/* ===============================
   Main Stylesheet — Scratch Education Platform
   =============================== */

/* ---- Base ---- */
body {
  font-family: var(--font-family-base);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text-primary);
}

#main-content { flex: 1; }

/* ---- Accessibility ---- */
.skip-link {
  position: absolute; top: -100px; left: var(--space-md);
  background: var(--color-primary); color: #fff;
  padding: var(--space-sm) var(--space-base);
  z-index: 100000; border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  font-size: var(--text-sm); text-decoration: none;
}
.skip-link:focus { top: 0; }

*:focus-visible {
  outline: 3px solid var(--color-primary) !important;
  outline-offset: 2px;
}

/* ---- Micro-interactions ---- */
.layui-btn {
  transition: all var(--transition-fast);
}
.layui-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.layui-btn:active {
  transform: scale(0.97);
}
a {
  transition: color var(--transition-fast);
}

/* ---- Homepage: Hero ---- */
#top_box {
  position: relative; left: 0; top: 0; width: 100%;
  min-height: 55vh;
  padding: var(--space-xxl) 0 var(--space-xl) 0;
  display: flex; align-items: center; justify-content: center;
}
#top_bg {
  position: absolute; left: 0; top: 0; right: 0; bottom: 0;
  z-index: -10;
  background-position: center; background-size: cover;
  background-attachment: fixed;
  background-image: url("/img/web/sybj.png");
}
#top_overlay {
  position: absolute; left: 0; top: 0; right: 0; bottom: 0;
  z-index: -9; opacity: .75;
  background: var(--color-bg-dark);
}
#header-box { text-align: center; }
#avatar_img {
  border-radius: var(--radius-lg);
  width: 8em; height: 8em;
  box-shadow: var(--shadow-lg);
  border: 3px solid rgba(255,255,255,0.3);
}
.avatar-link {
  display: inline-block;
  position: relative;
}
.avatar-link::after {
  content: '个人中心';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 30%;
  background: rgba(0,0,0,0.55);
  color: #fff;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  opacity: 0;
  transition: opacity 0.2s;
  pointer-events: none;
}
.avatar-link:hover::after {
  opacity: 1;
}
#txt_username {
  margin: var(--space-sm) 0;
  color: #FFF;
  text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

/* ---- Homepage: Project Cards ---- */
.img-slt {
  width: calc(100% - 2px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}
.img-slt:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}
.txt-project-title {
  width: calc(100% - 2px);
  color: var(--color-text-secondary);
  text-align: center; line-height: 40px;
  border: 1px solid var(--color-border); border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  background: var(--color-bg-white);
}

.project-card {
  position: relative;
}
.project-card-stats {
  position: absolute; top: 8px; right: 8px;
  display: flex; align-items: center; gap: 2px;
  background: rgba(0,0,0,0.5); color: #fff;
  font-size: 11px; padding: 3px 8px;
  border-radius: var(--radius-sm);
  pointer-events: none; z-index: 2;
  opacity: 0; transition: opacity var(--transition-fast);
}
.project-card:hover .project-card-stats {
  opacity: 1;
}

/* ---- Project Management Cards ---- */
.txt-project-title1 {
  width: calc(100% - 2px);
  color: var(--color-text-primary); text-align: center; line-height: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  background-color: var(--color-bg-white);
  display: flex;
}
.img-slt1 {
  width: calc(100% - 2px);
  border-left: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
}
.txt-project-title2 {
  width: calc(100% - 2px);
  color: var(--color-text-primary); text-align: center; line-height: 40px;
  border: 1px solid var(--color-border); border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  background-color: var(--color-border);
  display: flex;
}
.project-top-right {
  border-top-right-radius: var(--radius-lg);
  flex: 1;
  color: var(--color-text-tertiary);
  font-size: var(--text-xs);
}
.project-bottom-left {
  flex: 1;
  border-bottom-left-radius: var(--radius-lg);
  margin-right: 1px;
  background-color: var(--color-bg-white);
}
.project-bottom-right {
  flex: 1;
  border-bottom-right-radius: var(--radius-lg);
  background-color: var(--color-bg-white);
}
.project-bottom-left:hover,
.project-bottom-right:hover,
.project-top-right:hover {
  cursor: pointer;
  background-color: var(--color-primary);
  color: #FFF;
}
.is_null {
  display: flex; justify-content: center; align-items: center;
  width: 100%; height: 200px;
}

/* ---- User Nav Bar ---- */
#head_box {
  display: flex; align-items: center;
  height: 68px; max-width: 980px; width: 100%;
  margin: 0 auto; padding: 0 var(--space-base);
  box-sizing: border-box;
}
#head_avatar {
  width: 50px; height: 50px;
  border-radius: var(--radius-base);
}
#head_username {
  width: 180px;
  font-size: var(--text-md);
  margin-left: var(--space-sm);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  color: var(--color-text-primary);
}
#head_menu {
  width: 100%; display: flex; justify-content: flex-end;
}
#head_menu > a {
  color: var(--color-text-primary);
  padding: var(--space-xs) var(--space-sm);
  min-height: 44px; display: flex; align-items: center;
}
#head_menu > a:hover {
  color: var(--color-primary);
}

/* ---- Content Area ---- */
#content_box {
  display: flex; justify-content: center;
  background-color: var(--color-bg-page);
  text-align: center; padding: var(--space-lg);
}
.content-item {
  display: flex; justify-content: left; align-items: center;
  margin: var(--space-xl) 0 var(--space-lg) var(--space-xl);
}
#content_box2 {
  display: flex; justify-content: center !important; text-align: center;
}

/* ---- Section Title ---- */
.section-title {
  font-size: var(--text-xl); font-weight: 700;
  color: var(--color-text-primary);
  margin: var(--space-xxl) 0 var(--space-base);
  padding-left: var(--space-md);
  border-left: 4px solid var(--color-primary);
}

/* ---- Guide Cards ---- */
.guide-row { margin: var(--space-sm) 0 var(--space-xxl); }
.guide-card {
  text-align: center; padding: var(--space-lg) var(--space-base) var(--space-lg);
  background: var(--color-bg-white); border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  margin: var(--space-sm) var(--space-xs);
  transition: box-shadow var(--transition-normal), transform var(--transition-normal);
}
.guide-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.guide-icon {
  display: flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; margin: 0 auto var(--space-md);
  border-radius: 50%;
  background: var(--color-primary-light); color: var(--color-primary);
}
.guide-card h4 {
  font-size: var(--text-md); font-weight: 500;
  color: var(--color-text-primary); margin: 0 0 var(--space-sm);
}
.guide-card p {
  font-size: var(--text-sm); color: var(--color-text-secondary); margin: 0;
}

/* ---- Site Footer ---- */
.site-footer {
  display: flex; justify-content: center; flex-wrap: wrap;
  background: var(--color-bg-dark);
  padding: var(--space-lg) var(--space-base);
  color: var(--color-text-tertiary);
  font-size: var(--text-sm); line-height: 2;
  gap: var(--space-base);
}
.site-footer a {
  color: var(--color-text-tertiary);
  text-decoration: none;
}
.site-footer a:hover {
  color: var(--color-primary);
}

/* ---- Empty State ---- */
.empty-state {
  text-align: center;
  padding: var(--space-xxl) var(--space-base);
  color: var(--color-text-tertiary);
}
.empty-state svg {
  margin-bottom: var(--space-base); opacity: 0.4;
}
.empty-state p {
  font-size: var(--text-md); margin-bottom: var(--space-md);
}

/* ---- Skeleton Loading ---- */
.skeleton-card {
  background: var(--color-bg-page);
  border-radius: var(--radius-lg);
  animation: skeleton-pulse 1.5s ease-in-out infinite;
  min-height: 200px;
}
@keyframes skeleton-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* ---- Avatar Crop Modal ---- */
.crop-overlay {
  position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 99999;
  background: rgba(0,0,0,0.7); display: none;
  align-items: center; justify-content: center; flex-direction: column;
}
.crop-box { max-width: 500px; max-height: 60vh; }
.crop-box img { max-width: 100%; display: block; }
.crop-bar { margin-top: var(--space-md); text-align: center; }
#cropProgress { margin-right: var(--space-md); color: #fff; font-size: var(--text-base); }

/* ---- Form Enhancements ---- */
.form-section {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin: var(--space-lg) auto;
  max-width: 900px; width: 100%;
  box-sizing: border-box;
}
.form-row {
  display: flex; justify-content: left; align-items: center;
  margin: var(--space-xl) 0 var(--space-lg) var(--space-xl);
}
.form-label {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  min-width: 80px; text-align: right;
  margin-right: var(--space-md);
}
.layui-input:focus,
.layui-textarea:focus {
  border-color: var(--color-primary) !important;
  box-shadow: 0 0 0 2px var(--color-primary-light);
}

/* ---- Touch-friendly ---- */
.layui-laypage a {
  min-width: 36px; min-height: 36px;
  line-height: 36px; margin: 0 2px;
}