/* ===== Light theme (default) ===== */
:root {
  --bg: #f5f7fa;
  --bg-card: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #4a5568;
  --text-muted: #a0aec0;
  --border: #edf0f4;
  --accent: #4f6ef7;
  --accent-hover: #3b5bdb;
  --accent-soft: rgba(79, 110, 247, 0.07);
  --link: #4f6ef7;
  --link-hover: #3b5bdb;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --icon-invert: 0;
}

/* ===== Dark theme ===== */
@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) {
    --bg: #0e1525;
    --bg-card: #171f31;
    --text: #e4e8f0;
    --text-secondary: #9ba4b5;
    --text-muted: #5a6580;
    --border: #232e45;
    --accent: #6b8aff;
    --accent-hover: #93b0ff;
    --accent-soft: rgba(107, 138, 255, 0.1);
    --link: #6b8aff;
    --link-hover: #93b0ff;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
    --icon-invert: 1;
  }
}

html[data-theme="dark"] {
  --bg: #0e1525;
  --bg-card: #171f31;
  --text: #e4e8f0;
  --text-secondary: #9ba4b5;
  --text-muted: #5a6580;
  --border: #232e45;
  --accent: #6b8aff;
  --accent-hover: #93b0ff;
  --accent-soft: rgba(107, 138, 255, 0.1);
  --link: #6b8aff;
  --link-hover: #93b0ff;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
  --icon-invert: 1;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 2rem;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.3s, color 0.3s;
}

/* Layout */

.container {
  width: 100%;
  max-width: 1280px;
  padding: 3rem 3rem 2rem;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0 4rem;
  align-items: start;
}

/* Sidebar / Profile */

.profile {
  position: sticky;
  top: 3rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.avatar {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 1.25rem;
  border: 4px solid var(--bg-card);
  box-shadow: 0 0 0 2px var(--accent), var(--shadow-md);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.avatar:hover {
  transform: scale(1.05);
  box-shadow: 0 0 0 2px var(--accent-hover), 0 8px 24px rgba(79, 110, 247, 0.2);
}

.handle {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.125rem;
}

.real-name {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.motto {
  color: var(--text-muted);
  font-style: italic;
  font-size: 0.85rem;
  margin-bottom: 1.5rem;
  padding: 0 0.25rem;
  line-height: 1.5;
}

/* Social links */

.links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0;
  border-radius: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.2s, box-shadow 0.2s;
}

.links a:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.links a svg.link-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.links a img.link-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  opacity: 0.5;
  filter: invert(var(--icon-invert));
  transition: opacity 0.2s;
}

.links a:hover img.link-icon {
  opacity: 0.9;
}

/* Action buttons (lang + theme) */

.sidebar-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 1.25rem;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 600;
  font-family: inherit;
  color: var(--text-muted);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 99px;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.15s, box-shadow 0.2s;
}

.action-btn svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.action-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Sidebar divider */

.sidebar-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
  width: 100%;
}

/* Sidebar nav */

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  width: 100%;
}

.sidebar-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  padding: 0.5rem 0.875rem;
  border-radius: 8px;
  transition: color 0.2s, background 0.2s;
}

.sidebar-nav a:hover {
  color: var(--text);
  background: var(--accent-soft);
}

.sidebar-nav a.active {
  color: var(--accent);
  background: var(--accent-soft);
  font-weight: 600;
}

/* Content */

.content {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Sections */

.section {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--border);
}

.section:last-child {
  border-bottom: none;
}

.section-icon {
  display: inline-flex;
  align-items: center;
  margin-right: 0.4rem;
  vertical-align: middle;
}

.section-icon svg {
  width: 15px;
  height: 15px;
}

.section-title {
  display: flex;
  align-items: center;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.section-content {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.8;
}

.section-content p {
  margin-bottom: 0.5rem;
}

.section-content p:last-child {
  margin-bottom: 0;
}

.section-content b,
.section-content strong {
  color: var(--text);
  font-weight: 600;
}

/* Section lists */

.section-content ul {
  list-style: none;
}

.section-content li {
  padding: 0.35rem 0 0.35rem 1.125rem;
  position: relative;
}

.section-content li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.9em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.4;
}

.section-content a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s;
}

.section-content a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

/* Section tables */

.section-content table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.section-content th,
.section-content td {
  padding: 0.6rem 0.875rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.section-content th {
  font-weight: 600;
  color: var(--text);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.section-content tr:last-child td {
  border-bottom: none;
}

/* ===== Timeline ===== */

.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--border);
  border-radius: 1px;
}

.timeline-item {
  position: relative;
  padding: 0.5rem 0;
  margin-bottom: 0.5rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -2rem;
  top: 0.75rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg);
  border: 2.5px solid var(--accent);
  z-index: 1;
  transition: background 0.2s, box-shadow 0.2s;
}

.timeline-item:hover .timeline-dot {
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.timeline-date {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  margin-bottom: 0.2rem;
  letter-spacing: 0.02em;
}

.timeline-item:hover .timeline-date {
  color: var(--accent);
}

.timeline-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.timeline-desc b,
.timeline-desc strong {
  color: var(--text);
  font-weight: 600;
}

.timeline-desc a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s;
}

.timeline-desc a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

/* ===== Per-section accents ===== */

#about .section-icon svg { color: var(--accent); }

#education .section-icon svg { color: #38bdf8; }
#education .section-title { color: #38bdf8; }
#education .timeline-dot { border-color: #38bdf8; }
#education .timeline-item:hover .timeline-dot { background: #38bdf8; box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15); }
#education .timeline-item:hover .timeline-date { color: #38bdf8; }
#education .timeline-item:hover { background: rgba(56, 189, 248, 0.06); }

#experience .section-icon svg { color: #8b5cf6; }
#experience .section-title { color: #8b5cf6; }
#experience .timeline-dot { border-color: #8b5cf6; }
#experience .timeline-item:hover .timeline-dot { background: #8b5cf6; box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15); }
#experience .timeline-item:hover .timeline-date { color: #8b5cf6; }
#experience .timeline-item:hover { background: rgba(139, 92, 246, 0.06); }

#awards .section-icon svg { color: #f59e0b; }
#awards .section-title { color: #f59e0b; }
#awards .timeline-dot { border-color: #f59e0b; }
#awards .timeline-item:hover .timeline-dot { background: #f59e0b; box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.15); }
#awards .timeline-item:hover .timeline-date { color: #f59e0b; }
#awards .timeline-item:hover { background: rgba(245, 158, 11, 0.06); }

#cves .section-icon svg { color: #ef4444; }
#cves .section-title { color: #ef4444; }
#cves .section-content li::before { background: #ef4444; }

.hobbies .section-icon svg { color: #ec4899; }
.hobbies .section-title { color: #ec4899; justify-content: center; }
.hobbies .section-content {
  font-size: 1.75rem;
  letter-spacing: 0.3rem;
  text-align: center;
  padding: 0.25rem 0;
}

/* Dark-mode section accent overrides — system dark */
@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) #education .section-icon svg { color: #67e8f9; }
  html:not([data-theme="light"]) #education .section-title { color: #67e8f9; }
  html:not([data-theme="light"]) #education .timeline-dot { border-color: #67e8f9; }
  html:not([data-theme="light"]) #education .timeline-item:hover .timeline-dot { background: #67e8f9; box-shadow: 0 0 0 3px rgba(103, 232, 249, 0.15); }
  html:not([data-theme="light"]) #education .timeline-item:hover .timeline-date { color: #67e8f9; }
  html:not([data-theme="light"]) #experience .section-icon svg { color: #a78bfa; }
  html:not([data-theme="light"]) #experience .section-title { color: #a78bfa; }
  html:not([data-theme="light"]) #experience .timeline-dot { border-color: #a78bfa; }
  html:not([data-theme="light"]) #experience .timeline-item:hover .timeline-dot { background: #a78bfa; box-shadow: 0 0 0 3px rgba(167, 139, 250, 0.15); }
  html:not([data-theme="light"]) #experience .timeline-item:hover .timeline-date { color: #a78bfa; }
  html:not([data-theme="light"]) #awards .section-icon svg { color: #fbbf24; }
  html:not([data-theme="light"]) #awards .section-title { color: #fbbf24; }
  html:not([data-theme="light"]) #awards .timeline-dot { border-color: #fbbf24; }
  html:not([data-theme="light"]) #awards .timeline-item:hover .timeline-dot { background: #fbbf24; box-shadow: 0 0 0 3px rgba(251, 191, 36, 0.15); }
  html:not([data-theme="light"]) #awards .timeline-item:hover .timeline-date { color: #fbbf24; }
  html:not([data-theme="light"]) #cves .section-icon svg { color: #f87171; }
  html:not([data-theme="light"]) #cves .section-title { color: #f87171; }
  html:not([data-theme="light"]) #cves .section-content li::before { background: #f87171; }
  html:not([data-theme="light"]) .hobbies .section-icon svg { color: #f472b6; }
  html:not([data-theme="light"]) .hobbies .section-title { color: #f472b6; }
}

/* Dark-mode section accent overrides — manual dark */
html[data-theme="dark"] #education .section-icon svg { color: #67e8f9; }
html[data-theme="dark"] #education .section-title { color: #67e8f9; }
html[data-theme="dark"] #education .timeline-dot { border-color: #67e8f9; }
html[data-theme="dark"] #education .timeline-item:hover .timeline-dot { background: #67e8f9; box-shadow: 0 0 0 3px rgba(103, 232, 249, 0.15); }
html[data-theme="dark"] #education .timeline-item:hover .timeline-date { color: #67e8f9; }
html[data-theme="dark"] #experience .section-icon svg { color: #a78bfa; }
html[data-theme="dark"] #experience .section-title { color: #a78bfa; }
html[data-theme="dark"] #experience .timeline-dot { border-color: #a78bfa; }
html[data-theme="dark"] #experience .timeline-item:hover .timeline-dot { background: #a78bfa; box-shadow: 0 0 0 3px rgba(167, 139, 250, 0.15); }
html[data-theme="dark"] #experience .timeline-item:hover .timeline-date { color: #a78bfa; }
html[data-theme="dark"] #awards .section-icon svg { color: #fbbf24; }
html[data-theme="dark"] #awards .section-title { color: #fbbf24; }
html[data-theme="dark"] #awards .timeline-dot { border-color: #fbbf24; }
html[data-theme="dark"] #awards .timeline-item:hover .timeline-dot { background: #fbbf24; box-shadow: 0 0 0 3px rgba(251, 191, 36, 0.15); }
html[data-theme="dark"] #awards .timeline-item:hover .timeline-date { color: #fbbf24; }
html[data-theme="dark"] #cves .section-icon svg { color: #f87171; }
html[data-theme="dark"] #cves .section-title { color: #f87171; }
html[data-theme="dark"] #cves .section-content li::before { background: #f87171; }
html[data-theme="dark"] .hobbies .section-icon svg { color: #f472b6; }
html[data-theme="dark"] .hobbies .section-title { color: #f472b6; }

/* Footer */

.footer {
  width: 100%;
  margin-top: auto;
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.footer a:hover {
  color: var(--text-secondary);
}

/* Responsive */

@media (max-width: 768px) {
  .container {
    grid-template-columns: 1fr;
    max-width: 640px;
    padding: 2rem 1rem 1.5rem;
    gap: 1.5rem;
  }

  .profile {
    position: static;
  }

  .avatar {
    width: 90px;
    height: 90px;
  }

  .links {
    justify-content: center;
  }

  .sidebar-actions {
    margin-top: 1rem;
  }

  .sidebar-divider {
    margin: 1rem auto;
    width: 3rem;
  }

  .sidebar-nav {
    flex-direction: row;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.375rem;
  }

  .sidebar-nav a {
    border-radius: 99px;
    padding: 0.3rem 0.75rem;
    font-size: 0.8rem;
  }

  .handle {
    font-size: 1.3rem;
  }

  .section-content table {
    font-size: 0.75rem;
  }

  .section-content th,
  .section-content td {
    padding: 0.375rem 0.5rem;
  }
}