:root{
    --bg:#0b0b0d;
    --panel:#0f1720;
    --muted:#9aa6b2;
    --accent:#4f7cff;
    --accent-2:#3db56b;
    --glass:rgba(255,255,255,0.03);
}
/* Base */
html,body{height:100%}
body{font-family:Inter, 'Segoe UI', Tahoma, Arial, sans-serif;margin:0;background:linear-gradient(180deg,var(--bg),#071018);color:#e6eef8;display:flex;flex-direction:column}
.site-header{display:flex;justify-content:space-between;align-items:center;padding:12px 18px;background:linear-gradient(90deg,#071018, #0b131a);backdrop-filter: blur(6px);box-shadow:0 6px 20px rgba(2,6,12,0.6)}
.md-container{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;gap:18px}
.brand{display:flex;align-items:center;gap:12px}
.logo{height:44px;border-radius:8px;box-shadow:0 6px 18px rgba(2,6,12,0.6)}
.title{font-weight:600;font-size:18px}
.title .muted{color:var(--muted);font-weight:500;margin-left:6px}

.md-surface{background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.12));padding:8px;border-radius:12px;display:flex;align-items:center;gap:10px;box-shadow:0 6px 18px rgba(3,8,18,0.55)}
.happyrf-panel{display:flex;align-items:center;gap:10px}

/* Filled text field (M3 inspired) */
.md-textfield{position:relative;border-radius:10px;overflow:hidden}
.md-textfield.md-filled{background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.08));padding:6px 8px}
.md-textfield input{border:0;background:transparent;color:var(--bg);font-size:14px;padding:8px 10px;width:320px;outline:none;color:#eaf4ff}
.md-textfield input::placeholder{color:var(--muted)}
.md-textfield input:focus{box-shadow:0 8px 24px rgba(79,124,255,0.12);}

/* Buttons */
.md-btn{display:inline-flex;align-items:center;gap:8px;border:0;padding:8px 12px;border-radius:10px;font-weight:600;cursor:pointer}
.md-btn .material-icons{font-size:18px}
.md-btn-filled{background:linear-gradient(90deg,var(--accent),#3268d6);color:#fff;box-shadow:0 6px 16px rgba(79,124,255,0.18)}
.md-btn-tonal{background:linear-gradient(90deg,var(--accent-2),#2ea55a);color:#04210a;box-shadow:0 6px 12px rgba(61,181,107,0.12)}

.output{min-width:220px;max-width:420px;padding:8px 12px;background:transparent;border-radius:8px;color:#cfe8ff;font-size:13px;font-family:SFMono-Regular,Menlo,Monaco,monospace}
.output.empty{color:var(--muted)}

/* Canvas full screen */
#canv{display:block;width:100%;height:100vh;position:fixed;left:0;top:0;z-index:0;}

/* Center card (main content) */
.center-card{position:relative;z-index:12;display:flex;justify-content:center;align-items:center;padding:24px}
.center-card .card{width:min(920px,94%);border-radius:14px;padding:18px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.12));box-shadow:0 20px 50px rgba(3,8,18,0.65);backdrop-filter: blur(6px)}
.card-row{display:flex;justify-content:space-between;align-items:center;gap:18px}
.card .label{font-size:12px;color:var(--muted);margin-bottom:6px}
.hrf-large{font-family:Roboto, Inter, sans-serif;font-size:22px;font-weight:700;color:#eaf4ff}
.hrf-info{font-size:13px;color:var(--muted);margin-top:6px}
.controls{display:flex;align-items:center;gap:10px}
#wordCanv{display:none}

/* Responsive */
@media (max-width:900px){
    .happyrf-panel input{width:180px}
}
@media (max-width:640px){
    .site-header{flex-direction:column;align-items:stretch;gap:10px;padding:12px}
    .center-card{padding:12px}
    .card-row{flex-direction:column;align-items:stretch}
    .controls{justify-content:flex-end}
    .output{display:none}
}

/* Utility */
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(1px,1px,1px,1px);white-space:nowrap}