/* ============================================================
   madeby.ajaxjiang.com — Portfolio
   Token architecture: primitive → semantic → component
   ============================================================ */

/* ── Layer 1: Primitive Tokens ──────────────────────────── */
:root {
  /* Color primitives */
  --prm-cream:            #faf8f5;
  --prm-ivory:            #f3f0eb;
  --prm-white:            #ffffff;
  --prm-dark:             #1a1814;
  --prm-ink:              #2c2416;
  --prm-charcoal:         #5e5d59;
  --prm-stone:            #8a8680;
  --prm-warm-gray:        #a09c94;
  --prm-warm-light:       #e8e4db;
  --prm-terracotta:       #c7512e;
  --prm-terracotta-hover: #b84726;
  --prm-terracotta-pale:  #fdf0eb;
  --prm-coral:            #d97757;
  --prm-border-subtle:    rgba(0,0,0,0.07);
  --prm-border-strong:    rgba(0,0,0,0.12);

  /* Type primitives */
  --prm-font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --prm-font-sans:  'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --prm-font-mono:  'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  /* Spacing scale (4px base) */
  --prm-space-1:  0.25rem;
  --prm-space-2:  0.5rem;
  --prm-space-3:  0.75rem;
  --prm-space-4:  1rem;
  --prm-space-5:  1.25rem;
  --prm-space-6:  1.5rem;
  --prm-space-8:  2rem;
  --prm-space-10: 2.5rem;
  --prm-space-12: 3rem;
  --prm-space-16: 4rem;
  --prm-space-20: 5rem;
  --prm-space-24: 6rem;

  /* Radii */
  --prm-radius-sm: 6px;
  --prm-radius-md: 10px;
  --prm-radius-lg: 16px;
  --prm-radius-xl: 24px;
  --prm-radius-full: 999px;
}

/* ── Layer 2: Semantic Tokens (Light) ───────────────────── */
:root {
  --color-surface:         var(--prm-cream);
  --color-surface-raised:  var(--prm-white);
  --color-surface-subdued: var(--prm-ivory);
  --color-surface-inverse: var(--prm-dark);

  --color-text:            var(--prm-ink);
  --color-text-secondary:  var(--prm-charcoal);
  --color-text-muted:      var(--prm-stone);
  --color-text-inverse:    var(--prm-warm-light);
  --color-text-inverse-muted: var(--prm-warm-gray);

  --color-accent:          var(--prm-terracotta);
  --color-accent-hover:    var(--prm-terracotta-hover);
  --color-accent-subtle:   var(--prm-terracotta-pale);
  --color-accent-alt:      var(--prm-coral);

  --color-border:          var(--prm-border-subtle);
  --color-border-strong:   var(--prm-border-strong);

  --font-heading:          var(--prm-font-serif);
  --font-body:             var(--prm-font-sans);
  --font-mono:             var(--prm-font-mono);
}

/* ── Layer 2: Semantic Tokens (Dark) ────────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --color-surface:         #1e1c18;
    --color-surface-raised:  #282620;
    --color-surface-subdued: #24221d;
    --color-surface-inverse: var(--prm-cream);

    --color-text:            #e8e4db;
    --color-text-secondary:  #b8b5ad;
    --color-text-muted:      #8a8680;
    --color-text-inverse:    var(--prm-ink);
    --color-text-inverse-muted: var(--prm-charcoal);

    --color-accent:          var(--prm-coral);
    --color-accent-hover:    #e08565;
    --color-accent-subtle:   rgba(217,119,87,0.12);
    --color-accent-alt:      var(--prm-terracotta);

    --color-border:          rgba(255,255,255,0.07);
    --color-border-strong:   rgba(255,255,255,0.12);
  }
}

/* ── Layer 3: Component Tokens ───────────────────────────── */
:root {
  --card-radius:     var(--prm-radius-lg);
  --card-shadow:     0 1px 3px rgba(0,0,0,0.04),
                     0 3px 8px rgba(0,0,0,0.03);
  --card-shadow-hover: 0 2px 6px rgba(0,0,0,0.06),
                       0 8px 24px rgba(0,0,0,0.05);

  --btn-radius:      var(--prm-radius-md);
  --content-width:   1100px;
  --reading-width:   680px;
}

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  color: var(--color-text-secondary);
  background: var(--color-surface);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.3s, color 0.3s;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: var(--color-accent-hover); }

/* ── Typography ──────────────────────────────────────────── */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--color-text);
  font-weight: 600;
  line-height: 1.15;
}
h1 { font-size: clamp(2.4rem, 5vw, 3.6rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.8rem, 3.5vw, 2.6rem); letter-spacing: -0.01em; }
h3 { font-size: 1.4rem; }
h4 { font-size: 1.1rem; }

p + p { margin-top: 1em; }

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--color-surface-subdued);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--color-text);
}

/* ── Layout ──────────────────────────────────────────────── */
.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 2rem;
}
.section { padding: var(--prm-space-20) 0; }
.section-sm { padding: var(--prm-space-12) 0; }

.hero-line {
  width: 48px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
  margin: var(--prm-space-6) 0;
}

/* ── Header ──────────────────────────────────────────────── */
.site-header {
  padding: var(--prm-space-6) 0;
  background: transparent;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--color-surface) 85%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s;
}
.site-header.scrolled {
  border-bottom-color: var(--color-border);
}
.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
  display: inline-flex;
  align-items: center;
  gap: 0.1em;
}
.site-logo span { color: var(--color-accent); }
.site-logo:hover { color: var(--color-text); }

.site-nav {
  display: flex;
  gap: var(--prm-space-8);
  align-items: center;
}
.site-nav a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s;
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-1);
}
.site-nav a:hover { color: var(--color-text); }
.site-nav a i[data-lucide] {
  width: 16px;
  height: 16px;
}

/* ── Hero ────────────────────────────────────────────────── */
.hero {
  padding: var(--prm-space-12) 0 var(--prm-space-8);
  text-align: left;
}
.hero h1 { max-width: 700px; }
.hero .subtitle {
  font-family: var(--font-heading);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--color-text-secondary);
  max-width: 560px;
  line-height: 1.6;
  font-style: italic;
}

/* ── Project Grid ────────────────────────────────────────── */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--prm-space-6);
}

.project-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--card-radius);
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: box-shadow 0.3s, transform 0.3s;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  color: inherit;
  text-decoration: none;
}
.project-card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-3px);
}
.project-card:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.card-thumb {
  width: 100%;
  height: 200px;
  object-fit: contain;
  background: var(--color-surface-subdued);
  border-bottom: 1px solid var(--color-border);
}

.card-body {
  padding: var(--prm-space-6) var(--prm-space-8);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.card-number {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--prm-space-4);
}

.project-card h3 {
  font-size: 1.5rem;
  margin-bottom: var(--prm-space-2);
}

.card-desc {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  line-height: 1.55;
  flex: 1;
}

.card-tags {
  display: flex;
  gap: var(--prm-space-2);
  flex-wrap: wrap;
  margin-top: var(--prm-space-5);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3em;
  padding: 0.25em 0.7em;
  font-size: 0.78rem;
  font-weight: 500;
  border-radius: var(--prm-radius-full);
  background: var(--color-surface-subdued);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}
.tag i[data-lucide] {
  width: 13px;
  height: 13px;
}
.tag-accent {
  background: var(--color-accent-subtle);
  color: var(--color-accent);
  border-color: transparent;
}

/* ── Project Hero (detail pages) ─────────────────────────── */
.project-hero {
  padding: var(--prm-space-8) 0 var(--prm-space-12);
}
.project-hero .back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-1);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: var(--prm-space-8);
  transition: color 0.2s;
}
.project-hero .back-link:hover { color: var(--color-text); }
.project-hero .back-link i[data-lucide] {
  width: 16px;
  height: 16px;
}
.project-hero h1 { max-width: 700px; margin-bottom: var(--prm-space-4); }
.project-hero .project-subtitle {
  font-size: 1.15rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  line-height: 1.6;
}

.project-meta {
  display: flex;
  gap: var(--prm-space-6);
  flex-wrap: wrap;
  margin-top: var(--prm-space-6);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}
.project-meta span,
.project-meta a {
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-1);
}
.project-meta a { color: var(--color-accent); }
.project-meta a:hover { color: var(--color-accent-hover); }
.project-meta i[data-lucide] {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* ── App Icon ──────────────────────────────────────────── */
.app-icon {
  width: 72px;
  height: 72px;
  border-radius: 18px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  margin-bottom: var(--prm-space-4);
}

/* ── Project Image ───────────────────────────────────────── */
.project-image {
  width: 100%;
  max-height: 420px;
  object-fit: contain;
  border-radius: var(--prm-radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--card-shadow);
  margin-bottom: var(--prm-space-8);
}

/* ── Project Body ────────────────────────────────────────── */
.project-body {
  max-width: var(--reading-width);
}
.project-body h2 {
  margin-top: var(--prm-space-12);
  margin-bottom: var(--prm-space-3);
}
.project-body h2:first-child { margin-top: 0; }
.project-body p {
  color: var(--color-text-secondary);
  line-height: 1.7;
}
.project-body ul, .project-body ol {
  padding-left: 0;
  list-style: none;
  margin: var(--prm-space-4) 0;
}
.project-body li {
  padding: 0.4em 0 0.4em 1.5em;
  position: relative;
  color: var(--color-text-secondary);
  line-height: 1.55;
}
.project-body li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0.55;
}
.project-body ol {
  counter-reset: step;
}
.project-body ol li::before {
  content: counter(step);
  counter-increment: step;
  width: auto;
  height: auto;
  background: none;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
  top: 0.4em;
  opacity: 1;
}

/* ── Feature Grid (detail pages) ─────────────────────────── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--prm-space-6);
  margin: var(--prm-space-8) 0;
}
.feature-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--prm-radius-md);
  padding: var(--prm-space-6);
}
.feature-card h4 {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: var(--prm-space-2);
  display: flex;
  align-items: center;
  gap: var(--prm-space-2);
}
.feature-card h4 i[data-lucide] {
  width: 18px;
  height: 18px;
  color: var(--color-accent);
}
.feature-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ── Stats Row ───────────────────────────────────────────── */
.stats-row {
  display: flex;
  gap: var(--prm-space-8);
  flex-wrap: wrap;
  margin: var(--prm-space-8) 0;
}
.stat-item {
  display: flex;
  flex-direction: column;
  gap: var(--prm-space-1);
}
.stat-value {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1;
}
.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ── Status Banner ───────────────────────────────────────── */
.status-banner {
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-2);
  padding: var(--prm-space-2) var(--prm-space-5);
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: var(--prm-radius-full);
  background: var(--color-accent-subtle);
  color: var(--color-accent);
  margin-top: var(--prm-space-6);
}
.status-banner i[data-lucide] {
  width: 16px;
  height: 16px;
}
.status-banner.complete {
  background: color-mix(in srgb, #10b981 12%, transparent);
  color: #10b981;
}
.status-banner.in-progress {
  background: var(--color-accent-subtle);
  color: var(--color-accent);
}

/* ── Contact Section ─────────────────────────────────────── */
.contact-section {
  background: var(--color-surface-inverse);
  color: var(--color-text-inverse-muted);
  border-radius: var(--prm-radius-xl);
  padding: var(--prm-space-16) var(--prm-space-12);
  text-align: center;
  margin-top: var(--prm-space-16);
}
.contact-section h2 {
  color: var(--color-text-inverse);
  margin-bottom: var(--prm-space-4);
}
.contact-section p {
  font-size: 1.05rem;
  line-height: 1.6;
  max-width: 520px;
  margin: 0 auto var(--prm-space-8);
}
.contact-section .hero-line {
  background: var(--color-accent-alt);
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--prm-space-8);
}
.contact-links {
  display: flex;
  gap: var(--prm-space-4);
  justify-content: center;
  flex-wrap: wrap;
}
.contact-links .btn i[data-lucide] {
  width: 18px;
  height: 18px;
}

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-2);
  padding: 0.7rem 1.5rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--btn-radius);
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}
.btn i[data-lucide] {
  width: 18px;
  height: 18px;
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-accent-hover);
  color: #fff;
  transform: translateY(-1px);
}
.btn-outline {
  background: transparent;
  color: var(--color-text-inverse);
  border: 1px solid var(--color-text-inverse-muted);
}
.btn-outline:hover {
  border-color: var(--color-text-inverse);
  color: var(--color-text-inverse);
}
.btn-outline-light {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
}
.btn-outline-light:hover {
  border-color: var(--color-text);
  color: var(--color-text);
}

.btn-group {
  display: flex;
  gap: var(--prm-space-3);
  flex-wrap: wrap;
  margin-top: var(--prm-space-8);
}

/* ── Footer ──────────────────────────────────────────────── */
.site-footer {
  padding: var(--prm-space-12) 0;
  border-top: 1px solid var(--color-border);
  margin-top: var(--prm-space-16);
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}
.site-footer a {
  color: var(--color-text-secondary);
  display: inline-flex;
  align-items: center;
  gap: var(--prm-space-1);
}
.site-footer a:hover { color: var(--color-text); }
.site-footer a i[data-lucide] {
  width: 14px;
  height: 14px;
}
.site-footer .footer-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--prm-space-4);
  flex-wrap: wrap;
  margin-top: var(--prm-space-2);
}

/* ── 404 Page ────────────────────────────────────────────── */
.error-page {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.error-page .error-code {
  font-family: var(--font-heading);
  font-size: clamp(4rem, 8vw, 7rem);
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: var(--prm-space-4);
}
.error-page h2 { margin-bottom: var(--prm-space-4); }
.error-page p {
  color: var(--color-text-secondary);
  max-width: 400px;
  margin: 0 auto var(--prm-space-8);
  line-height: 1.6;
}

/* ── Animations ──────────────────────────────────────────── */
@media (prefers-reduced-motion: no-preference) {
  .fade-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  }
  .fade-up.visible {
    opacity: 1;
    transform: translateY(0);
  }

  .fade-in {
    opacity: 0;
    transition: opacity 0.6s ease-out;
  }
  .fade-in.visible { opacity: 1; }

  .slide-in-left {
    opacity: 0;
    transform: translateX(-24px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
  }
  .slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
  }

  .slide-in-right {
    opacity: 0;
    transform: translateX(24px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
  }
  .slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
  }

  /* Hero entrance */
  .hero-entrance h1 {
    opacity: 0;
    transform: translateY(16px);
    animation: hero-rise 0.7s 0.1s ease-out forwards;
  }
  .hero-entrance .hero-line {
    opacity: 0;
    transform: scaleX(0);
    animation: line-extend 0.5s 0.35s ease-out forwards;
  }
  .hero-entrance .subtitle {
    opacity: 0;
    transform: translateY(12px);
    animation: hero-rise 0.6s 0.5s ease-out forwards;
  }

  @keyframes hero-rise {
    to { opacity: 1; transform: translateY(0); }
  }
  @keyframes line-extend {
    to { opacity: 1; transform: scaleX(1); }
  }
}

@media (prefers-reduced-motion: reduce) {
  .fade-up, .fade-in, .slide-in-left, .slide-in-right {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .hero-entrance h1,
  .hero-entrance .hero-line,
  .hero-entrance .subtitle {
    opacity: 1;
    transform: none;
    animation: none;
  }
}

/* ── Section Tint (alternating backgrounds) ──────────────── */
.section-tinted {
  background: var(--color-surface-subdued);
}

/* ── About Text ─────────────────────────────────────────── */
.about-text {
  max-width: var(--reading-width);
  font-size: 1.05rem;
  line-height: 1.7;
}

/* ── Footer Copy ────────────────────────────────────────── */
.footer-copy {
  margin-top: var(--prm-space-2);
  font-size: 0.8rem;
}

/* ── Project Body Image ─────────────────────────────────── */
.project-body .project-image + .project-image,
.project-image-inline {
  margin: var(--prm-space-8) 0;
}

/* ── Inline Icon Helper ──────────────────────────────────── */
.icon-sm i[data-lucide] {
  width: 14px;
  height: 14px;
}
.icon-md i[data-lucide] {
  width: 18px;
  height: 18px;
}

/* ── Skip Link ───────────────────────────────────────────── */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--prm-space-4);
  background: var(--color-accent);
  color: #fff;
  padding: var(--prm-space-2) var(--prm-space-4);
  border-radius: var(--prm-radius-sm);
  font-weight: 600;
  z-index: 200;
}
.skip-link:focus {
  top: var(--prm-space-2);
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 768px) {
  .container { padding: 0 1.25rem; }
  .section { padding: var(--prm-space-12) 0; }
  .hero { padding: var(--prm-space-8) 0 var(--prm-space-6); }
  .project-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .project-meta { gap: var(--prm-space-4); }
  .site-nav { gap: var(--prm-space-5); }
  .contact-section {
    padding: var(--prm-space-12) var(--prm-space-6);
    border-radius: var(--prm-radius-lg);
  }
  .stats-row { gap: var(--prm-space-6); }
}

@media (max-width: 480px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .site-logo { font-size: 1.1rem; }
  .site-nav { gap: var(--prm-space-4); }
  .site-nav a { font-size: 0.85rem; }
}