:root{
    --primary:#c8102e;
    --primary-dark:#9f0d25;
    --text:#1f2937;
    --muted:#6b7280;
    --bg:#f7f7f8;
    --card:#ffffff;
    --border:#e5e7eb;
    --success:#0f8a4b;
    --warning:#a16207;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
    margin:0;
    font-family:Arial,"Noto Sans Thai",Tahoma,sans-serif;
    color:var(--text);
    background:var(--bg);
    line-height:1.6;
}
.container{width:min(1120px,calc(100% - 32px));margin:0 auto}
.site-header{
    background:#fff;
    border-bottom:1px solid var(--border);
    position:sticky;
    top:0;
    z-index:100;
}
.nav-wrap{min-height:72px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{font-size:1.35rem;font-weight:800;color:var(--primary);text-decoration:none}
.main-nav{display:flex;align-items:center;gap:20px}
.main-nav a{color:var(--text);text-decoration:none;font-weight:600}
.main-nav a:hover{color:var(--primary)}
.btn-nav,.btn{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    border:0;
    border-radius:10px;
    padding:11px 18px;
    text-decoration:none;
    font-weight:700;
    cursor:pointer;
}
.btn-nav,.btn-primary{background:var(--primary);color:#fff!important}
.btn-primary:hover{background:var(--primary-dark)}
.btn-secondary{background:#fff;border:1px solid var(--border);color:var(--text)}
.nav-toggle{display:none;background:none;border:0;font-size:1.65rem;cursor:pointer}
.hero{
    padding:72px 0;
    background:linear-gradient(135deg,#fff 0%,#fff4f6 100%);
}
.hero-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:40px;align-items:center}
.hero h1{font-size:clamp(2rem,5vw,4rem);line-height:1.08;margin:0 0 18px}
.hero p{font-size:1.1rem;color:var(--muted)}
.hero-card,.card{
    background:var(--card);
    border:1px solid var(--border);
    border-radius:18px;
    padding:24px;
    box-shadow:0 12px 30px rgba(0,0,0,.04);
}
.section{padding:56px 0}
.section-title{margin:0 0 24px;font-size:1.8rem}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.card h3{margin-top:0}
.muted{color:var(--muted)}
.form-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.form-group{display:flex;flex-direction:column;gap:7px}
.form-group.full{grid-column:1/-1}
label{font-weight:700}
input,select,textarea{
    width:100%;
    padding:12px 14px;
    border:1px solid var(--border);
    border-radius:10px;
    background:#fff;
    font:inherit;
}
textarea{min-height:130px;resize:vertical}
.gender-options{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.gender-card{
    border:2px solid var(--border);
    border-radius:14px;
    padding:18px;
    text-align:center;
    cursor:pointer;
    font-weight:800;
    background:#fff;
    transition:.2s ease;
}
.gender-card input{display:none}
.gender-card:has(input:checked){
    border-color:var(--primary);
    background:#fff4f6;
    color:var(--primary);
}
.alert{
    padding:14px 16px;
    border-radius:10px;
    margin-bottom:18px;
    border:1px solid var(--border);
    background:#fff;
}
.alert.success{border-color:#b7e4c7;color:var(--success);background:#f1fff6}
.alert.warning{border-color:#f4d19b;color:var(--warning);background:#fffaf0}
.table-wrap{overflow:auto}
table{width:100%;border-collapse:collapse;background:#fff}
th,td{padding:12px 14px;border-bottom:1px solid var(--border);text-align:left;white-space:nowrap}
.site-footer{background:#111827;color:#fff;padding:36px 0;margin-top:56px}
.footer-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.admin-shell{display:grid;grid-template-columns:240px 1fr;min-height:100vh}
.admin-sidebar{background:#111827;color:#fff;padding:24px}
.admin-sidebar a{display:block;color:#fff;text-decoration:none;padding:10px 0}
.admin-main{padding:28px}
.stat{font-size:2rem;font-weight:800;margin:0}
.login-wrap{min-height:100vh;display:grid;place-items:center;padding:24px}
.login-card{width:min(440px,100%);background:#fff;border:1px solid var(--border);border-radius:18px;padding:28px}
@media (max-width:820px){
    .nav-toggle{display:block}
    .main-nav{
        display:none;
        position:absolute;
        top:72px;
        left:0;
        right:0;
        background:#fff;
        border-bottom:1px solid var(--border);
        padding:18px 20px;
        flex-direction:column;
        align-items:stretch;
    }
    .main-nav.open{display:flex}
    .hero{padding:48px 0}
    .hero-grid,.grid-3,.grid-2,.form-grid,.footer-grid{grid-template-columns:1fr}
    .form-group.full{grid-column:auto}
    .admin-shell{grid-template-columns:1fr}
    .admin-sidebar{position:static}
}
@media (max-width:520px){
    .container{width:min(100% - 22px,1120px)}
    .gender-options{grid-template-columns:1fr 1fr}
    .hero-card,.card{padding:18px}
    .btn{width:100%}
}


/* =========================================================
   ADMIN FIXED SIDEBAR v11
   เมนู Admin คงที่ทุกหน้า ไม่หด ไม่หาย
   ========================================================= */
.admin-shell{
    display:block !important;
    min-height:100vh;
}

.admin-sidebar{
    position:fixed !important;
    left:0 !important;
    top:0 !important;
    bottom:0 !important;
    width:250px !important;
    min-width:250px !important;
    max-width:250px !important;
    height:100vh !important;
    overflow-y:auto !important;
    overflow-x:hidden !important;
    z-index:5000 !important;
    background:#111827 !important;
    color:#fff !important;
    padding:20px 16px !important;
    box-shadow:4px 0 18px rgba(0,0,0,.08);
}

.admin-main{
    margin-left:250px !important;
    width:calc(100% - 250px) !important;
    min-height:100vh;
    padding:28px !important;
}

.admin-sidebar-brand{
    display:flex;
    align-items:center;
    gap:11px;
    padding:4px 6px 18px;
    margin-bottom:8px;
    border-bottom:1px solid rgba(255,255,255,.12);
}

.admin-sidebar-logo{
    width:44px;
    height:44px;
    flex:0 0 44px;
    border-radius:50%;
    background:#c8102e;
    color:#fff;
    display:grid;
    place-items:center;
    font-size:.82rem;
    font-weight:900;
    letter-spacing:.04em;
}

.admin-sidebar-brand h2{
    margin:0;
    font-size:1.08rem;
    line-height:1.2;
    color:#fff;
}

.admin-sidebar-brand small{
    display:block;
    margin-top:3px;
    color:#aeb6c5;
    max-width:150px;
    overflow:hidden;
    text-overflow:ellipsis;
    white-space:nowrap;
}

.admin-sidebar-nav{
    display:flex;
    flex-direction:column;
    gap:3px;
}

.admin-sidebar .admin-sidebar-nav a{
    display:flex !important;
    align-items:center;
    min-height:43px;
    padding:10px 12px !important;
    border-radius:9px;
    color:#e9edf4 !important;
    text-decoration:none;
    font-weight:600;
    white-space:nowrap;
    transition:background .15s ease,color .15s ease;
}

.admin-sidebar .admin-sidebar-nav a:hover{
    background:rgba(255,255,255,.09);
    color:#fff !important;
}

.admin-sidebar .admin-sidebar-nav a.active{
    background:#c8102e;
    color:#fff !important;
}

.admin-sidebar .admin-sidebar-nav a.logout-link{
    color:#ffb7c2 !important;
}

.admin-sidebar-separator{
    height:1px;
    margin:8px 4px;
    background:rgba(255,255,255,.11);
}

/* บังคับให้ sidebar ไม่ยุบหรือหายแม้หน้าจอเล็ก */
@media (max-width:820px){
    .admin-shell{
        display:block !important;
        min-width:850px;
    }

    .admin-sidebar{
        position:fixed !important;
        width:250px !important;
        min-width:250px !important;
        max-width:250px !important;
        height:100vh !important;
    }

    .admin-main{
        margin-left:250px !important;
        width:calc(100% - 250px) !important;
        min-width:600px;
        padding:22px !important;
    }
}