/* ============================================
   张世权个人主页 — 样式表
   修改主题色只需更改 CSS 变量
   ============================================ */

:root {
  /* 主题色 — 修改这里即可全局生效 */
  --color-primary: #2c3e50;
  --color-accent:  #3498db;
  --color-bg:      #fafafa;
  --color-card-bg: #ffffff;
  --color-text:    #2c3e50;
  --color-muted:   #7f8c8d;
  --color-border:  #ecf0f1;
  --color-tag-bg:  #eaf2f8;
  --color-tag-text:#2980b9;

  /* 布局 */
  --max-width:     960px;
  --card-radius:   8px;
  --card-shadow:   0 2px 12px rgba(0,0,0,0.08);
  --card-shadow-hover: 0 6px 24px rgba(0,0,0,0.14);
  --transition:    0.25s ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ---- Header ---- */
.site-header {
  text-align: center;
  padding: 60px 20px 40px;
}

.site-header h1 {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-primary);
}

.site-header .subtitle {
  margin-top: 8px;
  font-size: 1.1rem;
  color: var(--color-muted);
}

.site-header .tagline {
  margin-top: 6px;
  font-size: 0.95rem;
  color: var(--color-muted);
  font-style: italic;
}

/* Social links */
.social-links {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 20px;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-border);
  color: var(--color-primary);
  font-size: 18px;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.social-links a:hover {
  background: var(--color-accent);
  color: #fff;
  transform: translateY(-2px);
}

/* ---- Divider ---- */
.divider {
  width: 40px;
  height: 3px;
  margin: 0 auto 36px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* ---- Section Title ---- */
.section-title {
  text-align: center;
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 32px;
}

/* ---- Projects Grid ---- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px 60px;
}

/* ---- Project Card ---- */
.project-card {
  background: var(--color-card-bg);
  border-radius: var(--card-radius);
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}

.project-card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-4px);
}

.project-card a {
  display: block;
}

.project-card .card-img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  display: block;
  transition: opacity var(--transition);
}

.project-card:hover .card-img {
  opacity: 0.88;
}

.project-card .card-body {
  padding: 14px 16px 16px;
}

.project-card .card-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-primary);
  line-height: 1.4;
}

.project-card .card-descr {
  margin-top: 6px;
  font-size: 0.85rem;
  color: var(--color-muted);
  line-height: 1.5;
}

.project-card .card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.project-card .card-tag {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 10px;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
}

/* ---- Footer ---- */
.site-footer {
  text-align: center;
  padding: 24px 20px;
  font-size: 0.8rem;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  max-width: var(--max-width);
  margin: 0 auto;
}

/* ---- Responsive ---- */
@media (max-width: 640px) {
  .site-header { padding: 40px 16px 28px; }
  .site-header h1 { font-size: 1.8rem; }
  .projects-grid { gap: 16px; padding: 0 16px 40px; }
}