/* AI Signature Generator - Styles */

/* ========== THEME SYSTEM ========== */

/* Theme: Default (Dark Neon) */
[data-theme="default"], :root {
  --bg: #08080F;
  --bg-secondary: #0F0F1A;
  --bg-card: #1A1A2E;
  --primary: #00E5CC;
  --primary-hover: #00FFE0;
  --accent: #FFBF00;
  --text: #E8ECF0;
  --text-secondary: #8888AA;
  --border: #2A2A3E;
  --watermark: rgba(255,255,255,0.06);
  --gradient-hero: 135deg, #fff, var(--primary);
  --hero-bg: transparent;
  --card-shadow: none;
  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', -apple-system, sans-serif;
  --nav-bg: rgba(8,8,15,0.9);
  --nav-blur: blur(12px);
}

/* Theme: Zen White (禅意白) */
[data-theme="zen"] {
  --bg: #FAFAF8;
  --bg-secondary: #F0F0EC;
  --bg-card: #FFFFFF;
  --primary: #7CA89D;
  --primary-hover: #6B9A8E;
  --accent: #C4A88A;
  --text: #2D2D2D;
  --text-secondary: #8A8A86;
  --border: #E2E2DE;
  --watermark: rgba(0,0,0,0.04);
  --gradient-hero: 135deg, #2D2D2D, #7CA89D;
  --hero-bg: transparent;
  --card-shadow: 0 4px 24px rgba(0,0,0,0.04);
  --font-heading: 'Inter', sans-serif;
  --font-body: 'Inter', -apple-system, sans-serif;
  --nav-bg: rgba(250,250,248,0.9);
  --nav-blur: blur(12px);
}

/* Theme: Warm Parchment (羊皮纸手作坊) */
[data-theme="warm"] {
  --bg: #FDF8F0;
  --bg-secondary: #F5EDE0;
  --bg-card: #FFFBF5;
  --primary: #C45A3C;
  --primary-hover: #B34D30;
  --accent: #D4A76A;
  --text: #3A2A1A;
  --text-secondary: #8A7A6A;
  --border: #E5D5C0;
  --watermark: rgba(0,0,0,0.04);
  --gradient-hero: 135deg, #3A2A1A, #C45A3C;
  --hero-bg: transparent;
  --card-shadow: 0 4px 24px rgba(0,0,0,0.04);
  --font-heading: 'Playfair Display', serif;
  --font-body: 'DM Sans', -apple-system, sans-serif;
  --nav-bg: rgba(253,248,240,0.9);
  --nav-blur: blur(12px);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* Navigation */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: var(--nav-blur);
  border-bottom: 1px solid var(--border);
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.nav-links { display: flex; gap: 2rem; align-items: center; }
.nav-links a { color: var(--text-secondary); text-decoration: none; font-size: 0.9rem; transition: color 0.2s; }
.nav-links a:hover { color: var(--text); }

.nav-cta {
  background: var(--primary);
  color: #000 !important;
  padding: 0.5rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.85rem !important;
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 6rem 2rem 4rem;
  text-align: center;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 1rem;
  background: linear-gradient(var(--gradient-hero));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p.subhead {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 2rem;
}

/* Signature Tool */
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2rem;
  max-width: 680px;
  width: 100%;
  margin: 0 auto;
  box-shadow: var(--card-shadow);
  position: relative;
  overflow: hidden;
}

.tool-input-row {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.tool-input-row input {
  flex: 1;
  min-width: 200px;
  padding: 0.85rem 1.25rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--bg-secondary);
  color: var(--text);
  font-size: 1.1rem;
  font-family: 'DM Sans', sans-serif;
  outline: none;
  transition: border-color 0.2s;
}

.tool-input-row input:focus {
  border-color: var(--primary);
}

.tool-input-row input::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

.tool-controls {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
}

.tool-controls-secondary {
  margin-bottom: 1rem;
}

.tool-controls select, .tool-controls input[type="color"] {
  padding: 0.6rem 1rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-secondary);
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  cursor: pointer;
}

.tool-controls select { min-width: 140px; flex: 1; }
.tool-controls input[type="color"] { width: 48px; height: 48px; padding: 4px; }
.tool-controls label { display: flex; align-items: center; gap: 0.5rem; color: var(--text-secondary); font-size: 0.85rem; }

.btn {
  padding: 0.75rem 1.75rem;
  border-radius: 12px;
  border: none;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  font-family: 'DM Sans', sans-serif;
}

.btn-primary {
  background: var(--primary);
  color: #000;
  flex: 1;
}

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

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text);
  border: 1px solid var(--border);
  flex: 1;
}

.btn-secondary:hover {
  border-color: var(--primary);
}

.btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* Tool Actions Row */
.tool-actions {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

/* Signature Preview */
.preview-area {
  position: relative;
  background: var(--bg-secondary);
  border-radius: 12px;
  min-height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  border: 1px dashed var(--border);
  overflow: hidden;
}

.preview-area canvas {
  max-width: 100%;
  max-height: 200px;
}

.watermark {
  position: absolute;
  bottom: 8px;
  right: 12px;
  font-size: 0.65rem;
  color: var(--watermark);
  pointer-events: none;
  letter-spacing: 0.5px;
}

.placeholder-text {
  color: var(--text-secondary);
  opacity: 0.3;
  font-size: 0.9rem;
}

.daily-count {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-align: center;
  margin-top: 0.75rem;
}

/* Example signatures */
.examples {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.example-sig {
  padding: 0.75rem 1.5rem;
  background: var(--bg-secondary);
  border-radius: 10px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all 0.2s;
  font-size: 1.2rem;
  font-family: 'Dancing Script', cursive;
}

.example-sig:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
}

/* Sections */
section {
  padding: 5rem 2rem;
  max-width: 1100px;
  margin: 0 auto;
}

section h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  text-align: center;
  margin-bottom: 1rem;
}

section .section-desc {
  text-align: center;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 3rem;
  font-size: 1rem;
}

/* How It Works */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
}

.step-number {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary);
  color: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin: 0 auto 1rem;
}

.step-card h3 { margin-bottom: 0.5rem; font-size: 1.1rem; }
.step-card p { color: var(--text-secondary); font-size: 0.9rem; }

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
}

.feature-icon {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.feature-card h3 { font-size: 1rem; margin-bottom: 0.4rem; }
.feature-card p { color: var(--text-secondary); font-size: 0.85rem; }

/* Use Cases */
.usecases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.usecase-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
}

.usecase-tag {
  display: inline-block;
  padding: 0.25rem 0.6rem;
  background: rgba(0,229,204,0.1);
  color: var(--primary);
  border-radius: 6px;
  font-size: 0.75rem;
  margin-bottom: 0.75rem;
}

.usecase-card h3 { font-size: 1rem; margin-bottom: 0.3rem; }

.usecase-card .before { color: #FF6B6B; font-size: 0.85rem; margin-bottom: 0.25rem; }
.usecase-card .after { color: #51CF66; font-size: 0.85rem; }

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  max-width: 600px;
  margin: 0 auto;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  position: relative;
}

.pricing-card.featured {
  border-color: var(--primary);
}

.pricing-card .plan-name { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1px; color: var(--text-secondary); margin-bottom: 0.5rem; }
.pricing-card .price { font-size: 2.5rem; font-weight: 700; font-family: var(--font-heading); }
.pricing-card .price span { font-size: 1rem; font-weight: 400; color: var(--text-secondary); }
.pricing-card ul { list-style: none; margin: 1.5rem 0; text-align: left; }
.pricing-card ul li { padding: 0.3rem 0; font-size: 0.85rem; color: var(--text-secondary); }
.pricing-card ul li::before { content: '✓ '; color: var(--primary); }

/* FAQ */
.faq-list {
  max-width: 640px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  cursor: pointer;
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 500;
  font-size: 0.95rem;
}

.faq-answer {
  margin-top: 0.75rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  display: none;
  line-height: 1.7;
}

.faq-item.open .faq-answer { display: block; }
.faq-item .toggle { font-size: 1.2rem; transition: transform 0.2s; }
.faq-item.open .toggle { transform: rotate(45deg); }

/* Language Switch */
.lang-switch {
  display: flex;
  gap: 0.25rem;
  margin-left: 1rem;
}

.lang-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 0.3rem 0.6rem;
  border-radius: 6px;
  font-size: 0.75rem;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s;
  font-family: 'DM Sans', sans-serif;
}

.lang-btn.active {
  background: var(--primary);
  color: #000;
  border-color: var(--primary);
}

.lang-btn:hover:not(.active) {
  border-color: var(--primary);
  color: var(--text);
}

/* Theme Switch */
.theme-switch {
  display: flex;
  gap: 0.25rem;
  align-items: center;
}

.theme-btn {
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.3rem 0.5rem;
  border-radius: 6px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  line-height: 1;
}

.theme-btn.active {
  border-color: var(--primary);
  background: var(--bg-card);
  box-shadow: 0 0 0 1px var(--primary);
}

.theme-btn:hover:not(.active) {
  border-color: var(--primary);
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.8rem;
}

footer a { color: var(--text-secondary); text-decoration: none; }
footer a:hover { color: var(--text); }

/* Responsive */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .steps, .features-grid, .usecases-grid { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.75rem; }
  .tool-input-row { flex-direction: column; }
  .tool-input-row input { min-width: auto; }
}