/* ========================================
   BSN 2026 Conference Landing Page Styles
   Colors: Royal Blue, Red, White
   ======================================== */

:root {
    --primary-blue: #1e3a8a;  /* Royal Blue */
    --accent-red: #dc2626;    /* Red */
    --neutral-white: #ffffff;
    --light-gray: #f9fafb;
    --dark-gray: #1f2937;
    --border-gray: #e5e7eb;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-gray);
    background-color: var(--neutral-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========================================
   Navigation Bar
   ======================================== */

.navbar {
    background: linear-gradient(135deg, var(--primary-blue) 0%, #0f3a66 100%);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--neutral-white);
    font-size: 1.5rem;
    font-weight: 700;
}

.logo {
    height: 40px;
    width: auto;
}

.brand-text {
    font-weight: 700;
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--neutral-white);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent-red);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-red);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.btn-register {
    background: var(--accent-red);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    color: var(--neutral-white);
}

.btn-register:hover {
    color: var(--neutral-white);
    background: #b91c1c;
    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.3);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--neutral-white);
    margin: 5px 0;
    border-radius: 3px;
    transition: var(--transition);
}

/* ========================================
   Hero Section
   ======================================== */

.hero {
    background: linear-gradient(135deg, var(--primary-blue) 0%, #0f3a66 50%, var(--accent-red) 100%);
    color: var(--neutral-white);
    padding: 120px 20px;
    text-align: center;
    position: relative;
    overflow: hidden;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.03" d="M0,96L48,112C96,128,192,160,288,165.3C384,171,480,149,576,144C672,139,768,149,864,154.7C960,160,1056,160,1152,149.3C1248,139,1344,117,1392,106.7L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid var(--accent-red);
    color: var(--neutral-white);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    margin-bottom: 2rem;
    backdrop-filter: blur(10px);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    font-weight: 300;
    letter-spacing: 0.5px;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.9rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent-red);
    color: var(--neutral-white);
    box-shadow: 0 4px 15px rgba(220, 38, 38, 0.3);
}

.btn-primary:hover {
    background: #b91c1c;
    box-shadow: 0 6px 20px rgba(220, 38, 38, 0.4);
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: var(--neutral-white);
    border: 2px solid var(--neutral-white);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: var(--neutral-white);
    color: var(--primary-blue);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1.2rem 2.5rem;
    font-size: 1.1rem;
}

/* ========================================
   About Section
   ======================================== */

.about {
    padding: 80px 20px;
    background: var(--light-gray);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-weight: 700;
}

.header-line {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-blue), var(--accent-red));
    margin: 0 auto;
    border-radius: 2px;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.about-card {
    background: var(--neutral-white);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(30, 58, 138, 0.1);
}

.card-icon {
    font-size: 3rem;
    color: var(--accent-red);
    margin-bottom: 1rem;
}

.about-card h3 {
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.about-card p {
    font-size: 0.95rem;
    color: #6b7280;
    line-height: 1.8;
}

.about-text {
    background: var(--neutral-white);
    padding: 2.5rem;
    border-radius: 10px;
    border-left: 4px solid var(--accent-red);
}

.about-text h3 {
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.about-text p {
    color: #4b5563;
    margin-bottom: 1rem;
    line-height: 1.8;
}

/* ========================================
   Themes Section
   ======================================== */

.themes {
    padding: 80px 20px;
    background: var(--neutral-white);
}

.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.theme-card {
    background: linear-gradient(135deg, var(--light-gray) 0%, var(--neutral-white) 100%);
    padding: 2rem;
    border-radius: 10px;
    border-top: 4px solid var(--accent-red);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.theme-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: var(--primary-blue);
    opacity: 0.05;
    border-radius: 50%;
    transform: translate(30%, -30%);
}

.theme-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(30, 58, 138, 0.15);
}

.theme-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    opacity: 0.7;
    margin-bottom: 0.5rem;
}

.theme-card h4 {
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.theme-card p {
    color: #6b7280;
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ========================================
   Leadership Section
   ======================================== */

.leadership {
    padding: 80px 20px;
    background: linear-gradient(135deg, var(--primary-blue) 0%, #0f3a66 100%);
    color: var(--neutral-white);
}

.leadership .section-header h2 {
    color: var(--neutral-white);
}

.leadership .header-line {
    background: linear-gradient(90deg, var(--accent-red), var(--neutral-white));
}

.leadership-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.leadership-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: 10px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition);
}

.leadership-card:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-5px);
}

.leadership-icon {
    font-size: 2.5rem;
    color: var(--accent-red);
    margin-bottom: 1rem;
}

.leadership-card h3 {
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.leadership-card p {
    font-size: 1rem;
    font-weight: 500;
}

/* ========================================
   Committees Section
   ======================================== */

.committees {
    padding: 80px 20px;
    background: var(--light-gray);
}

.committees-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.committee-card {
    background: var(--neutral-white);
    padding: 2rem;
    border-radius: 10px;
    border-left: 4px solid var(--primary-blue);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.committee-card:hover {
    box-shadow: 0 6px 16px rgba(30, 58, 138, 0.1);
    transform: translateY(-3px);
}

.committee-card h4 {
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.committee-card .chairman {
    color: var(--accent-red);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.committee-card .description {
    color: #6b7280;
    font-size: 0.9rem;
    line-height: 1.6;
    margin-top: 1rem;
}

/* ========================================
   Call to Action Section
   ======================================== */

.cta {
    background: linear-gradient(135deg, var(--accent-red) 0%, #991b1b 100%);
    color: var(--neutral-white);
    padding: 80px 20px;
    text-align: center;
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.cta-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    font-weight: 300;
}

.btn-large {
    background: var(--neutral-white);
    color: var(--accent-red);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-large:hover {
    background: var(--light-gray);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background: var(--primary-blue);
    color: var(--neutral-white);
    padding: 4rem 20px 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--accent-red);
    margin-bottom: 1rem;
    font-weight: 600;
}

.footer-section p {
    font-size: 0.9rem;
    line-height: 1.8;
    opacity: 0.9;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--neutral-white);
    text-decoration: none;
    transition: var(--transition);
    opacity: 0.9;
}

.footer-section a:hover {
    color: var(--accent-red);
    opacity: 1;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--accent-red);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.85rem;
    opacity: 0.8;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        display: none;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .theme-number {
        font-size: 2rem;
    }

    .about-grid,
    .themes-grid,
    .committees-grid,
    .leadership-grid {
        grid-template-columns: 1fr;
    }

    .cta-content h2 {
        font-size: 1.8rem;
    }

    .cta-content p {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .nav-brand {
        font-size: 1rem;
    }

    .hero {
        padding: 60px 15px;
        min-height: 400px;
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .section-header h2 {
        font-size: 1.5rem;
    }

    .about,
    .themes,
    .leadership,
    .committees,
    .cta {
        padding: 50px 15px;
    }
}