/* ==========================================================================
   Kevin Bhavsar — Portfolio Design System
   ========================================================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ==========================================================================
   CSS Custom Properties (Design Tokens)
   ========================================================================== */
:root {
  /* Primary — Deep Space */
  --color-primary: #0D1B2A;
  --color-primary-light: #1a2e42;
  --color-primary-dark: #050d16;

  /* Accent — Neon Cyan */
  --color-accent: #00D9FF;
  --color-accent-light: #33E5FF;
  --color-accent-dark: #00A8CC;

  /* Neutrals */
  --color-text: #0D1B2A;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-background: #ffffff;
  --color-background-alt: #f5f7fa;
  --color-surface: #ffffff;
  --color-surface-hover: #f1f5f9;
  --color-border: #e5e7eb;
  --color-border-light: #f1f5f9;

  /* Semantic */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #00D9FF;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  --leading-tight: 1.25;
  --leading-normal: 1.6;
  --leading-relaxed: 1.75;

  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --section-spacing: 5rem;

  /* Layout */
  --container-width: 1200px;
  --container-narrow: 800px;
  --container-wide: 1400px;

  /* Borders & Shadows */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* ==========================================================================
   Dark Mode
   ========================================================================== */
[data-theme="dark"] {
  --color-primary: #7dd3fc;
  --color-primary-light: #bae6fd;
  --color-primary-dark: #38bdf8;
  --color-accent: #00D9FF;
  --color-accent-light: #33E5FF;
  --color-accent-dark: #00A8CC;

  --color-text: #e0e7ff;
  --color-text-secondary: #a5b4fc;
  --color-text-muted: #818cf8;
  --color-background: #0f172a;
  --color-background-alt: #1e293b;
  --color-surface: #1e293b;
  --color-surface-hover: #334155;
  --color-border: #475569;
  --color-border-light: #1e293b;

  --shadow-sm: 0 1px 2px 0 rgba(0, 13, 27, 0.5);
  --shadow-md: 0 4px 6px -1px rgba(0, 13, 27, 0.5), 0 2px 4px -2px rgba(0, 13, 27, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 13, 27, 0.5), 0 4px 6px -4px rgba(0, 13, 27, 0.4);
  --shadow-xl: 0 20px 25px -5px rgba(0, 13, 27, 0.6), 0 8px 10px -6px rgba(0, 13, 27, 0.4);
}

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

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

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

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

ul, ol {
  list-style: none;
}

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

button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

h1, h2, h3, h4, h5, h6 {
  line-height: var(--leading-tight);
  color: var(--color-text);
  font-weight: var(--font-bold);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
  margin-bottom: var(--space-4);
}

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.container--wide {
  max-width: var(--container-wide);
}

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

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

.section__header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section__title {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-4);
  position: relative;
}

.section__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.section__label {
  display: inline-block;
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-accent-dark);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: var(--color-background);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition-base), background-color var(--transition-base);
}

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

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.navbar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-text);
  text-decoration: none;
}

.navbar__brand:hover {
  color: var(--color-primary);
}

.navbar__brand-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--color-primary);
  color: #ffffff;
  border-radius: var(--radius-md);
  font-weight: var(--font-bold);
  font-size: var(--text-sm);
}

.navbar__logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  border-radius: var(--radius-md);
}

.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.navbar__link {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  text-decoration: none;
}

.navbar__link:hover {
  color: var(--color-text);
  background-color: var(--color-surface-hover);
}

.navbar__link--active {
  color: var(--color-accent-dark);
  background-color: rgba(14, 165, 233, 0.08);
}

.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.navbar__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.navbar__social-link:hover {
  color: var(--color-accent-dark);
  background-color: var(--color-surface-hover);
}

.navbar__social-link svg {
  width: 18px;
  height: 18px;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

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

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

.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }

[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

/* Hamburger */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 6px;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.navbar__hamburger:hover {
  background-color: var(--color-surface-hover);
}

.navbar__hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.navbar__hamburger--active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.navbar__hamburger--active span:nth-child(2) {
  opacity: 0;
}
.navbar__hamburger--active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile nav */
.navbar__mobile {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-background);
  padding: var(--space-6);
  z-index: 999;
  overflow-y: auto;
}

.navbar__mobile--open {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.navbar__mobile .navbar__link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-lg);
  border-radius: var(--radius-md);
}

.navbar__mobile-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding-top: var(--space-4);
  margin-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
  padding: calc(72px + var(--space-16)) 0 var(--space-16);
  min-height: 85vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero__background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero__bg-graphic {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

[data-theme="dark"] .hero__background::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(17, 24, 39, 0.75);
  z-index: 1;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero__content {
  position: relative;
  z-index: 1;
}

.hero__label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background-color: rgba(14, 165, 233, 0.08);
  color: var(--color-accent-dark);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  margin-bottom: var(--space-6);
}

.hero__label-dot {
  width: 6px;
  height: 6px;
  background-color: var(--color-success);
  border-radius: 50%;
}

.hero__title {
  font-size: var(--text-5xl);
  font-weight: var(--font-extrabold);
  line-height: 1.1;
  margin-bottom: var(--space-6);
}

.hero__title-accent {
  color: var(--color-primary);
}

.hero__subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  font-weight: var(--font-medium);
}

.hero__description {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
  max-width: 540px;
  line-height: var(--leading-relaxed);
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.hero__image-wrapper {
  position: relative;
  width: 600px;
  height: 600px;
}

.hero__image {
  width: 100%;
  height: 100%;
  border-radius: 0;
  object-fit: cover;
  box-shadow: none;
}

.hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.hero__stat-value {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  color: var(--color-primary);
}

[data-theme="dark"] .hero__stat-value {
  color: var(--color-accent);
}

.hero__stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  border: 2px solid transparent;
  white-space: nowrap;
}

.btn svg {
  width: 16px;
  height: 16px;
}

.btn--primary {
  background-color: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

.btn--primary:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

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

.btn--accent {
  background-color: var(--color-accent);
  color: #ffffff;
  border-color: var(--color-accent);
}

.btn--accent:hover {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn--ghost {
  background: transparent;
  color: var(--color-accent-dark);
  border-color: transparent;
  padding: var(--space-2) var(--space-4);
}

.btn--ghost:hover {
  background-color: rgba(14, 165, 233, 0.08);
  color: var(--color-accent);
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

/* ==========================================================================
   Cards
   ========================================================================== */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.card__image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background-color: var(--color-background-alt);
}

.card__body {
  padding: var(--space-6);
}

.card__title {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-3);
}

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

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

.card__excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  line-height: var(--leading-relaxed);
}

.card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.card__footer {
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Project Card */
.project-card .card__image {
  height: 220px;
  position: relative;
}

.project-card .card__category {
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  border-radius: var(--radius-full);
}

/* Blog Card */
.blog-card .card__image {
  height: 200px;
}

.blog-card .card__category {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  color: var(--color-accent-dark);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-2);
}

/* ==========================================================================
   Tags / Badges
   ========================================================================== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  background-color: var(--color-background-alt);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.tag:hover {
  color: var(--color-accent-dark);
  border-color: var(--color-accent);
  background-color: rgba(14, 165, 233, 0.05);
}

.tag--active {
  color: #ffffff;
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-2);
  font-size: 0.6875rem;
  font-weight: var(--font-semibold);
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge--primary {
  background-color: rgba(30, 58, 95, 0.1);
  color: var(--color-primary);
}

.badge--accent {
  background-color: rgba(14, 165, 233, 0.1);
  color: var(--color-accent-dark);
}

/* ==========================================================================
   Skills Section
   ========================================================================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

.skill-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-base);
}

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

.skill-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: rgba(79, 70, 229, 0.05);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-4);
  color: var(--color-accent-dark);
}

.skill-card__icon svg {
  width: 24px;
  height: 24px;
}

.skill-card__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-4);
}

.skill-card__items {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* ==========================================================================
   Timeline
   ========================================================================== */
.timeline {
  position: relative;
  padding-left: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: var(--space-10);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: calc(-1 * var(--space-8) - 5px);
  top: 6px;
  width: 12px;
  height: 12px;
  background-color: var(--color-accent);
  border: 3px solid var(--color-background);
  border-radius: 50%;
  box-shadow: 0 0 0 3px var(--color-accent);
}

.timeline__date {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-accent-dark);
  margin-bottom: var(--space-2);
}

.timeline__card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: box-shadow var(--transition-base);
}

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

.timeline__title {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-1);
}

.timeline__company {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  font-weight: var(--font-medium);
  margin-bottom: var(--space-3);
}

.timeline__location {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.timeline__description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

.timeline__description ul {
  list-style: disc;
  padding-left: var(--space-5);
  margin-top: var(--space-3);
}

.timeline__description li {
  margin-bottom: var(--space-2);
}

.timeline__toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-accent-dark);
  font-weight: var(--font-medium);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

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

.timeline__details {
  display: none;
  margin-top: var(--space-4);
}

.timeline__details--open {
  display: block;
}

/* ==========================================================================
   Grid Layouts
   ========================================================================== */
.grid {
  display: grid;
  gap: var(--space-6);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--space-8);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-8);
}

/* ==========================================================================
   Expertise / Feature Cards
   ========================================================================== */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-6);
}

.expertise-card {
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  transition: all var(--transition-base);
}

.expertise-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.expertise-card__icon {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-4);
}

.expertise-card__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-2);
}

.expertise-card__description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

/* ==========================================================================
   Philosophy / Principles
   ========================================================================== */
.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-6);
}

.principle-card {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  transition: all var(--transition-base);
}

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

.principle-card__number {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--color-accent);
  min-width: 36px;
}

.principle-card__title {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-2);
}

.principle-card__description {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  background-color: var(--color-primary-dark);
  color: #cbd5e1;
  padding: var(--space-16) 0 var(--space-8);
}

[data-theme="dark"] .footer {
  background-color: #020617;
}

.footer__inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-10);
}

.footer__brand {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: #ffffff;
  margin-bottom: var(--space-3);
}

.footer__tagline {
  font-size: var(--text-sm);
  color: #94a3b8;
  margin-bottom: var(--space-6);
  line-height: var(--leading-relaxed);
}

.footer__heading {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: #ffffff;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
}

.footer__link {
  display: block;
  padding: var(--space-1) 0;
  font-size: var(--text-sm);
  color: #94a3b8;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-accent-light);
}

.footer__social {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background-color: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  color: #94a3b8;
  transition: all var(--transition-fast);
}

.footer__social-link:hover {
  background-color: var(--color-accent);
  color: #ffffff;
}

.footer__social-link svg {
  width: 16px;
  height: 16px;
}

.footer__bottom {
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
  color: #64748b;
}

/* ==========================================================================
   Page Header / Breadcrumbs
   ========================================================================== */
.page-header {
  padding: calc(72px + var(--space-12)) 0 var(--space-12);
  background-color: var(--color-background-alt);
  border-bottom: 1px solid var(--color-border);
}

.page-header__breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.page-header__breadcrumbs a {
  color: var(--color-text-muted);
}

.page-header__breadcrumbs a:hover {
  color: var(--color-accent-dark);
}

.page-header__breadcrumbs .separator {
  color: var(--color-text-muted);
}

.page-header__title {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-4);
}

.page-header__description {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 700px;
}

/* ==========================================================================
   Search
   ========================================================================== */
.search-box {
  position: relative;
  max-width: 500px;
}

.search-box__input {
  width: 100%;
  padding: var(--space-3) var(--space-4) var(--space-3) var(--space-10);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-box__input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15);
}

.search-box__input::placeholder {
  color: var(--color-text-muted);
}

.search-box__icon {
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  width: 18px;
  height: 18px;
}

.search-results {
  position: absolute;
  top: calc(100% + var(--space-2));
  left: 0;
  right: 0;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  max-height: 400px;
  overflow-y: auto;
  z-index: 50;
  display: none;
}

.search-results--open {
  display: block;
}

.search-result__item {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-light);
  text-decoration: none;
  transition: background-color var(--transition-fast);
}

.search-result__item:hover {
  background-color: var(--color-surface-hover);
}

.search-result__item:last-child {
  border-bottom: none;
}

.search-result__title {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-text);
}

.search-result__type {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* ==========================================================================
   Filters
   ========================================================================== */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}

.filter-btn {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover {
  color: var(--color-accent-dark);
  border-color: var(--color-accent);
}

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

/* ==========================================================================
   Contact Form
   ========================================================================== */
.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15);
}

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

.form-error {
  font-size: var(--text-xs);
  color: var(--color-error);
  margin-top: var(--space-1);
  display: none;
}

.form-group--error .form-input,
.form-group--error .form-textarea {
  border-color: var(--color-error);
}

.form-group--error .form-error {
  display: block;
}

/* ==========================================================================
   Back to Top
   ========================================================================== */
.back-to-top {
  position: fixed;
  bottom: var(--space-8);
  right: var(--space-8);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-primary);
  color: #ffffff;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 90;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
  transform: translateY(-2px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ==========================================================================
   Reading Progress
   ========================================================================== */
.reading-progress {
  position: fixed;
  top: 72px;
  left: 0;
  width: 0%;
  height: 3px;
  background: var(--color-primary);
  z-index: 999;
  transition: width 100ms linear;
}

/* ==========================================================================
   Scroll Reveal
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Certifications
   ========================================================================== */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

.cert-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  padding: var(--space-5);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: box-shadow var(--transition-base);
}

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

.cert-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  background: rgba(79, 70, 229, 0.05);
  border-radius: var(--radius-md);
  color: var(--color-accent-dark);
}

.cert-card__title {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  margin-bottom: var(--space-1);
}

.cert-card__issuer {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* ==========================================================================
   Contact Info
   ========================================================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-10);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.contact-info__item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}

.contact-info__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  height: 44px;
  background-color: rgba(14, 165, 233, 0.08);
  border-radius: var(--radius-md);
  color: var(--color-accent-dark);
}

.contact-info__label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
}

.contact-info__value {
  font-size: var(--text-base);
  font-weight: var(--font-medium);
}

.contact-info__value a {
  color: var(--color-text);
}

.contact-info__value a:hover {
  color: var(--color-accent-dark);
}

/* ==========================================================================
   CTA Section
   ========================================================================== */
.cta-section {
  text-align: center;
  padding: var(--space-16) 0;
  background: var(--color-primary);
  color: #ffffff;
}

.cta-section__title {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-4);
  color: #ffffff;
}

.cta-section__description {
  font-size: var(--text-lg);
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-8);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.cta-section .btn--primary {
  background-color: #ffffff;
  color: var(--color-primary);
  border-color: #ffffff;
}

.cta-section .btn--primary:hover {
  background-color: rgba(255, 255, 255, 0.9);
  color: var(--color-primary-dark);
}

.cta-section .btn--secondary {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
}

.cta-section .btn--secondary:hover {
  border-color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ==========================================================================
/* ==========================================================================
   Journey — Experience & Education Grid
   ========================================================================== */
.journey-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
}

@media (max-width: 768px) {
  .journey-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
}

@media (max-width: 768px) {
  .journey-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
}