* {
  box-sizing: border-box;
}

:root {
  --xanh-dam: #075985;
  --xanh-sang: #1677a8;
  --chu-dam: #172033;
  --chu-nhe: #667085;
  --vien: #dbe5eb;
}

html,
body {
  min-height: 100%;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--chu-dam);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background:
    linear-gradient(rgba(232, 245, 249, 0.88), rgba(245, 247, 251, 0.95)),
    url("../image/background_KTV - Copy.jpg") center / cover fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

.khung-noi-bo {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 28px 16px;
}

.the-noi-bo {
  width: min(100%, 470px);
  padding: 30px 34px 28px;
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: 26px;
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 24px 65px rgba(25, 66, 87, 0.16);
  backdrop-filter: blur(14px);
  text-align: center;
}

.logo-noi-bo {
  display: grid;
  place-items: center;
  width: 124px;
  height: 70px;
  margin: 0 auto 20px;
  padding: 0;
  border: 1px solid rgba(168, 85, 247, 0.4);
  border-radius: 16px;
  background: #180b2a;
  box-shadow: 0 10px 22px rgba(24, 11, 42, 0.3);
  overflow: hidden;
}

.logo-noi-bo img {
  width: 100%;
  height: 100%;
  border-radius: 15px;
  object-fit: cover;
}

.nhan-noi-bo {
  margin: 0 0 7px;
  color: var(--xanh-sang);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.2em;
}

.the-noi-bo h1 {
  margin: 0;
  font-size: clamp(1.7rem, 4vw, 2.2rem);
}

.mo-ta-noi-bo {
  margin: 10px auto 24px;
  color: var(--chu-nhe);
  font-size: 0.93rem;
}

.bieu-mau-noi-bo {
  display: grid;
  gap: 16px;
  text-align: left;
}

.thong-bao-noi-bo {
  margin: 0;
  padding: 10px 12px;
  border: 1px solid #f0b8b8;
  border-radius: 10px;
  color: #a33a3a;
  background: #fff2f2;
  font-size: 0.84rem;
  line-height: 1.45;
}

.chon-vai-tro {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0;
  border: 0;
}

.chon-vai-tro legend {
  width: 100%;
  margin-bottom: 8px;
  color: #344054;
  font-size: 0.85rem;
  font-weight: 700;
}

.o-vai-tro {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 7px;
  min-height: 44px;
  padding: 0 12px;
  border: 1px solid var(--vien);
  border-radius: 12px;
  color: #344054;
  font-size: 0.88rem;
  cursor: pointer;
}

.o-vai-tro:has(input:checked) {
  border-color: #65b4cc;
  color: var(--xanh-dam);
  background: #eef9fc;
}

.o-vai-tro:has(input[value="admin"]:checked) {
  border-color: #d6b15c;
  color: #795900;
  background: #fff8e6;
  box-shadow: inset 0 0 0 1px rgba(214, 177, 92, 0.18);
}

.o-vai-tro input,
.tuy-chon-noi-bo input {
  accent-color: var(--xanh-dam);
}

.nhom-noi-bo {
  display: grid;
  gap: 7px;
}

.nhom-noi-bo label {
  color: #344054;
  font-size: 0.85rem;
  font-weight: 700;
}

.nhom-noi-bo input {
  width: 100%;
  min-height: 46px;
  padding: 0 14px;
  border: 1px solid var(--vien);
  border-radius: 12px;
  outline: 0;
  color: var(--chu-dam);
  background: #fbfdfe;
  font: inherit;
}

.nhom-noi-bo input:focus {
  border-color: #65b4cc;
  box-shadow: 0 0 0 4px rgba(22, 119, 168, 0.1);
}

.tuy-chon-noi-bo {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  color: var(--chu-nhe);
  font-size: 0.8rem;
}

.tuy-chon-noi-bo a {
  color: var(--xanh-dam);
  font-weight: 700;
}

.nut-dang-nhap-noi-bo {
  min-height: 48px;
  border: 0;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, var(--xanh-sang), var(--xanh-dam));
  box-shadow: 0 12px 22px rgba(7, 89, 133, 0.2);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.nut-dang-nhap-noi-bo:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 26px rgba(7, 89, 133, 0.27);
}

.ve-trang-chu-noi-bo {
  display: inline-block;
  margin-top: 22px;
  color: #7b8794;
  font-size: 0.84rem;
}

.ve-trang-chu-noi-bo:hover,
.tuy-chon-noi-bo a:hover {
  text-decoration: underline;
}

@media (max-width: 480px) {
  .the-noi-bo {
    padding: 25px 20px 24px;
  }

  .chon-vai-tro,
  .tuy-chon-noi-bo {
    align-items: stretch;
    flex-direction: column;
  }
}