/* ============================================
   DESIGN SYSTEM — Ravi Jha Portfolio
   ============================================ */

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

/* --- Tokens --- */
:root {
  --color-bg: #0a0a0f;
  --color-bg-raised: #111118;
  --color-bg-card: #16161f;
  --color-bg-card-hover: #1c1c28;
  --color-border: #23232f;
  --color-border-subtle: #1a1a25;

  --color-text: #e4e4ec;
  --color-text-secondary: #9090a0;
  --color-text-muted: #606070;

  --color-accent: #5eead4;
  --color-accent-dim: rgba(94, 234, 212, 0.12);
  --color-accent-glow: rgba(94, 234, 212, 0.06);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 2rem;
  --fs-3xl: 2.75rem;
  --fs-4xl: 3.5rem;

  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  --space-5xl: 8rem;

  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;

  --max-width: 1100px;
  --nav-height: 64px;

  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
}

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

ul, ol {
  list-style: none;
}

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

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

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

.section {
  padding: var(--space-5xl) 0;
}

.section-label {
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.section-heading {
  font-size: var(--fs-2xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--color-text);
  margin-bottom: var(--space-lg);
}

/* scroll-reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--transition), transform 0.6s var(--transition);
}

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


/* ============================================
   NAVIGATION
   ============================================ */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border-subtle);
  z-index: 100;
  display: flex;
  align-items: center;
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.nav-logo span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-links a {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  position: relative;
}

.nav-links a:hover {
  color: var(--color-text);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-accent);
  transition: width var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-cta {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-bg) !important;
  background: var(--color-accent);
  padding: 8px 20px;
  border-radius: 999px;
  transition: opacity var(--transition), transform var(--transition);
}

.nav-cta:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.nav-cta::after {
  display: none !important;
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}


/* ============================================
   HERO
   ============================================ */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  max-width: 680px;
}

.hero-greeting {
  font-size: var(--fs-sm);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
}

.hero-title {
  font-size: var(--fs-4xl);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: var(--space-lg);
}

.hero-title .accent {
  color: var(--color-accent);
}

.hero-description {
  font-size: var(--fs-lg);
  line-height: 1.7;
  color: var(--color-text-secondary);
  max-width: 540px;
  margin-bottom: var(--space-2xl);
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-bg);
  background: var(--color-accent);
  padding: 12px 28px;
  border-radius: 999px;
  transition: opacity var(--transition), transform var(--transition), box-shadow var(--transition);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(94, 234, 212, 0.2);
}

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

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 12px 24px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  transition: color var(--transition), border-color var(--transition);
}

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

/* ============================================
   PROJECTS
   ============================================ */

.projects {
  background: var(--color-bg);
}

.projects-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.project-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  border-color: var(--color-border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.project-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: var(--space-xl);
  cursor: pointer;
  gap: var(--space-md);
}

.project-meta {
  flex: 1;
}

.project-name {
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.project-tagline {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: var(--space-sm);
}

.tech-tag {
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-dim);
  padding: 4px 10px;
  border-radius: 999px;
}

.project-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-bg-raised);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: var(--fs-lg);
  flex-shrink: 0;
  margin-top: 4px;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.project-card:hover .project-toggle {
  background: var(--color-accent-dim);
  color: var(--color-accent);
}

.project-card.expanded .project-toggle {
  transform: rotate(45deg);
  background: var(--color-accent-dim);
  color: var(--color-accent);
}

.project-detail {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.project-card.expanded .project-detail {
  max-height: 2500px;
}

.project-detail-inner {
  padding: 0 var(--space-xl) var(--space-xl);
  border-top: 1px solid var(--color-border-subtle);
}

.project-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.detail-block h4 {
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.detail-block p {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: 1.65;
}

.project-links {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border-subtle);
}

.project-link {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: opacity var(--transition);
}

.project-link:hover {
  opacity: 0.75;
}

.project-link svg {
  width: 14px;
  height: 14px;
}


/* ============================================
   ABOUT
   ============================================ */

.about {
  background: var(--color-bg-raised);
}

.about-content {
  max-width: 680px;
}

.about-content p {
  font-size: var(--fs-base);
  line-height: 1.75;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.about-content p:last-child {
  margin-bottom: 0;
}

.about-content strong {
  color: var(--color-text);
  font-weight: 600;
}


/* ============================================
   SKILLS
   ============================================ */

.skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.skill-tag {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), border-color var(--transition), background var(--transition);
}

.skill-tag:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: var(--color-accent-dim);
}


/* ============================================
   CONTACT
   ============================================ */

.contact {
  background: var(--color-bg-raised);
  text-align: center;
}

.contact .section-heading {
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.contact-subtext {
  font-size: var(--fs-base);
  color: var(--color-text-secondary);
  max-width: 460px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.7;
}

.contact-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
  margin-bottom: var(--space-2xl);
}

.contact-socials {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.social-link:hover {
  color: var(--color-text);
}

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


/* ============================================
   FOOTER
   ============================================ */

.footer {
  padding: var(--space-2xl) 0;
  border-top: 1px solid var(--color-border-subtle);
  text-align: center;
}

.footer p {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}


/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-md);
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  /* Nav */
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    height: calc(100vh - var(--nav-height));
    background: #0a0a0f; /* Dark solid background for clarity */
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-xl);
    padding-bottom: 20vh; /* Shift content up slightly for balance */
    z-index: 1000;
  }

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

  .nav-links a {
    font-size: var(--fs-xl);
    font-weight: 700;
    color: var(--color-text);
  }

  .nav-cta {
    font-size: var(--fs-lg);
    width: auto;
    text-align: center;
  }

  .nav-toggle {
    display: flex;
  }

  /* Hero */
  .hero-title {
    font-size: var(--fs-2xl);
  }

  .hero-description {
    font-size: var(--fs-base);
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-primary,
  .btn-secondary {
    justify-content: center;
  }

  /* Projects */
  .project-detail-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .project-header {
    padding: var(--space-lg);
  }

  .project-detail-inner {
    padding: 0 var(--space-lg) var(--space-lg);
  }

  /* Section headings */
  .section-heading {
    font-size: var(--fs-xl);
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .hero-title {
    font-size: var(--fs-3xl);
  }
}

/* ============================================
   WRITING SECTION
   ============================================ */

.writing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: var(--space-xl);
}

.writing-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
  height: 100%;
}

.writing-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-accent-dim);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
}

.writing-card-inner {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: var(--space-xl);
}

.writing-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-md);
}

.writing-date {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  font-weight: 500;
}

.writing-category {
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-accent-dim);
  padding: 4px 10px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.writing-title {
  font-size: var(--fs-lg);
  font-weight: 700;
  line-height: 1.4;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  transition: color var(--transition);
}

.writing-card:hover .writing-title {
  color: var(--color-accent);
}

.writing-excerpt {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-lg);
  flex-grow: 1;
}

.writing-footer {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: auto;
}

.read-more {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
}

.arrow-icon {
  width: 16px;
  height: 16px;
  transition: transform var(--transition);
}

.writing-card:hover .arrow-icon {
  transform: translateX(4px);
}

/* --- Responsive for Writing --- */
@media (max-width: 640px) {
  .writing-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   BLOG POST CONTENT (General Typography)
   ============================================ */

.post-container {
  max-width: 720px;
  margin: 0 auto;
  padding: var(--space-5xl) var(--space-lg);
}

.post-header {
  margin-bottom: var(--space-3xl);
  text-align: center;
}

.post-title {
  font-size: var(--fs-3xl);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-md);
}

.post-meta {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}

.post-content {
  font-size: var(--fs-base);
  line-height: 1.8;
  color: var(--color-text-secondary);
}

.post-content p {
  margin-bottom: var(--space-lg);
}

.post-content h2 {
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--color-text);
  margin: var(--space-2xl) 0 var(--space-md);
}

.post-content h3 {
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--color-text);
  margin: var(--space-xl) 0 var(--space-md);
}

.post-content ul, .post-content ol {
  margin-bottom: var(--space-lg);
  padding-left: var(--space-lg);
}

.post-content li {
  margin-bottom: var(--space-xs);
}

.post-content pre {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  overflow-x: auto;
  margin: var(--space-lg) 0;
}

.post-content code {
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.9em;
  background: var(--color-bg-raised);
  padding: 2px 6px;
  border-radius: 4px;
}

.post-content pre code {
  background: transparent;
  padding: 0;
}

.post-back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: var(--space-2xl);
  transition: transform var(--transition);
}

.post-back-link:hover {
  transform: translateX(-4px);
}