/* =============================================
   Get Color Code - 圖片取色工具
   Optimized UI Style Sheet
   ============================================= */

/* ─── CSS Variables ─────────────────────── */
:root {
  /* Colors */
  --bg: #ffffff;
  --bg-gradient: #ffffff;
  --card-bg: #ffffff;
  --card-border: rgba(0, 0, 0, 0.06);
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #aeaeb2;

  /* Brand - gradient theme for a color tool */
  --brand-start: #6366f1;
  --brand-mid: #8b5cf6;
  --brand-end: #a78bfa;
  --brand-gradient: linear-gradient(135deg, #6366f1, #8b5cf6, #a78bfa);
  --brand-subtle: rgba(99, 102, 241, 0.08);

  /* Semantic */
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: rgba(99, 102, 241, 0.12);
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;

  /* Surfaces */
  --border: rgba(0, 0, 0, 0.08);
  --border-light: rgba(0, 0, 0, 0.04);
  --hover-bg: rgba(0, 0, 0, 0.04);
  --code-bg: #f4f5f7;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow: 0 6px 28px rgba(0, 0, 0, 0.10);
  --shadow-md: 0 12px 40px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 16px 56px rgba(0, 0, 0, 0.14);
  --shadow-xl: 0 24px 72px rgba(0, 0, 0, 0.18);

  /* Radius */
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', 'JetBrains Mono', monospace;

  /* Transitions */
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Toast */
  --toast-bg: #1d1d1f;
  --toast-text: #ffffff;
}

/* ─── Dark Mode ─────────────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121214;
    --bg-gradient: linear-gradient(135deg, #121214 0%, #18181b 100%);
    --card-bg: #1c1c1e;
    --card-border: rgba(255, 255, 255, 0.06);
    --text: #f5f5f7;
    --text-secondary: #98989d;
    --text-tertiary: #636366;

    --border: rgba(255, 255, 255, 0.08);
    --border-light: rgba(255, 255, 255, 0.04);
    --hover-bg: rgba(255, 255, 255, 0.06);
    --code-bg: #2c2c2e;

    --brand-subtle: rgba(99, 102, 241, 0.12);
    --accent-light: rgba(99, 102, 241, 0.18);

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.35);

    --toast-bg: #f5f5f7;
    --toast-text: #1d1d1f;
  }

  .image-wrapper {
    background: repeating-conic-gradient(#2c2c2e 0% 25%, transparent 0% 50%) 50% / 20px 20px;
  }

  .upload-overlay {
    background: rgba(0, 0, 0, 0.75);
  }

  .magnifier {
    background: rgba(30, 30, 32, 0.95);
    border-color: rgba(255, 255, 255, 0.15);
  }
}

/* ─── Manual Dark Mode ──────────────────── */
[data-theme="dark"] {
  /* Colors */
  --bg: #121214;
  --bg-gradient: linear-gradient(135deg, #121214 0%, #18181b 100%);
  --card-bg: #1c1c1e;
  --card-border: rgba(255, 255, 255, 0.06);
  --text: #f5f5f7;
  --text-secondary: #98989d;
  --text-tertiary: #636366;

  --border: rgba(255, 255, 255, 0.08);
  --border-light: rgba(255, 255, 255, 0.04);
  --hover-bg: rgba(255, 255, 255, 0.06);
  --code-bg: #2c2c2e;

  --brand-subtle: rgba(99, 102, 241, 0.12);
  --accent-light: rgba(99, 102, 241, 0.18);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.35);

  --toast-bg: #f5f5f7;
  --toast-text: #1d1d1f;
}

[data-theme="dark"] .image-wrapper {
  background: repeating-conic-gradient(#2c2c2e 0% 25%, transparent 0% 50%) 50% / 20px 20px;
}

[data-theme="dark"] .upload-overlay {
  background: rgba(0, 0, 0, 0.75);
}

[data-theme="dark"] .magnifier {
  background: rgba(30, 30, 32, 0.95);
  border-color: rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .logo-icon {
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

[data-theme="dark"] .header-logo-img {
  filter: brightness(0.95);
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-gradient);
  color: var(--text);
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 80px 24px 28px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
}

/* ─── Animations ────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInScale {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes checkPop {
  0%   { transform: scale(0); opacity: 0; }
  50%  { transform: scale(1.2); }
  100% { transform: scale(1); opacity: 1; }
}

.header { animation: fadeInUp 0.5s ease both; }
.main-container { animation: fadeInUp 0.5s ease 0.1s both; }
.content-wrapper { animation: fadeInUp 0.5s ease 0.2s both; }

/* ─── Topbar ────────────────────────────── */
.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: 50px;
  display: flex;
  align-items: center;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0 16px;
}

.topbar-left {
  flex-shrink: 0;
  width: 190px;
}

.topbar-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text);
}

.topbar-logo svg {
  width: 20px;
  height: 20px;
  color: var(--accent);
  flex-shrink: 0;
}

.topbar-logo-img {
  width: 160px;
  height: 160px;
  flex-shrink: 0;
  object-fit: contain;
}

.topbar-tags {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 8px;
  mask-image: linear-gradient(to right, transparent, black 24px, black calc(100% - 24px), transparent);
  -webkit-mask-image: linear-gradient(to right, transparent, black 24px, black calc(100% - 24px), transparent);
}

.topbar-tags::-webkit-scrollbar {
  display: none;
}

.topbar-tags a {
  display: inline-block;
  padding: 0 10px;
  height: 32px;
  line-height: 32px;
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  flex-shrink: 0;
}

.topbar-tags a:hover {
  color: var(--accent);
  background: var(--accent-light);
}

.topbar-right {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 4px;
  width: 100px;
  justify-content: flex-end;
}

.topbar-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.topbar-btn:hover {
  color: var(--accent);
  background: var(--hover-bg);
}

.topbar-btn svg {
  width: 18px;
  height: 18px;
}

/* ─── Header ────────────────────────────── */
.header {
  text-align: center;
  margin-bottom: 20px;
  max-width: 600px;
}

.section-title,
#faq-title {
  scroll-margin-top: 70px;
}

#howto-title,
#usecase-title {
  scroll-margin-top: 100px;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 1px;
}

.logo-icon {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  background: var(--brand-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
  flex-shrink: 0;
  transition: box-shadow var(--transition);
}

.header-logo-img {
  width: 480px;
  height: 480px;
  object-fit: contain;
  flex-shrink: 0;
}

.logo-icon svg {
  width: 22px;
  height: 22px;
  color: #fff;
}

.logo h1 {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.5px;
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 400;
  margin-top: 2px;
}

/* ─── Theme Toggle ──────────────────────── */
.theme-toggle {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.theme-toggle:hover {
  color: var(--accent);
  background: var(--hover-bg);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

/* ─── Language Toggle ─────────────────────── */
.lang-toggle {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.3px;
  text-transform: uppercase;
  font-family: var(--font-sans);
}

.lang-toggle:hover {
  color: var(--accent);
  background: var(--hover-bg);
}

.lang-toggle .lang-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

/* ─── Main Container ────────────────────── */
.main-container {
  display: flex;
  gap: 24px;
  width: 100%;
  max-width: 1140px;
  align-items: flex-start;
}

/* ─── Image Area ────────────────────────── */
.image-section {
  flex: 1;
  min-width: 0;
}

.image-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  overflow: hidden;
  transition: box-shadow var(--transition);
}

.image-card:focus-within {
  box-shadow: var(--shadow-md), 0 0 0 2px var(--accent-light);
}

.image-wrapper {
  position: relative;
  width: 100%;
  min-height: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: repeating-conic-gradient(#e8e8ed 0% 25%, transparent 0% 50%) 50% / 20px 20px;
  cursor: crosshair;
  overflow: hidden;
}

.image-wrapper img {
  max-width: 100%;
  max-height: 620px;
  display: block;
  user-select: none;
  -webkit-user-drag: none;
}

/* ─── Upload Overlay ────────────────────── */
.upload-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: opacity 0.35s ease, background 0.3s ease;
  z-index: 10;
}

.upload-overlay.drag-over {
  background: rgba(99, 102, 241, 0.08);
  border: 2px dashed var(--accent);
  inset: 8px;
  border-radius: calc(var(--radius) - 4px);
}

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

.upload-icon-wrapper {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--brand-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px dashed var(--border);
  transition: all var(--transition);
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 4px;
}

.upload-overlay.drag-over .upload-icon-wrapper {
  border-color: var(--accent);
  background: var(--accent-light);
  transform: scale(1.05);
}

.upload-icon-wrapper svg {
  width: 32px;
  height: 32px;
}

.upload-text {
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  margin-top: 8px;
}

.upload-hint {
  font-size: 13px;
  color: var(--text-secondary);
}

.upload-overlay .upload-hint:last-child {
  margin-top: 8px;
}

.upload-btn {
  padding: 12px 28px;
  background: var(--brand-gradient);
  color: #fff;
  border: none;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
  letter-spacing: 0.3px;
}

.upload-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.upload-btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.2);
}

.upload-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

#fileInput {
  display: none;
}

/* ─── Magnifier ─────────────────────────── */
.magnifier {
  position: fixed;
  width: 140px;
  height: 140px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow:
    0 4px 24px rgba(0, 0, 0, 0.25),
    0 1px 4px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  pointer-events: none;
  z-index: 100;
  display: none;
  overflow: hidden;
  will-change: left, top;
}

.magnifier-content {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
  width: 100%;
  height: 100%;
  gap: 0;
}

.magnifier-content .mag-cell {
  width: 100%;
  height: 100%;
}

.magnifier-crosshair-h {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 20px;
  height: 1px;
  background: rgba(255, 0, 0, 0.85);
  box-shadow: 0 0 2px rgba(0, 0, 0, 0.4);
  z-index: 2;
}

.magnifier-crosshair-v {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 1px;
  height: 20px;
  background: rgba(255, 0, 0, 0.85);
  box-shadow: 0 0 2px rgba(0, 0, 0, 0.4);
  z-index: 2;
}

.magnifier-zoom-label {
  position: absolute;
  top: -24px;
  right: 0;
  font-size: 10px;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  background: var(--card-bg);
  padding: 2px 8px;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  line-height: 1.4;
  pointer-events: none;
}

.magnifier-info {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3px 0;
  z-index: 3;
}

.magnifier-hex {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.5px;
  line-height: 1.3;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}

/* ─── Sidebar ───────────────────────────── */
.sidebar {
  width: 360px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: sticky;
  top: 24px;
}

/* ─── Card ──────────────────────────────── */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  padding: 22px;
  transition: box-shadow var(--transition);
}

.card-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-tertiary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-title svg {
  width: 14px;
  height: 14px;
}

/* ─── Color Preview ─────────────────────── */
.color-preview {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-bottom: 18px;
}

.color-swatch {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  border: 2px solid var(--border);
  flex-shrink: 0;
  background: #e8e8ed;
  transition: background var(--transition), border-color var(--transition), transform var(--transition-bounce);
  will-change: transform;
}

.color-swatch.picked {
  animation: fadeInScale 0.3s ease;
}

.color-preview .placeholder {
  color: var(--text-tertiary);
  font-size: 13px;
  font-weight: 400;
}

/* ─── Color Code Rows ───────────────────── */
.color-codes {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.code-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--code-bg);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  cursor: pointer;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
}

.code-row::after {
  content: '點擊複製';
  position: absolute;
  right: 12px;
  font-size: 11px;
  color: var(--text-tertiary);
  opacity: 0;
  transition: opacity var(--transition);
  font-weight: 500;
}

.code-row:hover::after {
  opacity: 1;
}

.code-row:hover {
  background: var(--hover-bg);
  border-color: var(--border);
}

.code-row:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.code-row:active {
  transform: scale(0.98);
}

.code-row.copied {
  background: rgba(16, 185, 129, 0.1);
  border-color: var(--success);
}

[data-theme="dark"] .code-row.copied {
  background: rgba(16, 185, 129, 0.15);
}

.code-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
  letter-spacing: 0.5px;
  min-width: 32px;
  text-transform: uppercase;
}

.code-value {
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--text);
  flex: 1;
  text-align: right;
  letter-spacing: -0.2px;
}

.copy-btn {
  width: 30px;
  height: 30px;
  border-radius: 7px;
  border: none;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-tertiary);
  transition: all var(--transition);
  flex-shrink: 0;
}

.copy-btn svg {
  width: 15px;
  height: 15px;
}

.copy-btn:hover {
  background: rgba(0, 0, 0, 0.06);
  color: var(--accent);
}

[data-theme="dark"] .copy-btn:hover {
  background: rgba(255, 255, 255, 0.08);
}

.copy-btn.copied {
  background: var(--success);
  color: #fff;
}

.copy-btn.copied svg {
  animation: checkPop 0.3s ease;
}

/* ─── Color Palette / History ───────────── */
.palette-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.palette-count {
  font-size: 11px;
  color: var(--text-tertiary);
  font-weight: 500;
}

.palette-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 46px;
}

.palette-color {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.palette-color::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 8px;
  background: inherit;
}

.palette-color::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 8px;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
}

.palette-color:hover {
  transform: scale(1.18) translateY(-2px);
  border-color: var(--text);
  z-index: 3;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.palette-color:active {
  transform: scale(1.05);
}

.palette-color.selected {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
  z-index: 2;
}

.palette-color.selected::after {
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
}

.palette-empty {
  color: var(--text-tertiary);
  font-size: 13px;
  text-align: center;
  width: 100%;
  padding: 12px 0;
}

.clear-btn {
  display: block;
  width: 100%;
  margin-top: 14px;
  padding: 9px;
  border: 1px solid var(--border);
  background: transparent;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition);
}

.clear-btn:hover {
  background: rgba(239, 68, 68, 0.06);
  color: var(--danger);
  border-color: rgba(239, 68, 68, 0.3);
}

.clear-btn:active {
  transform: scale(0.97);
}

/* =========================================
   Content Sections
   ========================================= */

.content-wrapper {
  width: 100%;
  max-width: 1140px;
  margin-top: 56px;
}

/* ─── Section Title ─────────────────────── */
.section-title {
  font-size: 24px;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 6px;
  text-align: center;
  letter-spacing: -0.3px;
}

.section-desc {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 28px;
}

/* ─── Section Badge ─────────────────────── */
.section-badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--brand-subtle);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  letter-spacing: 0.3px;
}

.section-header {
  text-align: center;
  margin-bottom: 28px;
}

/* ─── Features Grid ─────────────────────── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
  margin-bottom: 56px;
}

.feature-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  padding: 26px 22px;
  text-align: center;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--brand-gradient);
  opacity: 0;
  transition: opacity var(--transition);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--brand-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 14px;
  color: var(--accent);
  transition: transform var(--transition);
}

.feature-card:hover .feature-icon {
  transform: scale(1.1);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--text);
}

.feature-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ─── How To Use ────────────────────────── */
.howto-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  padding: 36px 32px;
  margin-bottom: 56px;
}

.howto-card .section-header {
  margin-bottom: 0;
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
  margin-top: 28px;
}

.step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 16px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.step:hover {
  background: var(--hover-bg);
}

.step-number {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--brand-gradient);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 700;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.25);
}

.step-content h4 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text);
}

.step-content p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ─── FAQ ───────────────────────────────── */
.faq-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  padding: 36px 32px;
  margin-bottom: 56px;
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 0;
  transition: color var(--transition);
  -webkit-tap-highlight-color: transparent;
}

.faq-question:hover {
  color: var(--accent);
}

.faq-question:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
  border-radius: 4px;
}

.faq-arrow {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--text-tertiary);
  transition: transform var(--transition-slow);
}

.faq-item.open .faq-arrow {
  transform: rotate(180deg);
}

.faq-arrow svg {
  width: 20px;
  height: 20px;
}

.faq-answer {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.75;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  padding: 0;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-bottom: 18px;
}

/* ─── Use Cases ─────────────────────────── */
.usecase-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--card-border);
  padding: 36px 32px;
  margin-bottom: 48px;
}

.usecase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
  margin-top: 24px;
}

.usecase-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: var(--code-bg);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  transition: all var(--transition);
  cursor: default;
}

.usecase-item:hover {
  background: var(--hover-bg);
  transform: translateX(4px);
}

.usecase-item svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--accent);
}

/* ─── Footer ────────────────────────────── */
.footer {
  width: 100%;
  max-width: 1140px;
  margin-top: 16px;
  padding: 28px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer p {
  font-size: 12px;
  color: var(--text-tertiary);
  line-height: 1.9;
}

.footer strong {
  color: var(--text-secondary);
}

.footer-privacy {
  margin-top: 4px;
}

.footer-privacy a {
  color: var(--accent);
  text-decoration: none;
  font-size: 12px;
  transition: opacity 0.2s;
}

.footer-privacy a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

@media (prefers-color-scheme: dark) {
  .footer-privacy a {
    color: #a78bfa;
  }
}

[data-theme="dark"] .footer-privacy a {
  color: #a78bfa;
}
/* ─── Toast ─────────────────────────────── */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 12px 24px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 600;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-lg);
  white-space: nowrap;
}

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

/* =========================================
   Responsive
   ========================================= */

@media (max-width: 960px) {
  .main-container {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    position: static;
  }

  .image-wrapper {
    min-height: 300px;
  }

  .steps {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 820px) {
  .main-container {
    flex-direction: column;
    align-items: stretch;
  }

  .image-section {
    flex: none;
    width: 100%;
  }

  .sidebar {
    width: 100%;
    position: static;
  }
}

@media (max-width: 640px) {
  body {
    padding: 72px 12px 16px;
  }

  .header {
    margin-bottom: 24px;
  }

  .logo h1 {
    font-size: 22px;
  }

  .subtitle {
    font-size: 13px;
  }

  .topbar-left {
    width: auto;
  }

  .topbar-right {
    width: auto;
  }

  .image-wrapper {
    min-height: 300px;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .steps {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .howto-card,
  .faq-card,
  .usecase-card {
    padding: 24px 18px;
    border-radius: var(--radius);
  }

  .section-title {
    font-size: 20px;
  }

  .content-wrapper {
    margin-top: 40px;
  }

  .features-grid {
    margin-bottom: 40px;
  }

  .howto-card,
  .faq-card {
    margin-bottom: 40px;
  }

  .code-row::after {
    display: none;
  }

  .sidebar {
    gap: 12px;
  }

  .usecase-grid {
    grid-template-columns: 1fr 1fr;
  }

  .palette-color {
    width: 38px;
    height: 38px;
  }
}

@media (max-width: 420px) {
  .usecase-grid {
    grid-template-columns: 1fr;
  }

  .step {
    padding: 12px;
  }
}

/* ─── Reduced Motion ────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}