*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:"Inter","Noto Sans SC",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
  background:#141414;color:#f5f5f5;-webkit-font-smoothing:antialiased;
}

.mosaic-bg{
  position:fixed;inset:0;z-index:0;overflow:hidden;pointer-events:none;
  background:#141414;
}
.mosaic-rotate{
  position:absolute;left:50%;top:45%;
  width:max-content;
  transform:translate(-50%,-45%) rotate(-15deg) scale(2.4);
  transform-origin:center center;
}
.mosaic-track{
  display:flex;flex-direction:column;
  animation:scroll-mosaic 60s linear infinite;
  will-change:transform;
}
.mosaic-grid{
  display:grid;grid-template-columns:repeat(5,20vw);gap:5px;
  flex-shrink:0;
}
@media(min-width:768px){
  .mosaic-grid{grid-template-columns:repeat(6,16vw);gap:7px}
}
.mosaic-cell{
  position:relative;aspect-ratio:16/9;overflow:hidden;
  border-radius:2px;background:#1a1a1a;
}
.mosaic-cell img{
  display:block;width:100%;height:100%;object-fit:cover;
  filter:brightness(.55);image-rendering:auto;
}
.mosaic-overlay{
  position:absolute;inset:0;z-index:1;
  background:linear-gradient(
    to top,
    #141414 0%,
    rgba(20,20,20,.88) 28%,
    rgba(20,20,20,.62) 55%,
    rgba(20,20,20,.38) 100%
  );
}
@keyframes scroll-mosaic{
  from{transform:translateY(0)}
  to{transform:translateY(-50%)}
}

.app{
  position:relative;z-index:2;
  height:100%;max-width:640px;margin:0 auto;
  display:flex;flex-direction:column;
}

.hidden{display:none!important}

.lang-select{
  position:absolute;top:calc(14px + env(safe-area-inset-top));right:16px;z-index:10;
  border:1px solid rgba(255,215,0,.25);background:rgba(20,20,20,.75);
  border-radius:999px;padding:7px 12px;font:inherit;font-size:12px;font-weight:500;
  color:#ffd700;backdrop-filter:blur(12px);cursor:pointer;outline:none;
}
.lang-select option{color:#111;background:#fff}

/* ── Welcome ── */
.welcome{
  flex:1;display:flex;align-items:center;justify-content:center;
  padding:calc(56px + env(safe-area-inset-top)) 18px calc(24px + env(safe-area-inset-bottom));
  animation:fade-in .45s ease;
}
.welcome-card{
  width:100%;max-width:420px;
  background:linear-gradient(160deg,rgba(28,28,28,.92) 0%,rgba(18,18,18,.88) 100%);
  border:1px solid rgba(255,215,0,.18);
  border-radius:24px;padding:28px 22px 22px;
  box-shadow:0 24px 60px rgba(0,0,0,.45),inset 0 1px 0 rgba(255,255,255,.06);
  backdrop-filter:blur(20px);
}
.welcome-badge{
  display:inline-block;font-size:11px;font-weight:600;letter-spacing:.06em;
  text-transform:uppercase;color:#141414;background:linear-gradient(135deg,#ffe566,#ffd700);
  padding:5px 12px;border-radius:999px;margin-bottom:18px;
}
.welcome-text{
  font-size:14px;line-height:1.65;color:rgba(255,255,255,.72);
  margin-bottom:22px;
}
.welcome-title{
  font-size:20px;font-weight:700;line-height:1.35;color:#fff;
  margin-bottom:20px;letter-spacing:-.02em;
}
.options{display:flex;flex-direction:column;gap:10px}
.opt-btn{
  display:flex;align-items:center;gap:14px;width:100%;
  border:1px solid rgba(255,255,255,.08);
  background:rgba(255,255,255,.04);
  border-radius:16px;padding:14px 16px;
  font:inherit;text-align:left;cursor:pointer;color:#fff;
  transition:border-color .2s,background .2s,transform .15s,box-shadow .2s;
}
.opt-btn:hover{
  border-color:rgba(255,215,0,.35);
  background:rgba(255,215,0,.08);
  box-shadow:0 8px 24px rgba(0,0,0,.25);
}
.opt-btn:active{transform:scale(.985)}
.opt-btn:disabled{opacity:.55;pointer-events:none}
.opt-icon{
  flex-shrink:0;width:44px;height:44px;border-radius:12px;
  display:flex;align-items:center;justify-content:center;
  background:rgba(255,215,0,.12);color:#ffd700;
}
.opt-icon svg{width:22px;height:22px}
.opt-body{flex:1;min-width:0;display:flex;flex-direction:column;gap:3px}
.opt-title{font-size:15px;font-weight:600;line-height:1.35;color:#fff}
.opt-desc{font-size:12px;line-height:1.4;color:rgba(255,255,255,.5)}
.opt-arrow{
  flex-shrink:0;font-size:22px;line-height:1;color:rgba(255,215,0,.7);
  font-weight:300;
}

/* ── Chat ── */
.msgs{
  flex:1;overflow-y:auto;
  padding:calc(16px + env(safe-area-inset-top)) 16px 12px;
  display:flex;flex-direction:column;gap:10px;
}
.msgs:not(.hidden){
  display:flex;
  animation:fade-in .35s ease;
}
.msg{max-width:82%;font-size:15px;line-height:1.55;word-break:break-word;white-space:pre-wrap}
.msg.v{
  background:linear-gradient(135deg,#ffe566,#ffd700);color:#141414;
  padding:11px 15px;font-weight:500;
  border-radius:18px 18px 4px 18px;align-self:flex-end;
}
.msg.a{
  background:rgba(255,255,255,.1);color:#f0f0f0;padding:11px 15px;
  border:1px solid rgba(255,255,255,.08);
  border-radius:18px 18px 18px 4px;align-self:flex-start;
  backdrop-filter:blur(8px);
}
.msg.s{
  align-self:center;font-size:12px;color:rgba(255,255,255,.45);
  padding:6px 12px;background:rgba(0,0,0,.25);border-radius:999px;
}
.bar{
  border-top:1px solid rgba(255,255,255,.08);
  padding:12px 16px calc(12px + env(safe-area-inset-bottom));
  display:flex;gap:10px;
  background:rgba(18,18,18,.92);backdrop-filter:blur(16px);
}
.bar:not(.hidden){display:flex}
.bar input{
  flex:1;border:1px solid rgba(255,255,255,.1);
  background:rgba(255,255,255,.06);border-radius:22px;
  padding:12px 18px;font:inherit;font-size:15px;outline:none;color:#fff;
}
.bar input::placeholder{color:rgba(255,255,255,.35)}
.bar input:focus{border-color:rgba(255,215,0,.4);background:rgba(255,255,255,.08)}
.bar button{
  border:none;background:linear-gradient(135deg,#ffe566,#ffd700);
  color:#141414;font:inherit;font-size:14px;font-weight:700;
  padding:0 20px;border-radius:22px;cursor:pointer;
}
.bar button:disabled{opacity:.35;cursor:default}
.bar.disabled{opacity:.5;pointer-events:none}

@keyframes fade-in{
  from{opacity:0;transform:translateY(8px)}
  to{opacity:1;transform:translateY(0)}
}

@media(max-width:380px){
  .welcome-card{padding:22px 16px 18px;border-radius:20px}
  .opt-btn{padding:12px 14px;gap:12px}
  .opt-icon{width:40px;height:40px}
  .welcome-title{font-size:18px}
}