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

:root {
  --c-tianshan: #2A5C9E;
  --c-red: #D84B47;
  --c-orange: #F59A23;
  --c-green: #3D9E66;
  --c-ink: #1B2A3A;
  --c-cloud: #F5F7FA;
  --c-mist: #E8F0FE;
  --c-dusk: #FDE8E8;
  --c-border: #C0D0E0;
  --c-mono: #4A6B8A;
  --c-white: #FFFFFF;

  --font-heading: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "Courier Prime", "JetBrains Mono", "SFMono-Regular", Consolas, monospace;

  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.5rem;
  --sp-6: 2rem;
  --sp-7: 3rem;
  --sp-8: 4.5rem;

  --container: 1180px;
  --container-narrow: 780px;
  --radius: 6px;
  --radius-lg: 12px;
  --shadow-1: 0 1px 3px rgba(27, 42, 58, 0.08);
  --shadow-2: 0 6px 24px rgba(27, 42, 58, 0.1);
  --transition: 0.25s ease;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-ink);
  background: var(--c-cloud);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  font-weight: 800;
  line-height: 1.3;
  color: var(--c-ink);
}

h1 { font-size: clamp(2rem, 5vw, 3.2rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.2rem); }
h3 { font-size: 1.25rem; }
p + p { margin-top: 0.75em; }

a {
  color: var(--c-tianshan);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover { color: var(--c-red); }

ul,
ol {
  list-style: none;
}

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

button {
  font: inherit;
  cursor: pointer;
  background: none;
  border: none;
  color: inherit;
  -webkit-appearance: none;
  appearance: none;
}

table {
  border-collapse: collapse;
  width: 100%;
}

code {
  font-family: var(--font-mono);
  background: var(--c-cloud);
  border: 1px solid var(--c-border);
  padding: 0.1em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
}

blockquote {
  border-left: 4px solid var(--c-tianshan);
  background: var(--c-cloud);
  padding: 1rem 1.25rem;
  margin: 1rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

:focus-visible {
  outline: 3px solid var(--c-orange);
  outline-offset: 2px;
  border-radius: 3px;
}

/* ============ Layout utilities ============ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 32px);
}

.content {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 32px);
}

.content-narrow {
  max-width: var(--container-narrow);
  margin-inline: auto;
  padding-inline: 20px;
}

.content-wide {
  max-width: 100%;
  padding-inline: clamp(16px, 4vw, 48px);
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.92rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease;
  text-align: center;
  line-height: 1.4;
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--c-red);
  color: #fff;
  box-shadow: 0 4px 14px rgba(216, 75, 71, 0.25);
}
.btn-primary:hover {
  background: var(--c-tianshan);
  color: #fff;
  box-shadow: 0 6px 20px rgba(42, 92, 158, 0.3);
}

.btn-ghost {
  border-color: var(--c-border);
  color: var(--c-ink);
  background: var(--c-white);
}
.btn-ghost:hover { border-color: var(--c-tianshan); color: var(--c-tianshan); }

.btn-accent {
  background: var(--c-orange);
  color: var(--c-ink);
  font-weight: 800;
}
.btn-accent:hover { background: var(--c-red); color: #fff; }

/* ============ Header ============ */
.site-header {
  position: relative;
  overflow: hidden;
  background: var(--c-cloud);
  border-bottom: 1px solid var(--c-border);
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 38%;
  height: 100%;
  background: linear-gradient(140deg, rgba(216, 75, 71, 0.08), transparent 60%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
  z-index: 1;
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 8px;
  background: repeating-linear-gradient(90deg, rgba(42, 92, 158, 0.28) 0 10px, transparent 10px 20px);
  pointer-events: none;
  z-index: 5;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--c-ink);
  color: #fff;
  border-radius: 0 0 var(--radius) var(--radius);
  font-family: var(--font-mono);
  font-size: 13px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
  color: #fff;
}

.header-rail,
.footer-rail {
  position: absolute;
  top: 0;
  bottom: 0;
  width: clamp(32px, 3vw, 48px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  pointer-events: none;
  z-index: 2;
}

.header-rail-left,
.footer-rail-left { left: 8px; }
.header-rail-right,
.footer-rail-right { right: 8px; }

.rail-line {
  width: 1px;
  flex: 1;
  background: linear-gradient(to bottom, transparent, rgba(42, 92, 158, 0.5), transparent);
}

.rail-text {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.35em;
  color: var(--c-mono);
  text-transform: uppercase;
  white-space: nowrap;
}

.header-top {
  background: var(--c-ink);
  color: rgba(255, 255, 255, 0.78);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  position: relative;
  z-index: 3;
}

.header-top-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: 34px;
}

.header-edition {
  color: var(--c-orange);
  white-space: nowrap;
}

.header-divider {
  flex: 1;
  height: 1px;
  background: rgba(255, 255, 255, 0.2);
}

.header-direct {
  color: rgba(255, 255, 255, 0.8);
  padding: 0.2rem 0.75rem;
  border: 1px solid transparent;
  font-size: 11px;
  border-radius: 3px;
  white-space: nowrap;
}

.header-direct:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.header-direct-contact {
  background: var(--c-red);
  color: #fff;
  font-weight: 700;
}

.header-direct-contact:hover {
  background: var(--c-orange);
  color: var(--c-ink);
  border-color: var(--c-orange);
}

.header-main {
  position: relative;
  z-index: 2;
  background: linear-gradient(180deg, var(--c-mist) 0%, rgba(255, 255, 255, 0.86) 60%, var(--c-cloud) 100%);
  padding-block: var(--sp-5) var(--sp-4);
}

.header-main::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(27, 42, 58, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27, 42, 58, 0.03) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
}

.header-main-inner {
  position: relative;
  z-index: 1;
}

.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--sp-6);
  background: rgba(255, 255, 255, 0.62);
  border-top: 3px solid var(--c-tianshan);
  border-bottom: 1px solid var(--c-border);
  box-shadow: 0 2px 12px rgba(27, 42, 58, 0.05);
  padding: var(--sp-4) var(--sp-5);
}

.masthead-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.2rem;
}

.masthead-side {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.masthead-side-left { align-items: flex-start; text-align: left; }
.masthead-side-right { align-items: flex-end; text-align: right; }

.meta-mono {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-mono);
  text-transform: uppercase;
}

.meta-print {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--c-mono);
  border: 1px solid var(--c-border);
  padding: 0.1rem 0.5rem;
  background: var(--c-white);
  border-radius: 3px;
  letter-spacing: 0.08em;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--c-ink);
}

.brand-lockup:hover { color: var(--c-ink); }

.brand-emblem {
  position: relative;
  display: block;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--c-tianshan) 0%, var(--c-ink) 100%);
  border-radius: 14px 14px 14px 6px;
  transform: rotate(-6deg);
  box-shadow: 0 3px 10px rgba(27, 42, 58, 0.25);
  flex-shrink: 0;
}

.brand-emblem::after {
  content: "";
  position: absolute;
  inset: -5px;
  border: 1px solid var(--c-tianshan);
  border-radius: 18px 18px 18px 8px;
  opacity: 0.5;
  pointer-events: none;
}

.emblem-ring {
  position: absolute;
  inset: 7px;
  border: 1.5px dashed rgba(255, 255, 255, 0.5);
  border-radius: 50%;
  animation: emblem-spin 18s linear infinite;
  z-index: 1;
}

.emblem-blade {
  position: absolute;
  width: 10px;
  height: 30px;
  background: linear-gradient(to bottom, var(--c-orange), var(--c-red));
  border-radius: 3px 3px 2px 2px;
  left: 50%;
  top: 50%;
  transform-origin: 50% 0%;
  box-shadow: 0 0 4px rgba(255, 255, 255, 0.25);
  z-index: 1;
}

.emblem-blade-1 { transform: translate(-50%, -50%) rotate(0deg) translateY(-12px); }
.emblem-blade-2 { transform: translate(-50%, -50%) rotate(120deg) translateY(-12px); }
.emblem-blade-3 { transform: translate(-50%, -50%) rotate(240deg) translateY(-12px); }

.emblem-center {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 17px;
  z-index: 2;
}

@keyframes emblem-spin {
  to { transform: rotate(360deg); }
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  letter-spacing: 0.02em;
  line-height: 1.1;
  white-space: nowrap;
}

.brand-name-accent { color: var(--c-red); }

.brand-tagline {
  font-size: 12px;
  letter-spacing: 0.28em;
  color: var(--c-mono);
  font-family: var(--font-mono);
  text-transform: uppercase;
  margin-top: 0.2rem;
}

.nav-block {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: var(--sp-4);
  border-top: 2px solid var(--c-ink);
  background: rgba(255, 255, 255, 0.72);
}

.site-nav {
  flex: 1;
  display: flex;
  justify-content: center;
}

.nav-list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}

.nav-link {
  display: block;
  padding: 0.7rem 1.15rem;
  font-size: 15px;
  font-weight: 600;
  color: var(--c-ink);
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 0;
  height: 3px;
  background: var(--c-red);
  transform: translateX(-50%);
  transition: width 0.25s ease;
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  width: 60%;
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--c-red);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.8rem;
  background: var(--c-ink);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  border-radius: 4px;
}

.nav-toggle:hover { background: var(--c-red); color: #fff; }

.nav-toggle[aria-expanded="true"] { background: var(--c-red); color: #fff; }

.nav-toggle-box {
  display: grid;
  gap: 4px;
  width: 18px;
}

.toggle-line {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] .toggle-line:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .toggle-line:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .toggle-line:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }

.nav-toggle-text { line-height: 1; }

.header-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 8px;
  height: 3px;
  background: rgba(42, 92, 158, 0.12);
  z-index: 6;
}

.progress-bar {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--c-red), var(--c-orange));
  border-radius: 0 3px 3px 0;
  transition: width 0.08s linear;
}

/* ============ Footer ============ */
.site-footer {
  position: relative;
  background: var(--c-ink);
  color: rgba(255, 255, 255, 0.85);
  margin-top: var(--sp-8);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: repeating-linear-gradient(90deg, var(--c-orange) 0 12px, transparent 12px 24px);
  opacity: 0.4;
  z-index: 2;
}

.site-footer a { color: rgba(255, 255, 255, 0.75); }
.site-footer a:hover { color: var(--c-orange); }

.footer-rail .rail-line {
  background: linear-gradient(to bottom, transparent, rgba(255, 255, 255, 0.22), transparent);
}

.footer-rail .rail-text {
  color: rgba(255, 255, 255, 0.4);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--sp-6);
  padding-block: var(--sp-7);
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: var(--sp-3);
}

.footer-brand-mark {
  width: 38px;
  height: 38px;
  background: linear-gradient(140deg, var(--c-orange), var(--c-red));
  display: grid;
  place-items: center;
  border-radius: 9px 9px 9px 3px;
  font-family: var(--font-mono);
  font-weight: 800;
  color: var(--c-ink);
  font-size: 18px;
}

.footer-brand-name {
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #fff;
}

.footer-desc {
  font-size: 0.92rem;
  line-height: 1.7;
  max-width: 36ch;
  color: rgba(255, 255, 255, 0.7);
}

.footer-trust {
  margin-top: 1rem;
  padding: 0.65rem 0.8rem;
  background: rgba(61, 158, 102, 0.15);
  border-left: 3px solid var(--c-green);
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.65;
  max-width: 44ch;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.trust-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-green);
  margin-right: 0.4rem;
  vertical-align: middle;
}

.footer-heading {
  color: #fff;
  font-size: 13px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding-bottom: 0.6rem;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-weight: 700;
}

.footer-links li + li { margin-top: 0.5rem; }

.footer-links a {
  font-size: 0.9rem;
  display: inline-block;
  position: relative;
}

.footer-links a::before {
  content: "→";
  margin-right: 0.4rem;
  color: var(--c-orange);
  opacity: 0.7;
}

.contact-line {
  font-size: 0.85rem;
  margin-bottom: 0.4rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
}

.contact-note {
  color: var(--c-green);
  font-family: var(--font-mono);
  font-size: 12px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(0, 0, 0, 0.25);
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-block: var(--sp-4);
  gap: 1rem;
  flex-wrap: wrap;
}

.copyright,
.icp {
  font-size: 12px;
  font-family: var(--font-mono);
  color: rgba(255, 255, 255, 0.6);
}

.back-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  background: rgba(27, 42, 58, 0.92);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  box-shadow: var(--shadow-2);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.25s ease, transform 0.25s ease, background-color 0.25s ease;
}

.back-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-top:hover {
  background: var(--c-red);
  color: #fff;
}

.back-top-icon {
  font-size: 14px;
  line-height: 1;
}

/* ============ Breadcrumbs ============ */
.breadcrumbs {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--c-mono);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-bottom: var(--sp-4);
}

.breadcrumbs a {
  color: var(--c-mono);
}

.breadcrumbs a:hover { color: var(--c-tianshan); }

.crumb-current {
  color: var(--c-ink);
  font-weight: 700;
}

.crumb-sep {
  color: var(--c-border);
}

/* ============ Section headings ============ */
.section-head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--c-ink);
  padding-bottom: 0.5rem;
  flex-wrap: wrap;
}

.section-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-mono);
  letter-spacing: 0.1em;
}

.section-title {
  font-size: clamp(1.4rem, 2vw, 2rem);
  font-weight: 800;
}

/* ============ Grid & cards ============ */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.index-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.index-card {
  background: var(--c-white);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: relative;
  box-shadow: var(--shadow-1);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.index-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-2);
}

.index-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(to bottom, var(--c-tianshan), var(--c-orange));
  border-radius: var(--radius) 0 0 var(--radius);
}

.index-card-title {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.index-card-desc {
  font-size: 0.88rem;
  color: var(--c-mono);
  line-height: 1.65;
}

/* ============ Tags ============ */
.tag {
  display: inline-block;
  padding: 0.12rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  border-radius: 999px;
  background: var(--c-mist);
  color: var(--c-tianshan);
  border: 1px solid var(--c-border);
  white-space: nowrap;
}

.tag-blue {
  background: var(--c-mist);
  color: var(--c-tianshan);
  border-color: var(--c-tianshan);
}

.tag-red {
  background: var(--c-red);
  color: #fff;
  border-color: var(--c-red);
}

.tag-orange {
  background: #FFF3E0;
  color: #B45F06;
  border-color: var(--c-orange);
}

.tag-green {
  background: #E7F5EC;
  color: var(--c-green);
  border-color: var(--c-green);
}

/* ============ Accordion ============ */
.accordion {
  border-top: 1px solid var(--c-border);
}

.accordion-item {
  border-bottom: 1px solid var(--c-border);
}

.accordion-trigger {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 1rem 0;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1rem;
  color: var(--c-ink);
  text-align: left;
  gap: 1rem;
}

.accordion-trigger:hover { color: var(--c-red); }

.accordion-trigger::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.3rem;
  color: var(--c-orange);
  transition: transform 0.25s ease, color 0.25s ease;
  flex-shrink: 0;
}

.accordion-item[data-open] .accordion-trigger::after {
  transform: rotate(45deg);
  color: var(--c-red);
}

.accordion-panel {
  display: none;
  padding-bottom: 1rem;
  color: #42566B;
  line-height: 1.7;
}

.accordion-item[data-open] .accordion-panel {
  display: block;
}

/* ============ Skill path ============ */
.skill-path {
  position: relative;
  display: grid;
  gap: 1.25rem;
}

.skill-path::before {
  content: "";
  position: absolute;
  left: 24px;
  top: 24px;
  bottom: 24px;
  width: 2px;
  background: linear-gradient(to bottom, var(--c-tianshan), var(--c-orange));
}

.skill-node {
  position: relative;
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 1rem;
  align-items: center;
  background: var(--c-white);
  border: 1px solid var(--c-border);
  border-left: 4px solid var(--c-tianshan);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  box-shadow: var(--shadow-1);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.skill-node:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-2);
}

.skill-index {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--c-red);
  background: var(--c-mist);
  border-radius: 6px;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
}

.skill-title {
  font-weight: 800;
  font-size: 1rem;
  margin-bottom: 0.2rem;
}

.skill-desc {
  font-size: 0.85rem;
  color: var(--c-mono);
  line-height: 1.6;
}

/* ============ Data table ============ */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.data-table th,
.data-table td {
  padding: 0.65rem 0.8rem;
  border-bottom: 1px solid var(--c-border);
  text-align: left;
}

.data-table thead th {
  background: var(--c-ink);
  color: #fff;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
}

.data-table tr:hover td {
  background: var(--c-cloud);
}

/* ============ Shot boxes ============ */
.shot-box {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--c-mist), var(--c-cloud));
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  min-height: 80px;
}

.shot-box::before {
  content: attr(data-shot-label);
  position: absolute;
  bottom: 0.5rem;
  left: 0.75rem;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-mono);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: rgba(255, 255, 255, 0.72);
  padding: 0.1rem 0.4rem;
  border: 1px solid var(--c-border);
  border-radius: 3px;
}

.shot-box::after {
  content: "";
  display: block;
  background-image:
    linear-gradient(rgba(42, 92, 158, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 92, 158, 0.08) 1px, transparent 1px);
  background-size: 18px 18px;
}

.shot-box[data-ratio="16:9"]::after { padding-bottom: 56.25%; }
.shot-box[data-ratio="4:3"]::after { padding-bottom: 75%; }
.shot-box[data-ratio="3:4"]::after { padding-bottom: 133.33%; }
.shot-box[data-ratio="1:1"]::after { padding-bottom: 100%; }
.shot-box[data-ratio="3:1"]::after { padding-bottom: 32%; }
.shot-box[data-ratio="auto"]::after { padding-bottom: 0; min-height: 0; }

/* ============ Paper layer & status ============ */
.paper-layer {
  background: var(--c-white);
  border: 1px solid var(--c-border);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: 0 1px 2px rgba(27, 42, 58, 0.05);
  position: relative;
}

.paper-layer::before {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px dashed var(--c-border);
  border-radius: 8px;
  pointer-events: none;
}

.status-line {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-mono);
  align-items: center;
}

.status-line li {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-border);
  display: inline-block;
}

.status-dot.on { background: var(--c-green); }
.status-dot.warn { background: var(--c-orange); }
.status-dot.cold { background: var(--c-red); }

.notice-strip {
  background: linear-gradient(90deg, var(--c-mist), var(--c-cloud));
  border-left: 4px solid var(--c-orange);
  padding: var(--sp-2) var(--sp-4);
  font-size: 0.85rem;
  color: var(--c-mono);
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: var(--sp-5);
}

/* ============ Filter tabs ============ */
.filter-tabs {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  margin-bottom: var(--sp-5);
}

.filter-tab {
  padding: 0.4rem 1rem;
  border: 1px solid var(--c-border);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--c-white);
  color: var(--c-mono);
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-tab:hover {
  border-color: var(--c-tianshan);
  color: var(--c-tianshan);
}

.filter-tab[data-active="true"],
.filter-tab.active {
  background: var(--c-tianshan);
  color: #fff;
  border-color: var(--c-tianshan);
}

/* ============ Reveal ============ */
.js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.js .reveal.is-revealed {
  opacity: 1;
  transform: none;
}

/* ============ Media queries ============ */
@media (max-width: 1024px) {
  .header-rail,
  .footer-rail {
    display: none;
  }

  .masthead {
    gap: 1rem;
    padding: var(--sp-4);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-6);
  }
}

@media (max-width: 768px) {
  .masthead {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 0.75rem;
  }

  .masthead-side {
    display: none;
  }

  .brand-lockup {
    justify-content: center;
  }

  .nav-block {
    flex-wrap: wrap;
    justify-content: space-between;
  }

  .js .site-nav {
    display: none;
  }

  .js .site-nav[data-open] {
    display: block;
  }

  .js .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    flex-basis: 100%;
  }

  .nav-list {
    flex-direction: column;
  }

  .nav-link {
    padding: 0.8rem 0.5rem;
    border-bottom: 1px solid var(--c-border);
    font-size: 0.95rem;
  }

  .nav-link::after {
    width: 8%;
    left: 0;
    transform: none;
  }

  .nav-link:hover::after,
  .nav-link[aria-current="page"]::after {
    width: 24%;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom-inner {
    flex-direction: column;
    text-align: center;
  }

  .back-top {
    right: 1rem;
    bottom: 1rem;
  }
}

@media (max-width: 480px) {
  .header-top-inner {
    flex-wrap: wrap;
    gap: 0.4rem;
    padding-block: 0.4rem;
    font-size: 10px;
  }

  .header-divider {
    display: none;
  }

  .header-direct {
    font-size: 10px;
    padding: 0.15rem 0.5rem;
  }

  .brand-emblem {
    width: 42px;
    height: 42px;
  }

  .brand-name {
    font-size: 1.5rem;
  }

  .brand-tagline {
    font-size: 10px;
  }
}

/* ============ Reduced motion ============ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }

  .emblem-ring {
    animation: none;
  }

  .js .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}