:root {
  --bg: #111214; --bg2: #171717; --bg3: #1c1c1c; --bg4: #222222;
  --surface: #1a1a1a; --surface2: #222222; --surface3: #2a2a2a;
  --border: #1e2025; --border2: #252525;
  --text: #e8e8e8; --text2: #9a9fa6; --text3: #7a7f87;
  --accent: #3cae32; --accent2: #2d8f26; --accent3: #1f6b1a;
  --green: #34d399; --green-bg: rgba(52,211,153,0.1);
  --orange: #fb923c; --orange-bg: rgba(251,146,60,0.1);
  --red: #f87171; --red-bg: rgba(248,113,113,0.1);
  --purple: #a78bfa; --purple-bg: rgba(167,139,250,0.1);
  --blue: #60a5fa; --blue-bg: rgba(96,165,250,0.1);
  --yellow: #fbbf24; --yellow-bg: rgba(251,191,36,0.1);
  --pink: #f472b6; --pink-bg: rgba(244,114,182,0.1);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', ui-monospace, monospace;
  --radius: 12px; --radius-sm: 8px; --radius-xs: 6px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 14px; }
body { font-family: var(--font); background: var(--bg); color: var(--text); min-height: 100vh; line-height: 1.5; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent2); text-decoration: underline; }

/* HEADER */
.app-header { position: sticky; top: 0; z-index: 100; background: rgba(15,17,23,0.85); backdrop-filter: blur(16px); border-bottom: 1px solid var(--border); padding: 12px 24px; display: flex; align-items: center; gap: 16px; }
.logo { display: flex; align-items: center; gap: 10px; cursor: pointer; flex-shrink: 0; }
.logo-icon { font-size: 24px; }
.logo-text { font-size: 18px; font-weight: 700; letter-spacing: -0.02em; background: #c0ff00; -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.logo-sub { font-size: 11px; color: var(--text3); margin-left: 4px; }
.header-search { flex: 1; max-width: 480px; position: relative; }
.header-search input { width: 100%; padding: 9px 14px 9px 38px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text); font-size: 13px; outline: none; transition: all 0.2s; }
.header-search input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(60,174,50,0.15); }
.header-search input::placeholder { color: var(--text3); }
.header-search .search-ico { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--text3); font-size: 14px; }
.header-search .kbd { position: absolute; right: 10px; top: 50%; transform: translateY(-50%); font-size: 11px; color: var(--text3); background: var(--bg); border: 1px solid var(--border); padding: 1px 6px; border-radius: 4px; }
.header-right { display: flex; align-items: center; gap: 8px; margin-left: auto; }
.badge { display: inline-flex; align-items: center; gap: 4px; padding: 4px 10px; border-radius: 20px; font-size: 11px; font-weight: 600; }
.badge-tools { background: var(--green-bg); color: var(--green); }

/* MAIN LAYOUT */
.app-body { display: flex; min-height: calc(100vh - 53px); }
.sidebar { width: 240px; background: var(--bg2); border-right: 1px solid var(--border); position: fixed; top: 53px; bottom: 0; overflow-y: auto; z-index: 50; }
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 4px; }
.sb-section { padding: 12px 10px 4px; }
.sb-label { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text3); padding: 0 8px 6px; }
.sb-item { display: flex; align-items: center; gap: 8px; padding: 7px 10px; border-radius: var(--radius-xs); font-size: 12.5px; color: var(--text2); cursor: pointer; transition: all 0.15s; border: none; background: none; width: 100%; text-align: left; }
.sb-item:hover { background: var(--surface); color: var(--text); }
.sb-item.active { background: rgba(60,174,50,0.1); color: var(--accent); }
.sb-item .ico { width: 20px; text-align: center; font-size: 14px; flex-shrink: 0; display: flex; align-items: center; justify-content: center; }
.sb-item .ico i, .sb-item .ico svg { width: 15px; height: 15px; stroke: currentColor; flex-shrink: 0; }
.tc-icon i, .tc-icon svg { width: 22px; height: 22px; stroke: currentColor; }
.tv-title i, .tv-title svg { width: 20px; height: 20px; stroke: currentColor; vertical-align: middle; margin-right: 4px; }
.panel h3 i, .panel h3 svg { width: 16px; height: 16px; stroke: currentColor; vertical-align: middle; margin-right: 4px; }
.tab i, .tab svg { width: 13px; height: 13px; stroke: currentColor; vertical-align: middle; margin-right: 3px; }
.search-ico i, .search-ico svg { width: 14px; height: 14px; stroke: var(--text3); vertical-align: middle; }

/* Collapsible Sidebar Sections */
.sb-label {
  cursor: pointer;
  user-select: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: color 0.15s;
}
.sb-label:hover { color: var(--text); }
.sb-arrow {
  display: inline-block;
  font-size: 10px;
  color: var(--text3);
  transition: transform 0.25s cubic-bezier(0.4,0,0.2,1);
  flex-shrink: 0;
  line-height: 1;
}
.sb-label.sb-collapsed .sb-arrow { transform: rotate(-90deg); }
.sb-section-items {
  overflow: hidden;
  transition: max-height 0.28s cubic-bezier(0.4,0,0.2,1), opacity 0.22s ease;
  max-height: 800px;
  opacity: 1;
}
.sb-section-items.sb-collapsed {
  max-height: 0 !important;
  opacity: 0;
}
.sb-item .cnt { margin-left: auto; font-size: 10px; background: var(--surface); padding: 1px 6px; border-radius: 10px; color: var(--text3); }

.main { margin-left: 240px; flex: 1; padding: 24px; max-width: 1200px; min-width: 0; }

/* HOME GRID */
.home-section { margin-bottom: 32px; }
.home-section h2 { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text3); margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.home-section h2 .dot { width: 6px; height: 6px; border-radius: 50%; }
.tool-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; }
.tool-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; cursor: pointer; transition: all 0.2s; display: flex; flex-direction: column; gap: 6px; }
.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.3); }
.tool-card .tc-icon { font-size: 22px; }
.tool-card .tc-name { font-size: 13px; font-weight: 600; color: var(--text); }
.tool-card .tc-desc { font-size: 11.5px; color: var(--text3); line-height: 1.4; }
.tool-card .tc-tags { display: flex; flex-wrap: wrap; gap: 4px; margin-top: auto; padding-top: 6px; }
.tc-tag { font-size: 10px; padding: 2px 7px; border-radius: 10px; }

/* TOOL VIEW */
.tool-view { display: none; }
.tool-view.active { display: block; }
.tv-header { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; }
.tv-back { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-xs); padding: 6px 12px; cursor: pointer; color: var(--text2); font-size: 12px; transition: all 0.15s; display: flex; align-items: center; gap: 6px; }
.tv-back:hover { background: var(--surface2); color: var(--text); }
.tv-title { font-size: 20px; font-weight: 700; }
.tv-subtitle { font-size: 12px; color: var(--text3); }

/* FORM ELEMENTS */
.form-group { margin-bottom: 14px; }
.form-label { display: block; font-size: 12px; font-weight: 600; color: var(--text2); margin-bottom: 5px; }
.form-input, .form-select { width: 100%; padding: 9px 12px; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-xs); color: var(--text); font-size: 13px; font-family: var(--font); outline: none; transition: border 0.2s; }
.form-input:focus, .form-select:focus { border-color: var(--accent); }
.form-input::placeholder { color: var(--text3); }
.form-input.mono { font-family: var(--mono); }
textarea.form-input { resize: vertical; min-height: 80px; font-family: var(--mono); font-size: 12px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.form-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }
.btn { padding: 9px 18px; border-radius: var(--radius-xs); font-size: 13px; font-weight: 600; cursor: pointer; border: none; transition: all 0.15s; font-family: var(--font); }
.btn-primary { background: var(--accent); color: var(--bg); }
.btn-primary:hover { background: var(--accent2); }
.btn-secondary { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--surface3); }
.btn-sm { padding: 5px 12px; font-size: 12px; }
.btn-group { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 6px; }

/* RESULTS */
.result-box { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin-top: 16px; }
.result-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 10px; }
.result-item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-xs); padding: 10px 12px; }
.result-item .ri-label { font-size: 10px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text3); margin-bottom: 2px; }
.result-item .ri-value { font-family: var(--mono); font-size: 13px; color: var(--accent); word-break: break-all; }
.result-item .ri-value.green { color: var(--green); }
.result-item .ri-value.orange { color: var(--orange); }

/* CODE BLOCKS */
pre.code { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-xs); padding: 14px; font-family: var(--mono); font-size: 12px; line-height: 1.6; overflow-x: auto; color: var(--text); position: relative; white-space: pre-wrap; word-break: break-word; margin: 10px 0; }
.copy-btn { position: absolute; top: 8px; right: 8px; background: var(--surface2); border: 1px solid var(--border); border-radius: var(--radius-xs); padding: 3px 10px; font-size: 11px; cursor: pointer; color: var(--text3); transition: all 0.15s; }
.copy-btn:hover { background: var(--surface3); color: var(--text); }

/* TABLES */
.ref-table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.ref-table th { text-align: left; padding: 8px 10px; background: var(--surface); font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text3); border-bottom: 1px solid var(--border); position: sticky; top: 0; }
.ref-table td { padding: 7px 10px; border-bottom: 1px solid var(--border); color: var(--text2); }
.ref-table tr:hover td { background: var(--surface); color: var(--text); }
.ref-table .mono { font-family: var(--mono); color: var(--accent); font-size: 12px; }
.table-wrap { max-height: 480px; overflow-x: auto; overflow-y: auto; border: 1px solid var(--border); border-radius: var(--radius); }
.table-wrap::-webkit-scrollbar { width: 6px; }
.table-wrap::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 4px; }
.table-filter { margin-bottom: 10px; }

/* PANELS */
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; margin-bottom: 14px; overflow-x: auto; }
.panel h3 { font-size: 14px; font-weight: 700; margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }
.panel p { font-size: 12.5px; color: var(--text2); line-height: 1.6; }
.tip { border-left: 3px solid var(--accent); padding: 10px 14px; background: rgba(60,174,50,0.06); border-radius: 0 var(--radius-xs) var(--radius-xs) 0; margin: 10px 0; font-size: 12px; color: var(--text2); }
.warn { border-left: 3px solid var(--orange); padding: 10px 14px; background: var(--orange-bg); border-radius: 0 var(--radius-xs) var(--radius-xs) 0; margin: 10px 0; font-size: 12px; color: var(--text2); }

/* TABS */
.tabs { display: flex; gap: 2px; margin-bottom: 16px; background: var(--bg); border-radius: var(--radius-xs); padding: 3px; border: 1px solid var(--border); }
.tab { padding: 7px 16px; border-radius: var(--radius-xs); font-size: 12px; font-weight: 600; cursor: pointer; color: var(--text3); transition: all 0.15s; border: none; background: none; font-family: var(--font); }
.tab:hover { color: var(--text); }
.tab.active { background: var(--surface2); color: var(--accent); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* OSI */
.osi-stack { display: flex; flex-direction: column; gap: 3px; }
.osi-row { display: flex; border-radius: var(--radius-xs); overflow: hidden; }
.osi-num { width: 40px; display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 16px; color: #fff; flex-shrink: 0; }
.osi-body { flex: 1; padding: 10px 14px; background: var(--surface); border: 1px solid var(--border); }
.osi-body h4 { font-size: 13px; font-weight: 700; }
.osi-body .osi-pdu { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; margin-left: 8px; padding: 1px 6px; border-radius: 4px; background: rgba(255,255,255,0.08); }
.osi-body p { font-size: 11.5px; color: var(--text2); margin-top: 3px; }

/* FILTER PILLS */
.pills { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.pill { padding: 4px 12px; border-radius: 20px; font-size: 11px; font-weight: 600; cursor: pointer; border: 1px solid var(--border); background: var(--surface); color: var(--text3); transition: all 0.15s; }
.pill:hover { border-color: var(--accent); color: var(--text); }
.pill.active { background: rgba(60,174,50,0.15); border-color: var(--accent); color: var(--accent); }

/* HIDE ELEMENTS */
.hidden { display: none !important; }
.no-results-msg { text-align: center; padding: 40px; color: var(--text3); }
.no-results-msg .nr-icon { font-size: 40px; margin-bottom: 8px; }

/* HAMBURGER & SIDEBAR OVERLAY */
.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 6px; flex-direction: column; justify-content: center; gap: 5px; flex-shrink: 0; }
.hamburger span { display: block; width: 20px; height: 2px; background: var(--text2); border-radius: 2px; transition: all 0.2s; }
.sidebar-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.55); z-index: 49; }

/* APP FOOTER */
.app-footer {
    margin-top: 48px;
    padding: 24px;
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 11px;
    color: var(--text3);
    background: var(--bg2);
}

.app-footer .footer-warning {
    color: var(--orange);
    font-weight: 600;
    margin-top: 4px;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  /* Header */
  .hamburger { display: flex; }
  .logo-sub, .header-right { display: none; }
  .header-search { max-width: none; }
  .header-search .kbd { display: none; }
  .app-header { padding: 10px 14px; gap: 10px; }

  /* Sidebar: hidden off-screen by default, slides in when .open */
  .sidebar {
    display: block !important;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    z-index: 100;
    top: 53px;
  }
  .sidebar.open { transform: translateX(0); }
  body.sidebar-open .sidebar-overlay { display: block; }

  /* Main content */
  .main { margin-left: 0; padding: 16px; min-width: 0; }

  /* Grids collapse to single column */
  .tool-grid { grid-template-columns: 1fr; }
  .form-row, .form-row-3 { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }

  /* Tabs wrap */
  .tabs { flex-wrap: wrap; }
  .tab { flex: 1 1 auto; text-align: center; min-width: 70px; }

  /* Arch detail grids */
  .arch-detail-grid { grid-template-columns: 1fr !important; }

  /* Diagram/pre blocks scroll horizontally */
  .diagram-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .diagram-wrap pre { white-space: pre; min-width: 480px; }

  /* Home view title */
  #homeView h1 { font-size: 20px !important; }

  /* Footer */
  .app-footer { padding: 16px; }
}

/* Small phones */
@media (max-width: 480px) {
  /* Prevent iOS zoom on input focus (requires font-size >= 16px) */
  .form-input, .form-select, .header-search input { font-size: 16px; }
  .tv-title { font-size: 16px; }
  .panel { padding: 12px; }
  .tab { font-size: 11px; padding: 6px 10px; }
  .result-item { padding: 8px 10px; }
}