:root {
    --primary-50: #fef2f2;
    --primary-100: #fde3e2;
    --primary-200: #fbc9c7;
    --primary-500: #E8261E;
    --primary-600: #d01912;
    --primary-700: #b81c16;
    --primary-color: var(--primary-500);
    --primary-dark: var(--primary-700);
    --primary-tint: var(--primary-50);

    --secondary-color: #64748b;
    --success-color: #10b981;
    --success-tint: #ecfdf5;
    --danger-color: #dc2626;
    --danger-tint: #fef2f2;
    --warning-color: #f59e0b;
    --warning-tint: #fffbeb;
    --info-color: #0ea5e9;

    --bg-body: #f6f7fb;
    --bg-sidebar: #ffffff;
    --bg-card: #ffffff;

    --text-primary: #16202e;
    --text-secondary: #48566b;
    --text-muted: #94a1b4;

    --border-color: #e7eaf1;
    --border-color-strong: #d6dbe6;

    --shadow-xs: 0 1px 2px 0 rgb(16 24 40 / 0.05);
    --shadow-sm: 0 1px 3px 0 rgb(16 24 40 / 0.07), 0 1px 2px -1px rgb(16 24 40 / 0.06);
    --shadow-md: 0 6px 16px -4px rgb(16 24 40 / 0.09), 0 2px 6px -3px rgb(16 24 40 / 0.06);
    --shadow-lg: 0 20px 40px -12px rgb(16 24 40 / 0.16), 0 6px 12px -6px rgb(16 24 40 / 0.08);
    --shadow-brand: 0 12px 24px -10px rgb(232 38 30 / 0.45);

    --font-family: 'Roboto', system-ui, -apple-system, sans-serif;
    --sidebar-width: 264px;
    --header-height: 72px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

/* ---- Login ---- */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, var(--primary-700), var(--primary-500) 55%, var(--primary-600));
    padding: 24px;
}

.login-card {
    width: 100%;
    max-width: 380px;
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: 40px 32px;
}

.login-card img.logo {
    display: block;
    max-width: 220px;
    margin: 0 auto 8px;
}

.login-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    font-size: 0.75rem;
    margin-bottom: 28px;
}

.login-card label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.login-card input {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border-color-strong);
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-size: 1rem;
    transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.login-card input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

.login-card button {
    width: 100%;
    padding: 13px;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--primary-500);
    color: #fff;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    box-shadow: var(--shadow-brand);
    transition: background 0.2s var(--ease);
}

.login-card button:hover { background: var(--primary-600); }

.messages { list-style: none; margin-bottom: 16px; }
.messages li {
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    background: var(--danger-tint);
    color: var(--danger-color);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

/* ---- App shell ---- */
.app-shell { display: flex; min-height: 100vh; }

.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-brand {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid var(--border-color);
    padding: 0 16px;
}

.sidebar-brand img { max-width: 160px; }

.sidebar-section-label {
    font-size: 0.66rem;
    font-weight: 700;
    letter-spacing: 1.4px;
    text-transform: uppercase;
    color: var(--text-muted);
    padding: 18px 24px 6px;
}

.sidebar-nav { flex: 1; overflow-y: auto; padding: 6px 12px 20px; }

.sidebar-nav a {
    position: relative;
    display: flex;
    align-items: center;
    gap: 13px;
    padding: 12px 14px;
    border-radius: 14px;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.88rem;
    letter-spacing: 0.01em;
    margin-bottom: 4px;
    transition: background 0.15s var(--ease), color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}

.sidebar-nav a .nav-icon {
    width: 20px;
    flex-shrink: 0;
    text-align: center;
    font-size: 1rem;
    transition: color 0.15s var(--ease);
}

/* Colores propios por módulo (se mantienen en reposo y hover; se vuelven blancos cuando el ítem está activo) */
.icon-critico   { color: #ef4444; }
.icon-listado   { color: #7c3aed; }
.icon-sugeridos { color: #16a34a; }
.icon-recepcion { color: #2563eb; }
.icon-acero     { color: #e11d48; }
.icon-costo     { color: #a21caf; }
.icon-tabla     { color: #f97316; }

.sidebar-nav a:hover { background: var(--bg-body); }

.sidebar-nav a.active {
    background: linear-gradient(135deg, #7c3aed 0%, #4f46e5 100%);
    color: #fff;
    box-shadow: 0 8px 20px -8px rgb(79 70 229 / 0.55);
}
.sidebar-nav a.active .nav-icon { color: #fff; }

.sidebar-footer { padding: 16px; border-top: 1px solid var(--border-color); }
.sidebar-footer .user-name { font-weight: 600; font-size: 0.9rem; }
.sidebar-footer .user-sucursal { color: var(--text-muted); font-size: 0.78rem; margin-bottom: 10px; }
.sidebar-footer a.logout { color: var(--danger-color); font-weight: 600; font-size: 0.85rem; }

.main-content { flex: 1; min-width: 0; }

.topbar {
    height: var(--header-height);
    display: flex;
    align-items: center;
    padding: 0 28px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
}

.topbar h1 { font-size: 1.15rem; font-weight: 700; }

.content { padding: 28px; }

.card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    padding: 24px;
}