* {
  box-sizing: border-box;
}

:root {
  --xanh-dam: #7c3aed;
  --xanh-sang: #a855f7;
  --chu-dam: #172033;
  --chu-nhe: #667085;
  --vien: #e9d5ff;
}

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(236, 247, 250, 0.84), rgba(245, 247, 251, 0.94)),
    url("../image/background_KTV - Copy.jpg") center / cover fixed;
}

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

.khung-xac-thuc {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 32px 18px;
}

.the-xac-thuc {
  width: min(100%, 470px);
  padding: 30px 34px 28px;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 26px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 24px 65px rgba(25, 66, 87, 0.16);
  backdrop-filter: blur(14px);
}

.logo-xac-thuc {
  display: grid;
  place-items: center;
  width: 126px;
  height: 72px;
  margin: 0 auto 20px;
  padding: 0;
  border: 1px solid rgba(168, 85, 247, 0.4);
  border-radius: 18px;
  background: #180b2a;
  box-shadow: 0 10px 24px rgba(24, 11, 42, 0.3);
  overflow: hidden;
}

.logo-xac-thuc img {
  width: 100%;
  height: 100%;
  border-radius: 17px;
  object-fit: cover;
}

.noi-dung-xac-thuc {
  text-align: center;
}

.nhan-xac-thuc {
  margin: 0 0 8px;
  color: var(--xanh-sang);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.2em;
}

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

.mo-ta-xac-thuc {
  margin: 10px auto 25px;
  color: var(--chu-nhe);
  font-size: 0.93rem;
  line-height: 1.6;
}

.bieu-mau-xac-thuc {
  display: grid;
  gap: 16px;
  text-align: left;
}
.bieu-mau-xac-thuc[hidden] {
  display: none;
}

.thong-bao-xac-thuc:empty {
  display: none;
}
.thong-bao-xac-thuc {
  margin: 0;
  color: #b42318;
  font-size: 0.88rem;
  line-height: 1.5;
}
.thong-bao-xac-thuc[data-loai="thanh-cong"] {
  color: #067647;
}
.nut-xac-thuc:disabled {
  opacity: 0.7;
  cursor: wait;
}

.nut-quay-lai-dang-nhap {
  border: 0;
  color: var(--xanh-dam);
  background: transparent;
  font: inherit;
  font-size: 0.86rem;
  font-weight: 700;
  cursor: pointer;
}

.nut-quay-lai-dang-nhap:hover {
  text-decoration: underline;
}

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

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

.nhom-truong 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;
  font-size: 16px;
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.nhom-truong input:focus {
  border-color: #a855f7;
  box-shadow: 0 0 0 4px rgba(168, 85, 247, 0.15);
}

.tuy-chon-form {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.ghi-nho {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--chu-nhe);
  font-size: 0.8rem;
}

.ghi-nho input {
  accent-color: var(--xanh-dam);
}

.tuy-chon-form a,
.doi-form a {
  color: var(--xanh-dam);
  font-weight: 700;
}

.nut-xac-thuc {
  min-height: 48px;
  border: 0;
  border-radius: 999px;
  color: #fff;
  background: linear-gradient(135deg, #a855f7, #7c3aed);
  box-shadow: 0 12px 22px rgba(124, 58, 237, 0.28);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.nut-xac-thuc:hover {
  background: linear-gradient(135deg, #9333ea, #6d28d9);
  box-shadow: 0 14px 26px rgba(124, 58, 237, 0.4);
  transform: translateY(-2px);
}


.doi-form {
  margin: 22px 0 12px;
  color: var(--chu-nhe);
  font-size: 0.88rem;
}

.ve-trang-chu {
  color: #7b8794;
  font-size: 0.84rem;
}

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

.dieu-khoan {
  margin-top: -2px;
}

@media (max-width: 480px) {
  .khung-xac-thuc {
    padding: 18px 12px;
  }

  .the-xac-thuc {
    padding: 25px 20px 24px;
    border-radius: 22px;
  }

  .tuy-chon-form {
    align-items: flex-start;
    flex-direction: column;
  }
}