@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&display=swap');
:root {
    --gold: #d4af37;
    --light: #f9f9f9;
    --input-bg: rgba(255, 255, 255, 0.12);
    --transition: all 0.35s ease;
}

/* BODY + NỀN */
html, body {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    background: radial-gradient(circle at 50% 50%, #2b2b2b, #141414 90%);
    min-height: 100vh;
    overflow-x: hidden;
}

/* HIỆU ỨNG NỀN */
.bg-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;      /* thay vì 130% */
    height: 100%;     /* thay vì 130% */
    background: radial-gradient(circle at 60% 40%, rgba(212, 175, 55, 0.15), transparent 70%);
    filter: blur(100px);
    animation: movingLight 8s ease-in-out infinite alternate;
    z-index: -2;
    overflow: hidden;
}
@keyframes movingLight {
  from { transform: translate(0, 0); }
  to { transform: translate(5%, -5%); }
}

/* FORM */
.form-container {
    width: 500px;
    margin: 80px auto;
    background: rgba(0, 0, 0, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 24px;
    padding: 2.5rem 2.8rem;
    box-shadow: 0 10px 35px rgba(0, 0, 0, 0.7), inset 0 0 25px rgba(212, 175, 55, 0.15);
    text-align: center;
    color: var(--light);
    position: relative;
    z-index: 5;
}

/* LOGO */
.brand-logo {
    font-size: 3rem;
    text-shadow: 0 0 25px rgba(212, 175, 55, 0.6);
    animation: float 3s ease-in-out infinite, fadeInLogo 1.2s ease forwards;
}
@keyframes float {
    0%,100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}
@keyframes fadeInLogo {
    from { opacity: 0; transform: scale(0.8); }
    to { opacity: 1; transform: scale(1); }
}

/* TIÊU ĐỀ */
.shine-text {
    font-size: 2.2rem;
    background: linear-gradient(90deg, #fff, #d4af37, #fff);
    -webkit-background-clip: text;
    color: transparent;
    background-size: 200%;
    animation: shine 4s linear infinite;
}
@keyframes shine {
  from { background-position: 0%; }
  to { background-position: 200%; }
}

/* INPUT */
.input-group input {
  width: 100%;
  height: 50px;
  padding: 12px 18px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: var(--input-bg);
  color: #fff;
  font-size: 15px;
  transition: var(--transition);
  box-sizing: border-box;
  margin-bottom: 1rem;
}
.input-group input:focus {
  border-color: var(--gold);
  box-shadow: 0 0 10px rgba(212, 175, 55, 0.4);
}

/* CAPTCHA */
.captcha-container {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  margin-bottom: 1rem;
}
.captcha-box {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 50px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: var(--input-bg);
  padding: 0 15px;
}
.captcha-box span {
  font-family: 'Courier New', monospace;
  color: #ffe97a;
  font-size: 19px;
  letter-spacing: 4px;
  font-weight: bold;
  text-shadow: 0 0 10px rgba(255, 220, 100, 0.7);
}
.refresh-btn {
  background: var(--gold);
  border: none;
  padding: 5px 8px;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
}
.refresh-btn:hover {
  background: #fff;
  transform: scale(1.1);
}


/* Ô NHẬP MÃ CAPTCHA */
.captcha-container input[type="text"] {
  height: 55px;
  border-radius: 12px;
  border: 1px solid var(--gold);
  background: rgba(255, 255, 255, 0.1);
  color: #fffbe8;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 2px;
  text-align: center;
  box-shadow: 0 0 15px rgba(212, 175, 55, 0.4);
  transition: all 0.3s ease;
  box-sizing: border-box;
}

.captcha-container input[type="text"]:focus {
  box-shadow: 0 0 25px rgba(255, 220, 100, 0.8);
  background: rgba(255, 255, 255, 0.15);
}

/* NÚT */
.register-btn {
  width: 100%;
  height: 50px;
  background: var(--gold);
  color: #111;
  font-weight: 600;
  border: none;
  border-radius: 12px;
  font-size: 1.05rem;
  margin-top: 5px;
  transition: var(--transition);
}
.register-btn:hover {
  background: #fff;
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(212, 175, 55, 0.35);
}

/* LINK */
.form-links { margin-top: 1.3rem; }
.button-style-link {
  display: block;
  border: 2px solid var(--gold);
  color: var(--gold);
  border-radius: 12px;
  padding: 12px 0;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}
.button-style-link:hover {
  background: var(--gold);
  color: #111;
  transform: translateY(-3px);
}

/* ẢNH PHỤ */
.circle-img {
  position: fixed;
  width: 200px; height: 200px;
  border-radius: 50%;
  object-fit: cover;
  opacity: 0.9;
  border: 2px solid rgba(212, 175, 55, 0.5);
  box-shadow: 0 0 35px rgba(212, 175, 55, 0.5);
  filter: brightness(1.05);
  animation: floatCircle 8s ease-in-out infinite alternate;
  z-index: 0;
}
@keyframes floatCircle {
  0% { transform: translateY(0) scale(1); }
  100% { transform: translateY(-10px) scale(1.05); }
}
#img1 { top: 22%; left: 11%; animation-delay: 0s; }
#img2 { bottom: 18%; left: 12%; animation-delay: 1.5s; }
#img3 { top: 22%; right: 11%; animation-delay: 3s; }
#img4 { bottom: 18%; right: 12%; animation-delay: 4.5s; }

/* HIỆU ỨNG CHUYỂN CẢNH */
body {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
body.loaded {
  opacity: 1;
  transform: translateY(0);
}
body.fade-out {
  opacity: 0;
  transform: translateY(-20px);
}

/* FORM TRƯỢT LÊN */
.form-container {
  opacity: 0;
  transform: translateY(50px);
  transition: all 0.9s ease;
}
body.loaded .form-container {
  opacity: 1;
  transform: translateY(0);
}

/* RESPONSIVE */
@media (max-width: 900px) {
  .circle-img { display: none; }
  .form-container { width: 90%; }
}
/* ===== HIỆU ỨNG CHUYỂN CẢNH ===== */
body {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

body.loaded {
  opacity: 1;
  transform: translateY(0);
}

body.fade-out {
  opacity: 0;
  transform: translateY(-40px);
}

.form-container {
  opacity: 0;
  transform: translateY(60px);
  transition: opacity 1s ease, transform 1s ease;
}

body.loaded .form-container {
  opacity: 1;
  transform: translateY(0);
}