:root {
  --color-primary: rgba(139, 197, 193, 1);
  --color-primary-light: rgba(93, 138, 139, 1);
  --color-primary-dark: rgba(26, 47, 48, 1);
  --color-surface: rgba(248, 248, 248, 0.9);
  --color-border: rgba(0, 0, 0, 0.1);
  --color-text: rgb(18, 47, 45);
  --color-text-secondary: rgba(18, 47, 45, 0.7);
  --color-dimension-text: var(--color-text);
  --color-input-bg: rgba(255, 255, 255, 0.8);
  --color-input-border: rgba(0, 0, 0, 0.15);
  --color-input-focus-border: var(--color-primary);
  --color-input-text: var(--color-text);
  --color-background-fallback: #f0f4f8;

  --color-control-point: var(--color-text);
  --color-control-line: var(--color-primary);
  --color-hover: var(--color-primary-light);
  --color-dimension-line: var(--color-primary);
  --color-dimension-handle: var(--color-text);
  --color-dimension-handle-hover: var(--color-primary);
  --color-curve-line: var(--color-primary);
  --color-bounding-box: var(--color-primary);
  --color-grid-line: var(--color-text-secondary);
  --color-grid-center-line: var(--color-border);

  --shadow-subtle: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-medium: 0 4px 8px rgba(0, 0, 0, 0.08);
  --shadow-large: 0 10px 20px rgba(0, 0, 0, 0.12);

  --transition-duration: 0.3s;
  --transition-easing: cubic-bezier(0.4, 0, 0.2, 1);
  --transition-standard: all var(--transition-duration) var(--transition-easing);

  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 24px;
  --space-xxl: 32px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-circle: 50%;

  --font-xs: 0.8rem;
  --font-sm: 0.9rem;
  --font-md: 1rem;
  --font-lg: 1.1rem;
  --font-xl: 1.25rem;
  --font-xxl: 1.5rem;
  --font-hero: clamp(2rem, 5vw, 2.8rem);

  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;

  --top-bar-height: 65px;
}


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

html {
  font-family: "Inter", sans-serif;
  line-height: 1.5;
  color: var(--color-text);
  font-size: 16px;
}

body {
  background-color: var(--color-background-fallback);
  overflow: hidden;
  height: 100vh;
  width: 100vw;
  position: relative;
}

#gradient-background {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  z-index: -1;
}


.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

.hidden {
  display: none !important;
}


*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 3px rgba(139, 197, 193, 0.3);
}
*:focus:not(:focus-visible) {
  outline: none;
}
.button-base:focus-visible,
.close-intro:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 3px rgba(139, 197, 193, 0.3);
}
.form-control:focus:not([type="range"]) {
  border-color: var(--color-input-focus-border);
  box-shadow: 0 0 0 3px rgba(139, 197, 193, 0.3), inset 0 1px 2px var(--shadow-subtle);
}
input[type="range"].form-control:focus-visible::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px rgba(139, 197, 193, 0.3);
}
input[type="range"].form-control:focus-visible::-moz-range-thumb {
  box-shadow: 0 0 0 3px rgba(139, 197, 193, 0.3);
}


.top-bar {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  background-color: var(--color-surface);
  padding: var(--space-sm) var(--space-lg);
  box-shadow: var(--shadow-subtle);
  border-radius: var(--radius-md);
  position: fixed;
  top: var(--space-lg);
  left: var(--space-lg);
  right: var(--space-lg);
  height: var(--top-bar-height);
  z-index: 1000;
}

.logo-button {
  background: none; border: none; padding: 0; cursor: pointer; flex-shrink: 0;
  width: 40px; height: 40px;
  &:focus { outline: none; }
  &:focus-visible { box-shadow: none; }
}
.logo-button:focus-visible .flowerpot-logo {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

.flowerpot-logo {
  width: 100%; height: 100%; display: block;
  transition: transform 0.3s var(--transition-easing);
  fill: var(--color-text);
}
.logo-button:hover .flowerpot-logo { transform: scale(1.1); }

.app-title {
  font-size: var(--font-xl);
  font-weight: var(--weight-bold);
  white-space: nowrap;
  margin-right: var(--space-sm);
}

.app-subtitle {
  font-size: var(--font-sm);
  font-weight: var(--weight-normal);
  white-space: nowrap;
  opacity: 0.8;
}
#subtitle {
  transition: opacity 0.6s ease-in-out;
}

.creator-credit {
  margin-left: auto;
  font-size: var(--font-xs);
  opacity: 0.9;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 3px;
}
.creator-credit a {
  color: var(--color-text);
  font-weight: var(--weight-medium);
  text-decoration: none;
  position: relative;
}
.creator-credit a::after {
  content: ""; position: absolute; width: 0; height: 1px; bottom: -2px; left: 0;
  background-color: var(--color-primary-light); transition: width 0.3s ease;
}
.creator-credit a:hover::after { width: 100%; }

.heart-icon {
  display: inline-block;
  animation: heartBeat 4s infinite; transform-origin: center;
  fill: var(--color-primary-dark); vertical-align: middle;
  width: 14px; height: 14px;
}
@keyframes heartBeat {
   0%, 28%, 70%, 100% { transform: scale(1); }
   14%, 42% { transform: scale(1.1); }
}


.intro-text {
  position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(1);
  background-color: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-large); z-index: 1001;
  max-width: 700px; width: calc(100% - var(--space-xl) * 2);
  max-height: calc(100vh - var(--space-xl) * 2); overflow-y: auto;
  opacity: 1;
  transition: opacity var(--transition-duration) ease, transform var(--transition-duration) ease;
}


.intro-text.hidden {
  opacity: 0;
  transform: translate(-50%, -55%) scale(0.95);
  pointer-events: none;
}

.intro-content { padding: var(--space-xxl); }

.close-intro {
  position: absolute; top: var(--space-md); right: var(--space-md); background-color: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-border); width: 32px; height: 32px; border-radius: var(--radius-circle);
  display: flex; align-items: center; justify-content: center; cursor: pointer;
  transition: var(--transition-standard); font-size: 1.2rem; color: var(--color-text-secondary);
  box-shadow: var(--shadow-subtle);
}
.close-intro:hover {
  background-color: white; color: var(--color-primary); transform: rotate(90deg); box-shadow: var(--shadow-medium);
}


.intro-content h2 { font-size: var(--font-hero); color: var(--color-primary-dark); margin-bottom: var(--space-lg); text-align: center; }
.intro-description { font-size: var(--font-md); line-height: 1.6; margin-bottom: var(--space-xl); text-align: center; max-width: 90%; margin-left: auto; margin-right: auto; }

.how-it-works-intro {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-lg);
  margin: var(--space-xl) 0; padding-left: 0; list-style: none;
}
.how-it-works-intro .step-item {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  padding: var(--space-lg); border-radius: var(--radius-md); background-color: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-border); transition: transform 0.2s ease, box-shadow 0.2s ease; box-shadow: var(--shadow-subtle);
}
.how-it-works-intro .step-item:hover { transform: translateY(-4px); box-shadow: var(--shadow-medium); }
.step-number {
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
  width: 40px; height: 40px; background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-primary) 100%);
  border-radius: var(--radius-circle); color: white; font-weight: var(--weight-bold); margin-bottom: var(--space-md);
  box-shadow: 0 2px 6px rgba(93, 138, 139, 0.2); font-size: var(--font-md);
}
.step-content { display: flex; flex-direction: column; align-items: center; width: 100%; }
.step-title { font-size: var(--font-md); font-weight: var(--weight-semibold); color: var(--color-text); margin-bottom: var(--space-xs); }
.step-description { font-size: var(--font-sm); line-height: 1.4; color: var(--color-text-secondary); }

.cta-button {
  margin-top: var(--space-xl); background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: white; font-size: var(--font-md); font-weight: var(--weight-semibold); padding: var(--space-md) var(--space-xl);
  border: none; border-radius: 30px;
  box-shadow: 0 4px 10px rgba(93, 138, 139, 0.3);
  min-width: 180px;
  position: sticky;  bottom: var(--space-lg); left: calc(50% - 90px);
}
.cta-button:hover {
  transform: translateY(-3px); box-shadow: 0 6px 15px rgba(93, 138, 139, 0.4);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
}
.cta-button:active { transform: translateY(-1px); }
.cta-icon {  width: 18px; height: 18px; stroke: white; stroke-width: 2; transition: transform 0.3s ease; }
.cta-button:hover .cta-icon { transform: translateX(4px); }


.main-container {
  display: flex;
  width: 100%;
  height: 100%;
  position: relative;
  padding-top: calc(var(--top-bar-height) + var(--space-lg));
}

.sidebar {
  position: absolute;
  top: calc(var(--top-bar-height) + var(--space-lg) * 2);
  left: var(--space-lg);
  width: 340px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-medium);
  z-index: 900;
  overflow-y: auto;

  transition: transform var(--transition-duration) var(--transition-easing),
              visibility 0s linear var(--transition-duration);
  transform: translateX(calc(-100% - var(--space-lg)));
  visibility: hidden;
  height: calc(100vh - var(--top-bar-height) - var(--space-lg) * 3);
}


.sidebar[data-state="visible"] {
  transform: translateX(0);
  visibility: visible;
  transition-delay: 0s, 0s;
}

.sidebar-content {
  padding: var(--space-lg);
  padding-top: var(--space-sm);
}


.canvas-wrapper {
  display: flex;
  flex-grow: 1;
  position: relative;
  width: 100%;
  height: calc(100% + 80px);
  top: -80px;
}

.canvas-area {
  flex-grow: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  position: relative;
}

#canvas-container {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
}

#threejs-canvas {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: var(--radius-md);
}


.button-base {
  display: inline-flex; align-items: center; justify-content: center;
  padding: var(--space-sm) var(--space-lg); border: 1px solid var(--color-border);
  background-color: var(--color-surface); color: var(--color-text); border-radius: var(--radius-md);
  cursor: pointer; font-size: var(--font-sm); font-weight: var(--weight-medium); white-space: nowrap;
  transition: background-color 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, transform 0.1s ease;
  box-shadow: var(--shadow-subtle);
  gap: var(--space-sm);
  text-decoration: none;
}
.button-base svg,
.button-base i {
  width: 1.1em;
  height: 1.1em;
  flex-shrink: 0;
}
.button-base:hover {
  box-shadow: var(--shadow-medium); background-color: rgba(255, 255, 255, 0.95); border-color: rgba(0, 0, 0, 0.15);
}
.button-base:active {
  box-shadow: var(--shadow-subtle); transform: translateY(1px); background-color: rgba(0, 0, 0, 0.03);
}
.button-base.primary {
  background-color: var(--color-primary); color: white; border-color: var(--color-primary-dark);
}
.button-base.primary svg,
.button-base.primary i {
  color: white;
  fill: white;
  stroke: white;
}
.button-base.primary:hover { background-color: var(--color-primary-light); border-color: var(--color-primary); }
.button-base.primary:active { background-color: var(--color-primary-dark); }


.canvas-action-buttons-left {
  position: absolute;
  top: calc(var(--space-lg) + 80px);
  left: var(--space-lg);
  z-index: 950;
  display: flex;
  gap: var(--space-sm);
  transition: transform var(--transition-duration) var(--transition-easing);
  transform: translateX(0);
}


@media (min-width: 1024px) {
  .sidebar[data-state="visible"] + .canvas-wrapper > .canvas-action-buttons-left {
      transform: translateX(calc(340px + var(--space-lg)));
  }
}


#download-button {
  position: absolute;
  top: calc(var(--space-lg) + 80px);
  right: var(--space-lg);
  z-index: 950;
}

.control-panel {
  display: flex; flex-direction: column; gap: var(--space-sm);
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--color-border);
}
.control-panel:last-child { border-bottom: none; }

.control-section-title {
  font-size: var(--font-lg); font-weight: var(--weight-semibold);
  margin-bottom: var(--space-md); color: var(--color-primary-dark);
  padding: 0 var(--space-xs);
}

.control-group {
  display: flex; flex-direction: column;
  margin-bottom: var(--space-lg); padding: 0 var(--space-xs);
}

.control-group label {
  font-size: var(--font-sm); font-weight: var(--weight-medium);
  margin-bottom: var(--space-sm); display: flex; justify-content: space-between;
  align-items: baseline;
}

.control-group label .value-display {
  font-weight: var(--weight-normal); color: var(--color-text-secondary);
  font-size: var(--font-xs);
}


.form-control {
  padding: var(--space-sm); border: 1px solid var(--color-input-border);
  border-radius: var(--radius-sm); font-size: var(--font-sm);
  background-color: var(--color-input-bg); color: var(--color-input-text);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: inset 0 1px 2px var(--shadow-subtle); width: 100%;
  font-family: inherit;
}
select.form-control {
  padding-right: var(--space-xl);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23666'%3E%3Cpath d='M4.4 6.5l3.6 3.6 3.6-3.6z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-sm) center;
  background-size: 1em auto;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
}


.icon-button {
  width: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  font-size: var(--font-xl);
  line-height: 1;
  padding: 0;
  border-radius: var(--radius-lg);
}

#remove-point-button-external span {
  transform: translateY(-2px);
}



input[type="range"].form-control {
  -webkit-appearance: none; appearance: none; width: 100%; height: 6px;
  background: var(--color-border); border-radius: var(--radius-sm); outline: none;
  padding: 0; cursor: pointer; box-shadow: none;
  border: none;
}

input[type="range"].form-control::-webkit-slider-runnable-track {
  width: 100%; height: 6px; cursor: pointer;
  background: var(--color-border); border-radius: var(--radius-sm);
}
input[type="range"].form-control::-moz-range-track {
  width: 100%; height: 6px; cursor: pointer;
  background: var(--color-border); border-radius: var(--radius-sm);
}


input[type="range"].form-control::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 16px; height: 16px; margin-top: -5px;
  border-radius: var(--radius-circle); background: var(--color-primary); cursor: pointer; border: none;
  transition: background-color 0.2s ease, transform 0.2s ease; transform: scale(1);
}
input[type="range"].form-control::-moz-range-thumb {
  width: 16px; height: 16px;
  border-radius: var(--radius-circle); background: var(--color-primary);
  cursor: pointer; border: none;
  transition: background-color 0.2s ease, transform 0.2s ease; transform: scale(1);
}

input[type="range"].form-control:hover::-webkit-slider-thumb { background-color: var(--color-primary-light); transform: scale(1.1); }
input[type="range"].form-control:hover::-moz-range-thumb { background-color: var(--color-primary-light); transform: scale(1.1); }
input[type="range"].form-control:active::-webkit-slider-thumb { background-color: var(--color-primary-dark); transform: scale(0.95); }
input[type="range"].form-control:active::-moz-range-thumb { background-color: var(--color-primary-dark); transform: scale(0.95); }


.sidebar .button-group {
  display: flex;
  gap: var(--space-sm);
  padding: 0 var(--space-xs);
}
.sidebar .button-group .button-base {
  flex-grow: 1;
}


@media (max-width: 1023px) {

  .top-bar {
      gap: var(--space-md);
      padding: var(--space-sm) var(--space-md);
      left: var(--space-sm);
      right: var(--space-sm);
      top: var(--space-sm);
  }
  .top-bar .creator-credit {
      display: none;
  }
  .app-title { font-size: var(--font-lg); }
  .app-subtitle {
      display: none;
  }

  .main-container {
      padding-top: calc(var(--top-bar-height) + var(--space-sm));
      flex-direction: column;
      height: auto;
      min-height: 100vh;
  }

  .sidebar {
      top: calc(var(--top-bar-height) + var(--space-sm) * 2 + 42px);
      left: var(--space-sm);
      right: var(--space-sm);
      width: auto;
      max-height: calc(100vh - (var(--top-bar-height) + var(--space-sm) * 3 + 42px));
      transform: translateX(calc(-100% - var(--space-sm) * 2));
      height: auto;
  }
  .sidebar[data-state="visible"] {
      transform: translateX(0);
  }



  .sidebar[data-state="visible"] + .canvas-wrapper > .canvas-action-buttons-left {
      transform: translateX(0);
  }

  .sidebar-content { padding: var(--space-md); padding-top: var(--space-sm); }
  .control-panel { padding: var(--space-md) 0; }

  .canvas-wrapper {
    height: 100vh;
  }


  .canvas-action-buttons-left {
      top: calc(var(--top-bar-height) + var(--space-sm) * 3);
      left: var(--space-sm);

  }


  #download-button {
      top: calc(var(--top-bar-height) + var(--space-sm) * 3);
      right: var(--space-sm);
  }

  .button-base {
      padding: var(--space-sm) var(--space-md);
      font-size: var(--font-sm);
  }

  #remove-point-button-external span {
    transform: translateY(-2px);
  }


  input[type="range"].form-control { height: 8px; }
  input[type="range"].form-control::-webkit-slider-thumb {
      width: 20px; height: 20px; margin-top: -6px;
  }
  input[type="range"].form-control::-moz-range-thumb {
      width: 20px; height: 20px;
  }


  .intro-text {
      width: calc(100% - var(--space-md)*2);
      max-height: 85vh;
  }
  .intro-content {
      padding: var(--space-lg);
      padding-top: calc(var(--space-lg) + 32px);
  }
  .how-it-works-intro {
      grid-template-columns: 1fr;
  }
  .cta-button { padding: 12px 24px; min-width: 160px; }
}