:root {
  --bg-dark: #030508;
  --sidebar-dark: #07090e;
  --panel-dark: rgba(9, 13, 22, 0.6);
  --border-subtle: rgba(255, 255, 255, 0.05);
  --border-hover: rgba(255, 255, 255, 0.15);

  --text-pure: #ffffff;
  --text-normal: #f1f5f9;
  --text-muted: #64748b;

  --accent: #6366f1;
  --accent-glow: rgba(99, 102, 241, 0.25);
  --accent-gradient: linear-gradient(135deg, #4f46e5, #818cf8);

  --font-clean: "Inter", system-ui, -apple-system, sans-serif;
  --transition-smooth: all 0.4s cubic-bezier(0.25, 1, 0.5, 1);
  --transition-spring: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

body {
  margin: 0;
  font-family: var(--font-clean);
  background-color: var(--bg-dark);
  color: var(--text-normal);
  height: 100vh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(
      circle at top left,
      rgba(99, 102, 241, 0.08),
      transparent 24%
    ),
    radial-gradient(
      circle at bottom right,
      rgba(168, 85, 247, 0.06),
      transparent 18%
    );
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(
    90deg,
    transparent 25%,
    rgba(255, 255, 255, 0.04) 50%,
    transparent 75%
  );
  opacity: 0.18;
  transform: translateZ(0);
  animation: driftLines 18s linear infinite;
}

/* --- BACKGROUND GLOW ANIMÉ --- */
.bg-glow-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(140px);
  mix-blend-mode: screen;
  opacity: 0.45;
  will-change: transform, opacity;
}

.orb-1 {
  top: -10%;
  right: 15%;
  width: 500px;
  height: 500px;
  background: radial-gradient(
    circle,
    rgba(79, 70, 229, 0.22) 0%,
    transparent 68%
  );
  animation: floatOrb1 25s ease-in-out infinite alternate;
}

.orb-2 {
  bottom: -10%;
  left: 10%;
  width: 450px;
  height: 450px;
  background: radial-gradient(
    circle,
    rgba(129, 140, 248, 0.18) 0%,
    transparent 68%
  );
  animation: floatOrb2 20s ease-in-out infinite alternate;
}

.orb-3 {
  top: 40%;
  left: 45%;
  width: 300px;
  height: 300px;
  background: radial-gradient(
    circle,
    rgba(168, 85, 247, 0.13) 0%,
    transparent 68%
  );
  animation: floatOrb1 18s ease-in-out infinite alternate-reverse;
}

@keyframes floatOrb1 {
  0% {
    transform: translate(0, 0) scale(1);
  }
  100% {
    transform: translate(-60px, 50px) scale(1.1);
  }
}

@keyframes floatOrb2 {
  0% {
    transform: translate(0, 0) scale(1);
  }
  100% {
    transform: translate(70px, -60px) scale(0.95);
  }
}

@keyframes driftLines {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(120%);
  }
}

.app-layout {
  display: flex;
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 1;
  background:
    radial-gradient(
      circle at top left,
      rgba(99, 102, 241, 0.08),
      transparent 24%
    ),
    radial-gradient(
      circle at bottom right,
      rgba(168, 85, 247, 0.06),
      transparent 18%
    );
}

/* --- SIDEBAR CORRIGÉE & SYSTÈME DE REPLIEMENT --- */
.sidebar {
  width: 280px;
  background-color: rgba(7, 9, 14, 0.94);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  transition: var(--transition-smooth);
  visibility: visible;
  overflow: hidden;
  backdrop-filter: blur(16px);
  will-change: width, opacity;
}

.sidebar.collapsed {
  width: 0;
  border-right: 1px solid transparent;
  visibility: hidden;
}

.sidebar-header {
  padding: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-width: 232px;
}

.sidebar-header h3 {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 600;
}

#clear-history {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  padding: 8px;
  border-radius: 50%;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  will-change: transform, color, background-color;
}

#clear-history:hover {
  color: #ef4444;
  background: rgba(239, 68, 68, 0.12);
  transform: scale(1.06);
}

#history-list {
  flex: 1;
  overflow-y: auto;
  padding: 0 16px 16px 16px;
  min-width: 248px;
}

.history-item {
  padding: 14px;
  border-radius: 16px;
  cursor: pointer;
  margin-bottom: 8px;
  background: rgba(255, 255, 255, 0.01);
  border: 1px solid var(--border-subtle);
  transition: var(--transition-smooth);
  animation: popIn 0.45s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: transform, background-color, border-color;
  width: 100%;
  text-align: left;
  border: none;
  background: transparent;
  color: inherit;
}

.history-item:hover {
  background: rgba(255, 255, 255, 0.03);
  border-color: rgba(99, 102, 241, 0.3);
  transform: translateX(6px);
  box-shadow: 0 18px 35px rgba(0, 0, 0, 0.16);
}

.history-item.removing {
  animation: fadeOutUp 0.35s ease forwards;
}

.history-name {
  font-weight: 500;
  display: block;
  margin-bottom: 4px;
  font-size: 13px;
  color: var(--text-normal);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.history-time {
  font-size: 11px;
  color: var(--text-muted);
}

.export-modal {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(3, 5, 10, 0.72);
  backdrop-filter: blur(12px);
  z-index: 999;
  padding: 24px;
}

.export-modal.visible {
  display: flex;
}

.export-modal-panel {
  width: min(440px, 100%);
  background: rgba(6, 10, 20, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 24px;
  padding: 28px;
  box-shadow: 0 38px 90px rgba(0, 0, 0, 0.55);
  animation: popIn 0.26s cubic-bezier(0.22, 1, 0.36, 1);
}

.export-modal-panel h2 {
  margin: 0 0 10px;
  font-size: 20px;
  color: var(--text-pure);
}

.export-modal-panel p {
  margin: 0 0 22px;
  color: var(--text-muted);
  line-height: 1.6;
}

.export-options {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.export-options button {
  flex: 1 1 120px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  padding: 14px 18px;
  color: var(--text-normal);
  background: rgba(255, 255, 255, 0.03);
  cursor: pointer;
  transition: var(--transition-smooth);
  font-weight: 600;
}

.export-options button:hover {
  border-color: rgba(99, 102, 241, 0.45);
  background: rgba(99, 102, 241, 0.12);
  transform: translateY(-1px);
}

.export-cancel {
  width: 100%;
  border: none;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-normal);
  border-radius: 14px;
  padding: 14px 18px;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.export-cancel:hover {
  background: rgba(255, 255, 255, 0.12);
}

.history-time {
  font-size: 11px;
  color: var(--text-muted);
}

.empty-history {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding-top: 60px;
  color: var(--text-muted);
  animation: floatIn 1s ease;
}

.empty-icon {
  width: 22px;
  height: 22px;
  margin-bottom: 12px;
  animation: slowSpin 20s linear infinite;
  opacity: 0.3;
}

@keyframes slowSpin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* --- MAIN CONTENT --- */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#header {
  display: flex;
  align-items: center;
  padding: 24px 40px;
  z-index: 2;
  animation: fadeInUp 0.8s ease both;
}

#sidebar-toggle {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  color: var(--text-normal);
  cursor: pointer;
  margin-right: 24px;
  padding: 10px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  transition: var(--transition-smooth);
  will-change: transform, background-color, border-color;
}

#sidebar-toggle:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.18);
  color: var(--text-pure);
  transform: scale(1.02);
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 12px;
}

#logo {
  height: 50px;
  border-radius: 25%;
  opacity: 0;
  transform: translateY(-8px) rotate(-6deg);
  animation: logoReveal 0.8s ease forwards 0.2s;
}

#title {
  font-size: 18px;
  font-weight: 600;
  margin: 0;
  letter-spacing: -0.02em;
  background: linear-gradient(to right, #fff, #94a3b8);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  position: relative;
  overflow: hidden;
}

#title::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 16%,
    rgba(255, 255, 255, 0.35),
    transparent 82%
  );
  transform: translateX(-100%);
  animation: textShimmer 4.2s infinite;
}

.content-body {
  flex: 1;
  overflow-y: auto;
  padding: 10px 40px 60px 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

/* --- INTERFACE DU FILTRE DE DEV (SWITCH GLASSMORPHISM) --- */
.filter-panel {
  width: 90%;
  background: rgba(13, 18, 30, 0.45);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  padding: 16px 22px;
  margin-bottom: 20px;
  box-sizing: border-box;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.03);
  animation: floatIn 0.9s ease both;
  position: relative;
}

.filter-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background:
    radial-gradient(
      circle at top right,
      rgba(99, 102, 241, 0.16),
      transparent 32%
    ),
    radial-gradient(
      circle at bottom left,
      rgba(168, 85, 247, 0.1),
      transparent 26%
    );
  opacity: 0.5;
  pointer-events: none;
}

.filter-header {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-normal);
  font-size: 13px;
  font-weight: 500;
  position: relative;
  z-index: 1;
}

.filter-icon {
  width: 16px;
  height: 16px;
  color: var(--accent);
}

.switch-container {
  display: flex;
  align-items: center;
  cursor: pointer;
  gap: 12px;
  position: relative;
  z-index: 1;
}

.switch-container:hover .slider {
  transform: scale(1.04);
}

.switch-container input {
  display: none;
}

.slider {
  width: 46px;
  height: 24px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  position: relative;
  transition: var(--transition-smooth);
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
  overflow: hidden;
  will-change: transform, background-color, box-shadow;
}

.slider::before {
  content: "";
  position: absolute;
  width: 18px;
  height: 18px;
  left: 3px;
  top: 3px;
  background-color: #cbd5e1;
  border-radius: 50%;
  transition: var(--transition-smooth);
  box-shadow: 0 10px 18px rgba(0, 0, 0, 0.18);
}

.slider::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 999px;
  background: radial-gradient(
    circle at 70% 50%,
    rgba(255, 255, 255, 0.18),
    transparent 35%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
}

input:checked + .slider {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.92),
    rgba(168, 85, 247, 0.82)
  );
  box-shadow: 0 0 18px rgba(99, 102, 241, 0.36);
}

input:checked + .slider::before {
  transform: translateX(20px);
  background-color: var(--text-pure);
}

input:checked + .slider::after {
  opacity: 0.55;
}

.label-text {
  font-size: 13px;
  color: var(--text-normal);
}

.label-text small {
  color: var(--text-muted);
  display: inline-block;
  margin-left: 4px;
}

/* --- LE MIDDLER SUBLIMÉ --- */
#middler {
  width: 90%;
  min-height: 200px;
  height: 260px;
  border-radius: 28px;
  box-sizing: border-box;
  cursor: pointer;
  background: rgba(7, 10, 18, 0.72);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-spring);
  border: 1px solid var(--border-subtle);
  box-shadow:
    0 30px 70px rgba(0, 0, 0, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.03);
  transform-style: preserve-3d;
  will-change: transform, background-color;
  animation:
    floatIn 1s ease both,
    hoverBreath 8s ease-in-out infinite;
}

#middler::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(
    circle at center,
    rgba(99, 102, 241, 0.08),
    transparent 45%
  );
  pointer-events: none;
}

.interactive-border {
  position: absolute;
  inset: -1px;
  border-radius: 24px;
  padding: 1px;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.05),
    transparent 60%,
    rgba(255, 255, 255, 0.05)
  );
  mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  transition: var(--transition-smooth);
  background-size: 200% 200%;
  animation: borderFlow 10s linear infinite;
}

.drop-zone-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 2;
  position: relative;
  animation: floatContent 8s ease-in-out infinite;
}

#middler:hover {
  transform: translateY(-8px) scale(1.01);
  background: rgba(15, 22, 40, 0.78);
  box-shadow:
    0 48px 110px rgba(0, 0, 0, 0.46),
    0 0 60px rgba(99, 102, 241, 0.24);
  transition: all 0.6s ease;
}

#middler:hover .interactive-border {
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.24),
    rgba(99, 102, 241, 0.45),
    rgba(168, 85, 247, 0.12)
  );
}

#middler.drag-over {
  transform: scale(1.01);
  background: rgba(99, 102, 241, 0.12);
  box-shadow:
    0 0 90px rgba(99, 102, 241, 0.45),
    inset 0 0 40px rgba(168, 85, 247, 0.18);
  animation: dragPulse 1.6s ease-in-out infinite;
}

#middler.drag-over .interactive-border {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.6),
    rgba(168, 85, 247, 0.25),
    rgba(99, 102, 241, 0.6)
  );
}

.icon-wrapper {
  width: 52px;
  height: 52px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--text-normal);
  transition: var(--transition-spring);
  animation: pulseIcon 3.2s ease-in-out infinite;
  will-change: transform, background-color, box-shadow;
}

#middler:hover .icon-wrapper {
  color: var(--text-pure);
  background: var(--accent-gradient);
  transform: scale(1.1) rotate(90deg);
  box-shadow: 0 0 26px rgba(99, 102, 241, 0.46);
  border-color: transparent;
  transition: all 0.6s ease;
}

.upload-icon {
  width: 18px;
  height: 18px;
}

#import-txt {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-pure);
  margin: 0 0 6px 0;
  animation: popPulse 2.8s ease-in-out infinite;
}

#app-desc {
  font-size: 13px;
  margin: 0;
  color: var(--text-muted);
  max-width: 340px;
  text-align: center;
}

/* --- ARCHITECTURE EN SORTIE (RÉSULTAT) --- */
#structure-output {
  margin-top: 30px;
  width: 100%;
  max-width: 640px;
  animation: slideUpIn 0.55s cubic-bezier(0.16, 1, 0.3, 1);
}

.output-wrapper {
  background-color: #05070b;
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  box-shadow: 0 40px 90px rgba(0, 0, 0, 0.72);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transform-style: preserve-3d;
  will-change: transform, opacity;
}

.window-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  background-color: rgba(3, 5, 8, 0.75);
  border-bottom: 1px solid var(--border-subtle);
  backdrop-filter: blur(16px);
}

.window-controls {
  display: flex;
  gap: 6px;
}
.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.08);
  transition: var(--transition-smooth);
  will-change: background-color, transform;
}

.output-wrapper:hover .dot.red {
  background-color: #ef4444;
}
.output-wrapper:hover .dot.yellow {
  background-color: #eab308;
}
.output-wrapper:hover .dot.green {
  background-color: #22c55e;
}

.copy-btn,
.export-btn {
  background-color: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  color: var(--text-normal);
  padding: 8px 16px;
  border-radius: 12px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 500;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.08),
    rgba(255, 255, 255, 0.03)
  );
  will-change: transform, background-color, box-shadow;
}

.copy-btn:hover,
.export-btn:hover {
  background-color: var(--text-pure);
  color: var(--bg-dark);
  border-color: var(--text-pure);
  box-shadow: 0 16px 30px rgba(99, 102, 241, 0.16);
  transform: translateY(-1px);
}

.export-btn {
  justify-content: center;
}

.tree-container {
  padding: 24px;
  margin: 0;
  overflow-x: auto;
  font-family: "Fira Code", "SF Mono", monospace;
  font-size: 13px;
  line-height: 1.75;
  white-space: pre;
  color: #cbd5e1;
  animation: textFlow 0.9s ease both;
}

/* Syntax Highlighting amélioré */
.t-line {
  color: rgba(99, 102, 241, 0.25);
  user-select: none;
}
.t-folder {
  color: #60a5fa;
  font-weight: 600;
}
.t-file {
  color: #e2e8f0;
}

.ext-js {
  color: #facc15;
}
.ext-ts {
  color: #38bdf8;
}
.ext-html {
  color: #f97316;
}
.ext-css,
.ext-scss {
  color: #6366f1;
}
.ext-json {
  color: #34d399;
}
.ext-py {
  color: #a78bfa;
}
.ext-md {
  color: #94a3b8;
}
.ext-git {
  color: #f87171;
  opacity: 0.8;
}

/* --- LOADING BAR --- */
#loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 30px 0;
  gap: 14px;
  animation: floatIn 0.8s ease both;
}

.loader-wave {
  display: flex;
  gap: 6px;
}

.loader-wave span {
  width: 4px;
  height: 18px;
  background-color: var(--accent);
  border-radius: 2px;
  animation: waveEffect 1.2s ease-in-out infinite;
  will-change: transform, opacity, background-color;
}

.loader-wave span:nth-child(2) {
  animation-delay: 0.14s;
}
.loader-wave span:nth-child(3) {
  animation-delay: 0.28s;
}

@keyframes waveEffect {
  0%,
  100% {
    transform: scaleY(1);
    opacity: 0.35;
  }
  50% {
    transform: scaleY(2.2);
    opacity: 1;
    background-color: var(--text-pure);
  }
}

#progress-bar-container {
  width: 220px;
  height: 4px;
  background-color: rgba(255, 255, 255, 0.05);
  border-radius: 999px;
  overflow: hidden;
}

#progress-bar {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, #6366f1, #818cf8);
  transition: width 0.18s ease;
}

#file-count {
  font-size: 11px;
  color: var(--text-muted);
}

@keyframes slideUpIn {
  from {
    opacity: 0;
    transform: translateY(15px);
    filter: blur(4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
    filter: blur(0);
  }
}

@keyframes popIn {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeOutUp {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(-20px);
  }
}

@keyframes floatIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes borderFlow {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 100% 50%;
  }
}

@keyframes floatContent {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

@keyframes pulseIcon {
  0%,
  100% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
  }
  50% {
    transform: translateY(-2px) rotate(4deg);
    opacity: 0.92;
  }
}

@keyframes popPulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.02);
  }
}

@keyframes textShimmer {
  0% {
    transform: translateX(-100%);
  }
  100% {
    transform: translateX(100%);
  }
}

@keyframes logoReveal {
  from {
    opacity: 0;
    transform: translateY(-16px) rotate(-10deg);
  }
  to {
    opacity: 1;
    transform: translateY(0) rotate(0deg);
  }
}

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

@keyframes hoverBreath {
  0%,
  100% {
    box-shadow:
      0 30px 70px rgba(0, 0, 0, 0.35),
      inset 0 1px 0 rgba(255, 255, 255, 0.03);
  }
  50% {
    box-shadow:
      0 36px 88px rgba(0, 0, 0, 0.41),
      inset 0 1px 0 rgba(255, 255, 255, 0.05);
    transform: translateY(-2px);
  }
}

@keyframes dragPulse {
  0%,
  100% {
    transform: scale(1.01);
  }
  50% {
    transform: scale(1.02);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.18);
}

/* --- RESPONSIVE UI --- */
@media (max-width: 1100px) {
  .app-layout {
    flex-direction: column;
    align-items: stretch;
  }

  .sidebar {
    width: 100%;
    min-height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }

  .sidebar.collapsed {
    width: 100%;
    height: 0;
    border-bottom: none;
    visibility: hidden;
  }

  #header {
    padding: 20px 32px;
  }

  .content-body {
    padding: 10px 32px 40px 32px;
  }

  .filter-panel,
  #middler,
  #structure-output {
    width: 100%;
    max-width: 100%;
  }

  .window-header {
    flex-wrap: wrap;
    gap: 14px;
  }
}

@media (max-width: 820px) {
  #header {
    padding: 18px 24px;
    flex-direction: column;
    align-items: stretch;
  }

  #sidebar-toggle {
    margin-right: 0;
    align-self: flex-start;
  }

  .brand-container {
    gap: 10px;
  }

  #logo {
    height: 42px;
  }

  #title {
    font-size: 16px;
  }

  .content-body {
    padding: 10px 24px 36px 24px;
  }

  .filter-panel {
    flex-direction: column;
    align-items: stretch;
    gap: 14px;
    padding: 16px;
  }

  .switch-container {
    width: 100%;
    justify-content: space-between;
  }

  #middler {
    height: 230px;
  }

  .drop-zone-content {
    gap: 10px;
  }

  .tree-container {
    padding: 18px;
    font-size: 12px;
  }

  .output-wrapper {
    border-radius: 16px;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 14px;
  }

  #header {
    padding: 16px 18px;
    gap: 12px;
  }

  .sidebar {
    padding-bottom: 14px;
  }

  .sidebar-header {
    padding: 18px 18px 12px;
  }

  #clear-history {
    padding: 6px;
  }

  .filter-panel {
    padding: 14px 16px;
  }

  .switch-container {
    gap: 10px;
  }

  .slider {
    width: 42px;
    height: 22px;
  }

  .slider::before {
    width: 16px;
    height: 16px;
    top: 3px;
  }

  #middler {
    height: 210px;
  }

  #import-txt {
    font-size: 15px;
  }

  #app-desc {
    font-size: 12px;
  }

  .window-header {
    padding: 12px 14px;
  }

  .copy-btn,
  .export-btn {
    width: 100%;
    justify-content: center;
    font-size: 11px;
  }

  .window-controls {
    order: 2;
    width: 100%;
    justify-content: flex-start;
  }

  .copy-btn,
  .export-btn {
    min-width: 0;
  }

  .tree-container {
    padding: 16px;
  }
}

@media (max-width: 520px) {
  .filter-panel,
  #middler,
  .output-wrapper {
    border-radius: 16px;
  }

  .sidebar-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .history-item {
    padding: 12px;
    font-size: 13px;
  }

  .history-name {
    font-size: 12px;
  }

  #file-count {
    font-size: 10px;
  }
}