:root{
  --bg: radial-gradient(circle at 30% 30%, #09121b, #0b0f14 80%);
  --glass-bg: rgba(255,255,255,0.06);
  --glass-border: rgba(255,255,255,0.12);
  --glass-glow: rgba(255,255,255,0.15);
  --text: #e5ecf4;
  --muted: #9fb2c9;
  --ok: #4de1a1;
  --warn: #f7c85f;
  --err: #ff7070;
  --link: #a5c9ff;
  --blur-strength: 16px;
}
*{box-sizing:border-box}
html,body{height:100%}
[hidden]{display:none!important;}

body{
  margin:0;
  background:var(--bg);
  background-attachment: fixed;
  color:var(--text);
  font-family:"Segoe UI","Helvetica Neue",Arial,sans-serif;
  line-height:1.6;
  overflow-x:hidden;
}


.site-header,.topbar{
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  padding:16px 20px;position:sticky;top:0;z-index:100;
  background:var(--glass-bg);
  backdrop-filter:blur(var(--blur-strength)) saturate(180%);
  border-bottom:1px solid var(--glass-border);
  box-shadow:0 0 24px rgba(0,0,0,0.4);
}
.site-header h1,.topbar h1{margin:0;font-size:18px;letter-spacing:.5px;text-shadow:0 0 6px rgba(255,255,255,0.15)}
.btn-link{
  color:var(--link);text-decoration:none;border:1px solid var(--glass-border);
  padding:8px 14px;border-radius:12px;background:rgba(255,255,255,0.05);
  backdrop-filter:blur(var(--blur-strength));transition:.25s;
}
.btn-link:hover{background:rgba(255,255,255,0.12);box-shadow:0 0 12px rgba(173,216,255,0.25);transform:translateY(-1px)}


.container{max-width:1000px;margin:40px auto;padding:0 16px;display:grid;gap:24px}
.card{
  position:relative;border-radius:20px;border:1px solid var(--glass-border);
  background:var(--glass-bg);backdrop-filter:blur(var(--blur-strength)) saturate(160%);
  box-shadow:0 0 32px rgba(0,0,0,.45), inset 0 0 20px var(--glass-glow);
  padding:20px 24px;overflow:hidden;
}
.card h2,.card h3{margin-top:0}


.key-row,.input-row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.key-row input,.input-row input{
  flex:1 1 220px;padding:12px 14px;border-radius:14px;
  border:1px solid rgba(255,255,255,0.15);background:rgba(255,255,255,0.07);
  color:var(--text);outline:none;transition:.25s;
}
.key-row input:focus,.input-row input:focus{
  border-color:var(--link);box-shadow:0 0 8px rgba(173,216,255,0.28);
}
.key-row button,.input-row button,button,input[type="submit"]{
  padding:12px 16px;border-radius:12px;border:1px solid var(--glass-border);
  background:linear-gradient(180deg, rgba(100,150,255,0.20), rgba(60,90,160,0.18));
  color:var(--link);cursor:pointer;transition:.25s;
}
.key-row #redeemBtn{
  background:linear-gradient(180deg, rgba(80,140,255,0.30), rgba(40,90,200,0.26));
  color:#fff;border-color:rgba(255,255,255,0.18);
}
.key-row #redeemBtn:hover{filter:brightness(1.06)}
.btn-secondary{background:rgba(255,255,255,0.08);border:1px solid var(--glass-border);color:var(--link)}
.btn-secondary:hover{background:rgba(255,255,255,0.15)}

.msg{margin-top:10px;font-size:13px;color:var(--muted)}
.msg.ok{color:var(--ok)} .msg.warn{color:var(--warn)} .msg.error{color:var(--err)}


.content-host{
  min-height:60vh;border:1px solid rgba(255,255,255,0.1);border-radius:20px;
  background:rgba(255,255,255,0.04);backdrop-filter:blur(var(--blur-strength)) saturate(160%);
  display:flex;align-items:center;justify-content:center;overflow:hidden;
  box-shadow:inset 0 0 20px rgba(255,255,255,0.1);
}
.placeholder{color:var(--muted);text-align:center}


.tutorials-layout{
  display:grid;grid-template-columns:280px 1fr;gap:20px;
  height:calc(100vh - 80px); 
  padding:0 16px 16px;
}
.sidebar{
  position:sticky;top:80px;height:calc(100vh - 96px);
  background:var(--glass-bg);border:1px solid var(--glass-border);border-radius:16px;
  padding:16px;backdrop-filter:blur(var(--blur-strength));overflow:hidden; 
}
.sidebar h3{margin:4px 0 10px;color:var(--link);font-size:14px}
.sidebar a{
  display:block;padding:10px 12px;border-radius:10px;text-decoration:none;color:var(--link);
  transition:.2s;border:1px solid transparent;
}
.sidebar a:hover{background:rgba(255,255,255,0.08)}
.sidebar a.active{
  background:rgba(100,150,255,0.12);border-color:rgba(100,150,255,0.25);
  box-shadow:0 0 12px rgba(173,216,255,0.25);
}
.content-pane,.tutorial-content{
  background:var(--glass-bg);border:1px solid var(--glass-border);border-radius:16px;
  padding:24px;backdrop-filter:blur(var(--blur-strength)) saturate(160%);
  overflow:auto;box-shadow:0 0 28px rgba(0,0,0,0.4);
}


.drawer-search{
  display:flex;align-items:center;gap:8px;
  margin:10px 0 12px;padding:10px 12px;
  border:1px solid var(--glass-border);border-radius:12px;
  background:rgba(255,255,255,0.06);backdrop-filter:blur(8px);
  box-shadow: inset 0 0 12px rgba(0,0,0,.25);
}
.drawer-search input[type="search"]{
  flex:1 1 auto;min-width:0;height:36px;padding:0 10px;
  border:1px solid rgba(255,255,255,0.18);border-radius:10px;
  background:rgba(255,255,255,0.08);color:var(--text);
  outline:none;transition:.2s ease;
  box-shadow: inset 0 1px 3px rgba(0,0,0,.25);
}
.drawer-search input[type="search"]::placeholder{color:#b9c6d6;opacity:.85}
.drawer-search input[type="search"]:focus{
  border-color:rgba(165,201,255,0.55);
  box-shadow:0 0 0 3px rgba(165,201,255,.18), inset 0 1px 3px rgba(0,0,0,.25);
}


.modal-backdrop{
  position:fixed;inset:0;background:rgba(0,0,0,.45);backdrop-filter:blur(2px);z-index:400;
}
.modal,.modal-glass{
  position:fixed;left:50%;top:50%;transform:translate(-50%,-50%);z-index:401;
  width:min(780px,92vw);max-height:80vh;display:flex;flex-direction:column;
  border-radius:18px;border:1px solid var(--glass-border);background:var(--glass-bg);
  backdrop-filter:blur(var(--blur-strength)) saturate(160%);
  box-shadow:0 20px 60px rgba(0,0,0,.5), inset 0 0 20px var(--glass-glow);
}
.modal-header{
  display:flex;align-items:center;gap:12px;padding:14px 16px;
  border-bottom:1px solid var(--glass-border);
  background:linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.04));
}
.modal-header h3{margin:0;font-size:16px;color:var(--link)}
.modal-close{
  margin-left:auto;appearance:none;border:1px solid var(--glass-border);
  background:rgba(255,255,255,0.06);color:var(--link);border-radius:10px;
  padding:6px 10px;font-size:14px;line-height:1;box-shadow:0 4px 16px rgba(0,0,0,.25);cursor:pointer;
}
.modal-close:active{transform:scale(.98)}
.modal-body{padding:16px;overflow:auto;color:var(--text)}
.modal-footer{
  display:flex;justify-content:flex-end;gap:10px;border-top:1px solid var(--glass-border);
  padding:12px 16px;background:linear-gradient(0deg, rgba(255,255,255,0.08), rgba(255,255,255,0.04));
}
.btn-primary,.btn-secondary{border-radius:12px;padding:10px 14px;border:1px solid var(--glass-border);cursor:pointer}
.btn-primary{background:linear-gradient(180deg, rgba(100,150,255,0.28), rgba(60,90,160,0.22));color:var(--link)}
.btn-primary:hover{background:rgba(100,150,255,0.42)}
.btn-secondary{background:rgba(255,255,255,0.06);color:var(--link)}
.btn-secondary:hover{background:rgba(255,255,255,0.12)}


.table{width:100%;border-collapse:collapse;font-size:13px;background:rgba(255,255,255,0.03);backdrop-filter:blur(8px);border-radius:10px;overflow:hidden}
.table th,.table td{padding:10px 12px;border-bottom:1px solid rgba(255,255,255,0.08)}
.table th{background:rgba(255,255,255,0.08);color:var(--link)}
.table tr:hover{background:rgba(255,255,255,0.06)}


.toc-toggle{display:none}

.drawer-close{display:none !important}

.drawer-mask{
  position:fixed;inset:0;z-index:140;background:rgba(0,0,0,.35);
  backdrop-filter:blur(2px);opacity:0;pointer-events:none;transition:opacity .2s ease;
}
.drawer-mask.show{opacity:1;pointer-events:auto}

@media (max-width:768px){
  .site-header,.topbar{flex-wrap:wrap;gap:8px;padding:12px 14px}


  .tutorials-layout{grid-template-columns:1fr;gap:12px;height:auto;padding-bottom:70px}

  .toc-toggle{
    display:inline-flex;position:fixed;right:14px;bottom:16px;z-index:120;
    padding:10px 14px;border-radius:999px;border:1px solid var(--glass-border);
    background:rgba(255,255,255,0.08);color:var(--link);
    backdrop-filter:blur(var(--blur-strength));box-shadow:0 6px 24px rgba(0,0,0,.35);
  }
  .toc-toggle:active{transform:scale(.98)}

  .sidebar{
    position:fixed;left:0;right:0;top:0;height:70vh;margin:0;z-index:150;padding:12px;
    border-radius:0 0 16px 16px;overflow-y:auto;overflow-x:hidden;
    transform:translateY(-110%);transition:transform .28s ease;
    scrollbar-width:thin;
  }
  .sidebar.drawer.open{transform:translateY(0)}

  .drawer-header{
    position:sticky;top:0;display:flex;align-items:center;gap:10px;
    padding:12px 8px;margin:-12px -12px 10px;
    background:linear-gradient(180deg, rgba(255,255,255,.08), rgba(255,255,255,.04));
    border-bottom:1px solid var(--glass-border);backdrop-filter:blur(var(--blur-strength));z-index:2;
  }
  .drawer-title{font-size:15px;font-weight:600;color:var(--link);margin-right:auto}
  .drawer-close{
    display:inline-flex !important;justify-content:center;align-items:center;
    appearance:none;border:1px solid var(--glass-border);
    background:linear-gradient(180deg, rgba(255,255,255,0.10), rgba(255,255,255,0.06));
    color:var(--text);border-radius:12px;padding:10px 14px;font-size:14px;line-height:1;
    box-shadow:0 6px 20px rgba(0,0,0,.25), inset 0 0 10px rgba(255,255,255,.05);cursor:pointer;transition:.2s ease;
  }
  .drawer-close:hover{background:rgba(255,255,255,0.16);border-color:rgba(255,255,255,0.25)}
  .drawer-close:active{transform:translateY(1px)}


  .toc-list{display:grid;gap:8px}
  .toc-item{
    display:flex;align-items:center;gap:10px;padding:12px 14px;border-radius:14px;
    border:1px solid rgba(255,255,255,.12);background:rgba(18,27,43,.6);
    text-decoration:none;color:var(--link);position:relative;overflow:hidden;
  }
  .toc-item::after{
    content:"";position:absolute;inset:0;background:radial-gradient(60% 120% at 10% 0%, rgba(173,216,255,0.12), transparent 40%);
    opacity:0;transition:opacity .25s ease;pointer-events:none;
  }
  .toc-item:hover::after{opacity:.8}
  .toc-item .dot{width:8px;height:8px;border-radius:50%;background:rgba(165,201,255,0.85);box-shadow:0 0 8px rgba(165,201,255,0.6);flex:0 0 auto}
  .toc-item .title{font-size:14px;line-height:1.3;color:var(--text)}
  .toc-item.active{
    border-color:rgba(100,150,255,.35);
    background:linear-gradient(180deg, rgba(100,150,255,.16), rgba(100,150,255,.08));
    box-shadow:0 6px 20px rgba(0,0,0,.25), inset 0 0 10px rgba(100,150,255,.12);
  }
}


@media (max-width:600px){
  .modal,.modal-glass{width:94vw;max-height:86vh}
}

@media (max-width: 768px) {
  #keyInput {
    width: 100%;
    height: 40px !important;
    padding: 0 12px;
    line-height: 40px;
    font-size: 16px;
    box-sizing: border-box;
    border-radius: 8px;
    resize: none;
  }

@media (max-width: 768px) {
  .input-row input#keyInput {
    width: 100% !important;
    height: 40px !important;
    margin: 0 auto;
    display: block;
    border-radius: 14px;
    font-size: 16px;
    line-height: 40px;
    padding: 0 12px;
  }
}


  #redeemBtn,
  #howToUseBtn {
    width: 100%;
  }
}




.tutorial-bottom{
  max-width:1000px;
  margin:24px auto 40px;
  padding:0; 
}
.tutorial-bottom .tb-header{
  display:flex;align-items:center;gap:10px;
  padding:14px 16px;border-bottom:1px solid var(--glass-border);
  background:linear-gradient(180deg, rgba(255,255,255,0.08), rgba(255,255,255,0.04));
}
.tutorial-bottom .tb-header h3{
  margin:0;font-size:16px;color:var(--link)
}
.tutorial-bottom .tb-body{
  padding:16px;overflow:auto;color:var(--text);
}