:root {
  --purple: #7e57c2;          /* Purple moderate */
  --purple-hover: #5e3d99;    /* Darker purple */
  --green: #43a047;           /* Green medium */
  --green-hover: #2e7d32;     /* Darker green */
  --dark-bg: #121d12;         /* Dark greenish background */
  --dark-header: #214421;     /* Dark green header */
  --light-bg: #f9f5ff;        /* Very light purple background */
  --light-header: #eee7ff;    /* Light purple header */
  --dark-text: #d9f0d9;       /* Light greenish text */
  --light-text: #4b3b67;      /* Dark purple text */
  --border-radius: 12px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: var(--dark-bg);
  color: var(--dark-text);
  transition: background 0.3s, color 0.3s;
  min-height: 100vh;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--dark-header);
  padding: 2rem 4vw 1.5rem 4vw;
  user-select: none;
}

header h1 {
  margin: 0;
  font-size: 2.5rem;
  font-weight: bold;
  letter-spacing: 1px;
  color: var(--dark-text);
}

button {
  cursor: pointer;
  padding: 0.62rem 1.6rem;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  font-size: 1rem;
  background-color: var(--green);
  color: white;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  transition: background 0.22s;
  user-select: none;
}

button:hover,
.filter-btn.active {
  background-color: var(--green-hover);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 4vw 3rem 4vw;
}

#controls {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

#category-filters {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.filter-btn {
  background-color: #344d33;
  color: var(--dark-text);
  padding: 0.45rem 1.2rem;
  border-radius: var(--border-radius);
  user-select: none;
  font-weight: 600;
  font-size: 0.9rem;
}

.gallery {
  margin-top: 2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.gallery-item {
  background-color: #203420;
  border-radius: var(--border-radius);
  box-shadow: 0 3px 20px rgba(0, 0, 0, 0.25);
  overflow: hidden;
  position: relative;
  user-select: none;
  cursor: grab;
  transition: box-shadow 0.3s, transform 0.2s;
}

.gallery-item:active {
  cursor: grabbing;
}

.gallery-item.dragging {
  opacity: 0.7;
  transform: scale(1.05);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6);
}

.gallery-item img {
  width: 100%;
  height: 190px;
  object-fit: cover;
  display: block;
  transition: filter 0.3s;
}

/* Caption container */
.caption {
  padding: 0.9rem 1rem;
  color: var(--dark-text);
  font-weight: 600;
  font-size: 1rem;
  background: linear-gradient(180deg, transparent, rgba(20, 60, 20, 0.9));
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
}

.remove-btn {
  position: absolute;
  right: 12px;
  top: 12px;
  background: #52965e;  /* green tone */
  border: none;
  color: white;
  border-radius: 50%;
  width: 28px;
  height: 28px;
  font-size: 1.4rem;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  user-select: none;
  transition: background 0.25s;
  z-index: 4;
}

.remove-btn:hover {
  background: #34692b;
}

/* Lightbox */
#lightbox {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  justify-content: center;
  align-items: center;
  z-index: 9999;
  user-select: none;
}

#lightbox.active {
  display: flex;
}

#lightbox img {
  max-width: 90vw;
  max-height: 85vh;
  border-radius: var(--border-radius);
  box-shadow: 0 0 40px 6px #000c;
}

#close-lightbox {
  position: absolute;
  top: 26px;
  right: 30px;
  background: #34692b;
  border: none;
  color: white;
  font-size: 2.5rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  cursor: pointer;
  user-select: none;
  z-index: 10;
  transition: background 0.25s;
}

#close-lightbox:hover {
  background: #214a18;
}

/* Light mode styles */
body.light-mode {
  background: var(--light-bg);
  color: var(--light-text);
}

body.light-mode header {
  background: var(--light-header);
}

body.light-mode h1 {
  color: var(--light-text);
}

body.light-mode button,
body.light-mode .filter-btn.active {
  background-color: var(--purple);
}

body.light-mode button:hover,
body.light-mode .filter-btn.active:hover {
  background-color: var(--purple-hover);
}

body.light-mode #category-filters .filter-btn {
  background-color: #b4a6e9;
  color: var(--light-text);
}

body.light-mode #category-filters .filter-btn.active {
  background-color: var(--purple);
  color: #fff;
}

body.light-mode .gallery-item {
  background-color: #f5f0ff;
  box-shadow: 0 3px 18px rgba(0, 0, 0, 0.12);
  color: var(--light-text);
}

body.light-mode .caption {
  color: var(--light-text);
  background: linear-gradient(180deg, transparent, #d7ccff);
}

body.light-mode .remove-btn {
  background: var(--purple);
}

body.light-mode .remove-btn:hover {
  background: var(--purple-hover);
}

/* Responsive */
@media (max-width: 600px) {
  .gallery {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
  }

  .gallery-item img {
    height: 140px;
  }

  header h1 {
    font-size: 1.8rem;
  }

  #controls {
    flex-direction: column;
    gap: 1rem;
  }
}