:root {
    --bg:        #0d1117;
    --surface:   #161b22;
    --surface2:  #1c2128;
    --border:    #30363d;
    --text:      #e6edf3;
    --dim:       #7d8590;
    --green:     #3fb950;
    --blue:      #58a6ff;
    --yellow:    #d29922;
    --purple:    #bc8cff;
    --red:       #f85149;
    --orange:    #f0883e;
    --teal:      #4db6ac;
    --mono:      'SFMono-Regular', 'Cascadia Code', 'Consolas', monospace;
    --sans:      -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --sidebar:   220px;
    --max:       820px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--sans);
    font-size: 15px;
    line-height: 1.7;
    display: flex;
}

/* ── Sidebar ── */
aside {
    width: var(--sidebar);
    flex-shrink: 0;
    position: fixed;
    top: 0; left: 0; bottom: 0;
    border-right: 1px solid var(--border);
    background: var(--surface);
    display: flex;
    flex-direction: column;
    padding: 0;
    overflow-y: auto;
    z-index: 20;
}
.sidebar-logo {
    padding: 24px 20px 20px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}
.sidebar-logo a { display: block; line-height: 0; }
.sidebar-logo img { height: 28px; width: auto; }

.sidebar-nav { padding: 16px 0; flex: 1; }
.sidebar-nav a {
    display: flex; align-items: center; gap: 10px;
    padding: 8px 20px;
    color: var(--dim);
    text-decoration: none;
    font-size: 13px;
    border-left: 2px solid transparent;
    transition: color .15s, border-color .15s, background .15s;
    line-height: 1.3;
}
.sidebar-nav a:hover { color: var(--text); background: var(--surface2); }
.sidebar-nav a.active {
    color: var(--blue); border-left-color: var(--blue);
    background: rgba(88,166,255,.06); font-weight: 500;
}
.sidebar-nav .nav-icon { font-size: 13px; flex-shrink: 0; width: 16px; text-align: center; }

/* ── Main content ── */
main { margin-left: var(--sidebar); flex: 1; min-width: 0; }
.page { max-width: var(--max); margin: 0 auto; padding: 0 40px 80px; }

/* ── Hero ── */
.hero { padding: 56px 0 40px; border-bottom: 1px solid var(--border); margin-bottom: 48px; }
.hero h1 { font-size: 28px; font-weight: 700; margin-bottom: 10px; }
.hero h1 span { color: var(--blue); }
.hero p { color: var(--dim); max-width: 580px; }
.badge-row { display: flex; gap: 8px; margin-top: 16px; flex-wrap: wrap; }
.badge {
    padding: 3px 10px; border-radius: 20px; font-size: 11px; font-weight: 600;
    border: 1px solid; letter-spacing: .3px;
}
.badge.green  { border-color: var(--green);  color: var(--green);  }
.badge.blue   { border-color: var(--blue);   color: var(--blue);   }
.badge.purple { border-color: var(--purple); color: var(--purple); }
.badge.orange { border-color: var(--orange); color: var(--orange); }

/* ── Sections ── */
section { margin-bottom: 56px; scroll-margin-top: 32px; }
h2 {
    font-size: 20px; font-weight: 700;
    padding-bottom: 10px; border-bottom: 1px solid var(--border);
    margin-bottom: 20px; display: flex; align-items: center; gap: 10px;
}
h2 .icon { font-size: 18px; }
h3 { font-size: 15px; font-weight: 600; margin: 24px 0 8px; color: var(--blue); }
p { margin-bottom: 12px; }
p:last-child { margin-bottom: 0; }

/* ── Diagrams ── */
.diagram-wrap {
    background: var(--surface); border: 1px solid var(--border);
    border-radius: 8px; padding: 24px 16px; overflow-x: auto; margin: 20px 0;
}
.diagram-label {
    font-size: 11px; font-weight: 600; letter-spacing: .5px;
    text-transform: uppercase; color: var(--dim); margin-bottom: 12px;
}
.mermaid { display: flex; justify-content: center; }

/* ── Code blocks ── */
.code-block { position: relative; margin: 12px 0; }
.code-header {
    display: flex; align-items: center; justify-content: space-between;
    background: var(--surface2); border: 1px solid var(--border);
    border-bottom: none; border-radius: 8px 8px 0 0; padding: 6px 14px;
}
.code-header .pre-label {
    font-size: 10px; font-weight: 700; letter-spacing: .5px;
    text-transform: uppercase; color: var(--dim);
}
.run-env {
    font-size: 10px; font-weight: 700; letter-spacing: .3px;
    padding: 2px 8px; border-radius: 10px; border: 1px solid;
}
.run-env.server { border-color: var(--orange); color: var(--orange); }
.run-env.client { border-color: var(--blue);   color: var(--blue);   }
pre {
    background: var(--surface); border: 1px solid var(--border);
    border-radius: 8px; padding: 16px 18px; overflow-x: auto;
    font-family: var(--mono); font-size: 13px; line-height: 1.6; position: relative;
}
.code-block pre { border-radius: 0 0 8px 8px; margin: 0; }
.copy-btn {
    position: absolute; top: 10px; right: 10px;
    background: var(--surface2); border: 1px solid var(--border);
    color: var(--dim); border-radius: 5px;
    padding: 3px 9px; font-size: 11px; cursor: pointer; font-family: var(--sans);
    transition: color .15s, border-color .15s;
}
.copy-btn:hover { color: var(--text); border-color: var(--dim); }
.copy-btn.copied { color: var(--green); border-color: var(--green); }
code { font-family: var(--mono); font-size: 13px; }
p code, li code {
    background: var(--surface2); border: 1px solid var(--border);
    border-radius: 4px; padding: 1px 6px; font-size: 12px; color: var(--orange);
}
.kw  { color: var(--red);    }
.str { color: var(--green);  }
.cm  { color: var(--dim);    }
.num { color: var(--purple); }
.key { color: var(--blue);   }

/* ── Tables ── */
table { width: 100%; border-collapse: collapse; font-size: 13px; margin: 12px 0; }
th {
    text-align: left; padding: 8px 12px;
    background: var(--surface2); border: 1px solid var(--border);
    color: var(--dim); font-weight: 600; font-size: 11px;
    text-transform: uppercase; letter-spacing: .4px;
}
td { padding: 8px 12px; border: 1px solid var(--border); vertical-align: top; }
td code { color: var(--orange); }
tr:nth-child(even) td { background: #0f141a; }

/* ── Callouts ── */
.callout {
    border-left: 3px solid; padding: 12px 16px;
    border-radius: 0 6px 6px 0; font-size: 14px; margin: 16px 0;
}
.callout.info  { border-color: var(--blue);   background: #0d1f33; }
.callout.warn  { border-color: var(--yellow); background: #1c1708; }
.callout.tip   { border-color: var(--green);  background: #0d1f10; }
.callout strong { display: block; margin-bottom: 4px; font-size: 12px; letter-spacing: .3px; }
.callout.info  strong { color: var(--blue);   }
.callout.warn  strong { color: var(--yellow); }
.callout.tip   strong { color: var(--green);  }

/* ── Events ── */
.event-grid { display: grid; gap: 8px; margin: 12px 0; }
.event-row {
    display: grid; grid-template-columns: 140px 1fr;
    gap: 12px; align-items: start;
    background: var(--surface); border: 1px solid var(--border);
    border-radius: 6px; padding: 10px 14px; font-size: 13px;
}
.event-name { font-family: var(--mono); color: var(--purple); font-weight: 600; }
.event-desc { color: var(--dim); }

/* ── Footer ── */
footer {
    border-top: 1px solid var(--border); padding: 24px 0;
    text-align: center; font-size: 12px; color: var(--dim); direction: rtl;
}
footer a { color: var(--dim); text-decoration: none; }
footer a:hover { color: var(--text); }

/* ── Demo section ── */
.demo-warning {
    background: rgba(248,81,73,.1); border: 1px solid rgba(248,81,73,.4);
    border-radius: 8px; padding: 11px 15px; color: var(--orange);
    font-size: 13px; margin-bottom: 20px;
    display: flex; gap: 9px; align-items: flex-start;
}
.demo-warning .warn-icon { flex-shrink: 0; margin-top: 1px; }

/* Step card */
.demo-step {
    border: 1px solid var(--border);
    border-radius: 8px; overflow: hidden; margin-bottom: 14px;
}

/* Step header */
.demo-step-hd {
    display: flex; align-items: center; gap: 10px;
    padding: 9px 16px; border-bottom: 1px solid var(--border);
    background: var(--surface2);
}
.demo-step-hd--server {
    background: rgba(77,182,172,.07);
    border-bottom-color: rgba(77,182,172,.18);
}
.demo-step-hd--client {
    background: rgba(88,166,255,.07);
    border-bottom-color: rgba(88,166,255,.18);
}
.demo-step-num {
    width: 20px; height: 20px; border-radius: 50%;
    background: var(--border); color: var(--dim);
    font-size: 11px; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.demo-step-hd--server .demo-step-num { background: rgba(77,182,172,.2); color: var(--teal); }
.demo-step-hd--client .demo-step-num { background: rgba(88,166,255,.2); color: var(--blue); }
.demo-step-title-text { font-size: 13px; font-weight: 600; color: var(--text); flex: 1; }
.demo-step-subtitle { font-size: 12px; color: var(--dim); font-weight: 400; }

/* Environment badge (demo) */
.demo-env {
    font-size: 10px; font-weight: 600; letter-spacing: .3px;
    padding: 2px 8px; border-radius: 10px; border: 1px solid; margin-left: auto;
}
.demo-env--server { border-color: var(--teal); color: var(--teal); }
.demo-env--client { border-color: var(--blue); color: var(--blue); }

/* Step body */
.demo-step-body { padding: 16px 20px; }

/* Sub-panels (step 3) */
.demo-panel { padding: 14px 20px; }
.demo-panel + .demo-panel { border-top: 1px solid var(--border); }
.demo-panel--server { background: rgba(77,182,172,.04); }
.demo-panel--client { background: rgba(88,166,255,.04); }
.demo-panel-label {
    display: flex; align-items: center; gap: 8px;
    font-size: 12px; color: var(--dim); margin-bottom: 12px;
}

/* Fields */
.demo-field { margin-bottom: 12px; }
.demo-field:last-of-type { margin-bottom: 0; }
.demo-field label { display: block; font-size: 12px; color: var(--dim); margin-bottom: 4px; }
.demo-field label .warn-label { color: var(--yellow); font-style: italic; }
.demo-input-wrap { position: relative; display: flex; }
.demo-input-wrap input {
    flex: 1; background: var(--surface2); border: 1px solid var(--border);
    color: var(--text); font-family: var(--mono); font-size: 12px;
    padding: 7px 36px 7px 10px; border-radius: 6px; outline: none;
    transition: border-color .15s; min-width: 0;
}
.demo-input-wrap input:focus { border-color: var(--blue); }
.demo-input-wrap input:disabled { opacity: .35; cursor: not-allowed; }
.demo-input-wrap input[readonly] { color: var(--dim); cursor: default; border-style: dashed; }
.toggle-vis {
    position: absolute; right: 8px; top: 50%; transform: translateY(-50%);
    background: none; border: none; color: var(--dim);
    cursor: pointer; font-size: 14px; padding: 0 2px; line-height: 1;
}
.toggle-vis:hover { color: var(--text); }

/* Buttons */
.demo-btn {
    padding: 7px 18px; border-radius: 6px; border: 1px solid;
    font-size: 13px; font-family: var(--sans); cursor: pointer;
    transition: opacity .15s, background .15s; white-space: nowrap;
}
.demo-btn:disabled { opacity: .35; cursor: not-allowed; }
.demo-btn--primary  { background: var(--blue);  border-color: var(--blue);  color: #0d1117; font-weight: 600; }
.demo-btn--server   { background: transparent;  border-color: var(--teal);  color: var(--teal); }
.demo-btn--client   { background: transparent;  border-color: var(--blue);  color: var(--blue); }
.demo-btn--danger   { background: transparent;  border-color: var(--red);   color: var(--red);  }
.demo-btn--primary:not(:disabled):hover { opacity: .85; }
.demo-btn--server:not(:disabled):hover  { background: rgba(77,182,172,.1); }
.demo-btn--client:not(:disabled):hover  { background: rgba(88,166,255,.1); }
.demo-btn--danger:not(:disabled):hover  { background: rgba(248,81,73,.1);  }

.demo-btn-row { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; align-items: center; }

/* Iframe browser chrome */
.demo-iframe-chrome {
    margin-top: 14px; border: 2px solid var(--border); border-radius: 8px; overflow: hidden;
    display: none; box-shadow: 0 0 0 1px rgba(88,166,255,.12), 0 4px 24px rgba(0,0,0,.4);
}
.demo-iframe-chrome.visible { display: block; }
.demo-iframe-chrome-bar {
    background: var(--surface2); border-bottom: 1px solid var(--border);
    padding: 7px 12px; display: flex; align-items: center; gap: 8px;
}
.demo-iframe-chrome-dots { display: flex; gap: 5px; }
.demo-iframe-chrome-dots span {
    width: 10px; height: 10px; border-radius: 50%; background: var(--border); display: block;
}
.demo-iframe-chrome-url {
    flex: 1; background: var(--surface); border: 1px solid var(--border);
    border-radius: 4px; padding: 3px 10px; font-family: var(--mono); font-size: 11px;
    color: var(--dim); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.demo-iframe-chrome iframe {
    width: 100%; height: 260px; border: none; display: block; background: #000;
}

/* Status chip */
.status-chip {
    display: inline-flex; align-items: center; gap: 7px;
    padding: 4px 12px; border-radius: 20px; font-size: 12px; font-weight: 600;
    border: 1px solid var(--border); background: var(--surface2); color: var(--dim);
    transition: color .2s, border-color .2s, background .2s;
}
.status-chip .dot { width: 7px; height: 7px; border-radius: 50%; background: currentColor; flex-shrink: 0; }
.status-chip[data-state="idle"]       { color: var(--dim); }
.status-chip[data-state="loading"]    { color: var(--yellow); border-color: var(--yellow); background: #1c1708; }
.status-chip[data-state="registered"] { color: var(--green);  border-color: var(--green);  background: #0d1f10; }
.status-chip[data-state="dialing"]    { color: var(--blue);   border-color: var(--blue);   background: #0d1f33; }
.status-chip[data-state="in-call"]    { color: var(--purple); border-color: var(--purple); background: #1a1033; }
.status-chip[data-state="error"]      { color: var(--red);    border-color: var(--red);    background: #1f0d0d; }

/* Hang up note */
.demo-client-note {
    margin-top: 10px; font-size: 12px; color: var(--dim);
    font-family: var(--mono);
}

/* Toast */
.demo-toast {
    position: fixed; bottom: 32px; right: 32px;
    background: var(--surface2); border: 1px solid var(--green);
    color: var(--text); border-radius: 8px; padding: 12px 18px;
    font-size: 13px; box-shadow: 0 4px 20px rgba(0,0,0,.5);
    display: flex; align-items: flex-start; gap: 10px;
    max-width: 360px; z-index: 100;
    opacity: 0; transform: translateY(12px);
    transition: opacity .2s, transform .2s; pointer-events: none;
}
.demo-toast.visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.demo-toast-icon { color: var(--green); font-size: 15px; flex-shrink: 0; }
.demo-toast-body { flex: 1; }
.demo-toast-title { font-weight: 600; margin-bottom: 3px; color: var(--green); }
.demo-toast-value { font-family: var(--mono); font-size: 12px; color: var(--dim); word-break: break-all; }

/* ── Responsive ── */
@media (max-width: 800px) {
    body { flex-direction: column; }
    aside {
        position: relative; width: 100%; height: auto;
        flex-direction: row; border-right: none;
        border-bottom: 1px solid var(--border);
        overflow-x: auto; overflow-y: hidden;
    }
    .sidebar-logo { padding: 12px 16px; border-bottom: none; border-right: 1px solid var(--border); }
    .sidebar-logo img { height: 22px; }
    .sidebar-nav { display: flex; flex-direction: row; padding: 0; white-space: nowrap; }
    .sidebar-nav a { padding: 14px 14px; border-left: none; border-bottom: 2px solid transparent; }
    .sidebar-nav a.active { border-left-color: transparent; border-bottom-color: var(--blue); background: none; }
    main { margin-left: 0; }
    .page { padding: 0 20px 60px; }
}