/* ===========================================
   BASE & RESET – PHOTHESENSE
   Dùng chung cho mọi trang
=========================================== */

/* Box sizing reset + margin/padding reset */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Brand tokens dùng chung */
:root {
  --ph-primary:        #FBDC47;
  --ph-navy:           #1C4278;
  --ph-bg-soft:        #FFFCEE;
  --ph-text-light:     #FFFCEE;
}

/* HTML & BODY – default cho toàn site */
html,
body {
  font-family: 'Poppins', 'Roboto', sans-serif;
  color: var(--ph-navy);
  background-color: var(--ph-bg-soft);
  line-height: 1.5;
  scroll-behavior: smooth;
}

/* Links & Text Defaults */
a {
  text-decoration: none;
  transition: all 0.3s ease;
  color: inherit;
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Container Utility (chung, vẫn có thể dùng container của Bootstrap song song) */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}


/* ============================
   SCROLL TO TOP BUTTON
   ============================ */
.scroll-to-top {
  position: fixed;
  bottom: 22px;
  right: 22px;
  width: 40px;
  height: 40px;

  border-radius: 50%;
  border: none;
  outline: none;

  background: #1C4278;       /* Navy brand */
  color: #FFFCEE;            /* Cream text */
  font-size: 16px;

  display: flex;
  align-items: center;
  justify-content: center;

  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.25s ease;

  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
  z-index: 99999999;
}

.scroll-to-top:hover {
  background: #FBDC47;        /* Yellow brand */
  color: #1C4278;
}

/* Khi hiện */
.scroll-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* Mobile tweak */
@media (max-width: 576px) {
  .scroll-to-top {
    bottom: 18px;
    right: 16px;
    width: 36px;
    height: 36px;
  }
}