/* ------------------------------------------------------------------ *
 *  kmand.cn — personal homepage styles
 *  No external dependencies (self-hosted, system font stack).
 * ------------------------------------------------------------------ */

:root {
  --bg: #0b0e14;
  --bg-soft: #12161f;
  --card: rgba(255, 255, 255, 0.04);
  --card-border: rgba(255, 255, 255, 0.08);
  --text: #e6e9ef;
  --text-dim: #9aa4b2;
  --text-faint: #5b6472;
  --accent: #6d8bff;
  --accent-2: #59e0c5;
  --accent-glow: rgba(109, 139, 255, 0.35);
  --radius: 16px;
  --maxw: 1080px;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
}

:root[data-theme="light"] {
  --bg: #f6f7fb;
  --bg-soft: #ffffff;
  --card: rgba(255, 255, 255, 0.75);
  --card-border: rgba(15, 23, 42, 0.08);
  --text: #10151f;
  --text-dim: #4a5568;
  --text-faint: #94a0b3;
  --accent: #4361ee;
  --accent-2: #0aa189;
  --accent-glow: rgba(67, 97, 238, 0.18);
  --shadow: 0 10px 40px rgba(15, 23, 42, 0.08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  transition: background 0.4s ease, color 0.4s ease;
}

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

/* ---- decorative background ---- */
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(var(--card-border) 1px, transparent 1px),
    linear-gradient(90deg, var(--card-border) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
  opacity: 0.5;
}
.bg-glow {
  position: fixed;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  z-index: -1;
  background: radial-gradient(circle at 50% 50%, var(--accent-glow), transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}

/* ---- layout ---- */
main, .topbar, .footer { max-width: var(--maxw); margin: 0 auto; padding-left: 24px; padding-right: 24px; }

/* ---- topbar ---- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  padding-bottom: 24px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}
.brand-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 12px var(--accent-2);
}
.topnav { display: flex; align-items: center; gap: 22px; }
.topnav a { color: var(--text-dim); font-size: 0.92rem; transition: color 0.2s; }
.topnav a:hover { color: var(--text); }
.theme-toggle {
  width: 36px; height: 36px; border-radius: 10px;
  border: 1px solid var(--card-border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-size: 1rem;
  display: grid; place-items: center;
  transition: transform 0.2s, background 0.2s;
}
.theme-toggle:hover { transform: rotate(-15deg); }

/* ---- hero ---- */
.hero { padding: 60px 0 40px; text-align: center; }
.hero-eyebrow {
  color: var(--accent-2);
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 0.8rem;
  margin-bottom: 14px;
}
.hero-name {
  font-size: clamp(2.6rem, 8vw, 4.6rem);
  font-weight: 800;
  line-height: 1.05;
  background: linear-gradient(120deg, var(--text) 20%, var(--accent) 60%, var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 16px;
}
.hero-tagline { font-size: clamp(1.05rem, 2.5vw, 1.35rem); color: var(--text); font-weight: 500; }
.hero-bio { max-width: 640px; margin: 16px auto 0; color: var(--text-dim); }

.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-top: 30px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: 12px;
  font-weight: 600; font-size: 0.92rem;
  border: 1px solid var(--card-border);
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #fff; border-color: transparent;
  box-shadow: 0 8px 24px var(--accent-glow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px var(--accent-glow); }
.btn-ghost { background: var(--card); color: var(--text); }
.btn-ghost:hover { transform: translateY(-2px); border-color: var(--accent); }

.hero-stats { display: flex; justify-content: center; gap: 48px; margin-top: 48px; }
.stat { display: flex; flex-direction: column; align-items: center; }
.stat-num {
  font-size: 1.8rem; font-weight: 800;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.stat-label { font-size: 0.78rem; color: var(--text-faint); letter-spacing: 0.05em; }

/* ---- highlights ---- */
.highlights {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px; margin-top: 40px;
}
.hl-card {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: var(--radius); padding: 24px;
  backdrop-filter: blur(12px);
  transition: transform 0.25s, border-color 0.25s;
}
.hl-card:hover { transform: translateY(-4px); border-color: var(--accent); }
.hl-icon {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center; margin-bottom: 16px;
  background: linear-gradient(135deg, var(--accent-glow), transparent);
  color: var(--accent);
}
.hl-icon svg { width: 22px; height: 22px; }
.hl-card h3 { font-size: 1.05rem; margin-bottom: 6px; }
.hl-card p { font-size: 0.88rem; color: var(--text-dim); }

/* ---- generic block ---- */
.block { margin-top: 88px; scroll-margin-top: 90px; }
.block-title {
  display: flex; align-items: baseline; gap: 12px;
  font-size: 1.6rem; font-weight: 800; margin-bottom: 8px;
}
.block-title span {
  font-size: 0.9rem; color: var(--accent-2);
  font-family: ui-monospace, "SFMono-Regular", Menlo, monospace;
}
.block-sub { color: var(--text-dim); margin-bottom: 26px; font-size: 0.92rem; }

/* ---- skills ---- */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.skill-cat {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: var(--radius); padding: 22px;
}
.skill-cat h3 { font-size: 1rem; margin-bottom: 16px; color: var(--accent); }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 0.82rem; padding: 6px 12px; border-radius: 999px;
  background: var(--bg-soft); border: 1px solid var(--card-border);
  color: var(--text-dim);
  transition: color 0.2s, border-color 0.2s;
}
.tag:hover { color: var(--text); border-color: var(--accent-2); }

/* ---- links ---- */
.links-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.link-card {
  display: flex; align-items: center; gap: 14px;
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: var(--radius); padding: 18px 20px;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
  position: relative; overflow: hidden;
}
.link-card:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: var(--shadow); }
.link-card .arrow { margin-left: auto; color: var(--text-faint); transition: transform 0.2s, color 0.2s; }
.link-card:hover .arrow { transform: translate(3px, -3px); color: var(--accent); }
.link-icon {
  width: 42px; height: 42px; flex: 0 0 42px; border-radius: 11px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent-glow), transparent);
  color: var(--accent);
}
.link-icon svg { width: 20px; height: 20px; }
.link-meta h3 { font-size: 0.98rem; }
.link-meta p { font-size: 0.8rem; color: var(--text-dim); }

/* ---- guestbook ---- */
.gb-form { display: grid; gap: 10px; max-width: 620px; margin-bottom: 28px; }
.gb-form input, .gb-form textarea {
  width: 100%; padding: 12px 14px; border-radius: 12px;
  background: var(--bg-soft); border: 1px solid var(--card-border);
  color: var(--text); font-family: inherit; font-size: 0.92rem; resize: vertical;
}
.gb-form input:focus, .gb-form textarea:focus { outline: none; border-color: var(--accent); }
/* honeypot: kept in the DOM but off-screen so only bots fill it */
.gb-form .hp { position: absolute; left: -9999px; top: -9999px; width: 1px; height: 1px; opacity: 0; }
.gb-form button {
  justify-self: start;
  padding: 11px 26px; border-radius: 12px; border: none; cursor: pointer;
  font-weight: 600; font-family: inherit;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #fff; transition: transform 0.2s, opacity 0.2s;
}
.gb-form button:hover { transform: translateY(-2px); }
.gb-form button:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.gb-list { display: grid; gap: 12px; }
.gb-item {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: 12px; padding: 14px 18px;
}
.gb-item .gb-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 4px; }
.gb-item .gb-who { font-weight: 600; font-size: 0.92rem; color: var(--accent); }
.gb-item .gb-when { font-size: 0.75rem; color: var(--text-faint); }
.gb-item .gb-body { font-size: 0.9rem; color: var(--text-dim); word-break: break-word; }
.gb-empty { color: var(--text-faint); font-size: 0.9rem; }

/* ---- footer ---- */
.footer { text-align: center; padding: 70px 24px 50px; color: var(--text-faint); font-size: 0.85rem; }
.footer-sub { margin-top: 6px; font-family: ui-monospace, Menlo, monospace; font-size: 0.75rem; opacity: 0.7; }

/* ---- entrance animation ---- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (max-width: 640px) {
  .hero-stats { gap: 28px; }
  .topnav { gap: 14px; }
  .topnav a:not(#theme-toggle) { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .reveal { transition: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}