/**
 * Jean-Pierre Yin Photography Portfolio
 * Minimal, clean CSS following modern best practices
 */

/* ===========================================
   CSS Custom Properties
   =========================================== */
:root {
  /* Colors */
  --color-black: #000;
  --color-white: #fff;
  --color-gray: #767676;
  --color-border: #f0f0f0;

  /* Typography */
  --font-primary: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-size-xs: 10px;
  --font-size-sm: 11px;
  --font-size-base: 14px;
  --font-size-lg: 15px;

  /* Spacing */
  --page-padding: 7vw;
  --grid-gap: 34px;
  --header-height: 36px;
  --header-padding: 1.5vw;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-black);
  background-color: var(--color-white);
}

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

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

/* ===========================================
   Header
   =========================================== */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 1000;
  background-color: transparent;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.header.header-hidden {
  transform: translateY(-100%);
  opacity: 0;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--header-padding) var(--page-padding);
}

.logo {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  transition: opacity 0.3s ease;
}

.logo:hover {
  opacity: 0.6;
}

.nav {
  display: flex;
  align-items: center;
  gap: 40px;
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  transition: opacity 0.3s ease;
}

.nav-link:hover {
  opacity: 0.6;
}

/* Language Switcher */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 20px;
  padding-left: 20px;
  border-left: 1px solid #e0e0e0;
}

.lang-link {
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--color-gray);
  transition: color 0.3s ease;
}

.lang-link:hover,
.lang-link.active {
  color: var(--color-black);
}

.lang-sep {
  font-size: var(--font-size-xs);
  color: var(--color-gray);
}

/* Header spacer */
.header-spacer {
  height: calc(var(--header-height) + var(--header-padding) * 2);
}

/* Light header for project pages */
.page-project .header .logo,
.page-project .header .nav-link {
  color: var(--color-white);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.page-project .header .lang-link {
  color: rgba(255, 255, 255, 0.7);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.page-project .header .lang-link.active,
.page-project .header .lang-link:hover {
  color: var(--color-white);
}

.page-project .header .lang-sep {
  color: rgba(255, 255, 255, 0.5);
}

.page-project .header .lang-switcher {
  border-left-color: rgba(255, 255, 255, 0.3);
}

.page-project .header-spacer {
  display: none;
}

/* ===========================================
   Main Content
   =========================================== */
main {
  min-height: calc(100vh - 200px);
}

/* ===========================================
   Home Page Grid
   =========================================== */
.home-grid {
  display: grid;
  grid-template-columns: repeat(24, 1fr);
  gap: 20px var(--grid-gap);
  padding: 2vw var(--page-padding) 8vw;
  max-width: 1500px;
  margin: 0 auto;
}

/* Asymmetric layout positions */
.home-grid .grid-item:nth-child(1) { grid-column: 1 / 14; grid-row: 1 / 3; }
.home-grid .grid-item:nth-child(2) { grid-column: 15 / 25; grid-row: 1 / 2; margin-top: 8vw; }
.home-grid .grid-item:nth-child(3) { grid-column: 15 / 21; grid-row: 2 / 3; }
.home-grid .grid-item:nth-child(4) { grid-column: 1 / 8; grid-row: 3 / 4; }
.home-grid .grid-item:nth-child(5) { grid-column: 9 / 25; grid-row: 3 / 5; }
.home-grid .grid-item:nth-child(6) { grid-column: 1 / 12; grid-row: 5 / 6; }
.home-grid .grid-item:nth-child(7) { grid-column: 14 / 25; grid-row: 5 / 6; margin-top: 4vw; }
.home-grid .grid-item:nth-child(8) { grid-column: 1 / 10; grid-row: 6 / 7; margin-top: 2vw; }
.home-grid .grid-item:nth-child(9) { grid-column: 11 / 25; grid-row: 6 / 8; }
.home-grid .grid-item:nth-child(10) { grid-column: 1 / 13; grid-row: 8 / 9; }
.home-grid .grid-item:nth-child(11) { grid-column: 14 / 22; grid-row: 8 / 9; margin-top: 6vw; }
.home-grid .grid-item:nth-child(12) { grid-column: 1 / 9; grid-row: 9 / 10; }

.grid-item {
  position: relative;
  overflow: hidden;
}

.grid-item a {
  display: block;
}

.grid-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: opacity 0.3s ease;
}

.grid-item:hover img {
  opacity: 0.95;
}

.grid-item-title {
  position: absolute;
  inset: auto 0 0 0;
  padding: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-white);
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.4));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.grid-item:hover .grid-item-title {
  opacity: 1;
}

/* ===========================================
   Work/Gallery Index Page
   =========================================== */
.work-page {
  padding: 4vw var(--page-padding) 8vw;
  max-width: 1500px;
  margin: 0 auto;
}

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

.work-item {
  position: relative;
  overflow: hidden;
}

.work-item a {
  display: block;
}

.work-item img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  transition: opacity 0.3s ease;
}

.work-item:hover img {
  opacity: 0.95;
}

.work-item-info {
  padding: 16px 0;
}

.work-item-title {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.work-item-category {
  font-size: var(--font-size-sm);
  color: var(--color-gray);
  margin-top: 4px;
}

/* Filter bar */
.filter-bar {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin-bottom: 50px;
}

.filter-btn {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-gray);
  transition: color 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
  color: var(--color-black);
}

/* ===========================================
   Project Detail Page
   =========================================== */
.project-page {
  padding: 0;
}

/* Hero section */
.project-hero {
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
}

.project-hero-image {
  position: absolute;
  inset: 0;
}

.project-hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Hero overlay */
.project-hero-overlay {
  position: fixed;
  inset: 0 0 auto 0;
  padding: calc(var(--header-height) + var(--header-padding) * 2 + 3vw) var(--page-padding) 0;
  z-index: 100;
  pointer-events: none;
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.project-hero-overlay.hidden {
  opacity: 0;
  transform: translateY(-20px);
}

.project-hero-info {
  max-width: 600px;
}

.project-title {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-white);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* Project details (two columns) */
.project-details {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 60px;
  padding: 80px var(--page-padding);
  max-width: 1400px;
}

.project-details-left {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.project-detail-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.project-detail-label {
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gray);
}

.project-detail-value {
  font-size: var(--font-size-base);
  line-height: 1.8;
}

.project-details-right p {
  font-size: var(--font-size-lg);
  line-height: 2;
}

/* Project gallery grid */
.project-gallery {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
  padding: 0 var(--page-padding) 60px;
  max-width: 1500px;
  margin: 0 auto;
}

.project-gallery-item {
  overflow: hidden;
}

.project-gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Asymmetric gallery pattern */
.project-gallery-item:nth-child(6n+1) { grid-column: span 7; }
.project-gallery-item:nth-child(6n+2) { grid-column: span 5; }
.project-gallery-item:nth-child(6n+3) { grid-column: span 5; }
.project-gallery-item:nth-child(6n+4) { grid-column: span 7; }
.project-gallery-item:nth-child(6n+5) { grid-column: span 8; }
.project-gallery-item:nth-child(6n+6) { grid-column: span 4; }

/* Project navigation */
.project-nav {
  display: flex;
  justify-content: space-between;
  padding: 60px var(--page-padding);
  border-top: 1px solid var(--color-border);
}

.project-nav-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 150px;
}

.project-nav-prev { text-align: left; }
.project-nav-next { text-align: right; }

.project-nav-label {
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gray);
}

.project-nav-title {
  font-size: var(--font-size-base);
  transition: opacity 0.3s ease;
}

.project-nav-link:hover .project-nav-title {
  opacity: 0.6;
}

/* ===========================================
   Contact Page
   =========================================== */
.contact-page {
  padding: 6vw var(--page-padding) 8vw;
  max-width: 800px;
  margin: 0 auto;
}

.contact-header {
  text-align: center;
  margin-bottom: 60px;
}

.contact-header h1 {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 30px;
}

.contact-info {
  font-size: var(--font-size-base);
  color: var(--color-gray);
  line-height: 1.8;
}

.contact-info a {
  color: var(--color-black);
  border-bottom: 1px solid var(--color-black);
}

.contact-info a:hover {
  opacity: 0.6;
}

.contact-form {
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 30px;
}

.form-group label {
  display: block;
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gray);
  margin-bottom: 10px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 0;
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  color: var(--color-black);
  background: transparent;
  border: none;
  border-bottom: 1px solid #e0e0e0;
  outline: none;
  transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
  border-bottom-color: var(--color-black);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: #c0c0c0;
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.form-error {
  display: block;
  font-size: 12px;
  color: #c00;
  margin-top: 8px;
}

.form-submit {
  margin-top: 40px;
}

.btn-submit {
  display: inline-block;
  padding: 14px 40px;
  font-family: var(--font-primary);
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-white);
  background-color: var(--color-black);
  border: none;
  cursor: pointer;
  transition: opacity 0.3s ease;
}

.btn-submit:hover {
  opacity: 0.8;
}

/* Success message */
.success-message {
  text-align: center;
  padding: 60px 0;
}

.success-message h2 {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.success-message p {
  font-size: var(--font-size-base);
  color: var(--color-gray);
  line-height: 1.8;
  max-width: 500px;
  margin: 0 auto 40px;
}

/* ===========================================
   Footer
   =========================================== */
.footer {
  padding: 60px var(--page-padding);
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  max-width: 1500px;
  margin: 0 auto;
}

.footer-email {
  font-size: 12px;
  letter-spacing: 0.15em;
  margin-bottom: 12px;
}

.footer-email a {
  border-bottom: 1px solid var(--color-black);
}

.footer-email a:hover {
  opacity: 0.6;
}

.footer-location {
  font-size: var(--font-size-sm);
  color: var(--color-gray);
  letter-spacing: 0.1em;
  margin-bottom: 30px;
}

.footer-copyright {
  font-size: var(--font-size-xs);
  color: var(--color-gray);
  letter-spacing: 0.1em;
}

/* ===========================================
   Utilities
   =========================================== */
.back-link {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-gray);
  margin-top: 60px;
  transition: color 0.3s ease;
}

.back-link:hover {
  color: var(--color-black);
}

.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 80px 0;
  color: var(--color-gray);
  font-size: var(--font-size-base);
}

.page-header {
  text-align: center;
  margin-bottom: 6vw;
}

.page-header h1 {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* HTMX loading states */
.htmx-request {
  opacity: 0.5;
  transition: opacity 0.3s ease;
}

/* ===========================================
   Responsive - Tablet
   =========================================== */
@media (max-width: 1024px) {
  .home-grid {
    grid-template-columns: repeat(12, 1fr);
  }

  .home-grid .grid-item:nth-child(1) { grid-column: 1 / 7; grid-row: 1 / 2; }
  .home-grid .grid-item:nth-child(2) { grid-column: 7 / 13; grid-row: 1 / 2; margin-top: 0; }
  .home-grid .grid-item:nth-child(3) { grid-column: 1 / 8; grid-row: 2 / 3; }
  .home-grid .grid-item:nth-child(4) { grid-column: 8 / 13; grid-row: 2 / 3; }
  .home-grid .grid-item:nth-child(5) { grid-column: 1 / 7; grid-row: 3 / 4; }
  .home-grid .grid-item:nth-child(6) { grid-column: 7 / 13; grid-row: 3 / 4; }
  .home-grid .grid-item:nth-child(n+7) { grid-column: span 6; margin-top: 0; }
}

/* ===========================================
   Responsive - Mobile
   =========================================== */
@media (max-width: 768px) {
  :root {
    --page-padding: 6vw;
    --header-padding: 4vw;
    --grid-gap: 20px;
  }

  .nav { gap: 20px; }
  .nav-link { font-size: var(--font-size-xs); }
  .logo { font-size: var(--font-size-xs); }

  .lang-switcher {
    margin-left: 12px;
    padding-left: 12px;
  }

  .home-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .home-grid .grid-item {
    grid-column: 1 !important;
    grid-row: auto !important;
    margin-top: 0 !important;
  }

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

  .contact-page {
    padding: 10vw 6vw;
  }

  .filter-bar {
    flex-wrap: wrap;
    gap: 16px;
  }

  .footer {
    padding: 40px var(--page-padding);
  }

  /* Project page mobile */
  .project-hero {
    height: 100svh;
  }

  .project-hero-overlay {
    padding-top: calc(var(--header-height) + var(--header-padding) * 2 + 6vw);
  }

  .project-title {
    font-size: 12px;
  }

  .project-details {
    grid-template-columns: 1fr;
    gap: 40px;
    padding: 50px var(--page-padding);
  }

  .project-details-left { gap: 24px; }
  .project-detail-label { font-size: 9px; }
  .project-detail-value { font-size: 13px; }
  .project-details-right p { font-size: var(--font-size-base); line-height: 1.9; }

  .project-gallery {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 0 var(--page-padding) 40px;
  }

  .project-gallery-item:nth-child(n) {
    grid-column: span 1;
  }

  .project-nav {
    flex-direction: column;
    gap: 30px;
    padding: 40px var(--page-padding);
  }

  .project-nav-next { text-align: left; }
}

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