styles.css

/* ==========================================================================
   lean — Minimal, Clean Developer Portfolio
   ========================================================================== */

/* --------------------------------------------------------------------------
   Design Tokens & Variables
   -------------------------------------------------------------------------- */
:root {
  color-scheme: dark;

  /* Color System — Dark Mode (Default) */
  --bg: #09090b;
  --bg-subtle: #0f0f13;
  --surface: #121217;
  --surface-hover: #181820;
  --surface-active: #1f1f28;

  --border: #222228;
  --border-hover: #33333d;
  --border-focus: #52525e;

  --text: #f4f4f7;
  --text-muted: #9c9ca8;
  --text-subtle: #636370;

  --accent: #f4f4f7;
  --accent-contrast: #09090b;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Monaco, Consolas, monospace;

  /* Layout & Spacing */
  --max-width: 820px;
  --header-height: 60px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;

  /* Transitions */
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 150ms var(--ease);
  --transition-normal: 220ms var(--ease);
}

/* Color System — Light Mode */
:root[data-theme="light"] {
  color-scheme: light;

  --bg: #fafaf9;
  --bg-subtle: #f4f4f2;
  --surface: #ffffff;
  --surface-hover: #f5f5f3;
  --surface-active: #ecece9;

  --border: #e4e4e0;
  --border-hover: #c9c9c3;
  --border-focus: #8e8e86;

  --text: #141413;
  --text-muted: #5e5e57;
  --text-subtle: #8a8a81;

  --accent: #141413;
  --accent-contrast: #fafaf9;
}

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

html {
  min-height: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 1.5rem);
  background: var(--bg);
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  transition: color var(--transition-normal), background-color var(--transition-normal);
}

::selection {
  color: var(--accent-contrast);
  background: var(--accent);
}

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

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

h1, h2, h3, h4, p, ul {
  margin: 0;
}

ul {
  padding: 0;
  list-style: none;
}

/* --------------------------------------------------------------------------
   Accessibility & Layout Containers
   -------------------------------------------------------------------------- */
.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.5rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent-contrast);
  background: var(--accent);
  border-radius: var(--radius-sm);
  transform: translateY(-160%);
  transition: transform var(--transition-fast);
}

.skip-link:focus {
  transform: translateY(0);
}

.container {
  width: min(var(--max-width), calc(100% - 2.5rem));
  margin-inline: auto;
}

/* --------------------------------------------------------------------------
   Site Header & Navigation
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--header-height);
  border-bottom: 1px solid transparent;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.site-header.is-scrolled {
  border-color: var(--border);
}

.header-inner {
  display: flex;
  height: 100%;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  transition: opacity var(--transition-fast);
}

.brand:hover {
  opacity: 0.8;
}

.brand-glyph {
  display: inline-grid;
  place-items: center;
  width: 22px;
  height: 22px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.nav-group {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.primary-nav a {
  transition: color var(--transition-fast);
}

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

/* Theme Toggle Button */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: color var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}

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

.theme-toggle svg {
  width: 15px;
  height: 15px;
  stroke-width: 1.8;
}

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

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

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
  padding: clamp(4.5rem, 9vw, 6.5rem) 0 clamp(2.5rem, 5vw, 4rem);
}

.hero-title {
  max-width: 680px;
  font-size: clamp(2.1rem, 5vw, 3.25rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.04em;
  color: var(--text);
}

.hero-bio {
  max-width: 580px;
  margin-top: 1.25rem;
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
}

.btn-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 1rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: all var(--transition-fast);
}

.btn-link:hover {
  border-color: var(--border-hover);
  background: var(--surface-hover);
  transform: translateY(-1px);
}

.btn-link svg {
  width: 14px;
  height: 14px;
  color: var(--text-subtle);
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.btn-link:hover svg {
  color: var(--text);
  transform: translate(2px, -2px);
}

.btn-link-primary {
  color: var(--accent-contrast);
  background: var(--accent);
  border-color: var(--accent);
}

.btn-link-primary svg {
  color: var(--accent-contrast);
}

.btn-link-primary:hover {
  color: var(--accent-contrast);
  background: color-mix(in srgb, var(--accent) 90%, black);
  border-color: transparent;
}

/* --------------------------------------------------------------------------
   Section Layout & Headings
   -------------------------------------------------------------------------- */
.section-block {
  padding: 3.5rem 0;
  border-top: 1px solid var(--border);
}

.section-header {
  margin-bottom: 2rem;
}

.section-title {
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--text);
}

.section-desc {
  margin-top: 0.35rem;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   Featured Projects (Cards)
   -------------------------------------------------------------------------- */
.featured-grid {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.featured-card {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1.5rem;
  padding: 1.6rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  transition: border-color var(--transition-normal), background-color var(--transition-normal), transform var(--transition-normal);
}

.featured-card:hover {
  border-color: var(--border-hover);
  background: var(--surface-hover);
  transform: translateY(-2px);
}

.card-content {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-width: 0;
}

.card-title {
  font-size: 1.18rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 0.3rem;
}

.card-tagline {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
}

.card-desc {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--text-muted);
}

.tag-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1.15rem;
}

.tag-pills span {
  padding: 0.2rem 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-subtle);
}

.card-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.15rem;
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.card-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text);
  transition: opacity var(--transition-fast);
}

.card-links a:hover {
  opacity: 0.75;
}

.card-links svg {
  width: 12px;
  height: 12px;
  color: var(--text-subtle);
  transition: transform var(--transition-fast);
}

.card-links a:hover svg {
  transform: translate(2px, -2px);
}

/* Card Visual Box (App Icon or Clean Wordmark) */
.card-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 88px;
  height: 88px;
  flex-shrink: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-subtle);
  overflow: hidden;
  align-self: flex-start;
}

.card-visual.app-icon {
  background: transparent;
  border: none;
}

.card-visual.app-icon img {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  transition: transform var(--transition-normal);
}

.featured-card:hover .card-visual.app-icon img {
  transform: scale(1.04);
}

.card-visual-symbol {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   Developer Tools & CLI (High-Density Grid)
   -------------------------------------------------------------------------- */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.tool-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.35rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  transition: border-color var(--transition-normal), background-color var(--transition-normal), transform var(--transition-normal);
}

.tool-card:hover {
  border-color: var(--border-hover);
  background: var(--surface-hover);
  transform: translateY(-2px);
}

.tool-card-header {
  display: flex;
  align-items: center;
  margin-bottom: 0.35rem;
}

.tool-card-title-group {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.tool-avatar {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.tool-card-title {
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text);
}

.tool-card-tagline {
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--text-subtle);
  margin-bottom: 0.6rem;
}

.tool-card-desc {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.tool-card-bottom {
  margin-top: auto;
}

.tool-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.85rem;
}

.tool-card-tags span {
  padding: 0.15rem 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  color: var(--text-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-subtle);
}

.tool-card-links {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.tool-card-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.74rem;
  font-weight: 500;
  color: var(--text);
  transition: opacity var(--transition-fast);
}

.tool-card-links a:hover {
  opacity: 0.75;
}

.tool-card-links svg {
  width: 11px;
  height: 11px;
  color: var(--text-subtle);
  transition: transform var(--transition-fast);
}

.tool-card-links a:hover svg {
  transform: translate(2px, -2px);
}

/* --------------------------------------------------------------------------
   About & Toolkit Section
   -------------------------------------------------------------------------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 3rem;
}

.about-copy {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.about-lead {
  font-size: 1.15rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  line-height: 1.5;
  color: var(--text);
}

.toolkit-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.toolkit-item {
  padding: 1rem 1.15rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.toolkit-category {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-subtle);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.toolkit-items {
  font-size: 0.84rem;
  color: var(--text);
  line-height: 1.5;
}

/* --------------------------------------------------------------------------
   Connect / Contact Section
   -------------------------------------------------------------------------- */
.connect-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.connect-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.4rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  transition: border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
}

.connect-card:hover {
  border-color: var(--border-hover);
  background: var(--surface-hover);
  transform: translateY(-1px);
}

.connect-info {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.connect-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.connect-value {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
}

.connect-card svg {
  width: 16px;
  height: 16px;
  color: var(--text-subtle);
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.connect-card:hover svg {
  color: var(--text);
  transform: translate(2px, -2px);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
  padding: 2.5rem 0 3.5rem;
  margin-top: 3.5rem;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-subtle);
}

.footer-inner a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-subtle);
  transition: color var(--transition-fast);
}

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

/* --------------------------------------------------------------------------
   Responsive Media Queries
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

@media (max-width: 600px) {
  .container {
    width: min(var(--max-width), calc(100% - 2rem));
  }

  .header-inner {
    justify-content: space-between;
  }

  .primary-nav {
    display: none;
  }

  .featured-card {
    grid-template-columns: 1fr;
    padding: 1.25rem;
  }

  .card-visual {
    order: -1;
    margin-bottom: 0.5rem;
  }

  .hero {
    padding: 3.5rem 0 2rem;
  }

  .hero-title {
    font-size: clamp(1.85rem, 8.5vw, 2.35rem);
  }
}

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