/* ═══════════════════════════════════════════
   Day 09 — Masonry Gallery
   ═══════════════════════════════════════════ */

/* ── Custom Properties ────────────────────── */
:root {
  color-scheme: dark;

  /* Backgrounds */
  --bg-deep:       #0a0a0f;
  --bg-surface:    #12121a;
  --bg-elevated:   #1a1a26;

  /* Glass */
  --glass:         rgba(18, 18, 26, 0.72);
  --glass-border:  rgba(255, 255, 255, 0.08);
  --glass-glow:    rgba(139, 92, 246, 0.08);

  /* Text */
  --text-primary:   #f0eef6;
  --text-secondary: rgba(255, 255, 255, 0.55);
  --text-muted:     rgba(255, 255, 255, 0.3);

  /* Accent */
  --accent:       #8b5cf6;
  --accent-soft:  rgba(139, 92, 246, 0.15);
  --accent-glow:  rgba(139, 92, 246, 0.4);

  /* Heart */
  --heart:      #f43f5e;
  --heart-glow: rgba(244, 63, 94, 0.4);

  /* Skeleton */
  --skeleton-base:  rgba(255, 255, 255, 0.04);
  --skeleton-shine: rgba(255, 255, 255, 0.08);

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;

  /* Shadows */
  --shadow-card:  0 2px 12px rgba(0, 0, 0, 0.4), 0 0 1px rgba(255, 255, 255, 0.05);
  --shadow-hover: 0 8px 32px rgba(0, 0, 0, 0.6), 0 0 1px rgba(255, 255, 255, 0.08);
}

/* ── Reset ────────────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

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

img {
  display: block;
  max-width: 100%;
}

/* ── Sticky Header ────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 clamp(1rem, 3vw, 2rem);
  background: var(--glass);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--glass-border);
  transition: box-shadow 0.3s ease;
}

.site-header.scrolled {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}

.header-left {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.eyebrow {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

.header-title {
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
  cursor: pointer;
}

.header-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.image-counter {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.header-right {
  display: flex;
  align-items: center;
}

/* ── Column Toggle ────────────────────────── */
.col-toggle {
  display: flex;
  gap: 4px;
  padding: 3px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
}

.col-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 28px;
  border-radius: 6px;
  color: var(--text-muted);
  transition: color 0.2s, background 0.2s;
}

.col-btn:hover {
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.06);
}

.col-btn.active {
  color: var(--accent);
  background: var(--accent-soft);
}

/* ── Gallery Main ─────────────────────────── */
.gallery-main {
  padding: 16px clamp(1rem, 3vw, 2rem) 4rem;
}

/* ── Masonry Grid ─────────────────────────── */
.masonry {
  columns: 4;
  column-gap: 16px;
  transition: opacity 0.25s ease;
}

/* ── Scroll Sentinel ──────────────────────── */
.scroll-sentinel {
  height: 1px;
}

/* ── Loader ───────────────────────────────── */
.loader {
  display: none;
  padding: 2rem 0;
  text-align: center;
}

.loader.active {
  display: block;
}

/* ── Card ─────────────────────────────────── */
.card {
  --stagger: 0ms;
  break-inside: avoid;
  margin-bottom: 16px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg-surface);
  box-shadow: var(--shadow-card);
  cursor: pointer;
  position: relative;

  /* Entry animation — start hidden */
  opacity: 0;
  transform: translateY(28px) scale(0.96);
}

.card.in-view {
  opacity: 1;
  transform: translateY(0) scale(1);
  transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1) var(--stagger),
              transform 0.6s cubic-bezier(0.22, 1, 0.36, 1) var(--stagger),
              box-shadow 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.card.in-view:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: var(--shadow-hover);
}

/* ── Card Image Wrapper ───────────────────── */
.card-image-wrap {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-md);
}

.card-image-wrap img {
  display: block;
  width: 100%;
  height: auto;
  transition: transform 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.card:hover .card-image-wrap img {
  transform: scale(1.04);
}

/* ── Skeleton Placeholder ─────────────────── */
.skeleton {
  position: absolute;
  inset: 0;
  background: var(--skeleton-base);
  border-radius: var(--radius-md);
  overflow: hidden;
  z-index: 2;
  transition: opacity 0.4s ease;
}

.skeleton::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    var(--skeleton-shine) 50%,
    transparent 100%
  );
  animation: shimmer 1.5s ease-in-out infinite;
  transform: translateX(-100%);
}

@keyframes shimmer {
  to { transform: translateX(100%); }
}

.card.loaded .skeleton {
  opacity: 0;
  pointer-events: none;
}

/* ── Card Overlay (hover) ─────────────────── */
.card-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 12px;
  background: linear-gradient(
    to top,
    rgba(0, 0, 0, 0.72) 0%,
    rgba(0, 0, 0, 0.18) 45%,
    transparent 100%
  );
  opacity: 0;
  z-index: 3;
  transition: opacity 0.3s ease;
  border-radius: var(--radius-md);
}

.card:hover .card-overlay {
  opacity: 1;
}

.card-overlay-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-dim {
  font-size: 0.72rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.7);
  letter-spacing: 0.03em;
}

.card-actions {
  display: flex;
  gap: 6px;
}

/* ── Action Buttons ───────────────────────── */
.action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: rgba(255, 255, 255, 0.85);
  transition: background 0.2s, transform 0.2s, color 0.2s;
}

.action-btn:hover {
  background: rgba(255, 255, 255, 0.22);
  transform: scale(1.1);
}

.action-btn svg {
  width: 16px;
  height: 16px;
}

/* ── Heart Animation ──────────────────────── */
@keyframes heart-pop {
  0%   { transform: scale(1); }
  25%  { transform: scale(1.35); }
  50%  { transform: scale(0.92); }
  100% { transform: scale(1); }
}

.heart-btn.liked {
  background: rgba(244, 63, 94, 0.2);
}

.heart-btn.liked svg {
  fill: var(--heart);
  stroke: var(--heart);
  animation: heart-pop 0.45s cubic-bezier(0.22, 1, 0.36, 1);
  filter: drop-shadow(0 0 8px var(--heart-glow));
}

/* ── Loader Skeletons ─────────────────────── */
.loader-skeleton {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.loader-bone {
  width: 100%;
  max-width: 200px;
  height: 180px;
  border-radius: var(--radius-md);
  background: var(--skeleton-base);
  position: relative;
  overflow: hidden;
}

.loader-bone::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    var(--skeleton-shine) 50%,
    transparent 100%
  );
  animation: shimmer 1.5s ease-in-out infinite;
  transform: translateX(-100%);
}

/* ═══════════════════════════════════════════
   Lightbox
   ═══════════════════════════════════════════ */

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.35s ease, visibility 0.35s ease;
}

.lightbox.open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.lightbox-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.88);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}

.lightbox-content {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  padding: 3rem;
}

.lightbox-image-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
  max-height: 100%;
}

.lightbox-img {
  max-width: 88vw;
  max-height: 82vh;
  object-fit: contain;
  border-radius: var(--radius-lg);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.55), 0 0 1px rgba(255, 255, 255, 0.08);
  transform: scale(0.92);
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1),
              opacity 0.4s ease;
}

.lightbox.open .lightbox-img {
  transform: scale(1);
  opacity: 1;
}

/* Close button */
.lightbox-close {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--text-primary);
  transition: background 0.2s, transform 0.2s;
}

.lightbox-close:hover {
  background: rgba(255, 255, 255, 0.16);
  transform: scale(1.08);
}

/* Nav arrows */
.lightbox-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--text-primary);
  flex-shrink: 0;
  transition: background 0.2s, transform 0.2s;
}

.lightbox-nav:hover {
  background: rgba(255, 255, 255, 0.14);
  transform: scale(1.08);
}

.lightbox-prev { margin-right: 1rem; }
.lightbox-next { margin-left: 1rem; }

/* Footer info */
.lightbox-footer {
  position: absolute;
  bottom: 1.2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0.5rem 1.2rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.lightbox-author {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.lightbox-counter {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

/* ═══════════════════════════════════════════
   Responsive
   ═══════════════════════════════════════════ */

/* Tablet — 3 columns */
@media (max-width: 1199px) {
  .masonry { columns: 3; }
}

/* Small tablet — 2 columns */
@media (max-width: 767px) {
  .masonry { columns: 2; column-gap: 12px; }

  .gallery-main { padding: 12px clamp(0.75rem, 2vw, 1rem) 3rem; }

  .card { margin-bottom: 12px; }

  .header-center { display: none; }
  .col-toggle { display: none; }

  .site-header { height: 52px; }
  .eyebrow { font-size: 0.58rem; }

  /* Lightbox adjustments */
  .lightbox-content { padding: 1rem; }
  .lightbox-img { max-width: 96vw; max-height: 80vh; }
  .lightbox-nav { width: 36px; height: 36px; }
  .lightbox-prev { margin-right: 0.4rem; }
  .lightbox-next { margin-left: 0.4rem; }
  .lightbox-footer { padding: 0.4rem 1rem; gap: 1rem; }
}

/* Small phone — 1 column */
@media (max-width: 479px) {
  .masonry { columns: 1; }

  .lightbox-nav { width: 30px; height: 30px; }
  .lightbox-nav svg { width: 20px; height: 20px; }
}