:root {
    --bg-dark: #0f172a;
    --bg-panel: rgba(30, 41, 59, 0.75);
    --bg-input: rgba(15, 23, 42, 0.95);
    --bg-secondary: rgba(20, 30, 50, 0.9);
    --text-primary: #f8fafc;
    --text-muted: #cbd5e1;
    --text-secondary: #94a3b8;
    --accent: #6366f1;
    --accent-glow: rgba(99, 102, 241, 0.4);
    --border-dim: rgba(255, 255, 255, 0.1);
    --sidebar-w: 240px;
    --topbar-h: 48px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    height: 100dvh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ── Auth Gate ─────────────────────────────────────────── */
#auth-gate { display: none; position: fixed; inset: 0; background: var(--bg-dark); z-index: 200; justify-content: center; align-items: center; }
#auth-gate.active { display: flex; }

.auth-box {
    background: var(--bg-panel);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 44px 36px;
    border-radius: 16px;
    border: 1px solid var(--border-dim);
    width: 100%;
    max-width: 400px;
    text-align: center;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.6);
    animation: fadeIn 0.4s ease;
    margin: 16px;
}

.logo { color: var(--accent); margin-bottom: 18px; filter: drop-shadow(0 0 10px var(--accent-glow)); }

.auth-input {
    width: 100%; padding: 13px; background: var(--bg-input);
    border: 1px solid var(--border-dim); border-radius: 8px;
    color: white; font-family: 'Inter', sans-serif; font-size: 1rem;
    margin-bottom: 14px; text-align: center; transition: all 0.2s;
}
.auth-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-glow); }

.auth-btn {
    width: 100%; padding: 13px; background: transparent;
    border: 1px solid var(--accent); color: var(--accent);
    font-weight: 600; letter-spacing: 1px; border-radius: 8px;
    cursor: pointer; transition: all 0.2s;
}
.auth-btn:hover { background: var(--accent); color: var(--bg-dark); box-shadow: 0 0 15px var(--accent-glow); }

.toggle-auth { margin-top: 14px; font-size: 0.85rem; color: var(--text-muted); }
.toggle-auth span { color: var(--accent); cursor: pointer; }
.toggle-auth span:hover { text-decoration: underline; }
#auth-error { color: #ff4757; margin-top: 12px; font-size: 0.85rem; min-height: 18px; }

/* ── Chat App Shell ────────────────────────────────────── */
#chat-app {
    display: none;
    width: 100%;
    height: 100dvh;
    background: var(--bg-dark);
    position: relative;
    overflow: hidden;
}
#chat-app.active { display: flex; flex-direction: row; }

/* ── Mobile Top Bar (hidden on desktop) ────────────────── */
.mobile-topbar {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--topbar-h);
    background: rgba(15,17,21,0.97);
    border-bottom: 1px solid var(--border-dim);
    align-items: center;
    justify-content: space-between;
    padding: 0 14px;
    z-index: 150;
}

#hamburger-btn {
    background: none; border: none; cursor: pointer;
    display: flex; flex-direction: column; gap: 5px; padding: 4px;
}
#hamburger-btn span {
    display: block; width: 22px; height: 2px;
    background: var(--text-primary); border-radius: 2px; transition: all 0.2s;
}
.mobile-title { font-weight: 600; font-size: 1rem; letter-spacing: 1px; }

/* ── Sidebar Overlay (mobile) ──────────────────────────── */
.sidebar-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,0,0,0.55);
    z-index: 120;
}
.sidebar-overlay.open { display: block; }

/* ── Sidebar ───────────────────────────────────────────── */
.sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    background: rgba(12, 15, 21, 0.97);
    border-right: 1px solid var(--border-dim);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    height: 100dvh;
}

.sidebar-header {
    padding: 16px 16px 14px;
    border-bottom: 1px solid var(--border-dim);
}
.sidebar-header h3 { font-size: 0.92rem; letter-spacing: 1px; }

.agent-list { list-style: none; padding: 10px 10px; overflow-y: auto; flex: 1; display: flex; flex-direction: column; gap: 4px; }

.agent-item {
    padding: 10px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border-dim);
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 9px;
    cursor: pointer;
    transition: all 0.18s;
    user-select: none;
    position: relative;
}
.agent-item:hover { border-color: var(--accent); background: rgba(99,102,241,0.12); }
.agent-item:active { transform: scale(0.98); }
.agent-item h4 { font-size: 0.83rem; color: var(--text-primary); margin-bottom: 1px; }
.agent-item p { font-size: 0.68rem; color: var(--text-muted); }
.agent-icon { font-size: 1.1rem; flex-shrink: 0; }
.agent-arrow {
    margin-left: auto;
    font-size: 1rem;
    color: var(--text-muted);
    transition: color 0.18s, transform 0.18s;
}
.agent-item:hover .agent-arrow { color: var(--accent); transform: translateX(2px); }

/* ── Chat Main ─────────────────────────────────────────── */
.chat-main { flex: 1; display: flex; flex-direction: column; min-width: 0; height: 100dvh; }

header {
    padding: 12px 18px;
    border-bottom: 1px solid var(--border-dim);
    background: rgba(15,17,21,0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}
.header-content { display: flex; align-items: center; gap: 10px; }
header h2 { font-weight: 600; font-size: 1rem; letter-spacing: 1px; }

.status-indicator {
    width: 9px; height: 9px; border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    animation: pulse 2s infinite;
    flex-shrink: 0;
}

#chat-window {
    flex: 1;
    overflow-y: auto;
    padding: 16px 18px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    /* safe area for iOS notch at bottom */
    padding-bottom: max(16px, env(safe-area-inset-bottom));
}

.message { display: flex; gap: 12px; max-width: 88%; animation: slideUp 0.25s ease; }
.message.user-msg { justify-content: flex-end; align-self: flex-end; max-width: 80%; }
.message.bot-msg { align-self: flex-start; max-width: 92%; }
.system-msg { align-self: center; max-width: 100%; }

.msg-content {
    padding: 10px 16px;
    border-radius: 12px;
    line-height: 1.55;
    font-size: 0.93rem;
}
.system-msg .msg-content {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
    color: var(--text-muted);
    text-align: center;
}
.user-msg .msg-content { background: var(--bg-input); border: 1px solid var(--border-dim); color: white; }
.bot-msg .msg-content { background: transparent; color: var(--text-primary); }

/* Markdown inside bot msgs */
.bot-msg .msg-content p { margin-bottom: 8px; }
.bot-msg .msg-content code { background: var(--bg-input); padding: 2px 5px; border-radius: 4px; font-family: 'JetBrains Mono', monospace; font-size: 0.84em; color: var(--accent); }
.bot-msg .msg-content pre { background: var(--bg-input); padding: 13px; border-radius: 8px; overflow-x: auto; margin-bottom: 8px; border: 1px solid var(--border-dim); }
.bot-msg .msg-content pre code { background: transparent; padding: 0; color: #e0e0e0; }

/* Input area */
.input-area {
    padding: 12px 16px;
    padding-bottom: max(12px, env(safe-area-inset-bottom));
    background: var(--bg-panel);
    border-top: 1px solid var(--border-dim);
    display: flex;
    gap: 10px;
    align-items: flex-end;
    flex-shrink: 0;
}

#prompt-input {
    flex: 1;
    background: var(--bg-input);
    border: 1px solid var(--border-dim);
    color: white;
    padding: 12px 14px;
    border-radius: 10px;
    font-family: 'Inter', sans-serif;
    font-size: 0.97rem;
    resize: none;
    max-height: 140px;
    transition: border-color 0.2s;
}
#prompt-input:focus { outline: none; border-color: var(--accent); }

#send-btn {
    background: var(--accent); color: var(--bg-dark);
    border: none; width: 46px; height: 46px;
    border-radius: 10px; display: flex; justify-content: center;
    align-items: center; cursor: pointer; transition: all 0.2s; flex-shrink: 0;
}
#send-btn:hover { transform: scale(1.06); box-shadow: 0 0 14px var(--accent-glow); }
#send-btn:disabled { background: var(--bg-input); color: var(--text-muted); cursor: not-allowed; transform: none; box-shadow: none; }

/* Footer */
.legal-footer {
    text-align: center; padding: 10px;
    font-size: 0.72rem; color: var(--text-muted);
    border-top: 1px solid var(--border-dim);
    background: rgba(15,17,21,0.95);
    flex-shrink: 0;
}
.legal-footer a { color: var(--accent); text-decoration: none; }
.legal-footer a:hover { text-decoration: underline; }

/* ── Animations ────────────────────────────────────────── */
@keyframes fadeIn { from { opacity:0; transform:translateY(-8px); } to { opacity:1; transform:translateY(0); } }
@keyframes slideUp { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
@keyframes pulse {
    0%   { opacity:1; box-shadow:0 0 5px var(--accent); }
    50%  { opacity:0.5; box-shadow:0 0 2px transparent; }
    100% { opacity:1; box-shadow:0 0 5px var(--accent); }
}

/* ── Mobile (<= 700px) ─────────────────────────────────── */
@media (max-width: 700px) {
    .mobile-topbar { display: flex; }

    #chat-app.active { flex-direction: column; }

    .sidebar {
        position: fixed;
        top: 0; left: 0;
        height: 100dvh;
        width: min(280px, 82vw);
        z-index: 130;
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        border-radius: 0 12px 12px 0;
    }
    .sidebar.open { transform: translateX(0); }

    header { display: none; } /* replaced by mobile-topbar */

    .chat-main {
        margin-top: var(--topbar-h);
        height: calc(100dvh - var(--topbar-h));
    }

    #chat-window { padding: 12px 12px; gap: 12px; }

    .message { max-width: 96%; }
    .message.user-msg { max-width: 86%; }
    .msg-content { padding: 9px 13px; font-size: 0.9rem; }

    .input-area { padding: 10px 12px; padding-bottom: max(10px, env(safe-area-inset-bottom)); gap: 8px; }
    #prompt-input { padding: 11px 12px; font-size: 0.93rem; }
    #send-btn { width: 44px; height: 44px; }

    .auth-box { padding: 32px 20px; margin: 12px; }
}