:root { 
  --bg: #2c3541;
  --card: #3a4452;
  --text: #f3f3f3;
  --muted: #9ca3af;
  --accent: #5b9cf5;
  --bad: #ef5350;
  --btn-bg: #4a5568;
  --disabled: #6b7280;
}

* { 
  box-sizing: border-box; 
  margin: 0;
  padding: 0;
}

html, body { 
  height: 100%; 
  margin: 0; 
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Inter', Ubuntu, Arial, sans-serif;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* Header */
.header { 
  display: flex; 
  justify-content: space-between; 
  align-items: center; 
  padding: 16px 24px;
  gap: 16px; 
  position: relative; 
  z-index: 100; 
  border-bottom: 1px solid rgba(255,255,255,.05);
}

.logo { 
  font-size: 28px; 
  font-weight: 700; 
  color: var(--text); 
  letter-spacing: -0.5px; 
}

.header-menu {
  display: flex;
  gap: 12px;
  align-items: center;
}

/* Settings Panel */
.settings-panel {
  position: relative;
  background: var(--card);
  border-bottom: 1px solid rgba(255,255,255,.05);
  padding: 20px 24px;
  z-index: 99;
  box-shadow: 0 4px 16px rgba(0,0,0,.2);
  max-height: 450px;
  opacity: 1;
  transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.3s ease,
              padding 0.4s ease;
  overflow-y: auto;
  overflow-x: hidden;
  scroll-behavior: smooth;
}

.settings-panel::-webkit-scrollbar {
  width: 6px;
}

.settings-panel::-webkit-scrollbar-track {
  background: rgba(0,0,0,.2);
  border-radius: 3px;
}

.settings-panel::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 3px;
}

.settings-panel::-webkit-scrollbar-thumb:hover {
  background: #7ab5ff;
}

.settings-panel.hidden {
  max-height: 0;
  opacity: 0;
  padding: 0 24px;
}

.settings-content {
  max-width: 600px;
  margin: 0 auto;
}

.settings-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.slider-container {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 8px;
}

.radius-slider {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: linear-gradient(to right, 
    rgba(91,156,245,0.2) 0%, 
    var(--accent) 100%);
  outline: none;
  -webkit-appearance: none;
  cursor: pointer;
}

.radius-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(91,156,245,0.4);
  transition: all 0.2s ease;
}

.radius-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 3px 12px rgba(91,156,245,0.6);
}

.radius-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 8px rgba(91,156,245,0.4);
  transition: all 0.2s ease;
}

.radius-slider::-moz-range-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 3px 12px rgba(91,156,245,0.6);
}

.slider-value {
  display: flex;
  align-items: baseline;
  gap: 4px;
  min-width: 70px;
  padding: 8px 16px;
  background: rgba(91,156,245,0.15);
  border-radius: 20px;
  border: 1px solid rgba(91,156,245,0.3);
}

.slider-value span:first-child {
  font-size: 18px;
  font-weight: 600;
  color: var(--accent);
}

.slider-unit {
  font-size: 13px;
  color: var(--muted);
  font-weight: 500;
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--muted);
  padding: 0 4px;
}

.settings-divider {
  height: 1px;
  background: rgba(255,255,255,.1);
  margin: 20px 0;
}

.slider-label {
  font-size: 14px;
  color: var(--text);
  font-weight: 500;
  min-width: 90px;
}

/* Main Container */
.main-container {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 16px 20px 20px;
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  position: relative; /* so our loading overlays can absolutely position inside */
}

/* ===== ghost loading / empty blocks ===== */
.loading-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;

  /* visually it's up at the top of main-container */
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;

  /* but: kill layout impact */
  pointer-events: none;
  height: 0;
  overflow: visible;
  z-index: 10;
  /* no margin, no padding: it will not push anything down */
}

.loading-overlay.hidden {
  /* script can toggle this, fine */
  opacity: 0;
  visibility: hidden;
}

.loading-box {
  /* purely cosmetic if you ever want to debug;
     you can style this if you want a spinner overlay */
  background: rgba(0,0,0,0); 
  color: var(--muted);
  font-size: 14px;
  line-height: 1.4;
  text-align: center;
  padding: 0;
  margin-top: 0;
}

.loading-title {
  font-weight: 600;
  color: var(--text);
}

.loading-sub {
  color: var(--muted);
  font-size: 13px;
}

/* Section Title */
.section-title {
  font-size: 20px;
  margin-top: 0;
  margin-bottom: 16px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}

.effects-count {
  font-size: 16px;
  color: var(--accent);
  font-weight: 500;
}

/* Carousel */
.carousel-section {
  margin-bottom: 40px;
}

.carousel-section.hidden {
  display: none;
}

.carousel-container {
  position: relative;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: visible;
  background: transparent;
  border-radius: 16px;
}

.carousel-track {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 100%;
  height: 100%;
}

.carousel-item {
  position: absolute;
  transition: all 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  cursor: pointer;
  overflow: visible;
}

.carousel-item img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
  pointer-events: none;
}

.carousel-nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: var(--btn-bg);
  border: none;
  color: var(--text);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 20px;
  transition: all 0.3s ease;
  z-index: 10;
  box-shadow: 0 4px 12px rgba(0,0,0,.3);
}

.carousel-nav:hover {
  background: #5a6578;
  transform: translateY(-50%) scale(1.08);
}

.carousel-nav.left {
  left: 20px;
}

.carousel-nav.right {
  right: 20px;
}

/* Effects Grid */
.effects-section {
  margin-bottom: 40px;
}

.effects-section.hidden {
  display: none;
}

.effects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 16px;
  padding: 20px;
  background: var(--card);
  border-radius: 16px;
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
  max-height: 450px;
  overflow-y: auto;
}

.effects-grid::-webkit-scrollbar {
  width: 8px;
}

.effects-grid::-webkit-scrollbar-track {
  background: rgba(0,0,0,.2);
  border-radius: 4px;
}

.effects-grid::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 4px;
}

.effect-item {
  position: relative;
  cursor: pointer;
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s ease;
  border: 3px solid transparent;
  background: rgba(0,0,0,.2);
}

.effect-item:hover {
  transform: translateY(-4px);
  border-color: rgba(91,156,245,0.5);
}

.effect-item.selected {
  border-color: var(--accent);
  box-shadow: 0 0 16px rgba(91,156,245,0.5);
}

.effect-item img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  display: block;
}

.effect-name {
  padding: 10px;
  text-align: center;
  font-size: 13px;
  background: rgba(0, 0, 0, 0.6);
  color: var(--text);
  font-weight: 500;
}

.selected-badge {
  position: absolute;
  top: 8px;
  right: 8px;
  background: var(--accent);
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 16px;
  box-shadow: 0 2px 8px rgba(0,0,0,.3);
}

/* Upload Section */
.upload-section {
  background: var(--card);
  border: 2px dashed rgba(91,156,245,0.4);
  border-radius: 16px;
  padding: 40px 30px;
  text-align: center;
  margin-bottom: 32px;
  transition: all 0.3s ease;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
}

.upload-section.hidden {
  display: none;
}

.upload-section:hover {
  border-color: var(--accent);
  background: #3f4a5a;
  transform: translateY(-2px);
}

.upload-section.dragging {
  border-color: var(--accent);
  background: #3f4a5a;
  border-width: 3px;
  transform: scale(1.01);
}

.upload-icon {
  font-size: 56px;
  margin-bottom: 16px;
  opacity: 0.8;
}

.upload-section h3 {
  font-size: 20px;
  margin-bottom: 8px;
  color: var(--text);
}

.upload-section p {
  color: var(--muted);
  margin-bottom: 16px;
  font-size: 15px;
}

input[type="file"] {
  display: none;
}

/* Uploaded Files */
.uploaded-files-section {
  margin-bottom: 32px;
  transition: opacity .3s ease;
}

.uploaded-files-section.hidden {
  display: none;
}

.uploaded-files {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
  gap: 16px;
  padding: 20px;
  background: var(--card);
  border-radius: 16px;
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
}

.uploaded-file {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: rgba(0,0,0,.2);
  padding: 12px;
  text-align: center;
  transition: transform .2s ease;
}

.uploaded-file:hover {
  transform: translateY(-2px);
}

.file-name {
  font-size: 11px;
  color: var(--muted);
  word-break: break-all;
  line-height: 1.3;
}

.warning-badge {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 28px;
  height: 28px;
  background: rgba(255, 193, 7, 0.95);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0,0,0,.3);
  transition: all 0.2s ease;
  z-index: 10;
}

.warning-badge:hover {
  transform: scale(1.1);
  background: rgba(255, 193, 7, 1);
}

/* Progress Section */
.progress-section {
  background: var(--card);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 32px;
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
  transition: opacity .3s ease;
}

.progress-section.hidden {
  display: none;
}

.progress-bar-container {
  width: 100%;
  height: 44px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 22px;
  overflow: hidden;
  margin-bottom: 12px;
  position: relative;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent) 0%, #4a8fd9 100%);
  border-radius: 22px;
  transition: width 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 15px;
}

.progress-status {
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

/* Buttons */
.menu-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--btn-bg);
  border: none;
  border-radius: 25px;
  color: var(--text);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0,0,0,.3);
  text-decoration: none;
}

.menu-btn:hover {
  background: #5a6578;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0,0,0,.4);
}

.menu-btn svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.link-btn {
  color: var(--text);
}

/* Floating Action Buttons */
.action-buttons {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 50;
}

.action-btn {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: var(--accent);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 4px 16px rgba(91,156,245,.4);
  transition: all 0.3s ease;
}

.action-btn:hover:not([disabled]) {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(91,156,245,.6);
}

.action-btn:active:not([disabled]) {
  transform: scale(0.95);
}

.action-btn.secondary {
  background: var(--btn-bg);
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
}

.action-btn.secondary:hover:not([disabled]) {
  background: #5a6578;
}

.action-btn[disabled] {
  opacity: 0.4;
  cursor: not-allowed;
}

.action-btn svg {
  width: 22px;
  height: 22px;
  stroke-width: 2;
}

/* Status Toast */
.status-toast {
  position: fixed;
  bottom: 110px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 14px 28px;
  border-radius: 25px;
  font-size: 14px;
  font-weight: 500;
  box-shadow: 0 4px 16px rgba(0,0,0,.4);
  transition: transform 0.3s ease, opacity 0.3s ease;
  opacity: 0;
  z-index: 1000;
  pointer-events: none;
  max-width: 90%;
  text-align: center;
  line-height: 1.4;
}

.status-toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.status-toast.success {
  background: #66bb6a;
  color: white;
}

.status-toast.error {
  background: var(--bad);
  color: white;
}

.status-toast.info {
  background: var(--accent);
  color: white;
}

/* How To Overlay */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 1;
  transition: opacity 0.3s ease;
  padding: 20px;
}

.overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.overlay-content {
  background: var(--card);
  border-radius: 20px;
  padding: 32px;
  max-width: 700px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
  position: relative;
}

.overlay-content h2 {
  font-size: 28px;
  margin-bottom: 24px;
  color: var(--text);
  font-weight: 700;
}

.overlay-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 36px;
  cursor: pointer;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: all 0.3s ease;
  line-height: 1;
  padding: 0;
}

.overlay-close:hover {
  background: rgba(255,255,255,0.1);
  transform: rotate(90deg);
}

.instructions {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.instruction-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.step-number {
  width: 36px;
  height: 36px;
  background: var(--accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 16px;
  margin-bottom: 6px;
  color: var(--text);
  font-weight: 600;
}

.step-content p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

/* Footer */
.footer {
  padding: 16px 24px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  border-top: 1px solid rgba(255,255,255,.05);
  background: rgba(0,0,0,.2);
}

.footer p {
  margin: 4px 0;
}

.copyright {
  margin-top: 8px;
  font-size: 12px;
}

.copyright a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.3s ease;
}

.copyright a:hover {
  color: #7ab5ff;
  text-decoration: underline;
}

/* Mobile tweaks */
@media (max-width: 768px) {
  .header {
    padding: 12px 16px;
    flex-wrap: wrap;
  }

  .logo {
    font-size: 24px;
  }

  .header-menu {
    flex-wrap: wrap;
    gap: 8px;
  }

  .menu-btn {
    padding: 10px 16px;
    font-size: 13px;
  }

  .settings-panel {
    padding: 16px 20px;
    max-height: 60vh;
  }

  .settings-panel.hidden {
    padding: 0 20px;
  }

  .slider-container {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .slider-value {
    align-self: center;
  }

  .main-container {
    padding: 12px 16px 16px;
  }

  .carousel-container {
    height: auto;
    min-height: 260px;
    overflow: visible;
  }

  .carousel-track {
    min-height: 260px;
  }

  .carousel-item {
    max-width: 80%;
    max-height: 70vh;
  }

  .carousel-item img {
    max-height: 70vh;
    object-fit: contain;
  }

  .carousel-nav {
    width: 40px;
    height: 40px;
    font-size: 18px;
  }

  .carousel-nav.left {
    left: 10px;
  }

  .carousel-nav.right {
    right: 10px;
  }

  .carousel-container::before,
  .carousel-container::after {
    content: "";
    position: absolute;
    top: 0;
    width: 80px;
    height: 100%;
    z-index: 5;
    pointer-events: none;
  }

  .carousel-container::before {
    left: 0;
    background: linear-gradient(to right, var(--bg) 0%, transparent 100%);
  }

  .carousel-container::after {
    right: 0;
    background: linear-gradient(to left, var(--bg) 0%, transparent 100%);
  }

  .effects-grid {
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
    gap: 12px;
    padding: 16px;
    max-height: 350px;
  }

  .effect-item img {
    height: 100px;
  }

  .uploaded-files {
    grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    gap: 12px;
    padding: 16px;
  }

  .upload-section {
    padding: 32px 20px;
  }

  .upload-icon {
    font-size: 50px;
  }

  .action-buttons {
    bottom: 20px;
    right: 20px;
  }

  .action-btn {
    width: 52px;
    height: 52px;
  }

  .section-title {
    font-size: 18px;
  }
}

@media (max-width: 480px) {
  .effects-grid {
    grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
  }

  .uploaded-files {
    grid-template-columns: repeat(auto-fill, minmax(75px, 1fr));
  }
}