/* ==========================================================================
   Marcus Tan — Portfolio Site
   Warm palette inspired by shiori.sh. Inter font. Icons. Depth.
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

/* ---------- Theme Tokens ---------- */
:root {
  /* Light — warm cream palette */
  --bg: #FAF6F0;
  --bg-secondary: #F3EDE4;
  --text: #1C1710;
  --text-secondary: #6B5E4F;
  --text-tertiary: #9B8E7A;
  --accent: #D4703A;
  --accent-light: #E8923A;
  --accent-bg: rgba(212, 112, 58, 0.08);
  --accent-bg-strong: rgba(212, 112, 58, 0.14);
  --card-bg: #FFFFFF;
  --card-border: #E8E0D4;
  --card-shadow: 0 1px 3px rgba(28, 23, 16, 0.04), 0 6px 16px rgba(28, 23, 16, 0.04);
  --card-shadow-hover: 0 4px 12px rgba(28, 23, 16, 0.08), 0 12px 32px rgba(28, 23, 16, 0.06);
  --pill-bg: #F0EBE3;
  --pill-text: #7A6D5C;
  --pill-border: #E0D8CC;
  --divider: #E8E0D4;
  --toggle-bg: #FFFFFF;
  --toggle-border: #E0D8CC;
  --toggle-icon: #6B5E4F;
  --quote-border: var(--accent);
  --quote-bg: var(--accent-bg);
  --metric-value: var(--accent);
  --metric-bg: var(--accent-bg);
  --icon-bg: var(--accent-bg);
  --icon-color: var(--accent);
  --btn-primary-bg: var(--accent);
  --btn-primary-text: #FFFFFF;
  --btn-primary-hover: #C06030;
  --btn-ghost-text: var(--text);
  --btn-ghost-border: var(--card-border);
  --btn-ghost-hover-bg: var(--bg-secondary);
  --hero-orb: radial-gradient(circle, rgba(212, 112, 58, 0.12) 0%, rgba(212, 112, 58, 0) 70%);
  --selection-bg: var(--accent);
  --selection-text: #FFFFFF;
}

[data-theme="dark"] {
  --bg: #17130E;
  --bg-secondary: #1F1A14;
  --text: #F0EAE0;
  --text-secondary: #A89880;
  --text-tertiary: #7A6D5C;
  --accent: #E89840;
  --accent-light: #F0A850;
  --accent-bg: rgba(232, 152, 64, 0.10);
  --accent-bg-strong: rgba(232, 152, 64, 0.18);
  --card-bg: #1F1A14;
  --card-border: #2E2720;
  --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 6px 16px rgba(0, 0, 0, 0.2);
  --card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4), 0 12px 32px rgba(0, 0, 0, 0.3);
  --pill-bg: #2A2318;
  --pill-text: #A89880;
  --pill-border: #3A3228;
  --divider: #2E2720;
  --toggle-bg: #1F1A14;
  --toggle-border: #3A3228;
  --toggle-icon: #A89880;
  --quote-border: var(--accent);
  --quote-bg: var(--accent-bg);
  --metric-value: var(--accent);
  --metric-bg: var(--accent-bg);
  --icon-bg: var(--accent-bg);
  --icon-color: var(--accent);
  --btn-primary-bg: var(--accent);
  --btn-primary-text: #17130E;
  --btn-primary-hover: #F0A850;
  --btn-ghost-text: var(--text);
  --btn-ghost-border: var(--card-border);
  --btn-ghost-hover-bg: var(--bg-secondary);
  --hero-orb: radial-gradient(circle, rgba(232, 152, 64, 0.08) 0%, rgba(232, 152, 64, 0) 70%);
  --selection-bg: var(--accent);
  --selection-text: #17130E;
}

/* ---------- Body ---------- */
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  transition: background-color 0.4s ease, color 0.4s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ---------- Layout ---------- */
.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 28px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 10px;
  padding: 12px 24px;
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}

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

.btn--primary:hover {
  background: var(--btn-primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(212, 112, 58, 0.25);
}

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

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

.btn--lg {
  padding: 16px 32px;
  font-size: 1rem;
  border-radius: 12px;
}

/* ---------- Site Nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--divider);
  transition: background-color 0.4s ease, border-color 0.4s ease;
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.nav__logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--text);
  transition: color 0.3s ease;
}

.nav__logo-svg {
  height: 28px;
  width: auto;
}

.nav__logo:hover {
  color: var(--accent);
}

/* ---------- Theme Toggle ---------- */
.theme-toggle {
  position: relative;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--toggle-border);
  background: var(--toggle-bg);
  color: var(--toggle-icon);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  position: absolute;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.theme-toggle .icon-sun {
  opacity: 0;
  transform: rotate(-90deg) scale(0.6);
}

.theme-toggle .icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .theme-toggle .icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .theme-toggle .icon-moon {
  opacity: 0;
  transform: rotate(90deg) scale(0.6);
}

/* ---------- Hero ---------- */
.hero {
  padding: 80px 0 80px;
  min-height: 90vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero__accent-orb {
  position: absolute;
  top: -20%;
  right: -10%;
  width: 700px;
  height: 700px;
  background: var(--hero-orb);
  border-radius: 50%;
  pointer-events: none;
  animation: orbFloat 8s ease-in-out infinite;
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-30px, 20px) scale(1.05); }
}

.hero-content {
  width: 100%;
  position: relative;
  z-index: 1;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 100px;
  background: var(--accent-bg);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 28px;
  letter-spacing: 0.02em;
}

.hero__badge svg {
  flex-shrink: 0;
}

.hero__name {
  font-size: clamp(3.2rem, 9vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.02;
  margin-bottom: 10px;
  color: var(--text);
}

.hero__subtitle {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 44px;
}

.hero__headline {
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  font-weight: 600;
  line-height: 1.4;
  max-width: 640px;
  margin-bottom: 20px;
  color: var(--text);
  letter-spacing: -0.01em;
}

.hero__highlight {
  color: var(--accent);
}

.hero__description {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-secondary);
  max-width: 560px;
  margin-bottom: 36px;
}

.hero__cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ---------- Bridge ---------- */
.bridge {
  padding: 80px 0;
  border-top: 1px solid var(--divider);
}

.bridge__text {
  font-size: clamp(1.15rem, 2.5vw, 1.35rem);
  line-height: 1.75;
  color: var(--text-secondary);
  max-width: 640px;
  font-weight: 400;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.bridge__text em {
  font-style: normal;
  color: var(--text);
  font-weight: 500;
}

/* ---------- Section Header ---------- */
.section-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 40px;
}

.section-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-tertiary);
  white-space: nowrap;
}

.section-line {
  flex: 1;
  height: 1px;
  background: var(--divider);
}

/* ---------- Case Study Card ---------- */
.case-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  margin-bottom: 20px;
  box-shadow: var(--card-shadow);
  cursor: pointer;
  display: flex;
  overflow: hidden;
  /* Fade-in */
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.35s ease, border-color 0.35s ease;
}

.case-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.case-card:nth-child(3) { transition-delay: 0.08s; }
.case-card:nth-child(4) { transition-delay: 0.16s; }

.case-card:hover {
  box-shadow: var(--card-shadow-hover);
  border-color: var(--accent);
}

.case-card__accent {
  width: 4px;
  flex-shrink: 0;
  background: var(--accent);
  border-radius: 4px 0 0 4px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.case-card:hover .case-card__accent,
.case-card.expanded .case-card__accent {
  opacity: 1;
}

.case-card__inner {
  flex: 1;
  padding: 32px 36px;
  min-width: 0;
}

/* Card header */
.case-card__header {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.case-card__icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--icon-bg);
  color: var(--icon-color);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background-color 0.3s ease;
}

.case-card:hover .case-card__icon {
  background: var(--accent-bg-strong);
}

.case-card__header-text {
  flex: 1;
  min-width: 0;
}

.case-card__title {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: 4px;
}

.case-card__company {
  font-size: 0.88rem;
  color: var(--text-tertiary);
  margin-bottom: 0;
}

.case-card__expand-icon {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-tertiary);
  border-radius: 8px;
  transition: all 0.3s ease;
  margin-top: 8px;
}

.case-card:hover .case-card__expand-icon {
  background: var(--accent-bg);
  color: var(--accent);
}

.case-card.expanded .case-card__expand-icon {
  transform: rotate(45deg);
  background: var(--accent-bg);
  color: var(--accent);
}

/* Tags */
.case-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 16px 64px;
}

.pill {
  display: inline-block;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 8px;
  background: var(--pill-bg);
  color: var(--pill-text);
  border: 1px solid var(--pill-border);
  letter-spacing: 0.02em;
  transition: all 0.3s ease;
}

/* Summary */
.case-card__summary {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-left: 64px;
}

/* Expandable detail area */
.case-card__details {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.4s ease;
  opacity: 0;
  margin-left: 64px;
}

.case-card.expanded .case-card__details {
  opacity: 1;
}

.case-card__details-inner {
  padding-top: 28px;
  border-top: 1px solid var(--divider);
  margin-top: 24px;
}

/* Metrics grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 28px;
}

.metric {
  padding: 16px;
  border-radius: 12px;
  background: var(--metric-bg);
  border: 1px solid transparent;
  transition: background-color 0.3s ease;
}

.metric__value {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--metric-value);
  margin-bottom: 4px;
  letter-spacing: -0.02em;
}

.metric__label {
  font-size: 0.78rem;
  color: var(--text-tertiary);
  line-height: 1.45;
  font-weight: 500;
}

/* Detail section */
.detail-section {
  margin-bottom: 24px;
}

.detail-section__label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
  margin-bottom: 10px;
}

.detail-section__text {
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

/* Lesson quote */
.lesson-quote {
  padding: 20px 24px;
  border-left: 3px solid var(--quote-border);
  background: var(--quote-bg);
  border-radius: 0 12px 12px 0;
  margin-top: 4px;
}

.lesson-quote__text {
  font-size: 0.95rem;
  font-style: italic;
  line-height: 1.7;
  color: var(--text-secondary);
}

/* ---------- Contact ---------- */
.contact {
  padding: 80px 0 100px;
  border-top: 1px solid var(--divider);
}

.contact__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.contact__heading {
  font-size: clamp(2rem, 5vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  color: var(--text);
}

.contact__text {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-secondary);
  max-width: 420px;
}

/* ---------- Footer ---------- */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--divider);
}

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

.footer__text {
  font-size: 0.8rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .container {
    padding: 0 20px;
  }

  .hero {
    padding: 60px 0 60px;
    min-height: auto;
  }

  .hero__accent-orb {
    width: 400px;
    height: 400px;
    top: -10%;
    right: -20%;
  }

  .hero__subtitle {
    margin-bottom: 32px;
  }

  .case-card__inner {
    padding: 24px 20px;
  }

  .case-card__tags,
  .case-card__summary,
  .case-card__details {
    margin-left: 0;
  }

  .case-card__icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
  }

  .case-card__title {
    font-size: 1.2rem;
  }

  .metrics-grid {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .contact__inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .contact {
    padding: 60px 0 80px;
  }

  .site-nav__inner {
    height: 52px;
  }

  .nav__logo-svg {
    height: 24px;
  }

  .theme-toggle {
    width: 36px;
    height: 36px;
  }

  .footer__inner {
    flex-direction: column;
    gap: 4px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  .nav__wordmark {
    display: none;
  }

  .nav__logo-svg {
    height: 22px;
    width: 30px;
  }

  .hero {
    padding: 48px 0 48px;
  }

  .hero__subtitle {
    font-size: 0.85rem;
    margin-bottom: 24px;
  }

  .hero__badge {
    font-size: 0.75rem;
    margin-bottom: 20px;
  }

  .hero__cta {
    flex-direction: column;
  }

  .hero__cta .btn {
    justify-content: center;
  }

  .case-card {
    border-radius: 12px;
  }

  .case-card__header {
    gap: 12px;
  }

  .case-card__icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
  }

  .case-card__icon svg {
    width: 18px;
    height: 18px;
  }

  .metrics-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .metric {
    padding: 12px;
    border-radius: 10px;
  }

  .lesson-quote {
    padding: 16px 16px;
    border-radius: 0 10px 10px 0;
  }
}

/* ---------- Accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .case-card,
  .bridge__text,
  .contact__inner {
    opacity: 1;
    transform: none;
    transition: box-shadow 0.3s ease, background-color 0.3s ease;
  }

  .case-card__details {
    transition: max-height 0.2s ease;
  }

  .hero__accent-orb {
    animation: none;
  }

  .theme-toggle .icon-sun,
  .theme-toggle .icon-moon {
    transition: opacity 0.15s ease;
    transform: none !important;
  }

  [data-theme="dark"] .theme-toggle .icon-sun,
  [data-theme="dark"] .theme-toggle .icon-moon {
    transform: none !important;
  }
}