:root {
  --bg-primary: #fafafa;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f4f4f5;
  --bg-hover: #f0f0f2;

  --border-subtle: #e4e4e7;
  --border-medium: #d4d4d8;
  --border-hover: #18181b;

  --text-pure: #09090b;
  --text-body: #27272a;
  --text-muted: #71717a;
  --text-inverted: #ffffff;

  --btn-primary-bg: #18181b;
  --btn-primary-text: #ffffff;
  --btn-primary-hover: #000000;

  --btn-secondary-bg: #ffffff;
  --btn-secondary-text: #18181b;
  --btn-secondary-border: #e4e4e7;
  --btn-secondary-hover: #f4f4f5;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-card: 0 1px 3px 0 rgba(0, 0, 0, 0.04), 0 1px 2px -1px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 6px 16px -2px rgba(0, 0, 0, 0.08);

  --font-sans: "Vazirmatn", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "Plus Jakarta Sans", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --container-max: 960px;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-full: 9999px;

  --transition-fast: 0.15s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4.5rem;
  font-size: 16px;
  background-color: var(--bg-primary);
  color-scheme: light;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-body);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

::selection {
  background-color: var(--text-pure);
  color: var(--text-inverted);
}

:focus-visible {
  outline: 2px solid var(--text-pure);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  top: -100px;
  inset-inline-start: 1.5rem;
  background-color: var(--text-pure);
  color: var(--text-inverted);
  padding: 0.5rem 1.15rem;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  z-index: 1000;
  box-shadow: var(--shadow-hover);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
}

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

ul {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.section {
  padding-block: clamp(2.5rem, 5vw, 4.25rem);
}

.card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-fast),
              box-shadow var(--transition-fast),
              transform var(--transition-fast);
}

@media (hover: hover) {
  a.card:hover,
  .card-interactive:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.6rem 1.15rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
  transition: background-color var(--transition-fast),
              border-color var(--transition-fast),
              color var(--transition-fast),
              transform var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.btn:active {
  transform: scale(0.98);
}

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

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

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

.btn-secondary:hover {
  background-color: var(--btn-secondary-hover);
  border-color: var(--border-medium);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.825rem;
}

.section-meta {
  margin-bottom: 1.5rem;
}

.meta-tag {
  display: inline-block;
  font-size: 0.775rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}

.section-heading {
  font-size: clamp(1.4rem, 3.5vw, 1.85rem);
  font-weight: 800;
  color: var(--text-pure);
  line-height: 1.3;
}

.section-lead {
  font-size: 0.925rem;
  color: var(--text-muted);
  margin-top: 0.35rem;
  line-height: 1.7;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  background-color: rgba(250, 250, 250, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.site-header.is-scrolled {
  background-color: rgba(255, 255, 255, 0.96);
  border-bottom-color: var(--border-medium);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 58px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-pure);
}

.desktop-nav .nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  padding: 6px 12px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
}

.nav-link:hover {
  color: var(--text-pure);
  background-color: var(--bg-hover);
}

.nav-link.active {
  color: var(--text-pure);
  font-weight: 700;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.mobile-toggle-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--text-pure);
  position: relative;
  transition: background-color var(--transition-fast);
}

.mobile-toggle-btn:hover,
.mobile-toggle-btn:active {
  background-color: var(--bg-hover);
}

.hamburger-line {
  position: absolute;
  width: 18px;
  height: 2px;
  background-color: currentColor;
  border-radius: 1px;
  transition: transform 0.25s ease, opacity 0.2s ease;
}

.hamburger-line.line-1 { transform: translateY(-4px); }
.hamburger-line.line-2 { transform: translateY(4px); }

.mobile-toggle-btn[aria-expanded="true"] .hamburger-line.line-1 {
  transform: translateY(0) rotate(45deg);
}

.mobile-toggle-btn[aria-expanded="true"] .hamburger-line.line-2 {
  transform: translateY(0) rotate(-45deg);
}

.mobile-nav-panel {
  display: none;
  position: absolute;
  top: 100%;
  inset-inline: 0;
  background-color: #ffffff;
  border-bottom: 1px solid var(--border-subtle);
  box-shadow: 0 10px 24px -4px rgba(0, 0, 0, 0.08);
  opacity: 0;
  transform: translateY(-8px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.mobile-nav-panel.is-open {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.mobile-panel-inner {
  padding-block: 0.75rem;
}

.mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.mobile-nav-link {
  display: block;
  padding: 10px 14px;
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  color: var(--text-pure);
  background-color: var(--bg-hover);
  font-weight: 600;
}

.mobile-nav-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  top: 58px;
  background-color: rgba(0, 0, 0, 0.25);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.mobile-nav-backdrop.is-active {
  opacity: 1;
  pointer-events: auto;
}

.hero-section {
  padding-top: clamp(2.5rem, 6vw, 4.5rem);
  padding-bottom: clamp(2.5rem, 5vw, 3.5rem);
}

.hero-stage {
  max-width: 720px;
}

.hero-headline {
  font-size: clamp(2rem, 5.5vw, 3.2rem);
  font-weight: 800;
  color: var(--text-pure);
  line-height: 1.25;
  margin-bottom: 0.5rem;
}

.hero-role-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-muted);
}

.role-dot {
  color: var(--border-medium);
}

.hero-description {
  font-size: clamp(0.975rem, 2vw, 1.05rem);
  line-height: 1.85;
  color: var(--text-body);
  margin-bottom: 1.75rem;
}

.hero-description strong {
  color: var(--text-pure);
  font-weight: 700;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.hero-social-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.project-card {
  padding: clamp(1.25rem, 3.5vw, 2.25rem);
}

.project-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.15rem;
}

.project-title-group {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.project-title {
  font-size: clamp(1.3rem, 3vw, 1.5rem);
  font-weight: 800;
  color: var(--text-pure);
}

.project-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.75rem;
  font-family: var(--font-sans);
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
}

.external-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.825rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  direction: ltr;
  padding: 0.3rem 0.65rem;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface-elevated);
}

.external-link:hover {
  color: var(--text-pure);
  border-color: var(--border-medium);
}

.project-summary {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--text-body);
  margin-bottom: 1.5rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1.5rem;
}

.feature-item {
  padding: 1rem 1.15rem;
  background-color: var(--bg-surface-elevated);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.feature-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-pure);
  margin-bottom: 0.3rem;
}

.feature-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.project-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-subtle);
}

.tags-cluster {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  padding: 0.25rem 0.55rem;
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-body);
}

.timeline-wrapper {
  position: relative;
  padding-inline-start: 22px;
}

.timeline-wrapper::before {
  content: "";
  position: absolute;
  top: 15px;
  bottom: 15px;
  inset-inline-start: 5px;
  width: 2px;
  background-color: var(--border-subtle);
}

.timeline-container {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
}

.timeline-entry {
  position: relative;
}

.entry-marker {
  position: absolute;
  top: 20px;
  inset-inline-start: -22px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--bg-surface);
  border: 2px solid var(--text-pure);
}

.entry-card {
  padding: 1.15rem 1.35rem;
}

.entry-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-pure);
  margin-bottom: 0.35rem;
}

.entry-body {
  font-size: 0.885rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

@media (min-width: 768px) {
  .skills-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.skill-card {
  padding: 1.15rem 1.25rem;
}

.skill-title {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--text-pure);
  margin-bottom: 0.45rem;
}

.skill-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.about-card {
  padding: clamp(1.25rem, 3.5vw, 2rem);
}

.about-text {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-body);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1.15rem;
}

.contact-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-pure);
  flex-shrink: 0;
}

.contact-info {
  display: flex;
  flex-direction: column;
  min-width: 0;
  flex-grow: 1;
}

.contact-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 0.15rem;
}

.contact-value {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-pure);
  font-family: var(--font-mono);
  direction: ltr;
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.email-card {
  position: relative;
  justify-content: space-between;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 0.35rem 0.65rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.copy-btn:hover {
  color: var(--text-pure);
  border-color: var(--border-medium);
}

.copy-btn.is-copied {
  background-color: var(--text-pure);
  color: var(--text-inverted);
  border-color: var(--text-pure);
}

.toast-notice {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(50px);
  background-color: var(--text-pure);
  color: var(--text-inverted);
  padding: 0.5rem 1.15rem;
  border-radius: var(--radius-full);
  font-size: 0.825rem;
  font-weight: 500;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  z-index: 200;
  opacity: 0;
  pointer-events: none;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.toast-notice.is-show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding-block: 2rem;
  background-color: var(--bg-surface);
  margin-top: 2rem;
}

.footer-layout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.footer-profile {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-text {
  display: flex;
  flex-direction: column;
}

.footer-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-pure);
}

.footer-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

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

@media (max-width: 768px) {
  .container {
    padding-inline: 1.25rem;
  }

  .desktop-nav,
  .header-cta {
    display: none;
  }

  .mobile-toggle-btn {
    display: inline-flex;
  }

  .mobile-nav-panel,
  .mobile-nav-backdrop {
    display: block;
  }

  .hero-cta-group {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    gap: 0.65rem;
  }

  .hero-btn-main {
    width: 100%;
  }

  .hero-social-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.65rem;
    width: 100%;
  }

  .hero-social-group .btn {
    width: 100%;
    padding: 0.65rem 0.5rem;
  }

  .project-footer {
    flex-direction: column;
    align-items: stretch;
    gap: 0.85rem;
  }

  .project-footer .btn {
    width: 100%;
  }

  .footer-layout {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1rem;
  }

  .footer-profile {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .container {
    padding-inline: 1rem;
  }

  .hero-headline {
    font-size: 2.15rem;
  }

  .hero-role-row {
    font-size: 0.95rem;
    margin-bottom: 1rem;
  }

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

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

  .email-card {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .email-card .contact-info {
    min-width: calc(100% - 120px);
  }

  .email-card .copy-btn {
    margin-inline-start: auto;
  }

  .project-header {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .external-link {
    font-size: 0.775rem;
    padding: 0.25rem 0.5rem;
  }
}