/* --- Corporate Teal & Slate Color Palette --- */
:root {
    --bg-white: #FFFFFF;
    --bg-light-slate: #F8FAFC;
    --card-bg: #FFFFFF;
    
    --header-dark: #0F172A;       /* Deep Slate Navy */
    --accent-teal: #0D9488;       /* Emerald Teal Accent */
    --teal-hover: #0F766E;
    
    --text-dark: #1E293B;
    --text-light: #F8FAFC;
    --text-muted: #64748B;
    --border-color: #E2E8F0;
    --shadow-sm: 0 4px 12px rgba(15, 23, 42, 0.05);
    --shadow-hover: 0 10px 25px rgba(13, 148, 136, 0.15);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-white);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

/* --- Helper Utility Classes --- */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.color-teal { color: var(--accent-teal); }
.max-w-900 { max-width: 900px; margin: 0 auto; }
.max-w-600 { max-width: 600px; margin: 0 auto; }
.mb-20 { margin-bottom: 20px; }
.mt-8 { margin-top: 8px; }
.fs-09 { font-size: 0.9rem; }
.inline-block { display: inline-block; }

/* --- Full-Width Navigation Bar --- */
header {
    position: sticky;
    top: 0;
    width: 100%;
    background-color: var(--header-dark);
    border-bottom: 2px solid var(--accent-teal);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    z-index: 1000;
}

.nav-container {
    width: 100%;
    padding: 15px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-container img {
    height: 48px;
    width: auto;
    border-radius: 4px;
}

.logo-text {
    font-weight: 700;
    font-size: 1.35rem;
    color: #FFFFFF;
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 30px;
}

.nav-link {
    font-size: 0.95rem;
    color: #E2E8F0;
    font-weight: 500;
}

.nav-link:hover {
    color: var(--accent-teal);
}

.btn-join {
    background-color: var(--accent-teal);
    color: #FFFFFF;
    padding: 9px 24px;
    border-radius: 25px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(13, 148, 136, 0.3);
}

.btn-join:hover {
    background-color: var(--teal-hover);
    transform: translateY(-2px);
    color: #FFFFFF;
}

/* Mobile Toggle Controls */
.nav-toggle-checkbox { display: none; }
.nav-toggle-label {
    display: none;
    font-size: 1.6rem;
    color: var(--accent-teal);
    cursor: pointer;
    padding: 5px;
}
.nav-toggle-label .close-icon { display: none; }

/* --- 100% FULL-WIDTH HERO SLIDER BANNER --- */
.hero-banner-full {
    width: 100vw;
    position: relative;
    left: 50%;
    right: 50%;
    margin-left: -50vw;
    margin-right: -50vw;
    padding: 120px 20px;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.92) 0%, rgba(30, 41, 59, 0.95) 100%), 
                url('./image/RSB Group Logo.jpeg') center/cover no-repeat;
    color: #FFFFFF;
    text-align: center;
    box-shadow: inset 0 -10px 20px rgba(0, 0, 0, 0.1);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-banner-full h1 {
    font-size: 3.2rem;
    color: #FFFFFF;
    margin-bottom: 18px;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 700;
}

.hero-banner-full p {
    font-size: 1.2rem;
    color: #CBD5E1;
    max-width: 750px;
    margin: 0 auto 35px;
    line-height: 1.8;
}

.btn-primary {
    display: inline-block;
    background-color: var(--accent-teal);
    color: #FFFFFF;
    padding: 13px 36px;
    border-radius: 25px;
    font-weight: 600;
    transition: 0.3s ease;
    box-shadow: 0 4px 15px rgba(13, 148, 136, 0.3);
}

.btn-primary:hover {
    background-color: var(--teal-hover);
    transform: translateY(-2px);
}

/* --- Section Container Limits --- */
.content-section {
    padding: 80px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    color: var(--header-dark);
    margin-bottom: 45px;
    position: relative;
    font-weight: 700;
}

.section-title::after {
    content: '';
    width: 60px;
    height: 3px;
    background-color: var(--accent-teal);
    display: block;
    margin: 10px auto 0;
    border-radius: 2px;
}

/* Alternate Section Backgrounds */
#mission-vision, #concerns, #join {
    background-color: var(--bg-light-slate);
    max-width: 100%;
}

#mission-vision > div, #concerns > div, #join > div {
    max-width: 1200px;
    margin: 0 auto;
}

/* --- Cards Layouts --- */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.info-card {
    background-color: var(--card-bg);
    padding: 35px 30px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent-teal);
}

.info-card i {
    font-size: 2.5rem;
    color: var(--accent-teal);
    margin-bottom: 20px;
}

.info-card h3 {
    font-size: 1.35rem;
    margin-bottom: 15px;
    color: var(--header-dark);
}

/* --- Board of Directors --- */
.directors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.director-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    text-align: center;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: 0.3s ease;
}

.director-card:hover {
    border-color: var(--accent-teal);
    box-shadow: var(--shadow-hover);
    transform: translateY(-5px);
}

.director-img-wrapper {
    height: 350px;
    width: 100%;
    overflow: hidden;
    background-color: var(--bg-light-slate);
}

.director-img-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
    transition: transform 0.5s ease;
}

.director-card:hover img {
    transform: scale(1.05);
}

.director-info {
    padding: 20px;
}

.director-info h3 {
    color: var(--header-dark);
    font-size: 1.2rem;
    margin-bottom: 5px;
}

.director-info p {
    color: var(--accent-teal);
    font-size: 0.95rem;
    font-weight: 600;
}

/* --- Sister Concerns --- */
.concerns-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
}

.concern-item {
    background-color: var(--card-bg);
    padding: 20px 25px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 15px;
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--header-dark);
    box-shadow: var(--shadow-sm);
    transition: 0.3s ease;
    font-weight: 500;
}

.concern-item:hover {
    border-left-color: var(--accent-teal);
    transform: translateX(5px);
    box-shadow: var(--shadow-hover);
}

.concern-item i {
    color: var(--accent-teal);
    font-size: 1.2rem;
}

/* --- Contact Us Section --- */
.contact-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.contact-info-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-info-list h3 {
    color: var(--header-dark);
    font-size: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
}

.contact-item i {
    font-size: 1.4rem;
    color: var(--accent-teal);
    margin-top: 5px;
}

.contact-form {
    background-color: var(--card-bg);
    padding: 35px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input, 
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    background-color: var(--bg-light-slate);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-dark);
    outline: none;
    transition: 0.3s ease;
}

.form-group input:focus, 
.form-group textarea:focus {
    border-color: var(--accent-teal);
    background-color: #FFFFFF;
}

.btn-submit {
    background-color: var(--header-dark);
    color: #FFFFFF;
    border: none;
    padding: 12px 30px;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    width: 100%;
    transition: 0.3s ease;
}

.btn-submit:hover {
    background-color: var(--accent-teal);
}

/* --- Footer --- */
footer {
    background-color: var(--header-dark);
    color: #FFFFFF;
    padding: 60px 20px 20px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    padding-bottom: 40px;
}

.footer-brand {
    color: #FFFFFF;
    font-size: 1.3rem;
}

.footer-desc {
    color: #94A3B8;
    font-size: 0.85rem;
    margin-top: 10px;
}

.footer-col h4 {
    color: var(--accent-teal);
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 10px; }

.footer-col ul li a {
    color: #94A3B8;
    font-size: 0.9rem;
}

.footer-col ul li a:hover { color: #FFFFFF; }
.text-footer-muted { color: #94A3B8; }

.social-links {
    display: flex;
    gap: 12px;
    margin-top: 15px;
}

.social-icon {
    width: 38px;
    height: 38px;
    background-color: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #FFFFFF;
    transition: 0.3s ease;
}

.social-icon:hover {
    background-color: var(--accent-teal);
    color: #FFFFFF;
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 20px;
    color: #94A3B8;
    font-size: 0.85rem;
}

/* Dynamic Page Section Logic */
.page-content { display: block; }
.page-section { display: none; }
.page-section:target { display: block; }

/* ==========================================================================
   MOBILE & TABLET RESPONSIVE MEDIA QUERIES
   ========================================================================== */

@media (max-width: 900px) {
    
    .nav-container {
        padding: 15px 20px;
    }

    .nav-toggle-label {
        display: block;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--header-dark);
        border-bottom: 2px solid var(--accent-teal);
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        gap: 20px;
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    }

    .nav-toggle-checkbox:checked ~ .nav-menu {
        max-height: 500px;
        opacity: 1;
        padding: 25px 0;
    }

    .nav-toggle-checkbox:checked ~ .nav-toggle-label .open-icon { display: none; }
    .nav-toggle-checkbox:checked ~ .nav-toggle-label .close-icon { display: block; }

    .hero-banner-full {
        padding: 70px 15px;
    }

    .hero-banner-full h1 {
        font-size: 2rem;
    }

    .hero-banner-full p {
        font-size: 1rem;
    }

    .content-section {
        padding: 50px 15px;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .director-img-wrapper {
        height: 300px;
    }

    .concerns-grid, .contact-container, .footer-container {
        grid-template-columns: 1fr;
    }
}