/* ===== CSS Variables ===== */
:root {
    --primary-color: #2c5f8d;
    --secondary-color: #4a90c8;
    --accent-color: #e8b44f;
    --text-dark: #1a1a1a;
    --text-light: #666666;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --success-color: #28a745;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.16);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Playfair Display', serif;
    font-weight: 600;
    line-height: 1.3;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

img {
    max-width: 100%;
    height: auto;
}

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

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
    color: var(--accent-color);
}

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

.nav-link {
    color: var(--text-dark);
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
}

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

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: var(--transition);
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #2c5f8d 0%, #4a90c8 100%);
    color: white;
    overflow: hidden;
}

.hero-overlay {
    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 1200 600"><path d="M0,300 Q300,100 600,300 T1200,300 L1200,600 L0,600 Z" fill="rgba(255,255,255,0.05)"/></svg>');
    background-size: cover;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 3rem;
    opacity: 0.95;
    font-weight: 300;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-bottom: 3rem;
}

.stat-item {
    text-align: center;
}

.stat-item i {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

.stat-item h3 {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

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

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator i {
    font-size: 2rem;
    color: white;
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent-color);
    color: var(--text-dark);
}

.btn-primary:hover {
    background: #d4a043;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-large {
    padding: 1.25rem 3rem;
    font-size: 1.1rem;
}

/* ===== Sections ===== */
section {
    padding: 5rem 0;
}

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

.section-title {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.title-underline {
    width: 80px;
    height: 4px;
    background: var(--accent-color);
    margin: 0 auto 1rem;
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* ===== About Section ===== */
.about {
    background: var(--bg-light);
}

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

.about-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    text-align: center;
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.card-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.card-icon i {
    font-size: 2rem;
    color: white;
}

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

.about-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===== Articles Section ===== */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.article-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    cursor: pointer;
}

.article-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.article-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
}

.article-content {
    padding: 1.5rem;
}

.article-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: var(--text-light);
}

.article-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.article-excerpt {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.article-authors {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 500;
}

.text-center {
    text-align: center;
}

/* ===== Subscription Section ===== */
.subscription {
    background: linear-gradient(135deg, #2c5f8d 0%, #4a90c8 100%);
    color: white;
}

.subscription-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.subscription-info h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.subscription-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.benefits-list {
    list-style: none;
}

.benefits-list li {
    padding: 0.75rem 0;
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 1.05rem;
}

.benefits-list i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.subscription-card {
    background: white;
    padding: 3rem;
    border-radius: 20px;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.price-tag {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    margin-bottom: 1rem;
}

.currency {
    font-size: 2rem;
    color: var(--primary-color);
    margin-top: 0.5rem;
}

.amount {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: 'Playfair Display', serif;
}

.period {
    font-size: 1.5rem;
    color: var(--text-light);
    margin-top: 1.5rem;
}

.price-description {
    color: var(--text-light);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.terms {
    margin-top: 1.5rem;
    font-size: 0.875rem;
    color: var(--text-light);
}

/* ===== Submit Section ===== */
.submit-section {
    background: var(--bg-light);
}

.submit-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.submit-info h3 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.fee-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.fee-card:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.fee-card.highlight {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.fee-card h4 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.fee-amount {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-family: 'Playfair Display', serif;
}

.fee-card.highlight .fee-amount {
    color: var(--accent-color);
}

.submit-form-container {
    text-align: center;
    background: white;
    padding: 3rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

.submit-note {
    margin-top: 1.5rem;
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ===== Editorial Section ===== */
.editorial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.editor-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.editor-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.editor-avatar {
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.editor-avatar i {
    font-size: 3rem;
    color: white;
}

.editor-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.editor-role {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.editor-team {
    color: var(--text-light);
    font-size: 0.95rem;
}

.conference-announcement {
    background: linear-gradient(135deg, var(--accent-color), #d4a043);
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    color: var(--text-dark);
    margin-top: 2rem;
}

.conference-announcement i {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.conference-announcement h3 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

/* ===== Footer ===== */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--accent-color);
}

.footer-col p {
    color: rgba(255,255,255,0.8);
    margin-bottom: 1rem;
    line-height: 1.8;
}

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

.footer-col ul li {
    margin-bottom: 0.75rem;
}

.footer-col ul li a {
    color: rgba(255,255,255,0.8);
}

.footer-col ul li a:hover {
    color: var(--accent-color);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

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

.social-links a:hover {
    background: var(--accent-color);
    color: var(--text-dark);
}

.newsletter-form {
    display: flex;
    gap: 0.5rem;
}

.newsletter-form input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: none;
    border-radius: 25px;
    background: rgba(255,255,255,0.1);
    color: white;
}

.newsletter-form input::placeholder {
    color: rgba(255,255,255,0.6);
}

.newsletter-form button {
    width: 45px;
    height: 45px;
    border: none;
    border-radius: 50%;
    background: var(--accent-color);
    color: var(--text-dark);
    cursor: pointer;
    transition: var(--transition);
}

.newsletter-form button:hover {
    background: #d4a043;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.6);
}

/* ===== Animations ===== */
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeIn 0.8s ease-out;
}

.animate-fade-in-delay {
    animation: fadeIn 0.8s ease-out 0.2s both;
}

.animate-fade-in-delay-2 {
    animation: fadeIn 0.8s ease-out 0.4s both;
}

.animate-fade-in-delay-3 {
    animation: fadeIn 0.8s ease-out 0.6s both;
}

/* ===== Modal Styles ===== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    animation: fadeIn 0.3s forwards;
}

.modal {
    background: white;
    border-radius: 20px;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    transform: scale(0.9);
    animation: modalSlideIn 0.3s forwards;
}

@keyframes modalSlideIn {
    to {
        transform: scale(1);
    }
}

.modal-header {
    padding: 2rem;
    border-bottom: 1px solid var(--border-color);
    position: relative;
}

.modal-header h2 {
    font-size: 1.75rem;
    color: var(--primary-color);
}

.modal-close {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--text-dark);
}

.modal-body {
    padding: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-dark);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: white;
        width: 100%;
        padding: 2rem;
        box-shadow: var(--shadow-md);
        transition: var(--transition);
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

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

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }

    .subscription-content,
    .submit-grid {
        grid-template-columns: 1fr;
    }

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