/* ============================================
   Author Portfolio - Shared Styles
   A technology-meets-literature aesthetic
   ============================================ */

/* ---------- CSS Variables ---------- */
:root {
  /* Primary palette - Cool Blue/Cyan technology theme */
  --color-primary: #0ea5e9;
  --color-primary-light: #7dd3fc;
  --color-primary-dark: #0369a1;
  --color-accent: #06b6d4;

  /* Background colors */
  --color-bg-main: #f0f9ff;
  --color-bg-card: #ffffff;
  --color-bg-dark: #0c1929;
  --color-bg-gradient: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #ecfeff 100%);

  /* Text colors */
  --color-text-primary: #0c4a6e;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-text-light: #f0f9ff;

  /* Focus ring */
  --color-focus-ring: rgba(14, 165, 233, 0.5);

  /* Effects */
  --color-glow: rgba(14, 165, 233, 0.3);
  --color-node: #0ea5e9;
  --color-line: rgba(14, 165, 233, 0.3);

  /* Typography */
  --font-display: 'Space Mono', 'Courier New', monospace;
  --font-body: 'Source Sans 3', 'Segoe UI', sans-serif;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(14, 165, 233, 0.1);
  --shadow-md: 0 4px 20px rgba(14, 165, 233, 0.15);
  --shadow-lg: 0 10px 40px rgba(14, 165, 233, 0.2);
  --shadow-glow: 0 0 30px rgba(14, 165, 233, 0.3);

  /* Breakpoints (for documentation - CSS can't use vars in media queries)
     --breakpoint-sm: 600px;   Mobile small
     --breakpoint-md: 768px;   Tablet / Mobile nav
     --breakpoint-lg: 900px;   Desktop small
  */
}

/* ---------- Dark Mode Variables ---------- */
[data-theme="dark"] {
  --color-primary: #38bdf8;
  --color-primary-light: #7dd3fc;
  --color-primary-dark: #0ea5e9;
  --color-accent: #22d3ee;

  --color-bg-main: #0f172a;
  --color-bg-card: #1e293b;
  --color-bg-dark: #020617;
  --color-bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);

  --color-text-primary: #e2e8f0;
  --color-text-secondary: #cbd5e1;
  --color-text-muted: #94a3b8;
  --color-text-light: #f8fafc;

  --color-focus-ring: rgba(56, 189, 248, 0.5);

  --color-glow: rgba(56, 189, 248, 0.3);
  --color-node: #38bdf8;
  --color-line: rgba(56, 189, 248, 0.3);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(56, 189, 248, 0.3);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-primary);
  background: var(--color-bg-gradient);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  color: var(--color-primary-dark);
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  color: var(--color-primary-dark);
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: 1.25rem;
  color: var(--color-primary);
}

p {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* ---------- Focus States (Accessibility) ---------- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Skip to main content link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: var(--color-text-light);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-size: 0.875rem;
  text-decoration: none;
  z-index: 10000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--spacing-sm);
  outline: 2px solid var(--color-text-light);
  outline-offset: 2px;
}

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.page-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
  padding: var(--spacing-lg) 0;
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(240, 249, 255, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(14, 165, 233, 0.1);
  transition: box-shadow var(--transition-normal), background var(--transition-normal);
}

[data-theme="dark"] .nav {
  background: rgba(15, 23, 42, 0.9);
  border-bottom-color: rgba(56, 189, 248, 0.1);
}

.nav.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  max-width: 1200px;
  margin: 0 auto;
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}


@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.2); }
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.nav-link {
  font-family: var(--font-display);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-secondary);
  padding: var(--spacing-xs) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-primary-dark);
  transition: var(--transition-fast);
}

/* Dark Mode Toggle */
.theme-toggle {
  background: none;
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-full);
  width: 40px;
  height: 40px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.theme-toggle:hover {
  transform: scale(1.05);
  border-color: var(--color-primary-light);
}

.theme-toggle:hover .theme-icon {
  color: var(--color-primary-light);
}

.theme-icon {
  width: 20px;
  height: 20px;
  color: var(--color-primary);
  transition: all var(--transition-fast);
}

.theme-icon-sun,
.theme-icon-moon {
  position: absolute;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.theme-icon-sun {
  opacity: 1;
  transform: rotate(0deg);
}

.theme-icon-moon {
  opacity: 0;
  transform: rotate(-90deg);
}

[data-theme="dark"] .theme-icon-sun {
  opacity: 0;
  transform: rotate(90deg);
}

[data-theme="dark"] .theme-icon-moon {
  opacity: 1;
  transform: rotate(0deg);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-light);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* ---------- Cards ---------- */
.card {
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(14, 165, 233, 0.1);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-main);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.card-title {
  margin-bottom: var(--spacing-xs);
}

/* ---------- Section Styles ---------- */
.section {
  padding: var(--spacing-xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.section-subtitle {
  font-family: var(--font-display);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--spacing-xs);
}

/* ---------- Grid System ---------- */
.grid {
  display: grid;
  gap: var(--spacing-md);
}

/* ---------- Forms ---------- */
.form-group {
  margin-bottom: var(--spacing-md);
}

.form-label {
  display: block;
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--spacing-sm);
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text-primary);
  background: var(--color-bg-card);
  border: 2px solid rgba(14, 165, 233, 0.2);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-glow);
}

.form-input:hover,
.form-textarea:hover {
  border-color: var(--color-primary-light);
}

.form-textarea {
  min-height: 150px;
  resize: vertical;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--color-bg-dark);
  color: var(--color-text-light);
  padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--color-primary-light);
}

.footer-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

.footer-link {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--color-primary-light);
}

.footer-bottom {
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* ---------- Animations ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn 0.6s ease forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* ---------- Scroll-Triggered Animations ---------- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered animation delays for multiple items */
.animate-on-scroll:nth-child(1) { transition-delay: 0s; }
.animate-on-scroll:nth-child(2) { transition-delay: 0.1s; }
.animate-on-scroll:nth-child(3) { transition-delay: 0.2s; }
.animate-on-scroll:nth-child(4) { transition-delay: 0.3s; }
.animate-on-scroll:nth-child(5) { transition-delay: 0.4s; }
.animate-on-scroll:nth-child(6) { transition-delay: 0.5s; }

/* Slide-in variations */
.animate-slide-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-slide-left.animated {
  opacity: 1;
  transform: translateX(0);
}

.animate-slide-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-slide-right.animated {
  opacity: 1;
  transform: translateX(0);
}

/* Scale-in animation */
.animate-scale {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-scale.animated {
  opacity: 1;
  transform: scale(1);
}

/* ---------- Page Header (shared across pages) ---------- */
.page-header {
  padding-top: 120px;
  padding-bottom: var(--spacing-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--color-glow) 0%, transparent 70%);
  opacity: 0.3;
  pointer-events: none;
}

/* ---------- Spinner Animation (shared) ---------- */
.spinner {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ---------- Button Loading State (shared) ---------- */
.btn-loading {
  display: none;
}

.btn.loading .btn-text {
  visibility: hidden;
}

.btn.loading .btn-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

/* ---------- Form Messages (shared) ---------- */
.form-message {
  margin-top: var(--spacing-md);
  padding: 0;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  text-align: center;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: all var(--transition-normal);
}

.form-message.visible {
  opacity: 1;
  max-height: 100px;
  padding: var(--spacing-sm) var(--spacing-md);
}

.form-message.success {
  background: rgba(34, 197, 94, 0.1);
  color: #16a34a;
  border: 1px solid rgba(34, 197, 94, 0.3);
}

[data-theme="dark"] .form-message.success {
  background: rgba(34, 197, 94, 0.2);
  color: #4ade80;
}

.form-message.error {
  background: rgba(239, 68, 68, 0.1);
  color: #dc2626;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

[data-theme="dark"] .form-message.error {
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
}

/* Dark background form messages variant */
.form-message--dark.success {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.form-message--dark.error {
  background: rgba(239, 68, 68, 0.3);
  color: white;
  border: 1px solid rgba(239, 68, 68, 0.5);
}

/* Compact form message variant */
.form-message--compact {
  margin-top: var(--spacing-xs);
  font-size: 0.8rem;
}

.form-message--compact.visible {
  max-height: 60px;
  padding: var(--spacing-xs) var(--spacing-sm);
}

/* ---------- Form Submitting State (shared) ---------- */
.submitting .form-input,
.submitting .form-textarea,
.submitting .signup-input,
.submitting .signup-input-compact,
.submitting input[type="email"],
.submitting input[type="text"] {
  opacity: 0.7;
  pointer-events: none;
}

/* ---------- Utility Classes ---------- */
.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(240, 253, 250, 0.98);
    padding: var(--spacing-md);
    border-bottom: 1px solid rgba(14, 165, 233, 0.1);
    gap: var(--spacing-sm);
  }

  [data-theme="dark"] .nav-links {
    background: rgba(15, 23, 42, 0.98);
  }

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

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
  }

  .footer {
    padding: var(--spacing-md) 0;
  }

  .footer-logo {
    font-size: 1.1rem;
  }
}