/* ============================================================= */
/* GLOBAL RESET & TYPOGRAPHY */
/* ============================================================= */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 100%;
    scroll-behavior: smooth;
}

body {
    background: #121212;
    font-family: 'Segoe UI', Arial, Helvetica, sans-serif;
    color: #ffffff;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

img {
    max-width: 100%;
    display: block;
}

/* ============================================================= */
/* HERO SECTION */
/* ============================================================= */
.hero-section {
    padding: 80px 0;
    background: linear-gradient(145deg, #121212, #2a2f30);
    border-bottom: 2px solid #b7b7b7;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    color: #ffffff;
    text-align: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-content p {
    font-size: 1.5rem;
    font-weight: 400;
    color: #dfe6e9;
    max-width: 800px;
    margin: 0 auto;
}

/* ============================================================= */
/* COURSES SECTION & CARDS */
/* ============================================================= */
.courses-section {
    padding: 60px 0;
    background-color: #121212;
}

.course-card {
    background: linear-gradient(145deg, #1c2526, #2a2f30);
    border: 2px solid #fdfdfd;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
    margin: 0 auto 30px;
    width: 100%;
    max-width: 360px;
    height: 480px;
}

.course-card.featured {
    border-color: #818181;
    box-shadow: 0 6px 20px rgba(95, 95, 95, 0.5);
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.6);
}

/* Header */
.course-header {
    background: rgba(0, 0, 0, 0.3);
    padding: 15px;
    text-align: center;
    border-bottom: 1px solid #676766;
    flex-shrink: 0;
    height: 90px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.course-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: #ffffff;
    margin-bottom: 0.25rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.course-subtitle {
    font-size: 0.9rem;
    color: #dfe6e9;
    font-style: italic;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Body */
.card-body {
    padding: 15px;
    color: #ffffff;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.price {
    font-size: 1.75rem;
    font-weight: 700;
    color: #80807f;
    margin-bottom: 1rem;
    flex-shrink: 0;
}

.price-usd {
    font-size: 1rem;
    color: #dfe6e9;
}

.course-description {
    font-size: 0.9rem;
    color: #dfe6e9;
    margin-bottom: 1rem;
    flex-grow: 1;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}

/* Feature List */
.feature-list {
    list-style: none;
    padding: 0;
    margin-bottom: 1rem;
    flex-shrink: 0;
    max-height: 120px;
    overflow: hidden;
}

.feature-list li {
    font-size: 0.85rem;
    color: #ffffff;
    margin-bottom: 0.4rem;
    position: relative;
    padding-left: 22px;
}

.feature-list li::before {
    content: '\f058'; /* Font Awesome solid check-circle */
    font-family: 'Font Awesome 5 Free';
    font-weight: 900;
    color: #858482;
    position: absolute;
    left: 0;
    top: 2px;
    font-size: 0.85rem;
}

/* Button */
.btn-choose {
    display: inline-block;
    width: 100%;
    padding: 0.75rem 1.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    background: linear-gradient(145deg, #2a2f30, #4a4f50);
    border: 2px solid #494949;
    border-radius: 2rem;
    color: #ffffff !important;
    text-align: center;
    text-decoration: none;
    transition: all 0.3s ease;
    opacity: 0.9;
    flex-shrink: 0;
}

.btn-choose:hover {
    background: linear-gradient(145deg, #4a4f50, #2a2f30);
    box-shadow: 0 4px 15px rgba(122, 122, 122, 0.6);
    color: #7a7979 !important;
    opacity: 1;
}

.btn-choose i {
    margin-right: 8px;
}

/* Animation */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeIn 0.8s ease forwards;
}

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

/* ============================================================= */
/* RESPONSIVE DESIGN – TABLETS & PHONES */
/* ============================================================= */

/* Tablets (≤768px) */
@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2.5rem;
    }
    .hero-content p {
        font-size: 1.25rem;
    }

    .course-card {
        height: auto;
        min-height: 400px;
        max-width: 340px;
        margin-bottom: 35px;
        padding-bottom: 10px;
    }

    .course-header {
        height: auto;
        min-height: 80px;
        padding: 12px 10px;
    }

    .course-title {
        font-size: 1.35rem;
        white-space: normal;
        line-height: 1.3;
    }

    .course-subtitle {
        font-size: 0.85rem;
    }

    .price {
        font-size: 1.6rem;
        margin: 0.5rem 0;
    }

    .course-description {
        -webkit-line-clamp: 4;
        margin-bottom: 0.75rem;
    }

    .feature-list {
        max-height: none;
        overflow: visible;
        margin-bottom: 0.75rem;
    }

    .btn-choose {
        padding: 0.85rem 1rem;
        font-size: 0.95rem;
    }
}

/* Mobile Phones (≤576px) */
@media (max-width: 576px) {
    .hero-section {
        padding: 60px 0;
    }

    .hero-content h1 {
        font-size: 2rem;
        line-height: 1.2;
    }

    .hero-content p {
        font-size: 1rem;
        padding: 0 10px;
    }

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

    .course-card {
        max-width: 100%;
        height: auto;
        min-height: 360px;
        margin-bottom: 25px;
        border-radius: 12px;
        padding: 10px;
    }

    .course-header {
        min-height: 70px;
        padding: 10px 8px;
    }

    .course-title {
        font-size: 1.25rem;
        white-space: normal;
    }

    .course-subtitle {
        font-size: 0.8rem;
    }

    .price {
        font-size: 1.5rem;
    }

    .course-description {
        font-size: 0.85rem;
        -webkit-line-clamp: 4;
    }

    .feature-list li {
        font-size: 0.8rem;
        padding-left: 20px;
        margin-bottom: 0.35rem;
    }

    .feature-list li::before {
        font-size: 0.8rem;
        top: 3px;
    }

    .btn-choose {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
        border-radius: 1.8rem;
    }
}

/* Extra small phones (≤360px) */
@media (max-width: 360px) {
    .course-card {
        min-height: 340px;
    }

    .course-title {
        font-size: 1.15rem;
    }

    .price {
        font-size: 1.4rem;
    }

    .btn-choose {
        font-size: 0.85rem;
        padding: 0.7rem 0.9rem;
    }
}