/* ============================================
   CARDIAC ECHOCARDIOGRAPHY EXPERT WEBSITE
   Blue & White Professional Theme
   ============================================ */

:root {
    --primary-color: #0066CC;
    --secondary-color: #E6F2FF;
    --accent-color: #00B4D8;
    --text-color: #1A1A1A;
    --light-text: #555555;
    --border-color: #E0E0E0;
    --success-color: #28A745;
    --danger-color: #DC3545;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: #FFFFFF;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    margin-bottom: 0.5em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p { margin-bottom: 1em; }

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--accent-color);
}

/* ============================================
   LAYOUT & GRID
   ============================================ */

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

.section {
    padding: 60px 0;
}

.section.bg-light {
    background-color: var(--secondary-color);
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h2 {
    margin-bottom: 10px;
}

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

/* ============================================
   NAVIGATION
   ============================================ */

.navbar {
    background-color: #FFFFFF;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.nav-brand h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 2px;
}

.nav-brand .tagline {
    font-size: 0.75rem;
    color: var(--light-text);
    margin: 0;
}

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

.nav-menu a {
    font-weight: 500;
    padding: 5px 10px;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--primary-color);
    transition: 0.3s;
}

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

    .nav-menu {
        display: none;
        flex-direction: column;
        gap: 15px;
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background-color: #FFFFFF;
        padding: 20px;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    }

    .nav-menu.active { display: flex; }
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: #FFFFFF;
    padding: 100px 20px;
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 20px;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .hero-content h1 { font-size: 2rem; }
    .hero-content p { font-size: 1rem; }
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    text-align: center;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #FFFFFF;
}

.btn-primary:hover {
    background-color: #0052A3;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 102, 204, 0.3);
}

.btn-secondary {
    background-color: var(--accent-color);
    color: #FFFFFF;
}

.btn-secondary:hover {
    background-color: #0099B8;
    transform: translateY(-2px);
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--secondary-color);
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.btn-small {
    padding: 8px 15px;
    font-size: 0.9rem;
}

.btn-group {
    text-align: center;
    margin-top: 30px;
}

/* ============================================
   CARDS & GRIDS
   ============================================ */

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.expertise-card {
    background-color: #FFFFFF;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.expertise-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 102, 204, 0.15);
    border-color: var(--accent-color);
}

.card-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.expertise-card h3 {
    color: var(--primary-color);
}

/* Publication Cards */
.publication-card {
    background-color: #FFFFFF;
    padding: 25px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 20px;
    border-radius: 5px;
    transition: all 0.3s ease;
}

.publication-card:hover {
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transform: translateX(5px);
}

.publication-card h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

.publication-meta {
    font-size: 0.9rem;
    color: var(--light-text);
    margin-bottom: 10px;
}

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

/* Event Cards */
.event-card {
    background-color: #FFFFFF;
    padding: 25px;
    border-radius: 10px;
    margin-bottom: 20px;
    border-top: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.event-card:hover {
    box-shadow: 0 5px 15px rgba(0, 180, 216, 0.2);
}

.event-card h4 {
    color: var(--primary-color);
}

.event-meta {
    color: var(--light-text);
    font-size: 0.95rem;
    margin: 10px 0;
}

.difficulty {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--primary-color);
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-top: 10px;
}

/* Testimonial Cards */
.testimonial-card {
    background-color: #FFFFFF;
    padding: 30px;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    margin-bottom: 20px;
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    transform: translateY(-5px);
}

.stars {
    color: #FFC107;
    margin-bottom: 10px;
}

.quote {
    font-style: italic;
    color: var(--text-color);
    margin-bottom: 15px;
    font-size: 1rem;
}

.author {
    color: var(--primary-color);
    font-size: 0.95rem;
}

/* ============================================
   FORMS
   ============================================ */

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

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

input[type="text"],
input[type="email"],
input[type="tel"],
input[type="date"],
input[type="time"],
textarea,
select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.3s ease;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="tel"]:focus,
input[type="date"]:focus,
input[type="time"]:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

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

/* Newsletter Form */
.newsletter-form {
    display: flex;
    gap: 10px;
    max-width: 500px;
    margin: 20px auto;
    flex-wrap: wrap;
    justify-content: center;
}

.newsletter-form input {
    flex: 1;
    min-width: 250px;
}

.privacy-note {
    font-size: 0.85rem;
    color: var(--light-text);
    margin-top: 10px;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background-color: #1A3A52;
    color: #FFFFFF;
    padding: 40px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    color: var(--accent-color);
    margin-bottom: 15px;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section a {
    color: #FFFFFF;
}

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

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

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    border-radius: 50%;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background-color: var(--accent-color);
    transform: translateY(-3px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 20px;
    text-align: center;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
}

/* ============================================
   UTILITIES
   ============================================ */

.about-intro {
    background-color: var(--secondary-color);
    padding: 30px;
    border-radius: 10px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 30px;
}

.about-intro p {
    font-size: 1.05rem;
    line-height: 1.8;
}

.publications-preview {
    display: grid;
    gap: 20px;
}

.events-preview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.testimonials-slider {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 768px) {
    h1 { font-size: 1.8rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.2rem; }

    .section {
        padding: 40px 0;
    }

    .navbar .container {
        flex-direction: column;
        gap: 10px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .newsletter-form {
        flex-direction: column;
    }

    .newsletter-form input {
        min-width: 100%;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--light-text); }

.mt-20 { margin-top: 20px; }
.mb-20 { margin-bottom: 20px; }
.mt-40 { margin-top: 40px; }
.mb-40 { margin-bottom: 40px; }

.hidden { display: none; }

/* Newsletter Section */
.newsletter-section {
    text-align: center;
    padding: 40px 20px;
}

.newsletter-section h2 {
    color: var(--primary-color);
}

.newsletter-section p {
    color: var(--light-text);
    max-width: 600px;
    margin: 15px auto;
}