:root{
  --bg:#070a16; --bg2:#0b0e1a;
  --panel:rgba(28,33,58,.55); --panel2:rgba(40,46,78,.4);
  --accent:#6c8cff; --accent2:#b06cff; --gold:#ffd479;
  --text:#e8ecff; --muted:#8a90a8; --safe:#5fe6a0;
  --glow:rgba(108,140,255,.55);
  --speed:1;
}
body.day{
  --bg:#eef1ff; --bg2:#dfe5ff;
  --panel:rgba(255,255,255,.62); --panel2:rgba(255,255,255,.5);
  --text:#1a1f3d; --muted:#5a608c; --glow:rgba(108,140,255,.35);
  --accent:#4d6cff; --accent2:#9a4dff; --gold:#c98a16;
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:-apple-system,"PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  background:var(--bg); color:var(--text); overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
/* 深空背景 + 极光 */
.bg{position:fixed;inset:0;z-index:-2;background:
  radial-gradient(120% 80% at 50% -10%, #161c3d 0%, var(--bg2) 55%, var(--bg) 100%);}
.aurora{position:fixed;inset:-20% -20%;z-index:-2;filter:blur(80px);opacity:.5;
  background:
   radial-gradient(40% 40% at 20% 30%, rgba(108,140,255,.5), transparent 60%),
   radial-gradient(35% 35% at 80% 25%, rgba(176,108,255,.45), transparent 60%),
   radial-gradient(45% 45% at 60% 80%, rgba(95,230,160,.25), transparent 60%);
  animation:drift 24s ease-in-out infinite alternate;}
@keyframes drift{0%{transform:translate3d(-3%,-2%,0) scale(1)}100%{transform:translate3d(4%,3%,0) scale(1.12)}}
#stars{position:fixed;inset:0;z-index:-1;}

.wrap{max-width:1180px;margin:0 auto;padding:0 24px 120px;position:relative;z-index:1}

/* 顶栏 */
.nav{position:sticky;top:0;z-index:30;display:flex;align-items:center;justify-content:space-between;
  padding:18px 24px;backdrop-filter:blur(14px);background:rgba(7,10,22,.35);border-bottom:1px solid rgba(140,160,255,.12);}
.brand{display:flex;align-items:center;gap:14px;font-weight:800;letter-spacing:1px}
.logo{width:42px;height:42px;border-radius:13px;display:grid;place-items:center;font-size:22px;color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent2));box-shadow:0 8px 28px var(--glow);}
.brand small{display:block;font-weight:500;color:var(--muted);font-size:12px;letter-spacing:3px}
.nav-btns{display:flex;gap:10px;align-items:center}
.pill{border:1px solid rgba(140,160,255,.25);background:rgba(255,255,255,.05);color:var(--text);
  padding:9px 18px;border-radius:999px;font-size:14px;cursor:pointer;transition:.25s}
.pill:hover{border-color:var(--accent);box-shadow:0 0 18px var(--glow)}
.theme{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;cursor:pointer;
  border:1px solid rgba(140,160,255,.25);background:rgba(255,255,255,.05);font-size:18px}

/* Hero */
.hero{text-align:center;padding:90px 0 60px}
.hero h1{font-size:64px;font-weight:900;letter-spacing:4px;
  background:linear-gradient(120deg,#fff,var(--accent) 50%,var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent;}
.hero .slogan{font-size:20px;color:var(--muted);letter-spacing:8px;margin-top:14px}
.hero .cta{display:flex;gap:16px;justify-content:center;margin-top:38px;flex-wrap:wrap}
.btn{border:none;cursor:pointer;font-size:16px;font-weight:700;padding:15px 34px;border-radius:999px;transition:.25s;letter-spacing:1px}
.btn.primary{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;box-shadow:0 14px 40px var(--glow)}
.btn.ghost{background:rgba(255,255,255,.06);color:var(--text);border:1px solid rgba(140,160,255,.3)}
.btn:hover{transform:translateY(-3px)}
.tag-row{display:flex;gap:10px;justify-content:center;margin-top:30px;flex-wrap:wrap}
.tag{font-size:13px;color:var(--muted);border:1px solid rgba(140,160,255,.15);padding:6px 16px;border-radius:999px;background:rgba(255,255,255,.03)}

/* Section */
.section{margin-top:70px}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;margin-bottom:22px}
.section-head h2{font-size:30px;font-weight:800;letter-spacing:1px}
.section-head .sub{color:var(--muted);font-size:14px;margin-top:6px}
.glass{background:var(--panel);border:1px solid rgba(140,160,255,.14);border-radius:22px;
  padding:24px;backdrop-filter:blur(12px);box-shadow:0 18px 50px rgba(0,0,0,.35)}

/* Stats grid */
.grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.stat{background:var(--panel);border:1px solid rgba(140,160,255,.14);border-radius:20px;padding:22px 18px;text-align:center}
.stat .num{font-size:38px;font-weight:900;color:var(--accent);text-shadow:0 0 24px var(--glow)}
.stat .lbl{color:var(--muted);font-size:13px;margin-top:6px}
.quick{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:18px}
.q{background:var(--panel2);border:1px solid rgba(140,160,255,.12);border-radius:18px;padding:22px;text-align:center;cursor:pointer;transition:.2s}
.q:hover{transform:translateY(-4px);border-color:var(--accent);box-shadow:0 12px 30px var(--glow)}
.q .qi{font-size:30px}.q .qn{font-size:14px;margin-top:8px;color:var(--text)}

/* Capsule form */
.form-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.field label{display:block;font-size:13px;color:var(--muted);margin-bottom:8px}
.seg{display:flex;gap:8px;flex-wrap:wrap}
.seg button{flex:1;min-width:64px;border:1px solid rgba(140,160,255,.2);background:rgba(255,255,255,.04);color:var(--muted);
  padding:10px 8px;border-radius:12px;font-size:13px;cursor:pointer;transition:.2s}
.seg button.on{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;border-color:transparent;font-weight:700;box-shadow:0 6px 18px var(--glow)}
textarea,input[type=text]{width:100%;background:rgba(255,255,255,.05);border:1px solid rgba(140,160,255,.22);
  border-radius:14px;padding:14px 16px;color:var(--text);font-size:15px;font-family:inherit;resize:vertical}
textarea:focus,input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 16px var(--glow)}
.full{grid-column:1/-1}
.submit{margin-top:18px;width:100%;border:none;cursor:pointer;font-size:17px;font-weight:800;padding:16px;border-radius:999px;
  background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;letter-spacing:2px;box-shadow:0 14px 40px var(--glow)}
.toast{position:fixed;left:50%;bottom:40px;transform:translateX(-50%) translateY(20px);opacity:0;
  background:rgba(20,24,44,.95);border:1px solid var(--accent);color:#fff;padding:14px 26px;border-radius:14px;
  z-index:100;transition:.3s;pointer-events:none;box-shadow:0 10px 30px var(--glow)}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}

/* ===== 时空次元留言墙 ===== */
.wall-wrap{position:relative}
.wall-filters{display:flex;gap:18px;flex-wrap:wrap;align-items:center;margin-bottom:18px}
.fgroup{display:flex;align-items:center;gap:8px}
.fgroup .fl{font-size:13px;color:var(--muted)}
.fi{border:1px solid rgba(140,160,255,.2);background:rgba(255,255,255,.04);color:var(--muted);
  padding:8px 16px;border-radius:999px;font-size:13px;cursor:pointer;transition:.2s}
.fi.on{background:rgba(108,140,255,.22);color:var(--text);border-color:var(--accent)}
.wall-actions{margin-left:auto;display:flex;gap:10px}
.wall-stage{position:relative;height:620px;border-radius:24px;overflow:hidden;
  border:1px solid rgba(140,160,255,.14);
  background:linear-gradient(180deg, rgba(20,24,48,.4), rgba(7,10,22,.2));
  box-shadow:inset 0 0 80px rgba(0,0,0,.5);}
.frag{position:absolute;cursor:pointer;will-change:transform;user-select:none;
  animation:twinkle calc(4s / var(--speed)) ease-in-out infinite;
  opacity:0;transition:opacity .7s ease;}
.frag.in{opacity:1;}
@keyframes twinkle{0%,100%{filter:brightness(1)}50%{filter:brightness(1.35)}}
.frag.glow{font-size:22px;font-weight:800;color:#fff;text-shadow:0 0 18px var(--accent),0 0 36px var(--accent2);
  padding:6px 4px;max-width:240px;line-height:1.5}
.frag.glass{background:rgba(255,255,255,.07);border:1px solid rgba(160,180,255,.28);border-radius:18px;
  padding:18px 20px;max-width:260px;font-size:15px;line-height:1.6;backdrop-filter:blur(6px);
  box-shadow:0 10px 30px rgba(0,0,0,.4)}
.frag.note{background:linear-gradient(150deg,rgba(255,212,121,.16),rgba(176,108,255,.12));
  border:1px solid rgba(255,212,121,.3);border-radius:14px;padding:14px 16px;max-width:200px;font-size:14px;
  transform:rotate(-3deg);box-shadow:0 10px 26px rgba(0,0,0,.35)}
.frag .wm{display:block;margin-top:10px;font-size:10px;letter-spacing:1px;color:rgba(160,180,255,.6);opacity:.8}
.frag .lk{display:inline-block;margin-top:8px;font-size:12px;color:var(--gold)}
.frag .dim{font-size:10px;color:var(--muted);margin-top:4px}

/* 弹窗 */
.modal{position:fixed;inset:0;z-index:200;display:none;align-items:center;justify-content:center;
  background:rgba(4,6,14,.7);backdrop-filter:blur(6px)}
.modal.show{display:flex}
.modal-card{width:min(520px,92vw);background:var(--panel);border:1px solid rgba(140,160,255,.2);border-radius:22px;
  padding:28px;box-shadow:0 30px 80px rgba(0,0,0,.6)}
.modal-card h3{font-size:20px;margin-bottom:6px}
.modal-card .mc-wm{color:var(--gold);font-size:12px;letter-spacing:1px;margin-bottom:14px}
.modal-card .mc-body{font-size:18px;line-height:1.7;padding:16px 0;border-top:1px solid rgba(140,160,255,.14);border-bottom:1px solid rgba(140,160,255,.14)}
.reply{margin-top:14px}
.reply .rp{font-size:13px;color:var(--muted);padding:8px 0;border-bottom:1px solid rgba(255,255,255,.05)}
.mc-actions{display:flex;gap:10px;margin-top:18px}
.mc-actions .btn{flex:1;padding:13px}
.close{position:absolute;top:14px;right:18px;cursor:pointer;color:var(--muted);font-size:24px}

.foot{margin-top:80px;text-align:center;color:var(--muted);font-size:13px;line-height:2}

@media(max-width:760px){
  .hero h1{font-size:42px}.grid{grid-template-columns:repeat(2,1fr)}
  .quick{grid-template-columns:repeat(2,1fr)}.form-grid{grid-template-columns:1fr}
  .wall-stage{height:520px}
}