:root {
    /* Corporate Color Palette */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --dark: #0f172a;
    --dark-light: #1e293b;
    --light: #f8fafc;
    --white: #ffffff;
    --text-main: #334155;
    --text-heading: #0f172a;
    --text-muted: #64748b;

    /* Functional Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    /* Design Tokens */
    --border-radius: 12px;
    --border-radius-lg: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --shadow-premium: 0 20px 40px -12px rgba(37, 99, 235, 0.25);
    
    /* Header Heights */
    --header-height-desktop: 90px;
    --header-height-mobile: 70px;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--text-main);
    background-color: var(--white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    font-weight: 400;
    overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    color: var(--text-heading);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

a {
    text-decoration: none !important;
    transition: var(--transition);
}

/* Navbar Refined */
.main-navbar {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    padding: 0.75rem 0;
    transition: var(--transition);
    min-height: var(--header-height-desktop);
    display: flex;
    align-items: center;
}

@media (max-width: 991px) {
    .main-navbar {
        min-height: var(--header-height-mobile);
        padding: 0.5rem 0;
    }
    
    .main-navbar .container {
        display: flex;
        flex-wrap: nowrap !important;
        align-items: center;
        justify-content: space-between;
    }
    
    .navbar-brand {
        margin-right: 0;
        flex: 0 1 auto;
        max-width: 70%;
    }
    
    .navbar-toggler {
        padding: 0.25rem;
    }
}

.navbar-brand img {
    height: 70px !important;
    width: auto;
    max-width: 100%;
    object-fit: contain;
    transition: var(--transition);
}

@media (max-width: 991px) {
    .navbar-brand img {
        height: 55px !important;
    }
}

@media (max-width: 576px) {
    .navbar-brand img {
        height: 48px !important;
    }
}

.nav-link {
    font-weight: 500;
    color: var(--text-heading) !important;
    font-size: 0.95rem;
    padding: 0.5rem 1.25rem !important;
}

.nav-link:hover {
    color: var(--primary) !important;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.75rem;
    font-weight: 600;
    border-radius: var(--border-radius);
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background-color: var(--primary);
    border: none;
    color: var(--white) !important;
    box-shadow: var(--shadow-premium);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 25px 50px -12px rgba(37, 99, 235, 0.35);
}

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

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

/* Hero Section */
.hero-section {
    padding: 60px 0 80px;
    background: radial-gradient(circle at top right, rgba(37, 99, 235, 0.05), transparent),
        radial-gradient(circle at bottom left, rgba(96, 165, 250, 0.03), transparent);
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    line-height: 1.1;
    margin-bottom: 1.25rem;
    font-weight: 800;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 2rem;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary), #60a5fa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Cards */
.card-corporate {
    background: var(--white);
    border-radius: var(--border-radius);
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: var(--transition);
    padding: 2.5rem;
    height: 100%;
}

.card-corporate:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-xl);
    transform: translateY(-5px);
}

/* Stats */
.hero-visual {
    position: relative;
    z-index: 1;
}

.hero-img-reduced {
    width: 100% !important;
    height: 500px !important;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    object-fit: cover;
}

@media (max-width: 767px) {
    .hero-img-reduced {
        height: 300px !important;
        margin-top: 2rem;
    }
}

.stats-wrapper {
    background: var(--white);
    padding: 3.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    margin-top: -6rem;
    position: relative;
    z-index: 10;
}

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

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 0.5rem;
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

/* Course Card */
.course-card {
    background: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
}

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

.course-img {
    height: 240px;
    position: relative;
    overflow: hidden;
}

.course-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

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

.course-body {
    padding: 2rem;
    flex-grow: 1;
}

.course-category {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--primary);
    margin-bottom: 0.75rem;
    display: block;
}

.course-title {
    font-size: 1.35rem;
    margin-bottom: 1rem;
}

.course-footer {
    padding: 1.5rem 2rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    background: var(--light);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Testimonial */
.testimonial-card {
    background: var(--white);
    padding: 3rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(0, 0, 0, 0.05);
    height: 100%;
}

.testimonial-text {
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 2rem;
    color: var(--text-main);
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.testimonial-author img {
    width: 50px;
    height: 50px;
    border-radius: 50%;
}

/* Footer */
.main-footer {
    background: var(--dark);
    color: rgba(255, 255, 255, 0.7);
    padding: 100px 0 50px;
}

.footer-heading {
    color: var(--white);
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.footer-link {
    color: rgba(255, 255, 255, 0.6);
    display: block;
    margin-bottom: 0.75rem;
}

.footer-link:hover {
    color: var(--white);
    padding-left: 5px;
}

/* Animations */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
/* Course Details Page */
.course-hero {
    min-height: 450px;
    display: flex;
    align-items: center;
}

.hero-bg-blur {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.15;
    filter: blur(40px);
    transform: scale(1.1);
}

.course-meta-strip .meta-item {
    font-size: 1.1rem;
}

.accordion-custom .accordion-item {
    border: 1px solid rgba(0,0,0,0.05) !important;
    transition: var(--transition);
}

.accordion-custom .accordion-item:hover {
    border-color: var(--primary) !important;
}

.accordion-custom .accordion-button:not(.collapsed) {
    background-color: transparent;
    color: var(--primary);
}

.accordion-custom .accordion-button::after {
    background-size: 1rem;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%232563eb'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}

.icon-box-sm {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-size: 0.9rem;
}

.pulse-btn {
    animation: pulse-border 2s infinite;
}

@keyframes pulse-border {
    0% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(37, 99, 235, 0); }
    100% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0); }
}

.instructor-profile {
    border: 1px solid rgba(0,0,0,0.05);
}

@media (max-width: 991px) {
    .course-hero .display-3 { font-size: 2.5rem; }
    .course-sidebar { margin-top: 2rem; position: static !important; }
}

@media (max-width: 767px) {
    .hero-title {
        font-size: 2.25rem;
    }

    .hero-section {
        padding: 40px 0 60px;
    }
    
    .hero-subtitle {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }
}

/* Floating Contact Buttons */
.floating-contact {
    position: fixed;
    bottom: 30px;
    right: 30px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    z-index: 1050;
}

.whatsapp-btn,
.call-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white) !important;
    font-size: 1.75rem;
    box-shadow: var(--shadow-xl);
    transition: var(--transition);
}

@media (max-width: 767px) {
    .whatsapp-btn,
    .call-btn {
        width: 50px;
        height: 50px;
        font-size: 1.4rem;
    }
    
    .floating-contact {
        bottom: 20px;
        right: 20px;
        gap: 10px;
    }
}

.whatsapp-btn {
    background-color: #25d366;
}

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

.whatsapp-btn:hover,
.call-btn:hover {
    transform: scale(1.1) translateY(-5px);
    color: var(--white) !important;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}