/* =========================================================
   STUDYHUB NOTES SECTION
   CSS PART 1 / 4
   Main Section + Header + Class Selection
========================================================= */


/* =========================================================
   MAIN SECTION
========================================================= */

.studyhub-section {
    width: 100%;
    padding: 80px 0;
    background: #f5f8fc;
    position: relative;
    overflow: hidden;
    font-family: inherit;
}


/* Decorative Background */

.studyhub-section::before {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    background: rgba(13, 110, 253, 0.06);
    border-radius: 50%;
    top: -180px;
    right: -150px;
    pointer-events: none;
}

.studyhub-section::after {
    content: "";
    position: absolute;
    width: 320px;
    height: 320px;
    background: rgba(13, 110, 253, 0.04);
    border-radius: 50%;
    bottom: -150px;
    left: -120px;
    pointer-events: none;
}


/* Keep Content Above Decorations */

.studyhub-section .container {
    position: relative;
    z-index: 2;
}


/* =========================================================
   SECTION HEADER
========================================================= */

.studyhub-header {
    max-width: 750px;
    margin: 0 auto 50px;
}


/* Badge */

.studyhub-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;

    padding: 7px 16px;

    border-radius: 50px;

    background: #e8f1ff;
    color: #0d6efd;

    font-size: 12px;
    font-weight: 700;

    letter-spacing: 1.2px;
    text-transform: uppercase;

    margin-bottom: 15px;
}


/* Main Heading */

.studyhub-title {
    margin: 0 0 14px;

    color: #172033;

    font-size: 38px;
    line-height: 1.2;

    font-weight: 800;

    letter-spacing: -0.5px;
}


/* Description */

.studyhub-description {
    margin: 0 auto;

    max-width: 620px;

    color: #687386;

    font-size: 16px;
    line-height: 1.7;
}


/* =========================================================
   STEP CONTAINER
========================================================= */

.studyhub-step {
    width: 100%;

    background: #ffffff;

    border: 1px solid #e5eaf1;

    border-radius: 20px;

    padding: 30px;

    margin-bottom: 25px;

    box-shadow:
        0 10px 35px rgba(22, 42, 70, 0.06);

    transition:
        opacity 0.3s ease,
        transform 0.3s ease;
}


/* Hidden Step */

.studyhub-hidden {
    display: none !important;
}


/* =========================================================
   STEP HEADING
========================================================= */

.studyhub-step-heading {
    display: flex;
    align-items: center;

    gap: 15px;

    margin-bottom: 25px;
}


/* Step Number */

.studyhub-step-number {
    width: 45px;
    height: 45px;

    min-width: 45px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 13px;

    background: #0d6efd;
    color: #ffffff;

    font-size: 17px;
    font-weight: 800;

    box-shadow:
        0 6px 18px rgba(13, 110, 253, 0.25);
}


/* Step Heading */

.studyhub-step-heading h3 {
    margin: 0 0 3px;

    color: #172033;

    font-size: 21px;
    font-weight: 750;
}


/* Step Description */

.studyhub-step-heading p {
    margin: 0;

    color: #7a8495;

    font-size: 14px;
    line-height: 1.5;
}


/* =========================================================
   CLASS BUTTON AREA
========================================================= */

.studyhub-class-row {
    margin-top: 5px;
}


/* Class Button */

.studyhub-class-btn {
    width: 100%;

    min-height: 92px;

    padding: 15px 18px;

    display: flex;
    align-items: center;

    gap: 13px;

    border: 1px solid #e1e7ef;
    border-radius: 15px;

    background: #ffffff;

    color: #172033;

    text-align: left;

    cursor: pointer;

    transition:
        transform 0.25s ease,
        border-color 0.25s ease,
        box-shadow 0.25s ease,
        background 0.25s ease;
}


/* Class Button Hover */

.studyhub-class-btn:hover {
    transform: translateY(-4px);

    border-color: #0d6efd;

    background: #fafdff;

    box-shadow:
        0 12px 28px rgba(13, 110, 253, 0.12);
}


/* Class Icon */

.studyhub-class-icon {
    width: 52px;
    height: 52px;

    min-width: 52px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 13px;

    background: #eaf2ff;

    color: #0d6efd;

    font-size: 23px;

    transition:
        background 0.25s ease,
        color 0.25s ease;
}


/* Icon Hover */

.studyhub-class-btn:hover .studyhub-class-icon {
    background: #0d6efd;
    color: #ffffff;
}


/* =========================================================
   CLASS TEXT
========================================================= */

.studyhub-class-content {
    display: flex;
    flex-direction: column;

    flex: 1;

    min-width: 0;
}


/* Class Name */

.studyhub-class-content strong {
    display: block;

    margin-bottom: 3px;

    color: #172033;

    font-size: 16px;
    font-weight: 750;

    line-height: 1.3;
}


/* Class Subtitle */

.studyhub-class-content small {
    display: block;

    color: #8a94a5;

    font-size: 12px;

    line-height: 1.4;
}


/* =========================================================
   RIGHT ARROW
========================================================= */

.studyhub-arrow {
    width: 34px;
    height: 34px;

    min-width: 34px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 50%;

    background: #f1f4f8;

    color: #697586;

    font-size: 14px;

    transition:
        transform 0.25s ease,
        background 0.25s ease,
        color 0.25s ease;
}


/* Arrow Hover */

.studyhub-class-btn:hover .studyhub-arrow {
    background: #0d6efd;
    color: #ffffff;

    transform: translateX(3px);
}


/* =========================================================
   GENERAL BUTTON RESET
========================================================= */

.studyhub-class-btn,
.studyhub-back-btn,
.studyhub-subject-btn,
.studyhub-chapter-btn,
.studyhub-fullscreen-btn {
    font-family: inherit;
    outline: none;
}


/* Remove Bootstrap / Browser Focus Issue */

.studyhub-class-btn:focus,
.studyhub-class-btn:active {
    outline: none;
}


/* Accessible Keyboard Focus */

.studyhub-class-btn:focus-visible {
    outline: 3px solid rgba(13, 110, 253, 0.25);
    outline-offset: 3px;
}


/* =========================================================
   TABLET
========================================================= */

@media (max-width: 991.98px) {

    .studyhub-section {
        padding: 65px 0;
    }

    .studyhub-header {
        margin-bottom: 40px;
    }

    .studyhub-title {
        font-size: 34px;
    }

    .studyhub-step {
        padding: 25px;
        border-radius: 18px;
    }

    .studyhub-class-btn {
        min-height: 88px;
    }

}


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

@media (max-width: 767.98px) {

    .studyhub-section {
        padding: 50px 0;
    }


    .studyhub-header {
        padding: 0 10px;
        margin-bottom: 30px;
    }


    .studyhub-badge {
        font-size: 10px;
        padding: 6px 13px;
        letter-spacing: 1px;
    }


    .studyhub-title {
        font-size: 28px;
        line-height: 1.25;
    }


    .studyhub-description {
        font-size: 14px;
        line-height: 1.6;
    }


    .studyhub-step {
        padding: 20px 16px;
        border-radius: 16px;
        margin-bottom: 18px;
    }


    .studyhub-step-heading {
        gap: 11px;
        margin-bottom: 20px;
    }


    .studyhub-step-number {
        width: 40px;
        height: 40px;
        min-width: 40px;

        border-radius: 11px;

        font-size: 15px;
    }


    .studyhub-step-heading h3 {
        font-size: 18px;
    }


    .studyhub-step-heading p {
        font-size: 12px;
    }


    .studyhub-class-btn {
        min-height: 78px;

        padding: 12px;

        gap: 10px;

        border-radius: 13px;
    }


    .studyhub-class-icon {
        width: 44px;
        height: 44px;
        min-width: 44px;

        border-radius: 11px;

        font-size: 19px;
    }


    .studyhub-class-content strong {
        font-size: 14px;
    }


    .studyhub-class-content small {
        font-size: 11px;
    }


    .studyhub-arrow {
        width: 30px;
        height: 30px;
        min-width: 30px;

        font-size: 12px;
    }

}


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

@media (max-width: 400px) {

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


    .studyhub-title {
        font-size: 25px;
    }


    .studyhub-description {
        font-size: 13px;
    }


    .studyhub-step {
        padding: 17px 12px;
    }


    .studyhub-class-btn {
        min-height: 72px;
        padding: 10px;
    }


    .studyhub-class-icon {
        width: 40px;
        height: 40px;
        min-width: 40px;

        font-size: 17px;
    }


    .studyhub-class-content strong {
        font-size: 13px;
    }


    .studyhub-class-content small {
        font-size: 10px;
    }

}



/* part 2 */
/* =========================================================
   STUDYHUB NOTES SECTION
   CSS PART 2 / 4
   Subject Selection + Back Button
========================================================= */


/* =========================================================
   SUBJECT SELECTION AREA
========================================================= */

.studyhub-subject-row {
    margin-top: 5px;
}


/* =========================================================
   SUBJECT BUTTON
========================================================= */

.studyhub-subject-btn {
    width: 100%;

    min-height: 82px;

    padding: 14px 16px;

    display: flex;
    align-items: center;

    gap: 13px;

    border: 1px solid #e1e7ef;
    border-radius: 15px;

    background: #ffffff;

    color: #172033;

    text-align: left;

    cursor: pointer;

    transition:
        transform 0.25s ease,
        border-color 0.25s ease,
        box-shadow 0.25s ease,
        background 0.25s ease;
}


/* Subject Hover */

.studyhub-subject-btn:hover {
    transform: translateY(-4px);

    border-color: #0d6efd;

    background: #fafdff;

    box-shadow:
        0 12px 28px rgba(13, 110, 253, 0.12);
}


/* =========================================================
   SUBJECT ICON
========================================================= */

.studyhub-subject-icon {
    width: 50px;
    height: 50px;

    min-width: 50px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 13px;

    background: #eef5ff;

    color: #0d6efd;

    font-size: 21px;

    transition:
        background 0.25s ease,
        color 0.25s ease,
        transform 0.25s ease;
}


/* Subject Icon Hover */

.studyhub-subject-btn:hover .studyhub-subject-icon {
    background: #0d6efd;

    color: #ffffff;

    transform: scale(1.05);
}


/* =========================================================
   SUBJECT NAME
========================================================= */

.studyhub-subject-name {
    flex: 1;

    min-width: 0;

    color: #172033;

    font-size: 16px;

    font-weight: 700;

    line-height: 1.4;
}


/* =========================================================
   SUBJECT ARROW
========================================================= */

.studyhub-subject-btn .studyhub-arrow {
    flex-shrink: 0;
}


.studyhub-subject-btn:hover .studyhub-arrow {
    background: #0d6efd;

    color: #ffffff;

    transform: translateX(3px);
}


/* =========================================================
   BACK BUTTON
========================================================= */

.studyhub-back-btn {
    display: inline-flex;

    align-items: center;
    justify-content: center;

    gap: 8px;

    padding: 9px 15px;

    margin-bottom: 22px;

    border: 1px solid #dce3ec;

    border-radius: 9px;

    background: #f8fafc;

    color: #566174;

    font-size: 13px;

    font-weight: 600;

    line-height: 1;

    cursor: pointer;

    transition:
        background 0.25s ease,
        color 0.25s ease,
        border-color 0.25s ease,
        transform 0.25s ease;
}


/* Back Button Icon */

.studyhub-back-btn i {
    font-size: 13px;

    transition:
        transform 0.25s ease;
}


/* Back Button Hover */

.studyhub-back-btn:hover {
    background: #0d6efd;

    border-color: #0d6efd;

    color: #ffffff;

    transform: translateX(-2px);
}


/* Back Arrow Hover */

.studyhub-back-btn:hover i {
    transform: translateX(-3px);
}


/* =========================================================
   SUBJECT BUTTON FOCUS
========================================================= */

.studyhub-subject-btn:focus {
    outline: none;
}


.studyhub-subject-btn:focus-visible {
    outline: 3px solid rgba(13, 110, 253, 0.22);

    outline-offset: 3px;
}


/* Back Button Focus */

.studyhub-back-btn:focus {
    outline: none;
}


.studyhub-back-btn:focus-visible {
    outline: 3px solid rgba(13, 110, 253, 0.22);

    outline-offset: 3px;
}


/* =========================================================
   SUBJECT BUTTON ACTIVE EFFECT
========================================================= */

.studyhub-subject-btn:active {
    transform: translateY(-1px);

    box-shadow:
        0 6px 16px rgba(13, 110, 253, 0.10);
}


/* =========================================================
   TABLET
========================================================= */

@media (max-width: 991.98px) {

    .studyhub-subject-btn {
        min-height: 78px;

        padding: 13px 15px;
    }


    .studyhub-subject-icon {
        width: 47px;
        height: 47px;

        min-width: 47px;

        font-size: 20px;
    }


    .studyhub-subject-name {
        font-size: 15px;
    }

}


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

@media (max-width: 767.98px) {

    .studyhub-subject-row {
        margin-top: 0;
    }


    .studyhub-subject-btn {
        min-height: 70px;

        padding: 11px 12px;

        gap: 10px;

        border-radius: 13px;
    }


    .studyhub-subject-icon {
        width: 42px;
        height: 42px;

        min-width: 42px;

        border-radius: 10px;

        font-size: 18px;
    }


    .studyhub-subject-name {
        font-size: 14px;

        line-height: 1.3;
    }


    .studyhub-subject-btn .studyhub-arrow {
        width: 29px;
        height: 29px;

        min-width: 29px;

        font-size: 11px;
    }


    .studyhub-back-btn {
        padding: 8px 12px;

        margin-bottom: 18px;

        border-radius: 8px;

        font-size: 12px;
    }


    .studyhub-back-btn i {
        font-size: 12px;
    }

}


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

@media (max-width: 400px) {

    .studyhub-subject-btn {
        min-height: 66px;

        padding: 9px 10px;

        gap: 8px;
    }


    .studyhub-subject-icon {
        width: 39px;
        height: 39px;

        min-width: 39px;

        border-radius: 9px;

        font-size: 16px;
    }


    .studyhub-subject-name {
        font-size: 13px;
    }


    .studyhub-subject-btn .studyhub-arrow {
        width: 27px;
        height: 27px;

        min-width: 27px;

        font-size: 10px;
    }


    .studyhub-back-btn {
        padding: 7px 10px;

        font-size: 11px;
    }

}



/* part 3 */

/* =========================================================
   STUDYHUB NOTES SECTION
   CSS PART 3 / 4
   Chapter Cards + Chapter Actions
========================================================= */


/* =========================================================
   CHAPTER LIST
========================================================= */

.studyhub-chapter-list {
    width: 100%;

    display: flex;
    flex-direction: column;

    gap: 12px;
}


/* =========================================================
   CHAPTER CARD
========================================================= */

.studyhub-chapter-card {
    width: 100%;

    min-height: 92px;

    display: flex;
    align-items: center;

    gap: 15px;

    padding: 15px 17px;

    background: #ffffff;

    border: 1px solid #e1e7ef;

    border-radius: 15px;

    transition:
        transform 0.25s ease,
        border-color 0.25s ease,
        box-shadow 0.25s ease,
        background 0.25s ease;
}


/* Chapter Card Hover */

.studyhub-chapter-card:hover {
    transform: translateX(4px);

    border-color: #0d6efd;

    background: #fafdff;

    box-shadow:
        0 10px 25px rgba(13, 110, 253, 0.10);
}


/* =========================================================
   CHAPTER NUMBER
========================================================= */

.studyhub-chapter-number {
    width: 52px;
    height: 52px;

    min-width: 52px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 13px;

    background: #eaf2ff;

    color: #0d6efd;

    font-size: 15px;

    font-weight: 800;

    letter-spacing: 0.5px;

    transition:
        background 0.25s ease,
        color 0.25s ease;
}


/* Number Hover */

.studyhub-chapter-card:hover .studyhub-chapter-number {
    background: #0d6efd;

    color: #ffffff;
}


/* =========================================================
   CHAPTER INFORMATION
========================================================= */

.studyhub-chapter-info {
    flex: 1;

    min-width: 0;

    display: flex;

    flex-direction: column;

    justify-content: center;
}


/* Chapter Label */

.studyhub-chapter-label {
    display: block;

    margin-bottom: 4px;

    color: #8a94a5;

    font-size: 10px;

    font-weight: 750;

    letter-spacing: 1px;

    text-transform: uppercase;

    line-height: 1.3;
}


/* Chapter Name */

.studyhub-chapter-info h4 {
    margin: 0;

    color: #172033;

    font-size: 16px;

    font-weight: 700;

    line-height: 1.45;

    word-break: break-word;
}


/* =========================================================
   CHAPTER META
========================================================= */

.studyhub-chapter-meta {
    display: inline-flex;

    align-items: center;

    gap: 5px;

    margin-top: 6px;

    color: #8791a2;

    font-size: 11px;

    line-height: 1.3;
}


/* PDF Icon */

.studyhub-chapter-meta i {
    color: #dc3545;

    font-size: 13px;
}


/* =========================================================
   VIEW NOTES BUTTON
========================================================= */

.studyhub-chapter-btn {
    flex-shrink: 0;

    min-height: 42px;

    padding: 10px 14px;

    display: inline-flex;

    align-items: center;
    justify-content: center;

    gap: 8px;

    border: 1px solid #0d6efd;

    border-radius: 9px;

    background: #0d6efd;

    color: #ffffff;

    font-size: 12px;

    font-weight: 700;

    line-height: 1;

    cursor: pointer;

    white-space: nowrap;

    transition:
        background 0.25s ease,
        border-color 0.25s ease,
        transform 0.25s ease,
        box-shadow 0.25s ease;
}


/* Button Hover */

.studyhub-chapter-btn:hover {
    background: #0b5ed7;

    border-color: #0b5ed7;

    color: #ffffff;

    transform: translateY(-2px);

    box-shadow:
        0 7px 18px rgba(13, 110, 253, 0.22);
}


/* Button Arrow */

.studyhub-chapter-btn i {
    font-size: 13px;

    transition:
        transform 0.25s ease;
}


/* Arrow Hover */

.studyhub-chapter-btn:hover i {
    transform: translateX(3px);
}


/* =========================================================
   BUTTON ACTIVE
========================================================= */

.studyhub-chapter-btn:active {
    transform: translateY(0);

    box-shadow: none;
}


/* =========================================================
   CHAPTER BUTTON FOCUS
========================================================= */

.studyhub-chapter-btn:focus {
    outline: none;
}


.studyhub-chapter-btn:focus-visible {
    outline: 3px solid rgba(13, 110, 253, 0.22);

    outline-offset: 3px;
}


/* =========================================================
   TABLET
========================================================= */

@media (max-width: 991.98px) {

    .studyhub-chapter-card {
        min-height: 88px;

        gap: 13px;

        padding: 14px;
    }


    .studyhub-chapter-number {
        width: 49px;
        height: 49px;

        min-width: 49px;

        font-size: 14px;
    }


    .studyhub-chapter-info h4 {
        font-size: 15px;
    }


    .studyhub-chapter-btn {
        min-height: 40px;

        padding: 9px 12px;

        font-size: 11px;
    }

}


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

@media (max-width: 767.98px) {

    .studyhub-chapter-list {
        gap: 10px;
    }


    .studyhub-chapter-card {
        min-height: auto;

        padding: 13px;

        gap: 11px;

        border-radius: 13px;
    }


    .studyhub-chapter-number {
        width: 43px;
        height: 43px;

        min-width: 43px;

        border-radius: 10px;

        font-size: 12px;
    }


    .studyhub-chapter-label {
        margin-bottom: 3px;

        font-size: 9px;

        letter-spacing: 0.8px;
    }


    .studyhub-chapter-info h4 {
        font-size: 13px;

        line-height: 1.4;
    }


    .studyhub-chapter-meta {
        margin-top: 5px;

        font-size: 10px;
    }


    .studyhub-chapter-meta i {
        font-size: 11px;
    }


    .studyhub-chapter-btn {
        min-height: 38px;

        padding: 8px 10px;

        gap: 5px;

        border-radius: 8px;

        font-size: 10px;
    }


    .studyhub-chapter-btn i {
        font-size: 11px;
    }


    .studyhub-chapter-card:hover {
        transform: translateX(2px);
    }

}


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

@media (max-width: 480px) {

    .studyhub-chapter-card {
        display: grid;

        grid-template-columns: 42px minmax(0, 1fr);

        align-items: center;

        padding: 12px;

        gap: 10px;
    }


    .studyhub-chapter-number {
        grid-row: 1;

        width: 42px;
        height: 42px;

        min-width: 42px;
    }


    .studyhub-chapter-info {
        grid-column: 2;
    }


    .studyhub-chapter-btn {
        grid-column: 1 / -1;

        width: 100%;

        min-height: 40px;

        padding: 9px 12px;

        font-size: 11px;
    }


    .studyhub-chapter-btn i {
        font-size: 12px;
    }

}


/* =========================================================
   VERY SMALL DEVICES
========================================================= */

@media (max-width: 350px) {

    .studyhub-chapter-card {
        padding: 10px;
    }


    .studyhub-chapter-number {
        width: 38px;
        height: 38px;

        min-width: 38px;

        font-size: 11px;
    }


    .studyhub-chapter-info h4 {
        font-size: 12px;
    }


    .studyhub-chapter-label {
        font-size: 8px;
    }


    .studyhub-chapter-meta {
        font-size: 9px;
    }


    .studyhub-chapter-btn {
        min-height: 38px;

        font-size: 10px;
    }

}


/* part 4 */

/* =========================================================
   STUDYHUB NOTES SECTION
   CSS PART 4 / 4
   PDF Viewer + PDF Actions + Mobile Optimization
========================================================= */


/* =========================================================
   PDF STEP
========================================================= */

.studyhub-pdf-step {
    overflow: hidden;

    padding-bottom: 25px;
}


/* =========================================================
   PDF HEADER
========================================================= */

.studyhub-pdf-header {
    width: 100%;

    display: flex;

    align-items: center;
    justify-content: space-between;

    gap: 20px;

    margin-bottom: 20px;
}


/* =========================================================
   PDF TITLE AREA
========================================================= */

.studyhub-pdf-title-area {
    display: flex;

    align-items: center;

    gap: 13px;

    min-width: 0;
}


/* =========================================================
   PDF ICON
========================================================= */

.studyhub-pdf-icon {
    width: 50px;
    height: 50px;

    min-width: 50px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 13px;

    background: #fff0f0;

    color: #dc3545;

    font-size: 23px;
}


/* =========================================================
   PDF TITLE
========================================================= */

.studyhub-pdf-title-area h3 {
    margin: 0 0 4px;

    color: #172033;

    font-size: 19px;

    font-weight: 750;

    line-height: 1.35;

    word-break: break-word;
}


/* PDF Subtitle */

.studyhub-pdf-title-area p {
    margin: 0;

    color: #7b8596;

    font-size: 12px;

    line-height: 1.5;
}


/* =========================================================
   PDF ACTIONS
========================================================= */

.studyhub-pdf-actions {
    width: 100%;

    display: flex;

    align-items: center;

    justify-content: flex-end;

    gap: 10px;

    margin-bottom: 15px;
}


/* =========================================================
   DOWNLOAD BUTTON
========================================================= */

.studyhub-download-btn {
    min-height: 42px;

    padding: 10px 16px;

    display: inline-flex;

    align-items: center;
    justify-content: center;

    gap: 8px;

    border: 1px solid #198754;

    border-radius: 9px;

    background: #198754;

    color: #ffffff;

    text-decoration: none;

    font-size: 12px;

    font-weight: 700;

    line-height: 1;

    white-space: nowrap;

    transition:
        background 0.25s ease,
        border-color 0.25s ease,
        transform 0.25s ease,
        box-shadow 0.25s ease;
}


/* Download Hover */

.studyhub-download-btn:hover {
    background: #157347;

    border-color: #157347;

    color: #ffffff;

    text-decoration: none;

    transform: translateY(-2px);

    box-shadow:
        0 7px 18px rgba(25, 135, 84, 0.20);
}


/* Download Icon */

.studyhub-download-btn i {
    font-size: 14px;
}


/* =========================================================
   FULLSCREEN BUTTON
========================================================= */

.studyhub-fullscreen-btn {
    min-height: 42px;

    padding: 10px 16px;

    display: inline-flex;

    align-items: center;
    justify-content: center;

    gap: 8px;

    border: 1px solid #dce3ec;

    border-radius: 9px;

    background: #f8fafc;

    color: #566174;

    font-size: 12px;

    font-weight: 700;

    line-height: 1;

    cursor: pointer;

    white-space: nowrap;

    transition:
        background 0.25s ease,
        color 0.25s ease,
        border-color 0.25s ease,
        transform 0.25s ease;
}


/* Fullscreen Hover */

.studyhub-fullscreen-btn:hover {
    background: #0d6efd;

    border-color: #0d6efd;

    color: #ffffff;

    transform: translateY(-2px);
}


/* =========================================================
   PDF VIEWER CONTAINER
========================================================= */

.studyhub-pdf-viewer {
    width: 100%;

    height: 720px;

    background: #20252d;

    border: 1px solid #dfe4eb;

    border-radius: 13px;

    overflow: hidden;

    position: relative;

    box-shadow:
        inset 0 0 0 1px rgba(255, 255, 255, 0.03);
}


/* =========================================================
   PDF IFRAME
========================================================= */

.studyhub-pdf-viewer iframe {
    display: block;

    width: 100%;
    height: 100%;

    border: 0;

    background: #ffffff;
}


/* =========================================================
   MOBILE PDF INFORMATION
========================================================= */

.studyhub-mobile-pdf-info {
    width: 100%;

    display: flex;

    align-items: center;

    justify-content: center;

    gap: 8px;

    margin-top: 12px;

    padding: 10px 12px;

    border-radius: 9px;

    background: #f3f7fc;

    color: #697586;

    font-size: 11px;

    line-height: 1.5;

    text-align: center;
}


/* Mobile Info Icon */

.studyhub-mobile-pdf-info i {
    color: #0d6efd;

    font-size: 14px;

    flex-shrink: 0;
}


/* =========================================================
   PDF FULLSCREEN MODE
========================================================= */

.studyhub-pdf-viewer:fullscreen {
    width: 100vw;

    height: 100vh;

    border: 0;

    border-radius: 0;
}


/* Webkit Fullscreen */

.studyhub-pdf-viewer:-webkit-full-screen {
    width: 100vw;

    height: 100vh;

    border: 0;

    border-radius: 0;
}


/* =========================================================
   PDF BUTTON FOCUS
========================================================= */

.studyhub-download-btn:focus {
    outline: none;
}


.studyhub-download-btn:focus-visible {
    outline: 3px solid rgba(25, 135, 84, 0.25);

    outline-offset: 3px;
}


.studyhub-fullscreen-btn:focus {
    outline: none;
}


.studyhub-fullscreen-btn:focus-visible {
    outline: 3px solid rgba(13, 110, 253, 0.22);

    outline-offset: 3px;
}


/* =========================================================
   TABLET
========================================================= */

@media (max-width: 991.98px) {

    .studyhub-pdf-viewer {
        height: 650px;
    }


    .studyhub-pdf-title-area h3 {
        font-size: 18px;
    }


    .studyhub-download-btn,
    .studyhub-fullscreen-btn {
        min-height: 40px;

        padding: 9px 13px;

        font-size: 11px;
    }

}


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

@media (max-width: 767.98px) {

    /* PDF Step */

    .studyhub-pdf-step {
        padding: 16px 12px 20px;
    }


    /* PDF Header */

    .studyhub-pdf-header {
        align-items: flex-start;

        gap: 12px;

        margin-bottom: 16px;
    }


    /* PDF Title */

    .studyhub-pdf-title-area {
        gap: 10px;

        min-width: 0;
    }


    /* PDF Icon */

    .studyhub-pdf-icon {
        width: 42px;
        height: 42px;

        min-width: 42px;

        border-radius: 10px;

        font-size: 19px;
    }


    /* PDF Title */

    .studyhub-pdf-title-area h3 {
        font-size: 15px;

        line-height: 1.35;
    }


    .studyhub-pdf-title-area p {
        font-size: 10px;

        line-height: 1.4;
    }


    /* Header Back Button */

    .studyhub-pdf-header .studyhub-back-btn {
        flex-shrink: 0;

        margin-bottom: 0;

        padding: 8px 10px;

        font-size: 10px;
    }


    /* PDF Actions */

    .studyhub-pdf-actions {
        display: grid;

        grid-template-columns: 1fr 1fr;

        gap: 8px;

        margin-bottom: 10px;
    }


    /* Action Buttons */

    .studyhub-download-btn,
    .studyhub-fullscreen-btn {
        width: 100%;

        min-height: 40px;

        padding: 9px 8px;

        border-radius: 8px;

        font-size: 10px;
    }


    /* PDF Viewer */

    .studyhub-pdf-viewer {
        height: 560px;

        border-radius: 9px;
    }


    /* Mobile Info */

    .studyhub-mobile-pdf-info {
        margin-top: 9px;

        padding: 9px;

        font-size: 10px;

        border-radius: 8px;
    }

}


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

@media (max-width: 480px) {

    .studyhub-pdf-step {
        padding: 14px 10px 18px;
    }


    .studyhub-pdf-header {
        gap: 8px;
    }


    .studyhub-pdf-title-area {
        gap: 8px;
    }


    .studyhub-pdf-icon {
        width: 38px;
        height: 38px;

        min-width: 38px;

        font-size: 17px;
    }


    .studyhub-pdf-title-area h3 {
        font-size: 13px;
    }


    .studyhub-pdf-title-area p {
        font-size: 9px;
    }


    .studyhub-pdf-header .studyhub-back-btn {
        padding: 7px 8px;

        font-size: 9px;
    }


    .studyhub-pdf-actions {
        grid-template-columns: 1fr 1fr;

        gap: 6px;
    }


    .studyhub-download-btn,
    .studyhub-fullscreen-btn {
        min-height: 38px;

        padding: 8px 5px;

        font-size: 9px;
    }


    .studyhub-download-btn i,
    .studyhub-fullscreen-btn i {
        font-size: 11px;
    }


    .studyhub-pdf-viewer {
        height: 500px;

        border-radius: 8px;
    }


    .studyhub-mobile-pdf-info {
        font-size: 9px;

        line-height: 1.4;
    }

}


/* =========================================================
   VERY SMALL MOBILE
========================================================= */

@media (max-width: 350px) {

    .studyhub-pdf-viewer {
        height: 440px;
    }


    .studyhub-pdf-title-area h3 {
        font-size: 12px;
    }


    .studyhub-pdf-header .studyhub-back-btn {
        font-size: 8px;

        padding: 6px 7px;
    }


    .studyhub-download-btn,
    .studyhub-fullscreen-btn {
        font-size: 8px;

        min-height: 36px;
    }

}


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

@media (max-width: 767.98px) and (orientation: landscape) {

    .studyhub-pdf-viewer {
        height: 420px;
    }

}


/* =========================================================
   REDUCED MOTION ACCESSIBILITY
========================================================= */

@media (prefers-reduced-motion: reduce) {

    .studyhub-section *,
    .studyhub-section *::before,
    .studyhub-section *::after {
        scroll-behavior: auto !important;

        transition-duration: 0.01ms !important;

        animation-duration: 0.01ms !important;

        animation-iteration-count: 1 !important;
    }

}