/* === Reset & Base === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-primary: #f0f2f5;
  --bg-secondary: #ffffff;
  --bg-panel: #ffffff;
  --text-primary: #1a1a2e;
  --text-secondary: #555;
  --border-color: #e0e0e0;
  --accent: #6c5ce7;
  --accent-light: #a29bfe;
  --shadow-soft: rgba(0, 0, 0, 0.08);
  --radius: 12px;
  --header-bg: rgba(255, 255, 255, 0.85);
  --code-bg: #1e1e2e;
  --code-text: #cdd6f4;
  --toast-bg: #1a1a2e;
  --toast-text: #ffffff;
}

[data-theme="dark"] {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-panel: #16162a;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0b0;
  --border-color: #2a2a40;
  --shadow-soft: rgba(0, 0, 0, 0.3);
  --header-bg: rgba(15, 15, 26, 0.9);
  --code-bg: #11111b;
  --code-text: #cdd6f4;
  --toast-bg: #ffffff;
  --toast-text: #1a1a2e;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
  line-height: 1.6;
}

/* === Header === */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 24px;
}

.header-content {
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  font-size: 28px;
}

.logo-area h1 {
  font-size: 20px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), #fd79a8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  padding-left: 12px;
  border-left: 2px solid var(--border-color);
}

.icon-btn {
  background: none;
  border: 2px solid var(--border-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  font-size: 18px;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-btn:hover {
  border-color: var(--accent);
  transform: scale(1.1);
}

/* === Main Layout === */
.app-main {
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  gap: 24px;
  padding: 24px;
  min-height: calc(100vh - 140px);
}

/* === Controls Panel === */
.controls-panel {
  width: 380px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow-y: auto;
  max-height: calc(100vh - 100px);
  position: sticky;
  top: 80px;
}

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

.controls-panel::-webkit-scrollbar-track {
  background: transparent;
}

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

.panel-section {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 16px;
  transition: background 0.3s;
}

.section-title {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

/* === Control Groups === */
.control-group {
  margin-bottom: 12px;
}

.control-group label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.control-group label span {
  color: var(--accent);
  font-weight: 600;
  font-family: "SF Mono", "Fira Code", monospace;
}

input[type="range"] {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border-color);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid white;
  box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid white;
  box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

.color-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

input[type="color"] {
  width: 40px;
  height: 32px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  padding: 2px;
  background: var(--bg-panel);
}

.color-row span {
  font-size: 13px;
  font-family: "SF Mono", "Fira Code", monospace;
  color: var(--text-secondary);
}

/* === Presets Grid === */
.presets-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.preset-btn {
  padding: 8px 4px;
  font-size: 11px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.preset-btn:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--shadow-soft);
}

.preset-btn.active {
  border-color: var(--accent);
  background: var(--accent);
  color: white;
}

/* === Background Tabs === */
.bg-tabs, .element-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 12px;
  background: var(--bg-primary);
  border-radius: 8px;
  padding: 4px;
}

.bg-tab, .element-tab {
  flex: 1;
  padding: 8px;
  font-size: 13px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.bg-tab.active, .element-tab.active {
  background: var(--accent);
  color: white;
}

.bg-content.hidden {
  display: none;
}

/* === Gradient Grid === */
.gradient-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.gradient-swatch {
  width: 100%;
  aspect-ratio: 1;
  border-radius: 8px;
  border: 2px solid var(--border-color);
  cursor: pointer;
  transition: all 0.2s;
}

.gradient-swatch:hover {
  transform: scale(1.08);
  box-shadow: 0 4px 12px var(--shadow-soft);
}

.gradient-swatch.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent);
}

.upload-btn {
  display: block;
  padding: 12px;
  text-align: center;
  background: var(--bg-primary);
  border: 2px dashed var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.upload-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.uploaded-name {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 8px;
  text-align: center;
}

/* === Preview Panel === */
.preview-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.preview-container {
  flex: 1;
  min-height: 450px;
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background-size: cover;
  background-position: center;
  transition: background 0.3s;
}

/* === Glass Elements === */
.glass-element {
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all 0.15s ease;
}

.glass-content {
  padding: 32px;
  text-align: center;
  color: #ffffff;
  text-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.glass-content h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.glass-content p {
  font-size: 14px;
  opacity: 0.9;
  line-height: 1.5;
}

/* Navbar element type */
.glass-element.element-navbar {
  width: 100%;
  position: absolute;
  top: 0;
  left: 0;
}

.glass-element.element-navbar .glass-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
}

.glass-element.element-navbar .nav-items {
  display: flex;
  gap: 24px;
}

.glass-element.element-navbar .nav-items span {
  font-size: 14px;
  color: #fff;
  cursor: default;
}

.glass-element.element-navbar .nav-logo {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}

/* Sidebar element type */
.glass-element.element-sidebar {
  width: 200px;
  height: 80%;
  position: absolute;
  left: 20px;
  top: 10%;
}

.glass-element.element-sidebar .glass-content {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 24px;
  text-align: left;
}

.glass-element.element-sidebar .sidebar-item {
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 14px;
  color: #fff;
  background: rgba(255,255,255,0.1);
}

/* Button element type */
.glass-element.element-button {
  display: inline-block;
}

.glass-element.element-button .glass-content {
  padding: 14px 40px;
  font-size: 16px;
  font-weight: 600;
}

/* === Code Output === */
.code-output {
  background: var(--code-bg);
  border-radius: var(--radius);
  overflow: hidden;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: rgba(255,255,255,0.05);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  color: #888;
  font-size: 14px;
}

.copy-btn {
  padding: 6px 16px;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}

.copy-btn:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

.code-block {
  padding: 16px;
  overflow-x: auto;
  max-height: 250px;
  overflow-y: auto;
}

.code-block code {
  font-family: "SF Mono", "Fira Code", "Cascadia Code", monospace;
  font-size: 13px;
  line-height: 1.6;
  color: var(--code-text);
  white-space: pre;
}

.code-block::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

.code-block::-webkit-scrollbar-track {
  background: transparent;
}

.code-block::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.2);
  border-radius: 3px;
}

/* === Toast === */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 14px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
  opacity: 0;
  transition: all 0.3s;
  z-index: 1000;
}

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

.toast.hidden {
  display: none;
}

/* === Footer === */
.app-footer {
  text-align: center;
  padding: 20px;
  font-size: 13px;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-color);
}

.app-footer a {
  color: var(--accent);
  text-decoration: none;
}

.app-footer a:hover {
  text-decoration: underline;
}

/* === Responsive === */
@media (max-width: 1024px) {
  .app-main {
    flex-direction: column;
  }

  .controls-panel {
    width: 100%;
    max-height: none;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
  }

  .controls-panel .panel-section {
    flex: 1;
    min-width: 280px;
  }

  .preview-container {
    min-height: 350px;
  }
}

@media (max-width: 640px) {
  .app-header {
    padding: 10px 16px;
  }

  .logo-area h1 {
    font-size: 16px;
  }

  .subtitle {
    display: none;
  }

  .app-main {
    padding: 12px;
    gap: 12px;
  }

  .presets-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .gradient-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .controls-panel .panel-section {
    min-width: 100%;
  }
}