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

body {
    font-family: system-ui, 'Segoe UI', 'Roboto', 'Helvetica Neue', sans-serif;
    /* background: linear-gradient(145deg, #f8f9ff 0%, #f0f3fd 100%); */
    background-color:#16263F;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Modern Header with Glassmorphism */
header {
    /* background: rgba(56, 82, 180, 0.95); */
    background:#FFC107;
    backdrop-filter: blur(8px);
    padding: 0.7rem 2rem;
    /* color: white; */
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    position: sticky;
    top: 0;
    z-index: 100;
    color: #FFFFFF;
}

.brand-box{
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    /* background-color: #FFFFFF; */
}

.brand-img{
    width: 50px;
}

.brand {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, #FFFFFF, #E0E7FF);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    color: #1E2F4D;
    /* text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1); */
}

nav ul {
    display: flex;
    gap: 1rem;
    list-style: none;
    margin-bottom: 0.5rem;
}

nav ul li a {
    color:#1E2F4D;
    text-decoration: none;
    font-weight: 600;
    padding: 0.5rem 0.8rem;
    border-radius: 40px;
    transition: all 0.25s ease;
    font-size: 1rem;
}

nav ul li a:hover {
    background: rgba(255, 255, 255, 0.2);
    color: blue;
    transform: translateY(-2px);
}

/* Main Content */
main {
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    width: 100%;
}

.head {
    text-align: center;
    margin: 0.5rem 0 1rem;
    font-size: 2.4rem;
    font-weight: 800;
    background: linear-gradient(135deg, #1e2a5e, #3852B4);
    background-clip: text;
    -webkit-background-clip: text;
    color: #FFFFFF;
    position: relative;
    display: inline-block;
    width: 100%;
}

.head::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: #3852B4;
    margin: 0.5rem auto 0;
    border-radius: 4px;
}

/* Notes Grid */
.section-1 {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    margin: 1.5rem 0 2.5rem;
}

.notes {
    width: 260px;
    height: 300px;
    background: white;
    border-radius: 28px;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    font-weight: 800;
    font-size: 1.8rem;
    color: #1e2a5e;
    transition: all 0.35s cubic-bezier(0.2, 0.9, 0.4, 1.1);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
    border-left: 10px solid;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(2px);
    line-height: 1.3;
}

.notes br {
    display: block;
    content: "";
    margin: 4px 0;
}

.notes:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 25px 40px rgba(0, 0, 0, 0.18);
}

/* Ripple effect */
.ripple-effect {
    position: absolute;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.5);
    transform: scale(0);
    animation: rippleAnim 0.5s linear;
    pointer-events: none;
}

@keyframes rippleAnim {
    to {
        transform: scale(8);
        opacity: 0;
    }
}

/* Modal / Popup Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: white;
    width: 90%;
    max-width: 500px;
    border-radius: 28px;
    overflow: hidden;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }

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

.modal-header {
    background: #FFC107;
    padding: 1.2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    color: #1E2F4D;
    font-size: 1.3rem;
    margin: 0;
}

.close-modal {
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: #1E2F4D;
    transition: all 0.2s;
}

.close-modal:hover {
    transform: scale(1.1);
}

.chapter-list {
    padding: 1rem;
    max-height: 500px;
    overflow-y: auto;
}

.chapter-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.8rem 1rem;
    border-bottom: 1px solid #eee;
    transition: all 0.2s ease;
    gap: 1rem;
    flex-wrap: wrap;
}

.chapter-name {
    font-size: 1rem;
    color: #1e2a5e;
    font-weight: 500;
    flex: 1;
    min-width: 0;
    word-break: break-word;
    text-transform: uppercase;
}

.download-chapter {
    background: #3852B4;
    color: white;
    border: none;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 500;
    transition: all 0.2s;
    text-decoration: none;
    display: inline-block;
    white-space: nowrap;
    min-width: 85px;
    text-align: center;
}

.download-chapter:hover {
    background: #2a3f94;
    transform: scale(1.02);
}

/* Why Notes Section */
.why-notes {
    text-align: center;
    padding: 2rem;
    background: linear-gradient(120deg, #e9efff, #ffffff);
    border-radius: 48px;
    margin: 1rem 0 1rem;
    box-shadow: 0 8px 20px rgba(56, 82, 180, 0.1);
    border: 1px solid rgba(56, 82, 180, 0.15);
}

.why-notes h2 {
    font-size: 1.9rem;
    color: #1e2a5e;
    margin-bottom: 1rem;
    font-weight: 700;
}

.why-notes ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    margin-top: 1rem;
}

.why-notes li {
    font-size: 1.1rem;
    background: #3852B4;
    color: white;
    padding: 0.6rem 1.4rem;
    border-radius: 60px;
    font-weight: 500;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
}

.why-notes li:hover {
    transform: translateY(-3px);
    background: #2a3f94;
    box-shadow: 0 6px 12px rgba(56, 82, 180, 0.3);
}
/* Footer */
footer {
    background: #FFC107;
    text-align: center;
    padding: 0.5rem;
    color:#1E2F4D;
    font-weight: 500;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.social{
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
}

.social a{
    color: #1E2F4D;
    font-size: 1.5rem;
}

hr{
    margin-top: 0.5rem;
    border: 1px solid white;
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        padding: 0.8rem 1.2rem;
    }

    .brand {
        font-size: 1.4rem;
    }

    nav ul {
        gap: 1rem;
    }

    .head {
        font-size: 1.9rem;
    }

    .notes {
        width: 220px;
        height: 260px;
        font-size: 1.4rem;
    }

    .why-notes ul {
        gap: 1rem;
        flex-direction: column;
        align-items: center;
    }

    .why-notes li {
        width: 80%;
    }
}

@media (max-width: 480px) {
    header {
        display: flex;
        justify-content: center;
        align-items: center;
    }

    header .brand, nav{
        margin-bottom: -8px;
    }

    main {
        padding: 1rem;
    }

    .section-1 {
        gap: 1.2rem;
    }

    .modal-header h2 {
        font-size: 1rem;
    }

    .chapter-name{
        font-size: 0.75rem;
    }

    .download-chapter{
        padding: 0.3rem 0.8rem;
        font-size: 0.75rem;
    }

    .notes {
        width: 160px;
        height: 200px;
        font-size: 1.2rem;
    }

    .why-notes {
        padding: 1.5rem;
    }

    .why-notes h2 {
        font-size: 1.25rem;
    }

    .why-notes li {
        font-size: 0.95rem;
        padding: 0.5rem 1rem;
    }

    footer {
        font-size: 0.9rem;
    }
}

/* Download badge micro interaction */
.notes::before {
    content: "⬇️";
    font-size: 1.2rem;
    position: absolute;
    top: 15px;
    right: 20px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.notes:hover::before {
    opacity: 0.7;
}