/* =========================================
   ROOT VARIABLES
========================================= */
:root {
    --primary: #0d6efd;
    --accent: #ffc107;
    --dark: #0f172a;
    --light-soft: #f4f7fb;
}

/* =========================================
   GLOBAL RESPONSIVE HEADINGS SYSTEM
========================================= */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.5px;
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.4rem, 3vw, 2rem); }
h4 { font-size: clamp(1.2rem, 3vw, 1.6rem); }
h5 { font-size: clamp(1.1rem, 2vw, 1.3rem); }
h6 { font-size: clamp(1rem, 2vw, 1.2rem); }

/* Gradient text for main headings */
h1, h2 {
    background: linear-gradient(90deg, var(--accent), #ffdd57);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Hero Title */
.hero-title {
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* Display Utility */
.display-responsive {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
}

/* =========================================
   HERO SECTION
========================================= */
.hero-section {
    background: linear-gradient(rgba(0,0,0,.65), rgba(0,0,0,.65)),
                url('images/hero-courses.jpg') center/cover no-repeat;
    color: #fff;
    padding: 100px 0;
    text-align: center;
}

/* =========================================
   SECTION SPACING SYSTEM
========================================= */
.section {
    padding: 60px 0;
    position: relative;
}

.section-sm {
    padding: 40px 0;
}

.section:first-of-type {
    padding-top: 40px;
}

.section:last-of-type {
    padding-bottom: 40px;
}

.section h2 { margin-bottom: 1.5rem; }
.section h3 { margin-bottom: 1rem; }

/* =========================================
   BACKGROUNDS
========================================= */
.bg-gradient-primary {
    background: linear-gradient(135deg, var(--primary), #198754);
    color: #fff;
}

.bg-gradient-modern {
    background: linear-gradient(135deg, var(--primary), #003b8e);
    color: #fff;
}

.bg-light-soft {
    background: var(--light-soft);
}

/* =========================================
   MODERN CARDS
========================================= */
.card-modern {
    background: rgba(255,255,255,0.9);
    backdrop-filter: blur(8px);
    border-radius: 20px;
    padding: 25px;
    box-shadow: 0 15px 40px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    height: 100%;
}

.card-modern:hover {
    transform: translateY(-8px);
    box-shadow: 0 25px 60px rgba(0,0,0,0.15);
}

/* Highlight Box */
.highlight-box {
    background: #fff;
    padding: 35px 40px;
    border-radius: 20px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.08);
}

/* =========================================
   ICONS
========================================= */
.icon-lg {
    font-size: 2rem;
    margin-bottom: 15px;
    color: var(--primary);
}

/* =========================================
   BUTTONS
========================================= */
.btn {
    border-radius: 30px;
}

/* =========================================
   NAVBAR
========================================= */
.navbar-dark .navbar-nav .nav-link {
    position: relative;
    font-weight: 500;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

.navbar-dark .navbar-nav .nav-link:hover {
    color: var(--accent) !important;
    font-weight: 700;
}

.navbar-dark .navbar-nav .nav-link::after {
    content: "";
    position: absolute;
    width: 0;
    height: 2px;
    background: var(--accent);
    left: 0;
    bottom: 5px;
    transition: width 0.3s ease;
}

.navbar-dark .navbar-nav .nav-link:hover::after {
    width: 100%;
}

/* =========================================
   COURSE CARDS
========================================= */
.course-card {
    border-radius: 18px;
    transition: .3s ease;
}

.course-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.08);
}

.course-img {
    width: 150px;
    height: 150px;
    object-fit: cover;
    border-radius: 12px;
}

/* =========================================
   CATEGORY FILTER
========================================= */
.category-nav .nav-link {
    border-radius: 50px;
    margin: 5px;
    font-weight: 500;
    cursor: pointer;
    transition: .3s ease;
}

.category-nav .nav-link.active {
    background: var(--accent);
    color: #000 !important;
}

/* =========================================
   APPLICATION CARD
========================================= */
.application-card {
    background: #fff;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

/* =========================================
   FOOTER ACCORDION
========================================= */
.accordion-button {
    background-color: #000;
    color: #fff;
}

.accordion-button:not(.collapsed) {
    background-color: #111;
    color: var(--accent);
}

.accordion-button:focus {
    box-shadow: none;
}

.accordion-item { background-color: #000; }
.accordion-body { background-color: #111; }

/* =========================================
   SOCIAL ICONS
========================================= */
.social-icon {
    color: #ccc;
    font-size: 1.3rem;
    transition: all 0.3s ease;
}

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