/* ============================================================
   PNDx.ai — Theme dùng chung cho các trang (Landing/Pricing/
   Library/Explore). Trang tạo nhạc (index.html) tự chứa style
   riêng; file này giữ ĐỒNG BỘ thương hiệu cho các trang còn lại.
   ============================================================ */
:root{
  --bg-0:#070b14;--bg-1:#0b1220;--panel:rgba(18,28,48,.72);--panel-solid:#121c30;
  --stroke:rgba(120,160,210,.14);--stroke-strong:rgba(120,170,220,.28);
  --teal:#0fb8c4;--teal-2:#075b7a;--violet:#7c5cff;--magenta:#ff5cab;
  --accent-grad:linear-gradient(120deg,#0fb8c4 0%,#7c5cff 55%,#ff5cab 110%);
  --text:#eaf1fb;--muted:#8ea2c0;--muted-2:#5d6f8f;--good:#27d796;
  --radius:18px;--shadow:0 18px 50px -18px rgba(0,0,0,.7);
  --font:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  --font-display:'Sora','Inter',sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--text);min-height:100vh;-webkit-font-smoothing:antialiased;line-height:1.5;
  background:
    radial-gradient(1100px 600px at 12% -8%,rgba(124,92,255,.16),transparent 60%),
    radial-gradient(900px 600px at 100% 0%,rgba(15,184,196,.14),transparent 55%),
    radial-gradient(800px 700px at 80% 110%,rgba(255,92,171,.10),transparent 60%),
    var(--bg-0);}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}
.container{max-width:1280px;margin:0 auto;padding:0 22px}
::selection{background:rgba(124,92,255,.4)}

/* ---- header ---- */
header.topbar{position:sticky;top:0;z-index:50;backdrop-filter:blur(14px);
  background:linear-gradient(180deg,rgba(7,11,20,.86),rgba(7,11,20,.55));border-bottom:1px solid var(--stroke);}
.topbar-inner{display:flex;align-items:center;gap:22px;height:68px}
.brand{display:flex;align-items:center;gap:11px;font-family:var(--font-display);font-weight:800;font-size:19px;letter-spacing:-.02em}
.brand .logo{width:38px;height:38px;border-radius:11px;background:var(--accent-grad);display:grid;place-items:center;color:#fff;box-shadow:0 8px 22px -6px rgba(124,92,255,.6)}
.brand .logo svg{width:21px;height:21px}
.brand b{background:var(--accent-grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.brand .sub{font-family:var(--font);font-weight:600;font-size:11px;color:var(--muted);letter-spacing:.14em;text-transform:uppercase;margin-top:1px}
nav.mainnav{display:flex;gap:6px;margin-left:8px}
nav.mainnav a{padding:8px 14px;border-radius:10px;color:var(--muted);font-weight:600;font-size:14px;transition:.18s}
nav.mainnav a:hover{color:var(--text);background:rgba(255,255,255,.05)}
nav.mainnav a.active{color:var(--text);background:rgba(15,184,196,.12)}
.spacer{flex:1}
.credit-chip{display:flex;align-items:center;gap:9px;padding:7px 14px 7px 11px;border-radius:999px;background:rgba(15,184,196,.10);border:1px solid var(--stroke-strong);font-weight:700;font-size:14px}
.credit-chip .dot{width:9px;height:9px;border-radius:50%;background:var(--teal);box-shadow:0 0 12px var(--teal)}
.credit-chip small{color:var(--muted);font-weight:600;font-size:11px;text-transform:uppercase;letter-spacing:.08em}
.lang-toggle{display:flex;border:1px solid var(--stroke-strong);border-radius:999px;overflow:hidden;background:rgba(255,255,255,.03)}
.lang-toggle button{padding:7px 12px;font-weight:700;font-size:13px;color:var(--muted)}
.lang-toggle button.on{background:var(--accent-grad);color:#fff}
.btn-login{padding:9px 17px;border-radius:11px;font-weight:700;font-size:14px;background:rgba(255,255,255,.06);border:1px solid var(--stroke-strong);transition:.18s;display:inline-flex;align-items:center}
.btn-login:hover{background:rgba(255,255,255,.12)}

/* ---- buttons ---- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;padding:13px 22px;border-radius:13px;font-family:var(--font-display);font-weight:700;font-size:15px;transition:.2s}
.btn svg{width:18px;height:18px}
.btn-primary{color:#fff;background:var(--accent-grad);background-size:160% 160%;box-shadow:0 16px 40px -14px rgba(124,92,255,.6)}
.btn-primary:hover{transform:translateY(-1px);background-position:100% 0}
.btn-ghost{background:rgba(255,255,255,.06);border:1px solid var(--stroke-strong);color:var(--text)}
.btn-ghost:hover{background:rgba(255,255,255,.12)}

/* ---- generic section / cards ---- */
.section{padding:60px 0}
.section-head{text-align:center;max-width:680px;margin:0 auto 40px}
.section-head .eyebrow{font-size:13px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--teal)}
.section-head h2{font-family:var(--font-display);font-size:clamp(24px,3.4vw,34px);font-weight:800;letter-spacing:-.02em;margin:10px 0}
.section-head p{color:var(--muted);font-size:16px}
.panel{background:var(--panel);border:1px solid var(--stroke);border-radius:var(--radius);box-shadow:var(--shadow);backdrop-filter:blur(8px)}
.grid{display:grid;gap:20px}
.cols-3{grid-template-columns:repeat(3,1fr)}
.cols-4{grid-template-columns:repeat(4,1fr)}
.cols-2{grid-template-columns:repeat(2,1fr)}

/* ---- footer ---- */
footer{border-top:1px solid var(--stroke);padding:30px 0;margin-top:40px}
.foot{display:flex;align-items:center;gap:14px;color:var(--muted);font-size:13px;flex-wrap:wrap}
.foot a{color:var(--muted);transition:.15s}.foot a:hover{color:var(--text)}

/* ---- toast ---- */
.toast{position:fixed;bottom:26px;left:50%;transform:translateX(-50%) translateY(20px);background:var(--panel-solid);border:1px solid var(--stroke-strong);padding:12px 20px;border-radius:12px;font-weight:600;font-size:14px;box-shadow:var(--shadow);opacity:0;pointer-events:none;transition:.25s;z-index:100}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}

@media(max-width:900px){.cols-3,.cols-4{grid-template-columns:1fr 1fr}nav.mainnav{display:none}}
@media(max-width:560px){.cols-2,.cols-3,.cols-4{grid-template-columns:1fr}.credit-chip small,.brand .sub{display:none}}