@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

/* ── Tokens ── */
:root {
  --sidebar-w:           240px;
  --sidebar-w-collapsed: 52px;
  --mobile-header-h:     56px;
  --navy:                #070f1a;   /* sidebar — near-black navy */
  --navy-dark:           #020617;   /* sidebar-top accent strip */
  --navy-hover:          rgba(255,255,255,.08);
  --accent:              #60a5fa;   /* blue-400 */
  --accent-hover:        #93c5fd;   /* blue-300 */
  --text:                #94a3b8;   /* slate-400 */
  --heading:             #e2e8f0;   /* slate-200 */
  --bg:                  #0f172a;   /* slate-900 — main content */
  --bg-alt:              #0a1222;   /* darker alt rows/cards */
  --border:              #1e293b;   /* slate-800 */
  --sidebar-text:        #94a3b8;
  --sidebar-text-active: #f1f5f9;
  --transition:          0.22s ease;
}

/* ── Base ── */
html, body {
  height: 100%;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 1.0625rem; /* ~17px */
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  overflow: hidden; /* scroll happens inside .layout children */
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* ── Mobile header (hidden on desktop) ── */
#mobile-header {
  display: none;
}

/* ── Layout ── */
.layout {
  display: flex;
  height: 100vh;
}

/* ── Sidebar ── */
#sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--navy);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  transition: width var(--transition), min-width var(--transition);
  flex-shrink: 0;
}

#sidebar.collapsed {
  width: var(--sidebar-w-collapsed);
  min-width: var(--sidebar-w-collapsed);
}

/* ── Sidebar top row ── */
.sidebar-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0.75rem 1rem 1.25rem;
  gap: 0.5rem;
  flex-shrink: 0;
  min-height: 72px;
}

#sidebar.collapsed .sidebar-top {
  justify-content: center;
  padding: 1.25rem 0;
}

.sidebar-top .brand {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--sidebar-text-active);
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  opacity: 1;
  transition: opacity var(--transition), width var(--transition);
}

#sidebar.collapsed .sidebar-top .brand {
  opacity: 0;
  width: 0;
  pointer-events: none;
}

/* ── Collapse / expand button ── */
#collapse-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--sidebar-text);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 4px;
  flex-shrink: 0;
  transition: background var(--transition), color var(--transition);
}

#collapse-btn:hover {
  background: var(--navy-hover);
  color: var(--sidebar-text-active);
}

#collapse-btn svg {
  width: 20px;
  height: 20px;
}

/* Show chevron when expanded, burger when collapsed */
#collapse-btn .icon-burger  { display: none; }
#collapse-btn .icon-chevron { display: block; }

#sidebar.collapsed #collapse-btn .icon-chevron { display: none; }
#sidebar.collapsed #collapse-btn .icon-burger  { display: block; }

/* ── Nav links ── */
#main-nav {
  display: flex;
  flex-direction: column;
  padding: 0.5rem 0;
  overflow-y: auto;
  overflow-x: hidden;
  flex: 1;
}

/* Nav separator */
.nav-sep {
  border: none;
  border-top: 1px solid rgba(255,255,255,.1);
  margin: 0.4rem 1rem;
}

/* Sidebar nav links */
#main-nav .nav-link {
  display: block;
  padding: 0.65rem 1.25rem;
  color: var(--sidebar-text);
  font-size: 0.9rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border-left: 3px solid transparent;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
  text-decoration: none;
}

#sidebar.collapsed #main-nav .nav-link {
  /* hide text but keep the element for layout; labels invisible when collapsed */
  color: transparent;
  pointer-events: none;
}

#main-nav .nav-link:hover {
  background: var(--navy-hover);
  color: var(--sidebar-text-active);
  text-decoration: none;
}

#main-nav .nav-link.active {
  color: var(--sidebar-text-active);
  border-left-color: var(--accent);
  background: rgba(59,130,246,.12);
}

/* ── In-content nav links — styled as normal body links ── */
#content .nav-link {
  display: inline;
  padding: 0;
  color: var(--accent);
  font-weight: inherit;
  border-left: none;
  background: none;
  white-space: normal;
  text-overflow: unset;
  overflow: visible;
  pointer-events: auto;
}

#content .nav-link:hover {
  color: var(--accent-hover);
  background: none;
  text-decoration: underline;
}

/* CTA button variant */
#content .cta-button.nav-link {
  display: inline-block;
  background: var(--accent);
  color: #0f172a;  /* dark text on light-blue button */
  font-weight: 600;
  font-size: 1rem;
  padding: 0.75rem 2rem;
  border-radius: 6px;
  border-left: none;
  text-decoration: none;
  transition: background var(--transition);
  margin-bottom: 2.5rem;
}

#content .cta-button.nav-link:hover {
  background: var(--accent-hover);
  color: #0f172a;
  text-decoration: none;
}

/* ── Content area ── */
#content {
  flex: 1;
  overflow-y: auto;
  height: 100vh;
  background: var(--bg);
  display: flex;
  flex-direction: column;
}

/* ── Sections ── */
section {
  display: none;
  padding: 3rem 2.5rem;
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  flex-shrink: 0;
}

section.active {
  display: block;
  flex: 1; /* push footer toward bottom when content is short */
}

section h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--heading);
  margin-bottom: 0.35rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}

section h2 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--heading);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

section p {
  margin-bottom: 1rem;
}

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

section ul,
section ol {
  margin: 0.5rem 0 1rem 1.5rem;
}

section li {
  margin-bottom: 0.4rem;
}

.lead {
  font-size: 1.125rem;
  color: var(--text);
  margin-top: 1.25rem;
  margin-bottom: 2rem;
}

/* ── Home services list ── */
.home-services {
  list-style: none;
  margin-left: 0 !important;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-bottom: 1rem !important;
}

.home-services li {
  margin-bottom: 0;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-alt);
}

/* ── Skills list ── */
.skills-list {
  display: grid;
  gap: 0;
  margin-top: 1.25rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.skills-list > div {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 0.5rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border);
}

.skills-list > div:last-child {
  border-bottom: none;
}

.skills-list > div:nth-child(odd) {
  background: var(--bg-alt);
}

.skills-list dt {
  font-weight: 600;
  color: var(--heading);
  font-size: 0.9rem;
}

.skills-list dd {
  color: var(--text);
  font-size: 0.9rem;
}

/* ── Shared footer ── */
footer {
  flex-shrink: 0;
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
  padding: 1.25rem 2.5rem;
}

.footer-inner {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 2.5rem;
  font-size: 0.9rem;
  color: var(--text);
}

.footer-inner strong {
  color: var(--heading);
}

.footer-inner a {
  color: var(--accent);
}

.footer-inner a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* ── Scrollbar styling ── */
#content, #main-nav {
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.15) transparent;
}

#content {
  scrollbar-color: var(--border) transparent;
}

/* ── Mobile ── */
@media (max-width: 900px) {
  body {
    overflow: auto;
  }

  #mobile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 200;
    background: var(--navy);
    height: var(--mobile-header-h);
    padding: 0 1rem;
    box-shadow: 0 1px 4px rgba(0,0,0,.3);
  }

  #mobile-header .brand {
    font-size: 1rem;
    font-weight: 700;
    color: #f1f5f9;
  }

  /* Hamburger button — class="hamburger" must be on the element */
  .hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
  }

  .hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: #f1f5f9;
    border-radius: 2px;
    transition: transform 0.2s, opacity 0.2s;
  }

  .hamburger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .hamburger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .layout {
    flex-direction: column;
    height: auto;
  }

  #sidebar {
    position: fixed;
    top: var(--mobile-header-h);
    left: 0;
    height: calc(100vh - var(--mobile-header-h));
    width: var(--sidebar-w) !important;
    min-width: 0 !important;
    transform: translateX(-100%);
    transition: transform var(--transition);
    z-index: 150;
    box-shadow: 4px 0 16px rgba(0,0,0,.3);
  }

  #sidebar.mobile-open {
    transform: translateX(0);
  }

  /* Restore nav link visibility on mobile (collapsed class has no effect) */
  #sidebar #main-nav .nav-link {
    color: var(--sidebar-text);
    pointer-events: auto;
  }

  #sidebar #main-nav .nav-link.active {
    color: var(--sidebar-text-active);
  }

  /* Hide desktop collapse button on mobile */
  #collapse-btn {
    display: none;
  }

  /* Brand always visible in mobile sidebar */
  .sidebar-top .brand {
    opacity: 1 !important;
    width: auto !important;
  }

  #content {
    height: auto;
    overflow: visible;
  }

  section {
    padding: 2rem 1.25rem;
  }

  footer {
    padding: 1.25rem;
  }

  .skills-list > div {
    grid-template-columns: 1fr;
    gap: 0.15rem;
  }
}