/* =========================
   RESET
========================= */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Segoe UI", Arial, sans-serif;

    background: #f8fafc;

    color: #0f172a;
}


/* =========================
   NAVBAR
========================= */

.navbar {

    height: 70px;

    padding: 0 7%;

    display: flex;

    align-items: center;

    justify-content: space-between;

    background: rgba(255, 255, 255, 0.9);

    backdrop-filter: blur(15px);

    border-bottom: 1px solid #e5e7eb;

    position: sticky;

    top: 0;

    z-index: 100;
}

.brand {

    font-size: 22px;

    font-weight: 800;

    color: #4f46e5;
}

.nav-links {

    display: flex;

    gap: 30px;
}

.nav-links a {

    text-decoration: none;

    color: #475569;

    font-weight: 600;

    transition: 0.2s;
}

.nav-links a:hover {

    color: #4f46e5;
}


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

.hero {

    min-height: 500px;

    display: flex;

    align-items: center;

    justify-content: center;

    text-align: center;

    padding: 70px 20px;

    background:

        radial-gradient(
            circle at 20% 20%,
            rgba(99, 102, 241, 0.4),
            transparent 35%
        ),

        radial-gradient(
            circle at 80% 70%,
            rgba(139, 92, 246, 0.4),
            transparent 35%
        ),

        #0f172a;

    color: white;
}

.hero-content {

    max-width: 750px;
}

.badge {

    display: inline-block;

    padding: 8px 15px;

    border-radius: 50px;

    background: rgba(255, 255, 255, 0.1);

    border: 1px solid rgba(255, 255, 255, 0.2);

    color: #c7d2fe;

    margin-bottom: 20px;
}

.hero h1 {

    font-size: clamp(45px, 7vw, 75px);

    line-height: 1.05;

    margin-bottom: 20px;
}

.hero h1 span {

    color: #818cf8;
}

.hero p {

    max-width: 600px;

    margin: auto;

    color: #cbd5e1;

    font-size: 17px;

    line-height: 1.7;
}

.hero-btn {

    display: inline-block;

    margin-top: 30px;

    padding: 14px 25px;

    border-radius: 12px;

    background: #6366f1;

    color: white;

    text-decoration: none;

    font-weight: 700;

    transition: 0.3s;
}

.hero-btn:hover {

    background: #4f46e5;

    transform: translateY(-3px);
}


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

.classes-section {

    max-width: 1100px;

    margin: auto;

    padding: 90px 20px;
}

.section-title {

    text-align: center;

    margin-bottom: 40px;
}

.section-title span,
.notes-header span {

    font-size: 12px;

    font-weight: 800;

    color: #6366f1;

    letter-spacing: 2px;
}

.section-title h2 {

    font-size: 36px;

    margin: 8px 0;
}

.section-title p {

    color: #64748b;
}


/* Class Grid */

.class-grid {

    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 20px;
}

.class-card {

    display: flex;

    align-items: center;

    gap: 20px;

    padding: 25px;

    background: white;

    border: 1px solid #e5e7eb;

    border-radius: 18px;

    cursor: pointer;

    transition: 0.3s;

    box-shadow:
        0 5px 20px rgba(0, 0, 0, 0.04);
}

.class-card:hover {

    transform: translateY(-6px);

    border-color: #818cf8;

    box-shadow:
        0 15px 35px rgba(79, 70, 229, 0.12);
}

.class-number {

    width: 65px;

    height: 65px;

    display: flex;

    align-items: center;

    justify-content: center;

    border-radius: 15px;

    background: #eef2ff;

    color: #4f46e5;

    font-size: 22px;

    font-weight: 800;
}

.class-card h3 {

    font-size: 20px;

    margin-bottom: 5px;
}

.class-card p {

    color: #64748b;

    font-size: 14px;
}

.class-card > span {

    margin-left: auto;

    font-size: 25px;

    color: #6366f1;
}


/* =========================
   NOTES
========================= */

.notes-section {

    max-width: 1100px;

    margin: auto;

    padding: 30px 20px 90px;
}

.notes-header {

    display: flex;

    justify-content: space-between;

    align-items: center;

    gap: 20px;

    margin-bottom: 25px;
}

.notes-header h2 {

    font-size: 32px;

    margin-top: 6px;
}

#search {

    width: 280px;

    padding: 13px 16px;

    border: 1px solid #dbe1ea;

    border-radius: 12px;

    outline: none;

    font-size: 14px;

    background: white;
}

#search:focus {

    border-color: #6366f1;

    box-shadow:
        0 0 0 4px rgba(99, 102, 241, 0.1);
}


/* Subject Buttons */

.subject-buttons {

    display: flex;

    gap: 10px;

    margin-bottom: 25px;

    flex-wrap: wrap;
}

.subject-buttons button {

    border: none;

    padding: 11px 18px;

    border-radius: 10px;

    background: #eef2ff;

    color: #4f46e5;

    font-weight: 700;

    cursor: pointer;

    transition: 0.2s;
}

.subject-buttons button:hover {

    background: #4f46e5;

    color: white;
}


/* Notes Cards */

#notesContainer {

    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 16px;
}

.note-card {

    padding: 22px;

    background: white;

    border: 1px solid #e5e7eb;

    border-radius: 15px;

    display: flex;

    align-items: center;

    gap: 15px;

    transition: 0.25s;
}

.note-card:hover {

    transform: translateY(-3px);

    box-shadow:
        0 10px 25px rgba(0, 0, 0, 0.08);
}

.pdf-icon {

    width: 50px;

    height: 50px;

    display: flex;

    align-items: center;

    justify-content: center;

    border-radius: 12px;

    background: #fff1f2;

    font-size: 23px;
}

.note-info {

    flex: 1;
}

.note-info h3 {

    font-size: 16px;

    margin-bottom: 5px;
}

.note-info p {

    font-size: 13px;

    color: #64748b;
}

.view-btn {

    padding: 9px 14px;

    border-radius: 9px;

    background: #4f46e5;

    color: white;

    text-decoration: none;

    font-size: 13px;

    font-weight: 700;

    transition: 0.2s;
}

.view-btn:hover {

    background: #3730a3;
}


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

footer {

    text-align: center;

    padding: 40px 20px;

    background: #0f172a;

    color: white;
}

footer p {

    color: #94a3b8;

    margin-top: 7px;
}

.copyright {

    font-size: 12px;

    margin-top: 20px;
}


/* =========================
   MOBILE
========================= */

@media (max-width: 700px) {

    .nav-links {

        display: none;
    }

    .class-grid {

        grid-template-columns: 1fr;
    }

    #notesContainer {

        grid-template-columns: 1fr;
    }

    .notes-header {

        flex-direction: column;

        align-items: stretch;
    }

    #search {

        width: 100%;
    }

    .hero {

        min-height: 450px;
    }

    .hero h1 {

        font-size: 45px;
    }
}