*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    text-decoration: none;
    font-family: 'IBM Plex Sans', sans-serif;
    list-style: none;
}

.d-flex {
    display: flex;
    
}

.justify-content-between {
    justify-content: space-between;
}

.align-items-center {
    align-items: center;
}

.header {
    background-color: #000;
    color: #fff;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 160px;
    z-index: 1000; 
}

.header div {
    height: 100%;
}

.container {
    max-width: 1250px;
    margin-left: auto;
    margin-right: auto;
    padding-right: var(--bs-gutter-x,.75rem);
    padding-left: var(--bs-gutter-x,.75rem);
    
}

.header-description {
    display: block;
    font-size: 1.5rem;
    margin-left: 10px;
    transform: translateX(-96px);
}


.header-logo {
    display: block;
    height: 110px;
    transform: translate(-95.5px, 25px);
}

.header-nav li {
    margin-right:  0.8rem;
}

.header-nav-item {
    color: #fff;
    font-size: 1.125rem;
}

.header-nav-item:hover {
    color: #FF530A;
    transition: color .3s ease-in;
}

.header-nav li:last-child {
    margin-right: 0;
    margin-left: 20px;
}

.header-nav li:last-child > a {
    background-color: #FF530A;
    border-radius: 40px;
    padding: 7px 20px;
    font-weight: bold;
}

.header-nav li:last-child > a:hover {
    color: black;
    transition: color .3s ease-in;
}

.header-menu {
    display: none;
    width: 30px;
    align-items: center;
    position: relative;
    cursor: pointer;
    z-index: 30;
}

.faq {
  padding: 60px 0;
}

.faq__title {
  text-align: center;
  margin-bottom: 40px;
  font-size: 32px;
}

.faq__content {
  max-width: 700px;
  margin: 0 auto;
}

.details {
      position: relative;
  border: 1px solid #444;
  border-radius: 8px;
  margin-bottom: 15px;
  overflow: hidden;
  
  color: #fff; 
  display: block;
  max-width: 600px;
  margin: 0 10% 10px;
  background: none;
  border-radius: 5px;
  transition: 0.3s;
  overflow: hidden;
  //border-bottom: 1px solid #7695a9;
  z-index: 1;
 
 
}

.details__title {
    position: relative; /* важно для абсолютного позиционирования стрелки */
 
  
  cursor: pointer;

  padding: 16px 40px 16px 20px; /* справа место под стрелку */
  font-weight: 600;
  background: #333;
  font-size: 18px;
 
}

/* убираем стандартный маркер */
.details__title::-webkit-details-marker {
  display: none;
}
.details__title::marker {
  content: "";
}

/* стрелка справа */
.details__title::after {
    
content: '';
  position: absolute;
  right: 20px;
  top: 50%;
  width: 10px;
  height: 10px;
  border-right: 2px solid #fff;
  border-bottom: 2px solid #fff;
  transform: translateY(-50%) rotate(-45deg);
  transition: transform 0.3s ease;
  z-index: 1;
 
}

/* при открытии */
.details[open] > .details__title::after {
  transform: translateY(-50%) rotate(45deg); /* открыто */
}

.details__content {
  padding: 16px 20px;
  background: #2a2a2a;
  border-top: 1px solid #444;
  font-weight:300;
  font-size: 14px;
  
}

.details__content ul {
    list-style: none; /* убираем стандартные маркеры */
    padding-left: 0;
    margin: 0;
}

.details__content ul li {
    position: relative;
    padding-left: 20px; /* место под маркер */
    margin-bottom: 8px;
    font-size: 16px;
    line-height: 1.5;
    color: #f0f0f0;
}

/* маленький белый круглый маркер слева */
.details__content ul li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background-color: #ffffff; /* белый маркер */
    border-radius: 50%;
}

/* ссылки внутри списка */
.details__content ul li a {
    color: #FF530A;
    text-decoration: underline;
}

.details__content ul li a:hover {
    color: #FFB347;
}


.cross {
    background-color: inherit!important;
}

.btn-burger {
    display: block;
    width: 100%;
    height: 4px;
    background-color: #fff;
    position: absolute;
}

.btn-burger:before, .btn-burger:after {
    content: '';
    display: block;
    width: 100%;
    background-color: #fff;
    height: 4px;
    position: absolute;
}

.btn-burger:before {
    left: 0;
    top: -12.5px;
}

.cross:before{
    transform: rotate(45deg);
    top: 0;
    transition: transform 0.3s ease-in;
}

.btn-burger:after {
    bottom: -12.5px;
    left: 0;
}

.cross:after {
    bottom: 0;
    transform: rotate(-45deg);
    transition: transform 0.3s ease-in;
}

.hero {
   
    background: url(../img/bk-platform.jpg) no-repeat right top;
    background-size: cover;
    padding-top: 17rem;
    padding-bottom: 4rem;
    font-weight: 700;
    line-height: 1.2;
  
    
    
}


.hero-content {
    max-width: 560px;
}

.hero-content li:last-child {
    border: none;
}

.hero-content-item {
    font-size: 1.7rem;
    border-bottom: 1px solid #7695a9;
    display: block;
    color: #fff;
    padding-bottom: 10px;
    padding-top: 10px;
    cursor: pointer;
}

.hero-content-item:hover {
    color: #FF530A;
    transition: color .3s ease-in;
}

.section-title {
    font-size: 2.625rem;
    font-weight: bold;
    padding-bottom: 1.25rem;
    padding-top: 4rem;
}

.section-description {
    padding-bottom: 1rem;
    font-size: 1.125rem;
    line-height: 1.4;
}

.course-description {
    font-size: 1.125rem;
    line-height: 1.4;
    padding-bottom: 1rem;
    width: 75%;
}

.link {
    color: #FF530A;
}

.link:visited{
    color: #FF530A;
}

.link2 {
    font-size: 1.125rem;
    color: #000;
}

.link2:visited{
    color: #000;
}
.link2:hover { 
    text-decoration: underline; 
   }


.course-content {
    border-top: 1px solid black;
    padding-top: 2rem;
    padding-bottom: 2.125rem;
}

.course article:last-child {
    padding-bottom: 0;
}

.course-title {
    width: 15%;
}

.course-description li{
    padding-bottom: 1rem;
}

.custom-course {
    padding-bottom: 2rem;
}

.custom-item {
    font-size: 1.125rem;
    line-height: 1.4;
    padding-bottom: 1rem;
}

.custom-item-format {
    padding-bottom: 1rem;
}

.custom-item-format li{
    margin-left: 2.5rem;
    padding-top: 1rem;
    list-style: disc;
}

.clients {
    background-color: black;
    color: #fff;
    background-image: url(../img/phbk.jpg);
    background-repeat: no-repeat;
    background-size: 580px;
    background-attachment: fixed;
    background-position: center right 20%;
    padding-bottom: 2rem;
}

.clients-list li{
    border-bottom: 1px solid #333;
    font-size: 1.5rem;
    line-height: 1.4;
    max-width: 560px;
    padding: 0.5rem 0;
    font-weight: 700;
}

.clients-list li:last-child {
    border: none
}

.side-menu {
    position: absolute;
    width: 100%;
    height: 100vh!important;
    left: -100%;
    background: #eeeeee;
    text-align: center;
    transition: all 0.3s ease-in;
    z-index: 9999;
}

.side-menu.active {
    left: 0;
    transition: all 0.3s ease-in;
   
}

.side-menu li {
    padding-bottom: 1rem;
    padding-top: 1rem;
    font-size: 2rem;
    border-bottom: 1px solid #000 ;
    font-weight: 700;
}

.side-menu a:hover {
    color: #FF530A;
    transition: all .2s ease-in;
}

.side-menu a {
    color: #000;
    transition: all .2s ease-in;
}

.founder {
    margin-bottom: 2rem;
}

.founder-wrapper {
    justify-content: space-around;
    align-items: center;
    font-size: 1.5rem;
    line-height: 1.4;
    font-weight: 700;
}

.founder img {
    display: block;
    max-width: 450px;
    width: 100%;
    margin-right: 2rem;
}

.footer {
    background-color: #eeeeee;
    padding-bottom: 2.625rem;
     z-index: 1;
}

.footer-wrapper {
    padding-top: 1.125rem;
}

.email-block span {
    display: block;
    font-size: 1.125rem;
    line-height: 1.4;
    font-weight: bold;
}

.footer-email {
    display: block;
    color: #FF530A;
    padding-top: 1.125rem;
    font-size: 1.125rem;
    line-height: 1.4;
}

.form {
    width: 530px;
    margin-left: 4rem;
    position: relative;
}

.form-input {
    display: block;
    width: 100%;
    height: 40px;
    margin-bottom: 2rem;
}

.form-textarea {
    display: block;
    margin-bottom: 20px;
    padding: 10px;
    width: 100%;
    height: 240px;
}

.form-input, .form-textarea {
    border: none;
    border-radius: 10px;
    background-color: #fff;
    outline: none;
    box-shadow: inset 1px 1px 4px rgb(0 0 0 / 25%);
    padding-left: 1.25rem;
    resize: none;
    font-size: 0.875rem;
    font-family: 'IBM Plex Sans', sans-serif;
}

.form-btn {
    font-family: 'IBM Plex Sans', sans-serif;
    cursor: pointer;
    width: 25%;
    min-width: 150px;
    height: 60px;
    background-color: #FF530A;
    border-radius: 10px;
    color: #fff;
    font-size: 1.25rem;
    font-weight: bold;
    border: none;
    outline: none;
    display: block;
    margin-top: 2.5rem;
    
}

.email-error {
    position: absolute;
    top: -20px;
    right: 0;
    color: red
}

.text-error {
    position: absolute;
    top: 50px;
    right: 0;
    color: red
}

.header-scroll {
    height: 100px;
}

.logo-scroll {
    height: 100px;
    opacity: .4;
    transform: translate(-95.5px, 0);
}

.indicator-wrap {
    position: fixed;
    top: 0;
    z-index: 12;
    width: 5px;
    height: 1000px;
}

.indicator {
    display: block;
    width: 5px;
    background-color: #FF530A;
    height: 0;
    position: absolute;
    top: 78px;
    left: 0;
}

.up {
    opacity: 0;
    position: fixed;
    left: 2.5%;
    bottom: 20px;
    transition: all ease 0.5s;
    background-color: #EEEEEE;
    border-radius: 5px;
    z-index: 3;
    padding: 10px;
}

.up:hover {
    background-color: #FF530A;
}

.up a {
    display: block;
    width: 40px;
    height: 40px;
}

.up img {
    width: 40px;
}

.visible {
    opacity: 1;
    transition: all ease 0.5s;
}

.detail {
    display: none;
    margin-top: 2.125rem;
    background-color: #EEEEEE;
    padding: 2rem;
    font-size: 1.5rem;
    line-height: 140%;
    font-weight: 500;
}

.detail ul {
    padding-left: 15px;
}

.detail li {
    padding-bottom: 16px;
    text-indent: -28px;
}

.detail li::before {
    content: "—";
    padding-right: 8px;
}

.detail-visible {
    display: block;
}

.invalid {
    background: radial-gradient(#f58b8b, transparent)
}

.valid {
    border: 1px solid green;
}

.disabled {
    background-color: grey;
}

@media screen and (max-width: 1490px) {
    .container {
        margin-left: 10%;
        margin-right: 10%;
    }
}


@media screen and (max-width: 1200px) {
    .container {
        max-width: 1140px;
        margin-left: 10%;
        margin-right: 10%;
    }
    
    .header-logo {
        display: none;
    }

    .header-description {
        transform: translateX(0);
    }

    .indicator {
        top: 70px;
    }

    .header {
        height: 70px;
    }
}

@media screen and (max-width: 992px) {
    .container {
        max-width: 960px;
    }

    .clients {
        background-image: url(../img/phbk-small.jpg);
    }

    .hero {
        padding-top: 7.5rem;
    }

    .footer-wrapper {
        display: block;
    }

    .form {
        margin-left: 0;
        margin-top: 1.125rem;
    }

    .header-nav {
        display: none;
    }

    .header-menu {
        display: flex;
    }
}

@media screen and (max-width: 768px) {
    .container {
        max-width: 720px;
        margin-left: auto;
        margin-right: auto;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .hero {
        background-position: bottom;
    }

    .hero-content{
        max-width: 100%;
    }

    .course-content {
        display: block;
    }

    .course-title {
        margin-bottom: 1rem;
    }

    .course-content > * {
        width: 100%;
    }

    .form {
        width: 100%;
    }

    .indicator {
        display: none;
    }

    .founder-wrapper {
        display: block;
    }

    .founder img {
        margin-bottom: 2rem;
    }
    
    .form-btn {
        margin-left: auto;
        margin-right: auto;
    }
}

@media screen and (max-width: 576px) {
    .container {
        max-width: 540px;
    }
}