)}
  100%{opacity:0;transform:translateX(-50%) translateY(-30px) rotate(16deg) scale(.35)}
}

.hint{
  display:flex;align-items:center;gap:9px;
  font-size:15px;letter-spacing:.18em;color:var(--ink-soft);
  animation:floatY 3.2s ease-in-out infinite;
}
.hint svg{width:16px;height:16px;flex:none}
@keyframes floatY{
  0%,100%{transform:translateY(0);opacity:.85}
  50%{transform:translateY(-6px);opacity:1}
}

/* ---------- 展开后的信纸 ---------- */
.letter-overlay{
  position:fixed;inset:0;z-index:5;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  padding:22px;
  opacity:0;pointer-events:none;
  transition:opacity .55s ease;
}
.letter-overlay.show{opacity:1;pointer-events:auto}

.paper{
  position:relative;
  width:min(700px,92vw);
  max-height:min(84dvh,880px);
  overflow-y:auto;
  background:var(--paper);
  color:var(--ink);
  border-radius:16px;
  padding:clamp(26px,5vw,54px) clamp(22px,6vw,64px) clamp(26px,5vw,50px);
  box-shadow:
    0 34px 80px -22px rgba(var(--shadow-rgba),.42),
    0 10px 24px -10px rgba(var(--shadow-rgba),.22);
  transform:scale(.82) translateY(26px);
  transition:transform .85s cubic-bezier(.25,.7,.3,1);
  outline:none;
}
.letter-overlay.show .paper{transform:scale(1) translateY(0)}
.paper::-webkit-scrollbar{width:8px}
.paper::-webkit-scrollbar-thumb{background:rgba(226,103,143,.35);border-radius:8px}
.paper::-webkit-scrollbar-track{background:transparent}

.paper-head{
  display:flex;justify-content:space-between;align-items:center;gap:12px;
  padding-bottom:14px;margin-bottom:6px;
  border-bottom:1px solid #f3dbe4;
  font-size:13px;color:#b06a82;
}
.paper-head .flower{width:34px;height:34px;flex:none;opacity:.9}
.paper-head .paper-tip{
  font-size:12px;
  color:rgba(200, 150, 150, 0.5);
  letter-spacing:0.1em;
}

.letter-text{
  font-family:"Songti SC","STSong","Noto Serif SC","Source Han Serif SC",serif;
  font-size:clamp(16px,2.4vw,19px);
  line-height:2.05;letter-spacing:.03em;
}
.letter-text p{margin:0 0 1.05em;text-indent:2em;user-select:text;-webkit-user-select:text}
.letter-text p.greeting{text-indent:0;font-size:1.12em;font-weight:600;margin-bottom:.9em}
.letter-text .ch{display:inline;opacity:0;transition:opacity .4s ease}
.letter-text .ch.visible{opacity:1}

.paper-sign{
  margin-top:26px;text-align:right;
  font-family:"Songti SC","STSong","Noto Serif SC",serif;
  font-size:17px;color:#8a5267;
  user-select:text;-webkit-user-select:text;
}

.skip-hint{
  margin-top:14px;font-size:12.5px;color:#c08aa0;letter-spacing:.1em;
  opacity:0;transition:opacity .5s;
}
.skip-hint.on{opacity:.9}

.surprise-wrap{
  margin-top:18px;text-align:center;
}
.surprise-btn{
  position:relative;border:none;background:none;cursor:pointer;
  color:var(--rose);padding:0;
  -webkit-tap-highlight-color:transparent;
  transition:transform .2s;
}
.surprise-btn svg{width:36px;height:36px;filter:drop-shadow(0 2px 6px rgba(var(--shadow-rgba),.3));transition:transform .3s}
.surprise-btn:hover svg{transform:scale(1.15)}
.surprise-btn:active svg{transform:scale(.95)}
.surprise-tip{
  display:block;margin-top:8px;
  font-size:12px;color:#b06a82;letter-spacing:.06em;
}

.surprise-overlay{
  position:fixed;inset:0;z-index:20;
  display:flex;align-items:center;justify-content:center;
  background:rgba(60,30,40,.55);
  -webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  opacity:0;pointer-events:none;
  transition:opacity .35s ease;
  overflow-y:auto;
}
.surprise-overlay.show{opacity:1;pointer-events:auto}
.surprise-puzzle{
  position:relative;flex:0 0 auto;
  width:min(88vw,560px);
  border-radius:14px;overflow:hidden;
  box-shadow:0 24px 64px rgba(60,20,40,.45);
  margin:auto 0;
}
.surprise-puzzle .tile{
  position:absolute;
  background-size:var(--pw) var(--ph);
  background-repeat:no-repeat;
  border-radius:2px;
  opacity:0;
  transition:transform .8s cubic-bezier(.22,.9,.3,1), opacity .6s ease;
}
.surprise-puzzle .tile.merged{
  transform:translate(0,0) !important;
  opacity:1;
}
.surprise-close{
  position:fixed;top:max(16px,env(safe-area-inset-top));right:max(16px,env(safe-area-inset-right));
  width:40px;height:40px;border-radius:50%;border:1px solid rgba(255,255,255,.3);
  background:rgba(255,255,255,.5);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);
  color:#6b3f4e;font-size:22px;cursor:pointer;
  display:grid;place-items:center;line-height:1;
  transition:background .2s,transform .15s;z-index:21;
}
.surprise-close:hover{background:#fff}
.surprise-close:active{transform:scale(.9)}

.reseal{
  margin-top:28px;padding:12px 30px;
  border:1.5px solid rgba(194,80,120,.45);
  border-radius:999px;
  background:rgba(255,255,255,.6);color:#b05576;
  font-size:14.5px;letter-spacing:.1em;cursor:pointer;
  transition:background .25s, box-shadow .25s, transform .15s;
}
.reseal:hover{background:#fff;box-shadow:0 8px 20px rgba(var(--shadow-rgba),.25)}
.reseal:active{transform:scale(.97)}
.reseal:focus-visible{outline:2px dashed var(--rose);outline-offset:4px}

.music-toggle{
  position:fixed;z-index:10;
  top:max(16px, env(safe-area-inset-top));
  right:max(16px, env(safe-area-inset-right));
  width:44px;height:44px;border-radius:50%;
  border:1px solid rgba(194,80,120,.35);
  background:rgba(255,255,255,.62);
  -webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);
  color:#b05576;cursor:pointer;
  display:grid;place-items:center;
  box-shadow:0 6px 16px rgba(var(--shadow-rgba),.18);
  transition:background .25s, transform .15s, color .25s;
  -webkit-tap-highlight-color:transparent;
}
.music-toggle:hover{background:#fff;color:#c2476f}
.music-toggle:active{transform:scale(.94)}
.music-toggle:focus-visible{outline:2px dashed var(--rose);outline-offset:3px}
.music-toggle svg{width:22px;height:22px}
.music-toggle .ic-play{display:none}
.music-toggle.playing .ic-play{display:block;animation:musicSway 1.6s ease-in-out infinite}
.music-toggle.playing .ic-muted{display:none}
@keyframes musicSway{0%,100%{transform:scale(1)}50%{transform:scale(1.14)}}

/* ---------- 响应式与降级 ---------- */
@media (max-height:420px){
  .envelope-wrap{width:min(340px,70dvh*1.55,82vw);gap:14px}
  .hint{display:none}
  .seal{width:56px;height:56px;top:calc(56% - 28px)}
  .seal svg{width:24px;height:24px}
}
@media (max-width:480px){
  .hint{font-size:13.5px;letter-spacing:.14em}
  .paper{padding:24px 20px 28px;border-radius:14px}
  .reseal{padding:11px 26px;font-size:13.5px}
}

/* 中秋星空（信件主题内使用） */
#stars{
  position:fixed;inset:0;z-index:0;pointer-events:none;opacity:0;
  transition:opacity .8s ease;
  background:
    radial-gradient(2px 2px at 20% 30%, #fff4, transparent),
    radial-gradient(1px 1px at 60% 70%, #fff3, transparent),
    radial-gradient(1.5px 1.5px at 50% 50%, #fff5, transparent),
    radial-gradient(1px 1px at 80% 10%, #fff3, transparent),
    radial-gradient(2px 2px at 90% 60%, #fff4, transparent),
    radial-gradient(1px 1px at 33% 80%, #fff3, transparent),
    radial-gradient(1.5px 1.5px at 15% 55%, #fff4, transparent),
    radial-gradient(1px 1px at 70% 25%, #fff3, transparent),
    radial-gradient(2px 2px at 5% 90%, #fff4, transparent),
    radial-gradient(1px 1px at 95% 40%, #fff3, transparent),
    radial-gradient(1.5px 1.5px at 40% 15%, #fff4, transparent),
    radial-gradient(1px 1px at 25% 75%, #fff3, transparent),
    radial-gradient(2px 2px at 85% 85%, #fff4, transparent),
    radial-gradient(1px 1px at 55% 45%, #fff3, transparent),
    radial-gradient(1.5px 1.5px at 10% 20%, #fff4, transparent),
    radial-gradient(1px 1px at 65% 90%, #fff3, transparent),
    radial-gradient(2px 2px at 45% 65%, #fff4, transparent),
    radial-gradient(1px 1px at 30% 35%, #fff3, transparent),
    radial-gradient(1.5px 1.5px at 75% 55%, #fff4, transparent),
    radial-gradient(1px 1px at 20% 85%, #fff3, transparent);
}
#stars.show{opacity:1}

/* 打印隐藏交互元素 */
@media print{
  .music-toggle,.back-btn,.reseal,.skip-hint,.surprise-wrap{display:none!important}
}

/* ---------- 时光胶囊：上锁卡片与锁定信纸 ---------- */
.letter-card.locked{background:rgba(255,255,255,.42)}
.letter-card.locked::before{background:linear-gradient(90deg,#9a96b8,#8a86b0)}
.letter-card.locked .card-icon{
  background:linear-gradient(145deg,#a8a4c4,#7a76a0);
  box-shadow:0 6px 16px rgba(90,86,130,.28);
}
.letter-card.locked .card-title{color:#5c5878}
.letter-card.locked .card-summary{color:#8a86a4}
.lock-mystery{font-style:italic;letter-spacing:.05em}
.letter-locked{text-align:center;padding:30px 0 20px}
.letter-locked .ll-icon{font-size:46px}
.letter-locked .ll-title{
  font-family:"Songti SC","STSong","Noto Serif SC",serif;
  font-size:21px;color:var(--ink);margin:14px 0 8px;letter-spacing:.06em;
}
.letter-locked .ll-note{font-size:14px;color:#a45a76;letter-spacing:.1em}
.letter-locked .ll-count{margin-top:12px;font-size:15px;color:#b05576}
.letter-locked .ll-count b{font-size:24px;font-weight:600}
.letter-locked .ll-date{margin-top:8px;font-size:12px;color:#c08aa0;letter-spacing:.08em}