/* Always-dark variables + hard fallbacks */
:root{
  --bg:#0b0f14;
  --panel:#0f141b;
  --muted:#111823;
  --text:#e7eef7;
  --sub:#b4c3d6;
  --brand:#5aa9ff;
  --brand-2:#7af0c0;
  --ring:rgba(122,240,192,.35);
  --card:#0f141b;
}

*{box-sizing:border-box}
html,body{height:100%}
html{-webkit-text-size-adjust:100%}
img{max-width:100%;height:auto;display:block}

body{
  margin:0;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,"Helvetica Neue",Arial;
  color:var(--text);               /* var first */
  background-color:#0b0f14;        /* hard fallback */
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(90,169,255,.10), transparent 60%),
    radial-gradient(1000px 500px at -10% 20%, rgba(122,240,192,.08), transparent 60%),
    var(--bg);
  line-height:1.55;
}

/* NAV */
.nav{
  position:sticky; top:0; z-index:50;
  display:flex; align-items:center; justify-content:space-between;
  gap:12px; padding:12px 14px;
  background:rgba(8,12,18,.85);            /* avoid color-mix; solid fallback */
  border-bottom:1px solid rgba(255,255,255,.08);
  -webkit-backdrop-filter:saturate(1.2) blur(6px);
  backdrop-filter:saturate(1.2) blur(6px);
}
.brand{display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--text)}
.brand-logo{display:inline-grid; place-items:center; width:18px; height:18px; border-radius:4px; background:linear-gradient(135deg,var(--brand),var(--brand-2)); color:#000; font-size:.9rem}
.brand-name{font-weight:800; letter-spacing:.2px}
.nav-links{display:flex; flex-wrap:wrap; gap:10px; align-items:center}
.nav-links a{color:var(--text); text-decoration:none; opacity:.9; padding:8px 10px; border-radius:10px}
.nav-links a:hover{opacity:1; background:rgba(255,255,255,.06)}
.btn.small{padding:8px 12px; font-size:.95rem}

/* HERO */
.hero{position:relative; overflow:hidden; padding:56px 16px 36px}
.hero-wrap{max-width:950px; margin:0 auto; text-align:center}
.hero-title{font-size:clamp(1.8rem, 2.4vw + 1rem, 3rem); line-height:1.12; margin:0}
.accent{background:linear-gradient(135deg,var(--brand),var(--brand-2)); -webkit-background-clip:text; background-clip:text; color:transparent}
.hero-sub{max-width:880px; margin:10px auto 16px; color:var(--sub); font-size:clamp(1rem, .6vw + .9rem, 1.15rem)}
.hero-ctas{display:flex; gap:10px; justify-content:center; margin:16px 0}
.btn{
  appearance:none; border:none; cursor:pointer; text-decoration:none; color:#07101a; font-weight:800;
  background:linear-gradient(135deg,var(--brand),var(--brand-2)); padding:12px 18px; border-radius:12px;
  box-shadow:0 10px 30px var(--ring); font-size:1rem;
}
.btn:hover{transform:translateY(-1px)}
.btn.ghost{
  background:transparent; color:var(--text); border:1px solid rgba(255,255,255,.18)
}
.hero-tags{display:flex; flex-wrap:wrap; gap:8px; justify-content:center; margin-top:8px}
.hero-tags span{
  border:1px solid rgba(255,255,255,.18);
  padding:6px 10px; border-radius:999px; font-size:.9rem; color:var(--sub)
}
.hero-bg{
  position:absolute; inset:-20% -10% auto -10%; height:60%;
  background:
    radial-gradient(600px 300px at 70% 20%, rgba(90,169,255,.18), transparent 60%),
    radial-gradient(800px 400px at 20% 10%, rgba(122,240,192,.14), transparent 60%);
  filter:saturate(120%) blur(20px);
  z-index:-1;
}

/* SECTIONS */
.section{padding:44px 16px}
.section.muted{background:#111823}
.section-head{max-width:900px; margin:0 auto 16px; text-align:center}
.section-head h2{margin:0 0 6px; font-size:clamp(1.5rem, 1.2vw + 1rem, 2.1rem)}
.section-head p{color:var(--sub); margin:0}

/* GRID */
.grid{
  display:grid; gap:12px; width:min(1100px, 94%); margin:14px auto 0;
  grid-template-columns:1fr; /* mobile-first: single column */
}
.grid.small{grid-template-columns:1fr}

/* CARDS */
.card{
  background:var(--card); border:1px solid rgba(255,255,255,.10);
  border-radius:16px; overflow:hidden; display:flex; flex-direction:column;
}

/* THUMB (colored strip with centered logo) */
.thumb{
  position:relative; height:132px; display:grid; place-items:center;
  background:
    repeating-linear-gradient(135deg, rgba(255,255,255,.06) 0 2px, transparent 2px 6px),
    radial-gradient(600px 300px at 80% 10%, rgba(90,169,255,.25), transparent 60%),
    radial-gradient(600px 300px at 10% 90%, rgba(122,240,192,.20), transparent 60%);
}
.thumb::after{content:""; position:absolute; inset:0; background:linear-gradient(to bottom, rgba(0,0,0,.0), rgba(0,0,0,.06)); pointer-events:none;}
.thumb-logo{
  max-width:78%; max-height:60px; width:auto; height:auto;
  filter:drop-shadow(0 1px 1.5px rgba(0,0,0,.35));
}

/* Per-product gradients */
.thumb-music{background:
  linear-gradient(135deg,#1f3b73,#0a64bf),
  radial-gradient(600px 300px at 90% 0%, rgba(255,255,255,.2), transparent 60%)}
.thumb-docs{background:
  linear-gradient(135deg,#0b5d3b,#00bfa6),
  radial-gradient(600px 300px at 10% 100%, rgba(255,255,255,.2), transparent 60%)}
.thumb-quiz{background:
  linear-gradient(135deg,#5a2a9c,#a05bff),
  radial-gradient(600px 300px at 90% 0%, rgba(255,255,255,.2), transparent 60%)}
.thumb-sms{background:
  linear-gradient(135deg,#723a28,#f39b6d),
  radial-gradient(600px 300px at 10% 100%, rgba(255,255,255,.2), transparent 60%)}
.thumb-tutor{background:
  linear-gradient(135deg,#1c3550,#2bd4ff),
  radial-gradient(600px 300px at 90% 0%, rgba(255,255,255,.2), transparent 60%)}

.card-body{padding:16px}
.card h3{margin:0 0 4px; font-size:1.15rem}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace; font-size:.95rem; color:var(--sub)}
.card p{margin:.35rem 0 .6rem; font-size:1rem}
.chips{display:flex; gap:6px; flex-wrap:wrap; margin:.2rem 0 .2rem}
.chips span{font-size:.8rem; color:var(--sub); border:1px dashed rgba(255,255,255,.18); padding:4px 8px; border-radius:999px}
.card-actions{margin-top:.4rem; display:flex; gap:8px}
.btn.small{padding:9px 12px}

/* SERVICES */
.service{
  border:1px solid rgba(255,255,255,.10);
  background:var(--panel); border-radius:14px; padding:14px
}
.service h3{margin:.2rem 0 .4rem; font-size:1.05rem}
.service ul{margin:.2rem 0 0; padding-left:18px; color:var(--sub)}

/* STACK */
.tags{display:flex; flex-wrap:wrap; gap:8px; width:min(900px, 94%); margin:12px auto 0}
.tags span{border:1px solid rgba(255,255,255,.18); padding:6px 10px; border-radius:999px; color:var(--sub); font-size:.95rem}

/* ABOUT */
.about{width:min(900px, 94%); margin:0 auto; color:var(--text); font-size:1rem}

/* CONTACT */
.contact{display:flex; gap:10px; justify-content:center; flex-wrap:wrap}
.contact .btn{min-width:260px; text-align:center}

/* FOOTER */
.footer{padding:26px 16px; text-align:center; color:var(--sub); font-size:.95rem}

/* A11y focus */
:focus-visible{outline:2px solid var(--brand-2); outline-offset:2px; border-radius:10px}

/* ====== Desktop refinements (>= 768px) ====== */
@media (min-width: 768px){
  .nav{padding:14px 18px}
  .nav-links{gap:12px}
  .hero{padding:72px 18px 44px}
  .grid{grid-template-columns:repeat( auto-fit, minmax(260px, 1fr) ); gap:18px}
  .grid.small{grid-template-columns:repeat( auto-fit, minmax(220px, 1fr) )}
  .thumb{height:140px}
  .thumb-logo{max-height:64px}
  .section{padding:56px 18px}
}