:root{
  --radius:16px;
  --accent:#00b3ff;
  --dark-bg-1:#0a0a0f;
  --dark-bg-2:#071226;
  --panel-dark:#121218;
  --muted-dark:#9ca3af;
  --text-light:#111;
  --light-bg:#e6e7eb;
  --light-panel:#f0f1f5;
  --accent-light:#0077cc;
  --glass: rgba(255,255,255,0.03);
  font-family: 'Montserrat', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
}

/* Reset */
*{box-sizing:border-box;margin:0;padding:0}

body{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--dark-bg-1);color:var(--panel-dark);overflow:hidden}

/* animated background */
body.dark{
  background: radial-gradient(circle at 10% 10%, #0b1220, var(--dark-bg-1) 40%), linear-gradient(120deg, rgba(0,0,0,0.2), rgba(10,8,18,0.2));
  animation: bgShift 18s ease-in-out infinite;
  color: #f5f7fa;
}
@keyframes bgShift{0%{filter: hue-rotate(0deg)}50%{filter: hue-rotate(7deg)}100%{filter: hue-rotate(0deg)}}

body.light{
  background: linear-gradient(180deg,var(--light-bg),#d9dadd);
  color: var(--text-light);
}

/* main centered card */
.wrap{width:100%;max-width:820px;padding:20px;display:flex;align-items:center;justify-content:center;min-height:60vh}
.center-card{width:100%;background:rgba(255,255,255,0.02);border-radius:20px;padding:34px;box-shadow:0 12px 40px rgba(2,6,12,0.6);backdrop-filter:blur(8px);border:1px solid rgba(255,255,255,0.04);text-align:center;position:relative;overflow:visible;transform-origin:center;animation: cardEnter .9s cubic-bezier(.2,.9,.3,1);}

/* center animation */
@keyframes cardEnter{0%{opacity:0;transform:translateY(12px) scale(.98)}100%{opacity:1;transform:translateY(0) scale(1)}}

.title{font-size:clamp(28px,6vw,56px);font-weight:800;color:#fff;-webkit-text-stroke:2px #000;margin-bottom:18px;text-shadow:0 8px 30px rgba(0,179,255,0.14);animation: titleIn .9s cubic-bezier(.2,.9,.3,1);transform-origin:center}
@keyframes titleIn{0%{opacity:0;transform:translateY(20px) scale(.98)}60%{opacity:1;transform:translateY(-4px) scale(1.01)}100%{transform:translateY(0) scale(1)}}

/* tabs */
.tabs{display:flex;gap:12px;justify-content:center}
.tab{background:linear-gradient(180deg, rgba(0,179,255,0.16), rgba(0,179,255,0.06));border-radius:14px;padding:12px 20px;border:1px solid rgba(0,179,255,0.28);font-weight:700;color:var(--text-light);cursor:pointer;transition:all .28s;box-shadow:0 8px 26px rgba(0,179,255,0.08);outline:none;position:relative;overflow:hidden}
.tab:hover{transform:translateY(-6px);box-shadow:0 20px 50px rgba(0,179,255,0.18)}
.tab:active{transform:translateY(-2px) scale(.995)}

/* tab open animation (applied on click) */
.tab-opening{animation: tabOpen .45s cubic-bezier(.2,.9,.3,1)}
@keyframes tabOpen{0%{opacity:0;transform:scale(.96) translateY(6px)}100%{opacity:1;transform:scale(1) translateY(0)}}

/* footer */
.footer{margin-top:18px;font-size:13px;color:var(--muted-dark);text-align:center}

/* theme toggle */
.theme-toggle{position:fixed;top:16px;right:18px;z-index:1000}
.switch{position:relative;display:inline-block;width:62px;height:36px}
.switch input{opacity:0;width:0;height:0}
.slider{position:absolute;cursor:pointer;inset:0;background:#bfc7cf;border-radius:36px;transition:all .3s;box-shadow:0 4px 12px rgba(2,6,12,0.25)}
.slider:before{content:'';position:absolute;left:6px;top:6px;width:24px;height:24px;background:white;border-radius:50%;transition:all .3s;box-shadow:0 4px 10px rgba(2,6,12,0.18)}
input:checked + .slider{background:var(--accent)}
input:checked + .slider:before{transform:translateX(26px)}

/* light theme overrides */
body.light .center-card{background:var(--panel-light);border:1px solid #000;box-shadow:0 10px 30px rgba(0,0,0,0.06)}
body.light .tab{background:linear-gradient(180deg, rgba(0,119,204,0.08), rgba(0,119,204,0.02));color:var(--text-light);border:1px solid rgba(0,0,0,0.12);box-shadow:none}
body.light .title{-webkit-text-stroke:1px #000;color:var(--text-light);text-shadow:none}

/* small screens adjustments */
@media (max-width:520px){
  .center-card{padding:22px;border-radius:14px}
  .title{font-size:28px}
  .tab{padding:10px 14px;font-size:15px}
  .wrap{min-height:50vh}
}

/* ripple effect */
.ripple{position:absolute;border-radius:50%;transform:scale(0);animation:ripple .6s ease-out;background:rgba(255,255,255,0.35);pointer-events:none;opacity:.9}
@keyframes ripple{to{transform:scale(4);opacity:0}}

/* frame content styles for popup windows added inside their HTML */