/* ===== dichan.bot — Visual Design System ===== */
/* Inspired by lobsterhouse.manus.space */

/* --- CSS Variables --- */
:root {
  --color-primary: #E53E3E;
  --color-primary-dark: #C53030;
  --color-primary-light: #FED7D7;
  --color-primary-bg: #FFF5F5;
  --color-accent: #38A169;
  --color-accent-light: #C6F6D5;
  --color-text: #1A202C;
  --color-text-secondary: #4A5568;
  --color-text-muted: #718096;
  --color-bg: #FFFFFF;
  --color-bg-gray: #F7FAFC;
  --color-border: #E2E8F0;
  --color-border-light: #EDF2F7;
  --color-code-bg: #1A202C;
  --color-code-text: #68D391;
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 40px rgba(0,0,0,0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition: 0.2s ease;
  --max-width: 1100px;
  --nav-height: 64px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 24px;
}

.nav-inner {
  max-width: var(--max-width);
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

.nav-logo:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.nav-logo .logo-icon {
  font-size: 1.5rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.nav-links a:hover {
  color: var(--color-primary);
  background: var(--color-primary-bg);
  text-decoration: none;
}

.nav-links a.active {
  color: var(--color-primary);
  background: var(--color-primary-bg);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--color-text);
}

.nav-toggle svg {
  width: 24px;
  height: 24px;
}

/* --- Page Layout --- */
.page-body {
  padding-top: var(--nav-height);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Hero Section --- */
.hero {
  text-align: center;
  padding: 80px 24px 60px;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--color-primary-bg) 0%, var(--color-bg) 100%);
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(229, 62, 62, 0.04) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(56, 161, 105, 0.03) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  padding: 6px 16px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: 24px;
}

.hero-badge .badge-dot {
  width: 6px;
  height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero-icon {
  font-size: 3.5rem;
  margin-bottom: 16px;
  display: block;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition);
  line-height: 1.4;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(229, 62, 62, 0.3);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  box-shadow: 0 6px 20px rgba(229, 62, 62, 0.4);
}

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

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-bg);
}

.btn-accent {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 4px 14px rgba(56, 161, 105, 0.3);
}

.btn-accent:hover {
  background: #2F855A;
  box-shadow: 0 6px 20px rgba(56, 161, 105, 0.4);
}

.btn-sm {
  font-size: 0.85rem;
  padding: 8px 16px;
}

/* --- Stats Bar --- */
.stats-bar {
  display: flex;
  justify-content: center;
  gap: 48px;
  padding: 40px 24px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-text);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* --- Section --- */
.section {
  padding: 64px 24px;
}

.section-alt {
  background: var(--color-bg-gray);
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-bg);
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.section-header p {
  font-size: 1rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto;
}

.section-header .section-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.9rem;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
  margin-top: 8px;
}

.section-header .section-link:hover {
  text-decoration: underline;
}

/* --- Feature Cards (What You Can Do) --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.feature-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

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

.feature-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
  border-color: var(--color-primary-light);
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  background: var(--color-primary-bg);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- Skills Cards --- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.skill-card {
  background: var(--color-bg);
  border: 2px dashed var(--color-accent);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: all var(--transition);
  text-decoration: none;
  color: inherit;
  display: block;
}

.skill-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
  border-color: var(--color-accent);
  background: #F0FFF4;
  text-decoration: none;
}

.skill-card-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.skill-card-icon {
  width: 44px;
  height: 44px;
  background: var(--color-accent-light);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.skill-card-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.skill-card-desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.skill-card-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--color-border-light);
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

.skill-card-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* --- Terminal / Code Block --- */
.terminal {
  background: var(--color-code-bg);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 24px auto;
  max-width: 640px;
  position: relative;
  overflow: hidden;
}

.terminal-dots {
  display: flex;
  gap: 6px;
  margin-bottom: 16px;
}

.terminal-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.terminal-dots span:nth-child(1) { background: #FC8181; }
.terminal-dots span:nth-child(2) { background: #F6E05E; }
.terminal-dots span:nth-child(3) { background: #68D391; }

.terminal-line {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--color-code-text);
}

.terminal-line .prompt {
  color: #A0AEC0;
}

.terminal-line .cmd {
  color: #63B3ED;
}

.terminal-line .string {
  color: #68D391;
}

.terminal-line .success {
  color: #68D391;
}

/* --- Steps --- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.step-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
  position: relative;
  transition: all var(--transition);
}

.step-card:hover {
  box-shadow: var(--shadow-md);
}

.step-number {
  font-size: 3rem;
  font-weight: 900;
  color: var(--color-primary-light);
  line-height: 1;
  margin-bottom: 12px;
}

.step-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.step-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step-card p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- Prompt Block --- */
.prompt-block {
  background: var(--color-code-bg);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 24px 0;
  position: relative;
}

.prompt-block-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.prompt-block-header .prompt-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-primary);
  background: rgba(229, 62, 62, 0.15);
  padding: 3px 10px;
  border-radius: 100px;
  font-weight: 600;
}

.prompt-block pre {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #E2E8F0;
  line-height: 1.8;
  white-space: pre-wrap;
  word-break: break-word;
}

.prompt-block .copy-hint {
  text-align: right;
  margin-top: 12px;
  font-size: 0.8rem;
  color: #A0AEC0;
}

/* --- Info Box (for detail pages) --- */
.info-box {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  margin: 20px 0;
  transition: all var(--transition);
}

.info-box:hover {
  box-shadow: var(--shadow-sm);
}

.info-box h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.info-box ul {
  list-style: none;
  padding: 0;
}

.info-box ul li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border-light);
}

.info-box ul li:last-child {
  border-bottom: none;
}

.info-box ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: 50%;
}

/* --- Download Box --- */
.download-box {
  background: linear-gradient(135deg, var(--color-primary-bg) 0%, #FFF 100%);
  border: 2px dashed var(--color-primary);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  margin: 20px 0;
  text-align: center;
}

.download-box h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.download-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

/* --- Copy Button --- */
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.copy-btn:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(229, 62, 62, 0.3);
}

.copy-btn.copied {
  background: var(--color-accent);
}

/* --- Breadcrumb / Back Link --- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 20px 0;
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all var(--transition);
}

.breadcrumb a:hover {
  text-decoration: none;
  opacity: 0.8;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 40px 24px;
  border-top: 1px solid var(--color-border-light);
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

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

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

/* --- CTA Section --- */
.cta-section {
  text-align: center;
  padding: 64px 24px;
  background: linear-gradient(135deg, var(--color-primary-bg) 0%, #FFF 50%, var(--color-accent-light) 100%);
}

.cta-section h2 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.cta-section p {
  color: var(--color-text-secondary);
  margin-bottom: 24px;
  font-size: 1rem;
}

/* --- General Links --- */
a {
  color: var(--color-primary);
  text-decoration: none;
  transition: all var(--transition);
}

a:hover {
  text-decoration: underline;
}

/* --- Code Inline --- */
code {
  font-family: var(--font-mono);
  background: var(--color-bg-gray);
  border: 1px solid var(--color-border-light);
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 0.85em;
  color: var(--color-primary);
}

/* --- Manual Copy Area --- */
#manual-copy-area {
  margin-top: 12px;
}

#manual-copy-area p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

#manual-copy-area textarea {
  width: 100%;
  box-sizing: border-box;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  resize: vertical;
  background: var(--color-bg-gray);
}

/* --- Page Title (for sub pages) --- */
.page-title {
  padding: 48px 0 24px;
}

.page-title h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.page-title p {
  color: var(--color-text-secondary);
  font-size: 1rem;
}

/* --- Muted text --- */
.muted {
  color: var(--color-text-muted);
}

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

/* Tablet */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 12px 24px;
    gap: 4px;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    width: 100%;
    padding: 10px 14px;
    font-size: 0.95rem;
  }

  .nav-toggle {
    display: block;
  }

  .hero {
    padding: 48px 20px 40px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 0.95rem;
  }

  .hero-desc {
    font-size: 0.95rem;
  }

  .hero-icon {
    font-size: 2.5rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

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

  .steps {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .stats-bar {
    gap: 24px;
  }

  .stat-number {
    font-size: 1.6rem;
  }

  .section {
    padding: 48px 20px;
  }

  .section-header h2 {
    font-size: 1.5rem;
  }

  .hero-actions {
    flex-direction: column;
    gap: 10px;
  }

  .hero-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .download-actions {
    flex-direction: column;
  }

  .download-actions .btn,
  .download-actions .copy-btn {
    width: 100%;
    justify-content: center;
  }

  .cta-section h2 {
    font-size: 1.4rem;
  }

  .page-title {
    padding: 32px 0 16px;
  }

  .page-title h1 {
    font-size: 1.5rem;
  }

  .terminal {
    padding: 16px;
    margin: 16px auto;
  }

  .terminal-line {
    font-size: 0.78rem;
  }
}

/* Small mobile */
@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.7rem;
  }

  .hero-subtitle {
    font-size: 0.85rem;
  }

  .stats-bar {
    gap: 16px;
  }

  .stat-item {
    min-width: 80px;
  }

  .stat-number {
    font-size: 1.3rem;
  }

  .stat-label {
    font-size: 0.78rem;
  }

  .feature-card {
    padding: 20px 16px;
  }

  .section-header h2 {
    font-size: 1.3rem;
  }

  .btn {
    font-size: 0.88rem;
    padding: 10px 18px;
  }

  .info-box {
    padding: 20px 16px;
  }

  .download-box {
    padding: 20px 16px;
  }
}

/* Large screens */
@media (min-width: 1200px) {
  .hero h1 {
    font-size: 3.2rem;
  }

  .hero-subtitle {
    font-size: 1.3rem;
  }

  .features-grid {
    gap: 24px;
  }
}