/**
 * Main Stylesheet - Mobile-First Design
 * Responsive design for Yang Shuwen personal website
 *
 * Breakpoint Strategy:
 * - Mobile: default (< 768px) - single column layout
 * - Tablet: @media (min-width: 768px) - enhanced spacing
 * - Desktop: @media (min-width: 1024px) - two-column grid layout
 */

/* ========================================
   Reset & Base Styles
   ======================================== */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: var(--font-size-base);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover,
a:focus {
  color: var(--color-link-hover);
  text-decoration: underline;
}

/* ========================================
   Typography
   ======================================== */

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  color: var(--color-heading);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-md);
}

h1 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-top: var(--space-xl);
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
}

p {
  margin-bottom: var(--space-md);
}

/* Lists */
.content-area ul,
.content-area ol {
  margin: 0 0 var(--space-md) var(--space-lg);
  padding-left: 0;
}

.content-area li {
  margin-bottom: var(--space-xs);
}

.content-area li:last-child {
  margin-bottom: 0;
}

.content-area li ul,
.content-area li ol {
  margin-top: var(--space-sm);
}

/* Tables */
.content-area .table-wrapper {
  overflow-x: auto;
  margin-top: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  background-color: var(--color-bg);
  -webkit-overflow-scrolling: touch;
}

.content-area table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  background-color: var(--color-bg);
}

.content-area th,
.content-area td {
  border: 1px solid var(--color-border-light);
  padding: var(--space-sm);
  text-align: left;
  vertical-align: top;
  font-size: var(--font-size-sm);
}

.content-area tbody tr:nth-child(even) td,
.content-area tbody tr:nth-child(even) th {
  border-color: #ffffff;
}

.content-area .responsive-table th:last-child,
.content-area .responsive-table td:last-child {
  width: 50px;
  white-space: nowrap;
}

.content-area .responsive-table th:first-child,
.content-area .responsive-table td:first-child {
  min-width: 50px;
  white-space: nowrap;
}

.content-area .schedule-table th:first-child,
.content-area .schedule-table td:first-child,
.content-area .schedule-table th:nth-child(2),
.content-area .schedule-table td:nth-child(2) {
  min-width: 50px;
  white-space: nowrap;
}

.content-area thead th {
  background-color: var(--color-bg-alt);
  color: var(--color-heading);
  font-weight: 600;
}

.content-area caption {
  caption-side: top;
  width: 100%;
  text-align: left;
  padding: var(--space-sm) var(--space-md);
  font-weight: 600;
  color: var(--color-heading);
}

.content-area .responsive-table .cell-sub {
  display: none;
}

.content-area .responsive-table .cell-data {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-xs);
}

.content-area .table-caption {
  margin: var(--space-sm) 0 var(--space-sm);
  padding: 0;
  font-weight: 600;
  color: var(--color-heading);
}

.content-area .fee-list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-md);
}

.content-area .fee-list li {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: var(--space-sm);
  align-items: baseline;
  padding: var(--space-xs) 0;
}

.content-area .fee-label::after {
  content: "：";
}

.content-area .fee-price {
  font-weight: 600;
  white-space: nowrap;
}
.content-area tbody tr:nth-child(even) {
  background-color: var(--color-bg-alt);
}

@media (max-width: 767px) {
  .content-area .table-wrapper {
    border: none;
    margin-top: var(--space-sm);
  }

  .content-area .schedule-table {
    min-width: 0;
  }

  .content-area .schedule-table thead {
    display: none;
  }

  .content-area .schedule-table,
  .content-area .schedule-table tbody,
  .content-area .schedule-table tr,
  .content-area .schedule-table td {
    display: block;
    width: 100%;
  }

  .content-area .schedule-table tr {
    margin-bottom: var(--space-sm);
    padding: var(--space-sm);
    border: 1px solid var(--color-border-light);
    border-radius: var(--border-radius);
    background-color: var(--color-bg);
  }

  .content-area .schedule-table td {
    border: none;
    padding: var(--space-xs) 0;
    font-size: var(--font-size-sm);
    display: grid;
    grid-template-columns: 6em 1fr;
    gap: var(--space-xs) var(--space-sm);
  }

  .content-area .schedule-table td[data-label=""] {
    grid-template-columns: 6em 1fr;
    gap: var(--space-xs) var(--space-sm);
  }

  .content-area .schedule-table td::before {
    content: attr(data-label);
    font-weight: 600;
    color: var(--color-heading);
  }

  .content-area .schedule-table tbody tr:nth-child(even) {
    background-color: var(--color-bg-alt);
  }

  .content-area .responsive-table {
    min-width: 0;
  }

  .content-area .responsive-table thead {
    display: none;
  }

  .content-area .responsive-table,
  .content-area .responsive-table tbody,
  .content-area .responsive-table tr,
  .content-area .responsive-table td {
    display: block;
    width: 100%;
  }

  .content-area .responsive-table tr {
    margin-bottom: var(--space-sm);
    padding: var(--space-sm);
    border: 1px solid var(--color-border-light);
    border-radius: var(--border-radius);
    background-color: var(--color-bg);
  }

  .content-area .responsive-table td {
    border: none;
    padding: var(--space-xs) 0;
    font-size: var(--font-size-sm);
    display: grid;
    grid-template-columns: 6em 1fr;
    gap: var(--space-xs) var(--space-sm);
  }

  .content-area .responsive-table td[data-label="治疗项目"] {
    font-weight: 600;
  }

  .content-area .responsive-table td::before {
    content: attr(data-label);
    font-weight: 600;
    color: var(--color-heading);
  }

  .content-area .responsive-table .cell-sub {
    display: inline;
    font-weight: 600;
    color: var(--color-heading);
  }

  .content-area .responsive-table .cell-data {
    white-space: nowrap;
  }

  .content-area .responsive-table tbody tr:nth-child(even) {
    background-color: var(--color-bg-alt);
  }

  .content-area .media-card {
    padding: 0;
    overflow: hidden;
  }

  .content-area .media-card h3 {
    padding: var(--space-md);
    margin: 0;
  }

  .content-area .media-card .media-video {
    margin: 0;
    width: 100%;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
  }

  .content-area .media-video {
    margin: 0;
    width: 100%;
    max-width: none;
    border-radius: 0;
  }
}

/* ========================================
   Header & Navigation (Mobile-First)
   ======================================== */

.site-header {
  background-color: var(--color-primary);
  color: white;
  padding: var(--space-md) var(--space-md);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  position: relative;
  padding: 0;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.site-title {
  font-size: var(--font-size-2xl);
  margin: 0;
  color: white;
}

.site-title a {
  color: white;
  text-decoration: none;
}

/* Mobile Navigation - Hamburger Menu */
.nav-toggle {
  display: block;
  background: none;
  border: 2px solid white;
  color: white;
  font-size: var(--font-size-sm);
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  border-radius: var(--border-radius);
  min-width: 44px;
  min-height: 44px;
  transition: all var(--transition-normal);
  position: absolute;
  top: 0;
  right: 0;
}

.nav-toggle:hover,
.nav-toggle:focus {
  background-color: rgba(255, 255, 255, 0.1);
}

/* When menu is open, move button to left */
.nav-toggle.is-open {
  left: 0;
  right: auto;
}

.site-nav {
  display: block;
  margin-top: var(--space-md);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition: max-height var(--transition-normal),
    opacity var(--transition-normal),
    transform var(--transition-normal);
}

.site-nav.is-open {
  max-height: 70vh;
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}

.site-nav ul {
  list-style: none;
}

.site-nav li {
  margin-bottom: var(--space-sm);
  position: relative;
}

.site-nav a {
  color: white;
  display: block;
  padding: var(--space-sm) var(--space-md);
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius);
  min-height: 44px;
  display: flex;
  align-items: center;
  font-size: var(--font-size-sm);
}

.site-nav .submenu-toggle {
  width: 100%;
  text-align: left;
  color: white;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius);
  border: none;
  padding: var(--space-sm) var(--space-md);
  min-height: 44px;
  font-size: var(--font-size-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  transition: background-color var(--transition-normal);
}

.site-nav .submenu-toggle::after {
  content: "▾";
  font-size: 0.75em;
  transition: transform var(--transition-normal);
}

.site-nav .has-submenu.is-open .submenu-toggle::after {
  transform: rotate(180deg);
}

.site-nav a:hover,
.site-nav a:focus {
  background-color: rgba(255, 255, 255, 0.2);
  text-decoration: none;
}

.site-nav .submenu-toggle:hover,
.site-nav .submenu-toggle:focus {
  background-color: rgba(255, 255, 255, 0.2);
}

.site-nav a.active {
  background-color: rgba(255, 255, 255, 0.3);
  font-weight: 600;
  border-left: 3px solid white;
}

.site-nav .submenu-toggle.active {
  background-color: rgba(255, 255, 255, 0.3);
  font-weight: 600;
  border-left: 3px solid white;
}

.site-nav .submenu {
  list-style: none;
  margin: var(--space-xs) 0 0;
  padding-left: var(--space-md);
  display: none;
}

.site-nav .has-submenu.is-open .submenu {
  display: block;
}

.site-nav .submenu li {
  margin-bottom: var(--space-xs);
}

/* ========================================
   Main Container & Layout (Mobile-First)
   ======================================== */

.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: var(--space-sm);
}

.main-content {
  /* Mobile: single column, content stacks vertically */
}

/* ========================================
   Content Sections
   ======================================== */

.intro-section {
  background-color: var(--color-bg);
  padding: var(--space-sm);
  margin-bottom: var(--space-md);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border-light);
}

.service-card {
  background-color: var(--color-bg);
  padding: var(--space-sm);
  margin-bottom: var(--space-md);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border-light);
}

.books-section {
  background-color: var(--color-bg);
  padding: var(--space-sm);
  margin-bottom: var(--space-md);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border-light);
}

.services-section {
  background-color: var(--color-bg);
  padding: var(--space-sm);
  margin-bottom: var(--space-md);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border-light);
}

.intro-section,
.books-section,
.services-section,
.service-card h3 {
  font-size: var(--font-size-lg);
}

.intro-section,
.books-section,
.services-section,
.service-card p {
  font-size: var(--font-size-sm);
}

@media (max-width: 767px) {
  .intro-section,
  .books-section,
  .services-section {
    font-size: 1.1rem;
  }

  .service-card p {
    font-size: 1.1rem;
  }
}

.section-title {
  color: var(--color-primary);
  border-bottom: 2px solid var(--color-border);
  padding-bottom: var(--space-sm);
  margin: 0 0 var(--space-md);
}

/* Book Showcase Grid - Mobile: 2 columns */
.books-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.photo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
  grid-auto-flow: row;
}

.photo-grid.waterfall-grid {
  grid-template-columns: 1fr;
  grid-auto-rows: 10px;
  grid-auto-flow: row;
}

.photo-item {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.photo-img {
  width: 100%;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  display: block;
}

.photo-caption {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  text-align: center;
  line-height: var(--line-height-tight);
}

/* Restore 2 columns for the first books section (small book covers) */
.books-section:first-of-type .books-grid {
  grid-template-columns: repeat(2, 1fr);
}

.book-item {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.book-item h3 {
  font-size: var(--font-size-sm);
}

.book-cover {
  width: 100%;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  margin-top: auto;
}

.book-item img {
  height: 200px;
  object-fit: contain;
}

/* Services Grid */
.services-grid {
  display: grid;
  gap: var(--space-lg);
}

.service-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  gap: 1rem;
}

.service-card h3 {
  color: var(--color-primary);
  margin: 0;
  /* Reset margins, let gap handle spacing */
  line-height: 1.3;
  height: 2.6em;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 0 0 auto;
}

.service-card img:not(.book-cover) {
  width: 100%;
  height: 300px;
  object-fit: cover;
  flex: 0 0 auto;
  margin-top: 0;
  /* override .book-cover margin-top: auto */
}

.service-card img.book-cover {
  height: auto;
  object-fit: contain;
}

.media-video {
  width: 100%;
  border-radius: var(--border-radius);
  background-color: #000000;
}

.service-card p {
  margin-bottom: 0;
  /* Reset margin, let gap handle it */
}

.service-card h4 {
  margin: 0;
  /* Reset margin */
}

.service-card h4:first-of-type {
  margin-top: auto;
}

.service-card strong {
  color: var(--color-primary-dark);
}

.services-section h3,
.services-section h4 {
  margin-top: var(--space-lg);
}

/* ========================================
   Sidebar
   ======================================== */

.sidebar {
  /* Mobile: appears after main content */
  margin-top: var(--space-xl);
}

.sidebar-section {
  background-color: var(--color-bg-alt);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.profile-image {
  width: 100%;
  max-width: 260px;
  margin: 0 auto var(--space-lg);
  border-radius: var(--border-radius);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.contact-info p {
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-base);
}

.contact-info strong {
  font-weight: bold;
  color: var(--color-heading);
}

/* ========================================
   Footer
   ======================================== */

.site-footer {
  background-color: var(--color-bg-alt);
  border-top: 2px solid var(--color-border);
  padding: var(--space-lg) var(--space-md);
  margin-top: var(--space-3xl);
  text-align: center;
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
}

.site-footer a {
  color: var(--color-link);
}

/* ========================================
   Tablet Styles (768px+)
   ======================================== */

@media (min-width: 768px) {
  .container {
    padding: var(--space-xl);
  }

  .intro-section {
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
  }

  .service-card {
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
  }
  .books-section {
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
  }

  .services-section {
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
  }

  .section-title {
    margin-bottom: var(--space-lg);
  }

  h1 {
    font-size: var(--font-size-4xl);
  }

  h2 {
    font-size: var(--font-size-3xl);
  }

  /* Books Grid - Tablet: still 2 columns but larger */
  .books-grid {
    gap: var(--space-lg);
  }

  .photo-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
  }

  .photo-grid.waterfall-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  /* Header adjustments for tablet */
  .site-header {
    padding: var(--space-sm) var(--space-lg);
  }

  .site-header .container {
    display: flex;
    justify-content: flex-end;
    align-items: center;
  }

  /* Navigation - Horizontal for tablet */
  .nav-toggle {
    display: none;
  }

  .site-nav {
    display: block;
    margin-top: 0;
    max-height: none;
    opacity: 1;
    overflow: visible;
    pointer-events: auto;
    transform: none;
  }

  .site-nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
  }

  .site-nav li {
    margin-bottom: 0;
  }

  .site-nav a {
    white-space: nowrap;
  }

  .site-nav .submenu-toggle {
    white-space: nowrap;
  }

  .site-nav .submenu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 220px;
    background-color: var(--color-primary-dark);
    padding: var(--space-sm);
    border-radius: var(--border-radius);
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.18);
    z-index: 10;
    margin: 0;
    display: none;
  }

  .site-nav .submenu li {
    margin-bottom: var(--space-xs);
  }

  .site-nav .has-submenu:hover .submenu,
  .site-nav .has-submenu:focus-within .submenu {
    display: block;
  }

  /* Active state for horizontal menu */
  .site-nav a.active {
    border-left: none;
    border-bottom: 3px solid white;
  }

  .site-nav .submenu-toggle.active {
    border-left: none;
    border-bottom: 3px solid white;
  }
}

/* ========================================
   Desktop Styles (1024px+)
   ======================================== */

@media (min-width: 1024px) {

  /* Two-column grid layout */
  .main-content {
    display: grid;
    grid-template-columns: 1fr var(--sidebar-width);
    gap: var(--space-2xl);
    align-items: start;
  }

  .content-area {
    /* Main content column */
  }

  .sidebar {
    /* Sidebar column - appears beside content */
    margin-top: 0;
    position: static;
  }

  /* Books Grid - Desktop: 3 columns */
  .books-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .photo-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  }

  .photo-grid.waterfall-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  /* Reset first section to 3 columns on desktop */
  .books-section:first-of-type .books-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  /* Services Grid - Desktop: 2 columns */
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Enhanced header spacing */
  .site-header {
    padding: var(--space-md) var(--space-xl);
  }

  .site-nav {
    margin-top: 0;
  }

  .site-header .container {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    padding: 0;
  }

  .site-nav ul {
    gap: var(--space-md);
  }
}

/* ========================================
   Utility Classes
   ======================================== */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.text-center {
  text-align: center;
}

.mt-0 {
  margin-top: 0;
}

.mb-lg {
  margin-bottom: var(--space-lg);
}