/* ==========================================================================
   PIKKA.APP — DESIGN SYSTEM & CORE STYLES
   Aesthetic: Apple / Raycast / Linear Pro Design Suite
   ========================================================================== */

:root {
  /* Color Palette - Dark Obsidian (Default) */
  --bg-primary: #0a0b0e;
  --bg-secondary: #12141a;
  --bg-tertiary: #181b24;
  --bg-surface: #1e222d;
  --bg-elevated: #252a37;
  --bg-glass: rgba(18, 20, 26, 0.75);
  --bg-glass-card: rgba(24, 27, 36, 0.65);
  --bg-input: #151820;

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.14);
  --border-focus: #3b82f6;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #0a0b0e;

  /* Accent & Status Colors */
  --accent-primary: #3b82f6;
  --accent-primary-hover: #2563eb;
  --accent-glow: rgba(59, 130, 246, 0.25);
  --accent-cyan: #06b6d4;
  --accent-purple: #8b5cf6;
  --accent-amber: #f59e0b;
  --accent-emerald: #10b981;
  --accent-rose: #f43f5e;

  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Monaco, Consolas, monospace;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px var(--accent-glow);

  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-surface: #e2e8f0;
  --bg-elevated: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.85);
  --bg-glass-card: rgba(255, 255, 255, 0.9);
  --bg-input: #ffffff;

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-medium: rgba(0, 0, 0, 0.14);
  --border-focus: #2563eb;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  --accent-primary: #2563eb;
  --accent-primary-hover: #1d4ed8;
  --accent-glow: rgba(37, 99, 235, 0.2);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 28px rgba(0, 0, 0, 0.12);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
  background-image: 
    radial-gradient(at 10% 10%, rgba(59, 130, 246, 0.06) 0px, transparent 50%),
    radial-gradient(at 90% 20%, rgba(139, 92, 246, 0.05) 0px, transparent 50%),
    radial-gradient(at 50% 90%, rgba(6, 182, 212, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

img, svg {
  display: block;
  max-width: 100%;
}

/* Layout */
.container {
  width: 100%;
  max-width: 1240px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.container-narrow {
  max-width: 900px;
}

.container-prose {
  max-width: 800px;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition-normal);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #f43f5e 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.4);
}

.brand-icon svg {
  width: 18px;
  height: 18px;
  color: #ffffff;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.15);
  color: var(--accent-primary);
  border: 1px solid rgba(59, 130, 246, 0.3);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-item a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  padding: 0.4rem 0;
}

.nav-item a:hover,
.nav-item.active a {
  color: var(--text-primary);
}

.nav-item.highlight a {
  color: var(--accent-primary);
  font-weight: 600;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-medium);
  background: var(--bg-surface);
}

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  white-space: nowrap;
  line-height: 1;
}

.btn-sm {
  padding: 0.45rem 0.85rem;
  font-size: 0.8rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.85rem 1.65rem;
  font-size: 1rem;
  border-radius: var(--radius-lg);
}

.btn-primary {
  background: var(--accent-primary);
  color: #ffffff;
  box-shadow: 0 2px 10px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-primary-hover);
  box-shadow: 0 4px 16px var(--accent-glow);
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  background: var(--bg-surface);
  border-color: var(--border-focus);
  color: var(--text-primary);
}

.btn-ghost {
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.btn-accent-glow {
  background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  color: #ffffff;
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.35);
}

.btn-accent-glow:hover {
  box-shadow: 0 6px 24px rgba(99, 102, 241, 0.5);
  transform: translateY(-1px);
}

/* Hero Section */
.hero {
  padding: 4.5rem 0 3rem;
  text-align: center;
  position: relative;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.95rem;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-medium);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  transition: all var(--transition-fast);
}

.hero-pill:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

.hero-pill-badge {
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
  background: var(--accent-primary);
  color: #ffffff;
  font-size: 0.72rem;
  font-weight: 700;
}

.hero-title {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.hero-title-gradient {
  background: linear-gradient(135deg, #ffffff 30%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="light"] .hero-title-gradient {
  background: linear-gradient(135deg, #0f172a 30%, #3b82f6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

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

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

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

@media (max-width: 900px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* Cards */
.card {
  background: var(--bg-glass-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.card:hover {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-md);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.card-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1;
}

.badge-success {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-warning {
  background: rgba(245, 158, 11, 0.15);
  color: #f59e0b;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-danger {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.badge-neutral {
  background: var(--bg-surface);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

/* Breadcrumbs */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.breadcrumbs a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.breadcrumbs a:hover {
  color: var(--accent-primary);
}

.breadcrumbs-separator {
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumbs-current {
  color: var(--text-primary);
  font-weight: 600;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border-medium);
  color: var(--text-primary);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.88rem;
  font-weight: 500;
  animation: toastIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* Prose & Editorial Styling */
.prose {
  color: var(--text-secondary);
  line-height: 1.75;
  font-size: 1.05rem;
}

.prose h1, .prose h2, .prose h3, .prose h4 {
  color: var(--text-primary);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: 2.25rem;
  margin-bottom: 1rem;
}

.prose h1 { font-size: 2.25rem; }
.prose h2 { font-size: 1.75rem; border-bottom: 1px solid var(--border-subtle); padding-bottom: 0.5rem; }
.prose h3 { font-size: 1.35rem; }

.prose p { margin-bottom: 1.35rem; }
.prose ul, .prose ol { margin-bottom: 1.35rem; padding-left: 1.5rem; }
.prose li { margin-bottom: 0.45rem; }

.prose strong { color: var(--text-primary); font-weight: 600; }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--accent-primary);
}

.prose pre {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.prose blockquote {
  border-left: 3px solid var(--accent-primary);
  padding-left: 1.25rem;
  font-style: italic;
  color: var(--text-primary);
  margin: 1.5rem 0;
  background: rgba(59, 130, 246, 0.05);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

/* Footer */
.site-footer {
  margin-top: auto;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: 4.5rem 0 2.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 3.5rem;
}

@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.footer-brand p {
  margin-top: 0.75rem;
  max-width: 320px;
  line-height: 1.6;
}

.footer-col-title {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-subtle);
  padding-top: 2rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

@media (max-width: 768px) {
  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
}

@media (max-width: 860px) {
  .mobile-nav-toggle {
    display: flex;
  }
  .nav-links {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-medium);
    padding: 1.5rem;
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    display: none;
  }
  .nav-links.is-open {
    display: flex;
  }
}