/* reset */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0; font-family:"Poppins",system-ui,-apple-system,Segoe UI,Roboto,Arial;
  color:#232323; background: linear-gradient(180deg,#f8fafc,#fff);
  -webkit-font-smoothing:antialiased;
}

/* tokens */
:root{
  --ink:#111827;            /* đen chữ tiêu đề */
  --muted:#6b7280;
  --card:#ffffff;
  --bd:#e5e7eb;
  --radius:14px;
  --brand:#ffb74d;          /* vàng nắng */
  --brand-2:#ffe082;
  --note:#fff7db;           /* nền lưu ý */
  --note-bd:#ffe2a3;
  --shadow:0 10px 30px rgba(0,0,0,.06);
}

/* layout */
.nk-container{ width:min(980px,92%); margin-inline:auto }
.nk-header{
  position:relative; padding:38px 0 18px; background:linear-gradient(180deg,#fff6e9,#fff);
  border-bottom:1px solid #fff2d1;
}
.nk-title{
  margin:0; font-weight:800; color:var(--ink);
  font-size: clamp(28px, 6vw, 44px); letter-spacing:.3px;
}
.nk-sub{ margin:8px 0 14px; color:var(--muted) }

/* ảnh minh hoạ nhỏ */
.nk-ill{
  position:absolute; right:6%; bottom:-24px;
  width:min(180px,26vw); height:auto; border-radius:14px;
  box-shadow: var(--shadow);
  border:1px solid #fff; background:#fff; object-fit:cover;
}

/* main */
.nk-main{ padding:32px 0 40px }

/* note */
.nk-note{
  display:flex; gap:10px; align-items:flex-start;
  background:var(--note); border:1px solid var(--note-bd);
  padding:12px 14px; border-radius:12px; box-shadow: var(--shadow);
  margin: 10px 0 18px;
}
.nk-note__icon{ font-size:20px; line-height:1.2 }
.nk-note__body{ color:#4b5563 }
.nk-note--soft{ background:#f4fbff; border-color:#cfe8ff }

/* list */
.nk-list{ display:grid; gap:14px; margin-top:10px }
.nk-card{
  background:var(--card);
  border:1px solid var(--bd);
  border-radius:var(--radius);
  box-shadow: var(--shadow);
  overflow:hidden;
}
.nk-card__head{
  width:100%; border:0; background:#fff; cursor:pointer;
  display:grid; grid-template-columns:56px 1fr 32px; align-items:center; gap:10px;
  padding:14px 14px; text-align:left;
}
.nk-card__head:hover{ background:#fffdf5 }
.nk-card__num{
  width:38px; height:38px; display:grid; place-items:center;
  background:linear-gradient(135deg,var(--brand-2),var(--brand));
  color:#6b3a00; font-weight:800; border-radius:10px; border:1px solid #ffd180;
}
.nk-card__title{ margin:0; font-size:18px; color:#111827; font-weight:800 }
.nk-card__chev{ font-size:18px; color:#475569; transform: translateY(1px); transition:.2s }

.nk-card__body{ display:none; padding:0 16px 14px 68px; color:#374151 }
.nk-card.open .nk-card__body{ display:block }
.nk-card.open .nk-card__chev{ transform: rotate(180deg) }

/* actions */
.nk-actions{ margin-top:18px }
.nk-btn{
  display:inline-block; padding:10px 14px; border-radius:12px;
  border:1px solid #ffe2a3; background:linear-gradient(135deg,#fff,#fffaf0);
  color:#1f2937; text-decoration:none; font-weight:700; box-shadow: var(--shadow)
}

/* responsive */
@media (max-width: 680px){.nk-ill{ position:static; display:block; margin:8px 0 0; width:160px }
  .nk-card__body{ padding:0 14px 14px 14px }
}