/* ============================================================
   SADIE KIM PORTFOLIO — Notion/Anthropic Aesthetic
   ============================================================ */

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

:root {
  /* Anthropic-inspired palette: warm off-whites, deep charcoals, terracotta accent */
  --color-bg:          #F5F4EF;
  --color-bg-alt:      #EEEADE;
  --color-surface:     #FFFFFF;
  --color-border:      #E0DDD5;
  --color-text:        #1A1917;
  --color-text-muted:  #6B6860;
  --color-text-faint:  #A09E97;
  --color-accent:      #C96442;   /* Anthropic terracotta */
  --color-accent-soft: #F2E8E3;
  --color-tag-bg:      #ECEAE3;
  --color-tag-text:    #4A4845;

  /* Typography */
  --font-sans:   'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif:  'Newsreader', Georgia, serif;

  /* Spacing */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Layout */
  --max-width: 1040px;
  --nav-height: 60px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

@media (max-width: 640px) {
  .container { padding: 0 var(--space-lg); }
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: rgba(245, 244, 239, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: var(--space-xl);
}

.nav-links a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  font-weight: 400;
  transition: color 0.2s;
}

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

@media (max-width: 560px) {
  .nav-links { gap: var(--space-lg); }
  .nav-links a { font-size: 0.8rem; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  padding-top: calc(var(--nav-height) + var(--space-3xl));
  padding-bottom: var(--space-3xl);
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-border) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-border) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 0.45;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 30%, transparent 100%);
  pointer-events: none;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-soft);
  border: 1px solid rgba(201, 100, 66, 0.2);
  padding: var(--space-xs) var(--space-md);
  border-radius: 100px;
  margin-bottom: var(--space-xl);
}

.hero-tag::before {
  content: '';
  display: block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-lg);
  max-width: 700px;
}

.hero-title em {
  font-style: italic;
  color: var(--color-accent);
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin-bottom: var(--space-xl);
  line-height: 1.75;
}

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

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
  cursor: pointer;
  border: 1px solid transparent;
}

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

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

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

.btn-ghost:hover {
  background: var(--color-tag-bg);
  color: var(--color-text);
}

/* ============================================================
   SECTIONS
   ============================================================ */
.section {
  padding: var(--space-3xl) 0;
}

.section-alt {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-bottom: var(--space-lg);
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: var(--space-lg);
  color: var(--color-text);
}

.section-intro {
  color: var(--color-text-muted);
  font-size: 1rem;
  max-width: 560px;
  margin-bottom: var(--space-2xl);
}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-2xl);
  align-items: start;
}

@media (max-width: 800px) {
  .about-grid { grid-template-columns: 1fr; }
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  font-size: 1rem;
}

.about-skills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-xl);
}

.skill-tag {
  font-size: 0.8rem;
  font-weight: 500;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  border: 1px solid var(--color-border);
}

/* About card — Notion-style info block */
.about-card {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-xl));
}

.about-card-inner {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.about-card-avatar {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: var(--color-accent);
  color: white;
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
}

.about-card-name {
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
}

.about-card-role {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 2px;
}

.about-card-divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--space-lg) 0;
}

.about-card-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.about-card-links li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.about-card-link-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
}

.about-card-links a {
  font-size: 0.875rem;
  color: var(--color-accent);
  transition: opacity 0.2s;
}

.about-card-links a:hover { opacity: 0.7; }

/* ============================================================
   PROJECTS
   ============================================================ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

@media (max-width: 720px) {
  .projects-grid { grid-template-columns: 1fr; }
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  transition: box-shadow 0.2s, transform 0.2s;
}

.project-card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}

.project-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.project-tag {
  font-size: 0.75rem;
  color: var(--color-text-faint);
  font-weight: 500;
}

.project-status {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
}

.project-status--active  { background: #E6F4EA; color: #2D6A4F; }
.project-status--shipped { background: #EEF2FF; color: #3730A3; }
.project-status--research{ background: var(--color-accent-soft); color: var(--color-accent); }

.project-title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.35;
}

.project-desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  flex: 1;
}

.project-footer {
  margin-top: auto;
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
}

.project-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  transition: opacity 0.2s;
}

.project-link:hover { opacity: 0.7; }

/* ============================================================
   WRITING
   ============================================================ */
.writing-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--color-border);
}

.writing-item {
  display: grid;
  grid-template-columns: 120px 1fr 32px;
  gap: var(--space-xl);
  align-items: start;
  padding: var(--space-xl) 0;
  border-bottom: 1px solid var(--color-border);
  transition: background 0.15s;
  border-radius: var(--radius-md);
}

.writing-item:hover {
  background: var(--color-tag-bg);
  padding-left: var(--space-md);
  padding-right: var(--space-md);
  margin: 0 calc(-1 * var(--space-md));
}

@media (max-width: 640px) {
  .writing-item {
    grid-template-columns: 1fr 24px;
    gap: var(--space-md);
  }
  .writing-meta { display: none; }
}

.writing-meta {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  padding-top: 4px;
}

.writing-date {
  font-size: 0.8rem;
  color: var(--color-text-faint);
  font-weight: 500;
}

.writing-tag {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-soft);
  padding: 0.15rem 0.5rem;
  border-radius: 100px;
  width: fit-content;
}

.writing-title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  line-height: 1.4;
}

.writing-excerpt {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.65;
}

.writing-arrow {
  font-size: 1.1rem;
  color: var(--color-text-faint);
  padding-top: 4px;
  transition: color 0.2s, transform 0.2s;
}

.writing-item:hover .writing-arrow {
  color: var(--color-accent);
  transform: translateX(4px);
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-block {
  max-width: 560px;
}

.contact-block p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-xl);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-name {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 500;
}

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

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  transition: color 0.2s;
}

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

/* ============================================================
   SCROLL ANIMATIONS
   ============================================================ */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}