* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Inter', sans-serif;
    background: #f0f2f5;
    color: #1e293b;
    line-height: 1.6;
}

/* Login */
#login-container {
    max-width: 400px;
    margin: 100px auto;
    background: #fff;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}
#login-container h2 {
    text-align: center;
    margin-bottom: 30px;
    font-weight: 600;
    color: #0f172a;
}
.input-group { margin-bottom: 20px; }
.input-group label { display: block; margin-bottom: 8px; color: #334155; }
.input-group input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 1rem;
}
.input-group input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59,130,246,0.1);
}
button { 
    width: 100%; 
    padding: 12px; 
    background: #3b82f6; 
    color: white; 
    border: none; 
    border-radius: 8px; 
    cursor: pointer; 
}
button:hover { background: #2563eb; }
#login-error { color: #dc2626; margin-top: 15px; text-align: center; }

/* Dashboard */
#dashboard { display: none; min-height: 100vh; }
.sidebar {
    position: fixed;
    top:0; left:0;
    width:260px; height:100vh;
    background:#fff;
    padding:30px 20px;
    box-shadow: 2px 0 10px rgba(0,0,0,0.03);
}
.sidebar h3 { font-size:1.5rem; margin-bottom:40px; display:flex; align-items:center; gap:10px; }
.sidebar a { display:flex; align-items:center; gap:10px; padding:12px 16px; color:#334155; text-decoration:none; border-radius:8px; }
.sidebar a:hover, .sidebar a.active { background:#f1f5f9; color:#0f172a; }
.main-content { margin-left:260px; padding:30px 40px; }
.header { display:flex; justify-content:space-between; align-items:center; margin-bottom:30px; }
.logout-btn { background:#ef4444; padding:10px 20px; border:none; border-radius:8px; color:white; cursor:pointer; }
.logout-btn:hover { background:#dc2626; }

/* Cards */
.card {
    background:white;
    border-radius:16px;
    padding:24px;
    box-shadow:0 4px 6px -1px rgba(0,0,0,0.1);
    margin-bottom:30px;
}
.card h2 { font-size:1.25rem; font-weight:600; margin-bottom:20px; }

/* Table */
table { width:100%; border-collapse: collapse; }
th, td { padding:12px 8px; border-bottom:1px solid #e2e8f0; text-align:left; }
th { background:#f8fafc; color:#475569; font-weight:600; }

/* Messages */
.message-input { display:flex; gap:10px; margin-bottom:30px; }
.message-input textarea { flex:1; padding:12px; border:1px solid #cbd5e1; border-radius:8px; resize:vertical; min-height:80px; }
.message-input button { padding:12px 24px; }
.message-list { list-style:none; }
.message-item { background:#f8fafc; border-radius:8px; padding:16px; margin-bottom:12px; display:flex; justify-content:space-between; align-items:flex-start; }
.message-content { flex:1; }
.message-time { font-size:0.75rem; color:#64748b; margin-top:4px; }
.delete-btn { background:none; border:none; color:#ef4444; cursor:pointer; font-size:1.2rem; }
.delete-btn:hover { color:#dc2626; }