* {
  box-sizing: border-box;
}

:root {
  --page-width: min(92vw, 1680px);
  --main-width: 88ch;
  --sidebar-width: clamp(240px, 18vw, 320px);

  --bg: #ffffff;
  --text: #111111;
  --link-internal: #163d8f;
  --link-internal-hover: #0b2a66;
  --link-external: #8f2d16;
  --link-external-hover: #5f1d0e;
  --header-bg: #0a2f57;
  --header-text: #ffffff;
  --nav-bg: #d6d6d6;
  --box-bg: #f4f4f4;
  --project-bg: #f8f8f8;
  --border: #9a9a9a;
  --rule: #bcbcbc;
  --footer: #555555;
  --text-dim: #555555;

  --font-body: Verdana, Arial, sans-serif;
  --font-title: Arial, Helvetica, sans-serif;
  --font-mono: "Courier New", Courier, monospace;

  --fs-body: clamp(15px, 0.20vw + 14px, 19px);
  --fs-small: clamp(12px, 0.10vw + 11px, 14px);
  --fs-h1: clamp(30px, 1.1vw + 22px, 48px);
  --fs-h2: clamp(20px, 0.45vw + 18px, 30px);
  --fs-h3: clamp(14px, 0.18vw + 13px, 17px);

  --space-1: clamp(6px, 0.2vw, 10px);
  --space-2: clamp(10px, 0.4vw, 16px);
  --space-3: clamp(14px, 0.7vw, 24px);
  --space-4: clamp(20px, 1vw, 32px);
}

html {
  scroll-behavior: smooth;
}

:focus-visible {
  outline: 3px solid #ffbf47;
  outline-offset: 2px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: 12px;
  z-index: 1000;
  transform: translateY(-160%);
  background: #ffffff;
  color: #000000;
  border: 2px solid #000000;
  padding: 8px 10px;
  font-family: var(--font-mono);
}

.skip-link:focus {
  transform: translateY(0);
}

a {
  text-decoration: none;
  font-weight: 600;
  transition: color 0.15s ease;
}

a[href^="#"],
a[href$=".html"],
a[href^="/"] {
  color: var(--link-internal);
}

a[href^="#"]:hover,
a[href$=".html"]:hover,
a[href^="/"]:hover,
a[href^="#"]:focus,
a[href$=".html"]:focus,
a[href^="/"]:focus {
  color: var(--link-internal-hover);
}

a[rel~="external"],
a[href^="http://"],
a[href^="https://"],
a[href^="mailto:"] {
  color: var(--link-external);
}

a[rel~="external"]:hover,
a[href^="http://"]:hover,
a[href^="https://"]:hover,
a[href^="mailto:"]:hover,
a[rel~="external"]:focus,
a[href^="http://"]:focus,
a[href^="https://"]:focus,
a[href^="mailto:"]:focus {
  color: var(--link-external-hover);
}

a[rel~="external"]::after,
a[href^="http://"]::after,
a[href^="https://"]::after,
a[href^="mailto:"]::after {
  content: " [ext]";
  font-family: var(--font-mono);
  font-size: 0.8em;
  font-weight: normal;
}

a[href^="#"]::before {
  content: "# ";
  font-family: var(--font-mono);
  font-size: 0.85em;
  font-weight: normal;
}

.header a {
  color: #ffd9b8;
}

.header a:hover,
.header a:focus {
  color: #ffffff;
}

.header a[rel~="external"]::after,
.header a[href^="http://"]::after,
.header a[href^="https://"]::after,
.header a[href^="mailto:"]::after {
  content: " [ext]";
  color: #ffd9b8;
}

.nav a[href^="#"] {
  color: #0b2a66;
}

.nav a[href^="#"]:hover,
.nav a[href^="#"]:focus {
  color: #000000;
}

.page {
  max-width: var(--page-width);
  margin: 0 auto;
  padding: 0 clamp(12px, 1.4vw, 28px);
}

/* ===== HEADER ===== */
.header {
  margin-top: var(--space-2);
  background: var(--header-bg);
  color: var(--header-text);
  border: 1px solid #001e3a;
  position: relative;
}

.header::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 1%;
  right: 1%;
  height: 3px;
  background: #001e3a;
  opacity: 0.3;
  border-radius: 0 0 2px 2px;
}

.header-inner {
  max-width: min(1100px, 100%);
  margin: 0 auto;
  padding: var(--space-3) var(--space-4);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  justify-items: center;
  text-align: center;
}

.header-text {
  width: min(100%, 78ch);
}

.header h1 {
  margin: 0 0 var(--space-2) 0;
  font-family: var(--font-title);
  font-size: var(--fs-h1);
  line-height: 1.05;
  font-weight: bold;
  letter-spacing: -0.02em;
}

.header h3 {
  margin: 0 0 3px 0;
  font-family: var(--font-mono);
  font-size: var(--fs-h3);
  line-height: 1.35;
  font-weight: normal;
}

.header p {
  margin: var(--space-2) 0 0 0;
  color: #c0d4e8;
}

/* ===== NAV ===== */
.nav {
  background: var(--nav-bg);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-size: var(--fs-small);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 4px rgba(0,0,0,0.06);
}

.nav-inner {
  max-width: var(--page-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px 12px;
}

.nav a {
  display: inline-block;
  padding: 2px 0;
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1.5px;
  background: #0b2a66;
  transition: width 0.2s ease;
}

.nav a:hover::after {
  width: 100%;
}

.nav-sep {
  color: var(--border);
  user-select: none;
}

.lang-switcher {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
}

.lang-btn {
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: var(--fs-small);
  font-weight: 600;
  color: #0b2a66;
  cursor: pointer;
  padding: 2px 6px;
  position: relative;
  transition: color 0.15s;
}

.lang-btn:hover {
  color: #000000;
}

.lang-btn.active {
  color: #000000;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 2px;
  text-decoration-color: var(--link-internal);
}

.lang-btn.active::after {
  display: none;
}

.lang-btn:focus-visible {
  border-radius: 2px;
}

/* ===== LAYOUT ===== */
.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--sidebar-width);
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-4) 0;
}

.main {
  min-width: 0;
}

/* ===== SECTIONS ===== */
.section-block {
  max-width: var(--main-width);
  padding: 0 0 var(--space-3) 0;
}

.section-rule {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 0 0 var(--space-3) 0;
  height: 0;
}

h2 {
  margin: 0 0 var(--space-2) 0;
  font-family: var(--font-title);
  font-size: var(--fs-h2);
  line-height: 1.15;
  font-weight: bold;
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
}

h2::before {
  content: "▸";
  color: var(--link-internal);
  font-size: 0.7em;
  position: relative;
  top: -0.1em;
}

p {
  margin: 0 0 var(--space-2) 0;
}

ul {
  margin: var(--space-1) 0 0 0;
  padding-left: 18px;
}

li {
  margin-bottom: var(--space-1);
  position: relative;
}

/* ===== PROJECTS ===== */
.projects-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.project-card {
  border: 1px solid var(--border);
  background: var(--project-bg);
  padding: var(--space-2) var(--space-3);
  transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.1s ease;
  border-radius: 2px;
}

.project-card:hover {
  border-color: var(--link-internal);
  box-shadow: 0 2px 8px rgba(22, 61, 143, 0.08);
  transform: translateY(-1px);
}

.project-card.featured {
  border-color: var(--link-internal);
  border-width: 2px;
  background: #f0f4fa;
}

.project-card h3 {
  margin: 0 0 var(--space-2) 0;
  font-family: var(--font-title);
  font-size: clamp(15px, 0.18vw + 14px, 18px);
  line-height: 1.25;
}

.project-card p {
  margin: 0 0 var(--space-2) 0;
}

.project-meta {
  font-size: var(--fs-small);
  color: #333333;
  font-family: var(--font-mono);
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex-wrap: wrap;
}

.project-meta::before {
  content: "//";
  color: var(--link-internal);
  opacity: 0.5;
}

.stack-line {
  font-family: var(--font-mono);
  font-size: 0.95em;
  color: #333333;
}

.more-link {
  margin-top: var(--space-2);
}

.domain-tag {
  display: inline-block;
  padding: 1px 8px;
  border-radius: 2px;
  font-size: 0.85em;
  font-weight: 600;
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.tag-cyber { background: #e8d5c4; color: #5a3a1a; }
.tag-iot { background: #c4d8e8; color: #1a3a5a; }
.tag-data { background: #d4c4e8; color: #3a1a5a; }
.tag-infra { background: #c4e8d4; color: #1a5a3a; }
.tag-ai { background: #e6e6c4; color: #4d4d19; }
.tag-research { background: #e8c4d8; color: #5a1a3a; }

.page-meta {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  color: var(--text-dim);
}

.placeholder-note {
  border-left: 3px solid var(--link-internal);
  background: var(--project-bg);
  padding: var(--space-2) var(--space-3);
  font-size: 0.95em;
}

.table-wrap {
  overflow-x: auto;
  margin: var(--space-2) 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92em;
}

caption {
  text-align: left;
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  margin-bottom: var(--space-1);
}

th,
td {
  border: 1px solid var(--border);
  padding: 7px 9px;
  vertical-align: top;
}

th {
  background: var(--box-bg);
  text-align: left;
}

.project-image {
  display: block;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--border);
  margin: var(--space-2) 0;
}

/* ===== PARCOURS ===== */
.parcours-list {
  list-style: none;
  padding-left: 0;
}

.parcours-list > li {
  margin-bottom: var(--space-2);
  padding-left: 0;
}

.parcours-list > li::before {
  content: none;
}

.parcours-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.parcours-main {
  font-weight: 600;
}

.parcours-detail {
  padding-left: var(--space-3);
  color: #333;
  font-size: 0.95em;
}

.parcours-detail::before {
  content: "› ";
  color: var(--link-internal);
}

.parcours-nested {
  margin-top: var(--space-1);
  padding-left: var(--space-3);
}

.parcours-nested li {
  font-size: 0.95em;
  color: #333;
}

/* ===== SIDEBAR ===== */
.sidebar {
  min-width: 0;
}

.box {
  background: var(--box-bg);
  border: 1px solid var(--border);
  padding: var(--space-2) var(--space-3);
  margin-bottom: var(--space-2);
  border-radius: 2px;
  transition: box-shadow 0.15s ease;
}

.box:hover {
  box-shadow: 0 2px 6px rgba(0,0,0,0.04);
}

.box h3 {
  margin: 0 0 var(--space-2) 0;
  font-family: var(--font-title);
  font-size: var(--fs-h3);
  line-height: 1.2;
  color: var(--header-bg);
  border-bottom: 1px solid var(--rule);
  padding-bottom: var(--space-1);
}

.box p {
  margin: 0 0 var(--space-1) 0;
}

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

.box ul {
  margin: 0;
  padding-left: 0;
  list-style: none;
}

.box li {
  margin-bottom: var(--space-1);
  padding-left: var(--space-2);
  position: relative;
}

.box li::before {
  content: "·";
  position: absolute;
  left: 0;
  color: var(--link-internal);
  font-weight: bold;
}

.status-box {
  background: var(--header-bg);
  color: var(--header-text);
  border-color: #001e3a;
}

.status-box:hover {
  box-shadow: 0 2px 8px rgba(10, 47, 87, 0.2);
}

.status-box h3 {
  color: #ffd9b8;
  border-bottom-color: rgba(255,217,184,0.3);
}

.status-box p {
  color: #c0d4e8;
}

.status-detail {
  font-size: var(--fs-small);
  margin-top: var(--space-1);
}

.status-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: #3fb950;
  border-radius: 50%;
  margin-right: 6px;
  box-shadow: 0 0 4px #3fb950;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* ===== FOOTER ===== */
.footer {
  border-top: 1px solid var(--border);
  color: var(--footer);
  font-family: var(--font-body);
  font-size: var(--fs-small);
  text-align: center;
  padding: var(--space-2) 0 var(--space-4);
}

/* ===== RESPONSIVE ===== */
@media (min-width: 2200px) {
  :root {
    --main-width: 92ch;
    --fs-body: 19px;
    --fs-h1: 52px;
    --fs-h2: 32px;
    --sidebar-width: 340px;
  }
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .section-block {
    max-width: none;
  }

  .sidebar {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-2);
  }

  .box {
    margin-bottom: 0;
  }
}

@media (max-width: 640px) {
  .page {
    padding: 0 10px;
  }

  .header-inner {
    padding: 14px 12px 12px;
  }

  .header-text {
    width: 100%;
  }

  .nav-inner {
    justify-content: center;
  }

  .nav a {
    display: block;
    margin-right: 0;
    text-align: center;
    padding: 6px 0;
  }

  .lang-switcher {
    margin-left: 0;
    width: 100%;
    justify-content: center;
    margin-top: var(--space-1);
    padding-top: var(--space-1);
    border-top: 1px solid var(--border);
  }

  body {
    font-size: 14px;
  }

  .project-card:hover {
    transform: none;
  }

  .project-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .project-card:hover {
    transform: none;
  }
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-dim);
}