/* ============================================================
   DIGITAL BRUTALISM & BENTO GRID DESIGN SYSTEM (Etap 4 & 5)
   ZSE SŁUPSK - PHOTOGRAPHY ARCHIVE SPA
   Palette: Black #000000, White #FFFFFF, Accent Green #0d7328, Dark Gray #111111, Border #333333
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@800;900&family=Space+Mono:ital,wght@0,400;0,700;1,400&display=swap');

:root {
  --bg-black: #000000;
  --text-white: #ffffff;
  --accent-neon: #11a037;
  --border-gray: #333333;
  --meta-gray: #888888;
  --dark-surface: #0a0a0a;
  --card-bg: #050505;
  --font-heading: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'Space Mono', 'Courier New', monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* STRICT BRUTALISM & BENTO SHARP EDGES */
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-black);
  color: var(--text-white);
  font-family: var(--font-mono);
}

body {
  background-color: var(--bg-black);
  color: var(--text-white);
  line-height: 1.5;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-image: radial-gradient(#222 1px, transparent 1px);
  background-size: 20px 20px;
}

/* BENTO UTILITY CLASSES */
.brutalist-bg {
  background-color: var(--bg-black);
  color: var(--text-white);
  min-height: 100vh;
  background-image: radial-gradient(#222 1px, transparent 1px);
  background-size: 20px 20px;
}

.grid-bg {
  background-image: radial-gradient(#222 1px, transparent 1px);
  background-size: 20px 20px;
}

.brutal-border {
  border: 1px solid #333333;
}

.accent-text {
  color: #11a037;
}

.accent-bg {
  background-color: #11a037;
  color: #ffffff;
}

.accent-border {
  border: 1px solid #11a037;
}

.impact-font {
  font-family: 'Inter', sans-serif;
  font-weight: 900;
  letter-spacing: -0.05em;
}

/* SCANLINE OVERLAY EFFECT */
.scanline-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  background: linear-gradient(
    rgba(18, 16, 16, 0) 50%, 
    rgba(0, 0, 0, 0.25) 50%
  ), linear-gradient(
    90deg,
    rgba(255, 0, 0, 0.03),
    rgba(0, 255, 0, 0.01),
    rgba(0, 0, 255, 0.03)
  );
  background-size: 100% 4px, 3px 100%;
  z-index: 9999;
  opacity: 0.6;
}

/* TYPOGRAPHY */
h1, h2, h3, h4, h5, .glitch-title {
  font-family: var(--font-heading);
  text-transform: uppercase;
  letter-spacing: -0.03em;
  color: var(--text-white);
  line-height: 1.05;
}

h1 {
  font-size: clamp(2rem, 5vw, 4.5rem);
}

h2 {
  font-size: clamp(1.4rem, 3.5vw, 2.5rem);
  border-bottom: 2px solid var(--accent-neon);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
}

.mono-meta {
  font-family: var(--font-mono);
  color: var(--meta-gray);
  font-size: 0.825rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.mono-label {
  font-family: var(--font-mono);
  color: var(--accent-neon);
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: bold;
  display: block;
  margin-bottom: 0.4rem;
}

.mono-tag {
  display: inline-block;
  background: #111;
  color: var(--accent-neon);
  border: 1px solid var(--accent-neon);
  padding: 0.2rem 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
}

/* TOP BAR HEADER (<header>) */
.brutalist-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--accent-neon);
  padding: 0.9rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  transition: padding 0.3s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.3s ease, box-shadow 0.3s ease;
}

.brutalist-header.is-scrolled {
  padding: 0.35rem 1.25rem;
  background: rgba(0, 0, 0, 0.98);
  box-shadow: 0 4px 20px rgba(0, 255, 65, 0.2);
  border-bottom: 2px solid var(--accent-neon);
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand-logo {
  background: var(--accent-neon);
  color: #000000;
  font-family: var(--font-heading);
  padding: 0.4rem 0.8rem;
  font-weight: 900;
  font-size: 1.1rem;
  letter-spacing: 0.05em;
  transition: padding 0.3s ease, font-size 0.3s ease;
}

.brutalist-header.is-scrolled .brand-logo {
  padding: 0.25rem 0.6rem;
  font-size: 0.95rem;
}

.brand-title {
  font-size: 1rem;
  margin: 0;
  font-weight: 700;
  transition: font-size 0.3s ease;
}

.brutalist-header.is-scrolled .brand-title {
  font-size: 0.85rem;
}

/* NAV LINKS */
.brutalist-nav ul {
  display: flex;
  list-style: none;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.brutalist-nav a {
  color: var(--text-white);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-transform: uppercase;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--border-gray);
  transition: all 0.3s ease;
  background: #050505;
  display: inline-block;
}

.brutalist-header.is-scrolled .brutalist-nav a {
  padding: 0.2rem 0.5rem;
  font-size: 0.72rem;
  border-color: #333;
}

.brutalist-nav a:hover,
.brutalist-nav a.active-link {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  font-weight: bold;
}

.admin-link-btn {
  border-color: var(--accent-neon) !important;
  color: var(--accent-neon) !important;
}

/* MAIN CONTAINER & SECTIONS */
main.spa-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.spa-section {
  display: none; /* Controlled by JS SPA Hash Router */
  margin-bottom: 4rem;
}

.spa-section.active-section {
  display: block;
  animation: brutalistFade 0.15s ease-in-out;
}

@keyframes brutalistFade {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* HERO SECTION (#hero) */
.hero-box {
  background: #050505;
  border: 2px solid var(--text-white);
  padding: 3rem 2rem;
  position: relative;
  overflow: hidden;
  margin-bottom: 2.5rem;
}

.hero-box::after {
  content: "ZSE_2026";
  position: absolute;
  right: -20px;
  bottom: -30px;
  font-size: 10rem;
  font-family: var(--font-heading);
  color: rgba(255, 255, 255, 0.03);
  pointer-events: none;
  user-select: none;
}

.hero-headline {
  font-size: clamp(2.2rem, 6vw, 5rem);
  margin-top: 1rem;
  margin-bottom: 1.5rem;
  text-shadow: 2px 2px 0px rgba(0, 255, 65, 0.5);
}

.hero-subtext {
  max-width: 800px;
  font-size: 1.05rem;
  color: #cccccc;
  margin-bottom: 2rem;
  line-height: 1.6;
}

/* BUTTONS */
.brutalist-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #000000;
  color: var(--text-white);
  border: 2px solid var(--text-white);
  padding: 0.8rem 1.6rem;
  font-family: var(--font-mono);
  font-weight: bold;
  font-size: 0.9rem;
  text-transform: uppercase;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.05s ease, background 0.05s ease;
}

.brutalist-btn:hover {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  transform: translate(-3px, -3px);
  box-shadow: 4px 4px 0px var(--text-white);
}

.btn-primary {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
}

.btn-primary:hover {
  background: #ffffff;
  color: #000000;
  border-color: #ffffff;
}

.btn-secondary {
  border-color: var(--border-gray);
  color: var(--meta-gray);
}

.btn-danger {
  border-color: #ff3333;
  color: #ff3333;
}

.btn-danger:hover {
  background: #ff3333;
  color: #ffffff;
}

.btn-danger-sm {
  border: 1px solid #ff3333;
  color: #ff3333;
  padding: 0.3rem 0.6rem;
  font-size: 0.75rem;
  background: transparent;
  cursor: pointer;
}

.btn-danger-sm:hover {
  background: #ff3333;
  color: #ffffff;
}

/* FILTERS SECTION (#filters) */
.filter-panel {
  background: #080808;
  border: 1px solid var(--border-gray);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.filter-buttons-wrapper {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.filter-chip {
  background: #111111;
  color: var(--text-white);
  border: 1px solid var(--border-gray);
  padding: 0.5rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.1s ease;
}

.filter-chip:hover,
.filter-chip.active-chip {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  font-weight: bold;
}

/* GALLERY GRID SECTION (#gallery) */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.photo-card {
  background: var(--card-bg);
  border: 1px solid var(--border-gray);
  overflow: hidden;
  position: relative;
  transition: border-color 0.15s ease, transform 0.15s ease;
  display: flex;
  flex-direction: column;
}

.photo-card:hover {
  border-color: var(--accent-neon);
  transform: translateY(-4px);
}

.photo-image-frame {
  aspect-ratio: 4/3;
  width: 100%;
  overflow: hidden;
  position: relative;
  background: #111;
}

.photo-image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(20%) contrast(110%);
  transition: filter 0.2s ease, transform 0.2s ease;
}

.photo-card:hover .photo-image-frame img {
  filter: grayscale(0%) contrast(115%);
  transform: scale(1.03);
}

.photo-badge {
  position: absolute;
  top: 10px;
  left: 10px;
  background: rgba(0, 0, 0, 0.85);
  border: 1px solid var(--accent-neon);
  color: var(--accent-neon);
  padding: 0.2rem 0.5rem;
  font-size: 0.7rem;
  font-family: var(--font-mono);
}

.photo-details {
  padding: 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  flex: 1;
}

.photo-title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  margin: 0;
  color: var(--text-white);
}

.photo-description {
  font-size: 0.85rem;
  color: #aaaaaa;
  line-height: 1.4;
}

.photo-meta-grid {
  margin-top: auto;
  padding-top: 0.8rem;
  border-top: 1px dashed var(--border-gray);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
  font-size: 0.75rem;
  color: var(--meta-gray);
}

/* POSTS SECTION (#posts) */
.posts-feed {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 1.5rem;
}

.post-card {
  background: #080808;
  border: 1px solid var(--border-gray);
  border-top: 2px solid var(--accent-neon);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.3s ease;
  cursor: pointer;
}

.post-card:hover {
  transform: translateY(-6px);
  border-color: var(--accent-neon);
  box-shadow: 0 10px 25px rgba(0, 255, 65, 0.18);
}

.post-card-img-wrapper {
  width: 100%;
  height: 190px;
  background: #000;
  border: 1px solid #333;
  overflow: hidden;
  position: relative;
}

.post-card-img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.post-card:hover .post-card-img-wrapper img {
  transform: scale(1.10);
}

.post-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
}

.post-title {
  font-size: 1.1rem;
  color: var(--text-white);
}

.post-content {
  font-size: 0.85rem;
  line-height: 1.5;
  color: #dddddd;
}

/* INFO SECTION (#info) */
.info-block {
  background: #050505;
  border: 1px solid var(--border-gray);
  padding: 2rem;
}

.meta-spec-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1.5rem;
  font-size: 0.85rem;
}

.meta-spec-table td {
  padding: 0.8rem 1rem;
  border: 1px solid var(--border-gray);
}

.meta-spec-table tr:nth-child(even) {
  background: #090909;
}

.meta-spec-key {
  color: var(--accent-neon);
  font-weight: bold;
  width: 30%;
}

/* CONTACT SECTION (#contact) */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

@media (max-width: 850px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.brutalist-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.form-group {
  display: flex;
  flex-direction: column;
}

.brutalist-form input,
.brutalist-form textarea,
.brutalist-form select {
  background: #000000;
  color: var(--text-white);
  border: 1px solid var(--border-gray);
  padding: 0.8rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.15s ease;
}

.brutalist-form input:focus,
.brutalist-form textarea:focus,
.brutalist-form select:focus {
  border-color: var(--accent-neon);
  background: #050505;
}

/* SOCIALS SECTION (#socials) */
.socials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.2rem;
}

.social-card {
  background: #080808;
  border: 1px solid var(--border-gray);
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text-white);
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all 0.1s ease;
}

.social-card:hover {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  transform: translate(-3px, -3px);
  box-shadow: 4px 4px 0px #ffffff;
}

.social-card:hover .mono-meta {
  color: #000000;
}

.social-icon {
  font-size: 1.8rem;
  font-family: var(--font-heading);
}

/* FOOTER */
.brutalist-footer {
  border-top: 2px solid var(--border-gray);
  background: #000000;
  padding: 2.5rem 1.5rem;
  margin-top: 4rem;
}

.footer-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--meta-gray);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.1s ease;
}

.footer-links a:hover {
  color: var(--accent-neon);
}

/* ALERTS & MODALS */
.brutalist-alert {
  padding: 1rem;
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  border: 1px solid;
}

.alert-success {
  background: rgba(0, 255, 65, 0.1);
  border-color: var(--accent-neon);
  color: var(--accent-neon);
}

.alert-error {
  background: rgba(255, 51, 51, 0.1);
  border-color: #ff3333;
  color: #ff3333;
}

/* ADMIN PANEL STYLES */
.admin-layout {
  display: flex;
  min-height: 100vh;
}

.admin-sidebar {
  width: 280px;
  background: #050505;
  border-right: 2px solid var(--accent-neon);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.admin-main {
  flex: 1;
  padding: 2rem;
  background: #000000;
  overflow-y: auto;
}

.admin-nav {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.admin-nav a {
  color: var(--text-white);
  text-decoration: none;
  padding: 0.8rem 1rem;
  border: 1px solid var(--border-gray);
  font-size: 0.85rem;
  font-family: var(--font-mono);
  background: #0a0a0a;
}

.admin-nav a:hover,
.admin-nav a.active {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  font-weight: bold;
}

.admin-nav a.nav-logout {
  margin-top: auto;
  border-color: #ff3333;
  color: #ff3333;
}

.admin-nav a.nav-logout:hover {
  background: #ff3333;
  color: #ffffff;
}

.admin-section {
  background: #080808;
  border: 1px solid var(--border-gray);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.grid-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.grid-form .full-width {
  grid-column: 1 / -1;
}

.inline-form {
  display: flex;
  align-items: flex-end;
  gap: 1rem;
}

.admin-table-wrapper {
  overflow-x: auto;
}

.brutalist-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  font-size: 0.85rem;
}

.brutalist-table th,
.brutalist-table td {
  padding: 0.8rem 1rem;
  border: 1px solid var(--border-gray);
  text-align: left;
}

.brutalist-table th {
  background: #111111;
  color: var(--accent-neon);
  font-family: var(--font-heading);
}

.thumb-frame {
  width: 60px;
  height: 60px;
  overflow: hidden;
  border: 1px solid var(--border-gray);
}

.thumb-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* AUTH & LOGIN PAGE STYLES */
.login-container {
  min-height: 100vh;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1.5rem;
  box-sizing: border-box;
}

.auth-card {
  width: 100%;
  max-width: 520px;
  background: #08080a;
  border: 2px solid var(--accent-neon);
  box-shadow: 10px 10px 0px rgba(0, 255, 65, 0.4), 0 0 50px rgba(0, 255, 65, 0.15);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin: auto;
}

.auth-card .card-header {
  border-bottom: 1px solid #27272a;
  padding-bottom: 1.25rem;
}

.auth-card .card-header h1,
.auth-card .glitch-title {
  font-size: 1.9rem;
  margin: 0.6rem 0 0.4rem 0;
  letter-spacing: -0.02em;
  color: #ffffff;
}

.auth-card .form-group {
  margin-bottom: 1.25rem;
}

.auth-card .form-group input {
  width: 100%;
  box-sizing: border-box;
}

.auth-card .form-actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.auth-card .form-actions button,
.auth-card .form-actions a {
  width: 100%;
  justify-content: center;
  text-align: center;
  box-sizing: border-box;
}

.auth-card .card-footer {
  border-top: 1px solid #222222;
  padding-top: 1rem;
  text-align: center;
  font-size: 0.75rem;
  color: #71717a;
}

/* OFF-CANVAS MOBILE DRAWER */
.mobile-menu-btn {
  display: none;
  background: #000000;
  border: 2px solid var(--accent-neon);
  color: var(--accent-neon);
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 0.85rem;
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  box-shadow: 2px 2px 0px var(--accent-neon);
  transition: all 0.2s ease;
  text-transform: uppercase;
  align-items: center;
  gap: 0.4rem;
}

.mobile-menu-btn:hover,
.mobile-menu-btn:active {
  background: var(--accent-neon);
  color: #000000;
}

.offcanvas-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(6px);
  z-index: 10000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.offcanvas-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.offcanvas-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 85vw;
  max-width: 320px;
  background: #070709;
  border-left: 2px solid var(--accent-neon);
  box-shadow: -10px 0 40px rgba(0, 255, 65, 0.25);
  z-index: 10001;
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.5rem;
  box-sizing: border-box;
  overflow-y: auto;
}

.offcanvas-drawer.is-open {
  transform: translateX(0);
}

.offcanvas-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #222222;
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.offcanvas-close-btn {
  background: #000000;
  border: 1px solid var(--border-gray);
  color: var(--accent-neon);
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: bold;
  padding: 0.3rem 0.6rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.offcanvas-close-btn:hover {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
}

.offcanvas-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.offcanvas-link {
  display: block;
  padding: 0.8rem 1rem;
  background: #0c0c0e;
  border: 1px solid #222222;
  color: var(--text-white);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: 700;
  transition: all 0.2s ease;
}

.offcanvas-link:hover,
.offcanvas-link.active-link {
  background: var(--accent-neon);
  color: #000000;
  border-color: var(--accent-neon);
  box-shadow: 3px 3px 0px #ffffff;
}

.offcanvas-admin-btn {
  border-color: #ffffff;
  margin-top: 1rem;
  color: var(--accent-neon);
}

.offcanvas-footer {
  border-top: 1px solid #222222;
  padding-top: 1rem;
  margin-top: 1.5rem;
}

/* RESPONSIVE DESIGN */
@media (max-width: 900px) {
  .admin-layout {
    flex-direction: column;
  }
  .admin-sidebar {
    width: 100%;
    border-right: none;
    border-bottom: 2px solid var(--accent-neon);
  }
  .grid-form {
    grid-template-columns: 1fr;
  }
  .brutalist-nav.desktop-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: inline-flex;
  }
}

@media (max-width: 600px) {
  .gallery-grid {
    grid-template-columns: 1fr; /* Single column on mobile per spec */
  }
}