:root {
  --bg-top: #5d7385;
  --bg-bottom: #07111a;
  --panel-bg: rgba(10, 17, 25, 0.62);
  --panel-border: rgba(230, 238, 245, 0.14);
  --panel-shadow: rgba(2, 6, 9, 0.42);
  --text-main: #eef5fb;
  --text-muted: rgba(223, 233, 241, 0.75);
  --text-soft: rgba(203, 214, 223, 0.56);
  --accent: #f2c37a;
  --accent-soft: rgba(242, 195, 122, 0.22);
  --track: rgba(241, 245, 248, 0.12);
  --track-fill: linear-gradient(90deg, #f1b96a 0%, #f5ead7 100%);
  --grain-opacity: 0.12;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  overflow: hidden;
  background:
    radial-gradient(circle at 18% 22%, rgba(210, 224, 235, 0.38), transparent 32%),
    radial-gradient(circle at 74% 18%, rgba(247, 210, 144, 0.16), transparent 22%),
    linear-gradient(180deg, var(--bg-top) 0%, #223241 30%, #0c1721 64%, var(--bg-bottom) 100%);
  color: var(--text-main);
}

body {
  font-family: "Avenir Next", "Segoe UI", sans-serif;
}

.app-shell {
  position: relative;
  width: 100vw;
  height: 100vh;
  isolation: isolate;
}

#particle-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  cursor: none;
}

.backdrop-glow,
.grain,
.cursor-light,
.drop-hint,
.unsupported {
  pointer-events: none;
}

.backdrop-glow {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 24%, rgba(255, 248, 232, 0.22), transparent 26%),
    radial-gradient(circle at 72% 56%, rgba(245, 198, 118, 0.12), transparent 28%),
    radial-gradient(circle at 56% 80%, rgba(146, 188, 219, 0.16), transparent 34%);
  mix-blend-mode: screen;
  opacity: 0.72;
}

.grain {
  position: absolute;
  inset: 0;
  opacity: var(--grain-opacity);
  background-image:
    radial-gradient(circle at 15% 30%, rgba(255, 255, 255, 0.6) 0 0.6px, transparent 0.9px),
    radial-gradient(circle at 80% 70%, rgba(255, 255, 255, 0.35) 0 0.6px, transparent 0.9px),
    radial-gradient(circle at 40% 82%, rgba(255, 255, 255, 0.28) 0 0.6px, transparent 0.9px);
  background-size: 13px 13px, 17px 17px, 19px 19px;
  mix-blend-mode: soft-light;
}

.cursor-light {
  position: absolute;
  top: 0;
  left: 0;
  width: 22rem;
  height: 22rem;
  border-radius: 50%;
  background:
    radial-gradient(circle, rgba(255, 249, 235, 0.34) 0%, rgba(248, 207, 128, 0.18) 26%, rgba(118, 168, 211, 0.08) 52%, transparent 72%);
  filter: blur(26px);
  mix-blend-mode: screen;
  opacity: 0;
  transform: translate3d(-50%, -50%, 0);
  transition: opacity 180ms ease;
}

.control-panel {
  position: absolute;
  top: 1.5rem;
  left: 1.5rem;
  width: min(22rem, calc(100vw - 3rem));
  max-height: calc(100vh - 3rem);
  padding: 0.95rem 1rem 1rem;
  border: 1px solid var(--panel-border);
  border-radius: 1.6rem;
  background:
    linear-gradient(180deg, rgba(15, 23, 32, 0.58) 0%, rgba(9, 15, 22, 0.42) 100%);
  box-shadow:
    0 1.2rem 2.8rem -1.2rem var(--panel-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(18px);
  pointer-events: auto;
  transition:
    width 220ms ease,
    padding 220ms ease,
    background-color 220ms ease,
    border-color 220ms ease,
    box-shadow 220ms ease;
}

.eyebrow {
  margin: 0;
  color: rgba(253, 222, 176, 0.82);
  font-size: 0.76rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
}

.panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.8rem;
}

.panel-heading {
  min-width: 0;
}

.panel-note {
  margin: 0.35rem 0 0;
  color: rgba(230, 237, 242, 0.56);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.panel-toggle {
  appearance: none;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 999px;
  padding: 0.54rem 0.86rem;
  background: rgba(255, 255, 255, 0.05);
  color: rgba(245, 248, 251, 0.88);
  font: inherit;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition:
    transform 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease;
}

.panel-toggle:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
}

.panel-body {
  margin-top: 0.95rem;
  max-height: calc(100vh - 10rem);
  overflow: hidden;
  opacity: 1;
  transform: translateY(0);
  transition:
    max-height 220ms ease,
    opacity 180ms ease,
    transform 220ms ease,
    margin-top 220ms ease;
}

.control-panel.is-collapsed {
  width: auto;
  padding-bottom: 0.9rem;
  background:
    linear-gradient(180deg, rgba(13, 21, 30, 0.42) 0%, rgba(9, 15, 22, 0.34) 100%);
}

.control-panel.is-collapsed .panel-body {
  max-height: 0;
  margin-top: 0;
  opacity: 0;
  transform: translateY(-0.45rem);
  pointer-events: none;
}

.control-panel h1,
.unsupported h2 {
  margin: 0;
  font-family: "Baskerville", "Iowan Old Style", "Palatino Linotype", serif;
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: 0.01em;
}

.control-panel h1 {
  font-size: clamp(2rem, 4vw, 3.2rem);
  max-width: 11ch;
}

.intro,
.unsupported p {
  margin: 1rem 0 0;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.55;
}

.action-row {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.upload-button,
.ghost-button {
  appearance: none;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  padding: 0.86rem 1.18rem;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  font: inherit;
  font-size: 0.9rem;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition:
    transform 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease,
    box-shadow 180ms ease;
}

.upload-button {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(242, 195, 122, 0.18) 0%, rgba(255, 255, 255, 0.08) 100%);
}

.upload-button input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.upload-button:hover,
.ghost-button:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.24);
  box-shadow: 0 0.8rem 1.8rem -1rem rgba(255, 212, 145, 0.34);
}

.control-group {
  margin-top: 1rem;
}

.control-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.control-label {
  color: rgba(240, 244, 247, 0.92);
  font-size: 0.84rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.control-value {
  color: rgba(245, 211, 156, 0.92);
  font-size: 0.82rem;
  letter-spacing: 0.05em;
}

input[type="range"] {
  width: 100%;
  margin: 0;
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 0.5rem;
  border-radius: 999px;
  background:
    linear-gradient(90deg, rgba(242, 195, 122, 0.78), rgba(246, 239, 228, 0.9)),
    var(--track);
}

input[type="range"]::-moz-range-track {
  height: 0.5rem;
  border-radius: 999px;
  background:
    linear-gradient(90deg, rgba(242, 195, 122, 0.78), rgba(246, 239, 228, 0.9)),
    var(--track);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 1rem;
  height: 1rem;
  margin-top: -0.25rem;
  border: 0;
  border-radius: 50%;
  background: linear-gradient(180deg, #fffaf0 0%, #efc481 100%);
  box-shadow:
    0 0 0 0.22rem rgba(247, 211, 158, 0.2),
    0 0.3rem 0.9rem rgba(12, 18, 24, 0.36);
}

input[type="range"]::-moz-range-thumb {
  width: 1rem;
  height: 1rem;
  border: 0;
  border-radius: 50%;
  background: linear-gradient(180deg, #fffaf0 0%, #efc481 100%);
  box-shadow:
    0 0 0 0.22rem rgba(247, 211, 158, 0.2),
    0 0.3rem 0.9rem rgba(12, 18, 24, 0.36);
}

.status-line {
  margin: 1rem 0 0;
  color: var(--text-soft);
  font-size: 0.85rem;
  line-height: 1.5;
}

.drop-hint {
  position: absolute;
  left: 50%;
  bottom: 1.5rem;
  transform: translateX(-50%) translateY(1rem);
  width: min(30rem, calc(100vw - 3rem));
  padding: 1rem 1.15rem;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  background: rgba(7, 12, 18, 0.72);
  text-align: center;
  color: rgba(240, 246, 250, 0.9);
  backdrop-filter: blur(14px);
  opacity: 0;
  transition:
    opacity 180ms ease,
    transform 180ms ease;
}

.drop-hint p {
  margin: 0;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
}

.app-shell.drag-active .drop-hint {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.app-shell.drag-active .control-panel {
  border-color: rgba(250, 226, 180, 0.26);
  box-shadow:
    0 1.2rem 2.8rem -1.2rem rgba(2, 6, 9, 0.42),
    0 0 0 1px rgba(250, 226, 180, 0.14),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.unsupported {
  position: absolute;
  inset: auto 1.5rem 1.5rem auto;
  max-width: 22rem;
  padding: 1.25rem 1.3rem;
  border-radius: 1.4rem;
  background: rgba(11, 18, 24, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(12px);
}

.hidden {
  display: none;
}

@media (max-width: 820px) {
  .control-panel {
    top: auto;
    right: 1rem;
    bottom: 1rem;
    left: 1rem;
    width: auto;
    padding: 0.95rem;
  }

  .control-panel h1 {
    max-width: 14ch;
    font-size: clamp(1.7rem, 8vw, 2.4rem);
  }

  .intro {
    font-size: 0.92rem;
  }

  .action-row {
    flex-direction: column;
  }

  .panel-head {
    align-items: center;
  }

  .cursor-light {
    width: 16rem;
    height: 16rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cursor-light,
  .drop-hint,
  .upload-button,
  .ghost-button {
    transition: none;
  }
}