/* =========================================================
   05 HOW
   ========================================================= */

.how {
    background: var(--color-blue-pastel);
}

.how {
    padding: 36px 0 0;
}

.how_container {
    width: 92%;
    margin: 0 auto;
    padding-bottom: 30px;
}

.how__header {
    max-width: 800px;
    margin: 0 auto 40px;
}

.how-it-works, .how__bottom {
    max-width: 800px;
    margin: 0 auto 30px;
}

.how__header p {
    margin: 0;
    font-size: 18px;
    line-height: 1.55;
    opacity: 0.75;
}

.how-it-works__steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-block: 20px;
}

.how-step {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 18px 22px;
    border: 1px solid var(--color-blue-accent);
    border-radius: 12px;
    background: #fff;
    color: var(--color-blue-accent);
    cursor: pointer;
    text-align: left;
    transition:
        background 0.2s ease,
        border-color 0.2s ease,
        transform 0.2s ease;
}

.how-step:hover {
    transform: translateY(-2px);
}

.how-step.is-active {
    border-color: var(--color-blue-accent);
    background: var(--color-blue-accent);
    color: #fff;
}

.how-step__number {
    font-size: 13px;
    font-weight: 700;
    opacity: 1;
}

.how-step__title {
    font-size: 16px;
    font-weight: 600;
}

.how-works__diagram {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 80px 1fr 80px 1fr;
    grid-template-rows: auto 35px auto;
    align-items: center;
    gap: 24px;
    padding: 45px 30px;
    min-height: 250px;
    border: 1px solid #dfe3e6;
    border-radius: 20px;
    background: #fff;
    box-sizing: border-box;
}

.energy-node {
    min-height: 110px;
    padding: 20px;
    border: 1px solid var(--color-blue-accent);
    border-radius: 14px;
    background: var(--color-blue-pastel);
    text-align: center;
    box-sizing: border-box;
}

.energy-node__icon {
    display: block;
    margin-bottom: 8px;
    font-size: 28px;
    line-height: 1;
}

.energy-node strong {
    display: block;
    margin-bottom: 5px;
    font-size: 18px;
}

.energy-node small {
    display: block;
    font-size: 13px;
    line-height: 1.35;
    opacity: 1;
}

.energy-node--grid {
    grid-column: 1;
    grid-row: 1;
}

.energy-node--inverter {
    grid-column: 3;
    grid-row: 1;
    border-color: var(--color-blue-dark);
    background: var(--color-blue-dark);
    color: #fff;
}

.energy-node--load {
    grid-column: 5;
    grid-row: 1;
}

.energy-node--battery {
    grid-column: 3;
    grid-row: 3;
}

.energy-line {
    position: relative;
    height: 4px;
    background: var(--color-blue-pastel);
    border-radius: 4px;
}

.energy-line--grid {
    grid-column: 2;
    grid-row: 1;
}

.energy-line--load {
    grid-column: 4;
    grid-row: 1;
}

.energy-line--battery {
    grid-column: 3;
    grid-row: 2;
    width: 4px;
    height: 35px;
    justify-self: center;
}

.energy-flow {
    position: absolute;
    top: 50%;
    left: 0;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--color-blue-accent);
    transform: translateY(-50%);
    animation: energyFlow 1.5s linear infinite;
}

.energy-line--battery .energy-flow {
    top: 0;
    left: 50%;
    bottom: auto;
    transform: translateX(-50%);
    animation: energyFlowDown 1.5s linear infinite;
}

@keyframes energyFlow {
    from { left: 0; }
    to { left: calc(100% - 14px); }
}

@keyframes energyFlowDown {
    from {
        top: 0;
    }

    to {
        top: calc(100% - 14px);
    }
}

@keyframes energyFlowUp {
    from {
        top: calc(100% - 14px);
    }

    to {
        top: 0;
    }
}

.how-works__info {
    margin-top: 24px;
}

.how-info {
    display: none;
    padding: 28px 32px;
    border: 1px solid var(--color-blue-accent);
    border-radius: 16px;
    background: var(--color-blue-accent);
    color: #fff;
}

.how-info.is-active {
    display: block;
}

.how-info h3 {
    margin: 0 0 10px;
    font-size: 22px;
}

.how-info p {
    max-width: 850px;
    margin: 0;
    font-size: 16px;
    line-height: 1.6;
    opacity: 1;
}

.how__bottom {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 24px;
}

.how-info-card {
    display: none;
    padding: 28px 30px;
    border: 1px solid var(--color-blue-accent);
    border-radius: 16px;
    background: #fff;
    color: var(--color-blue-accent);
    box-sizing: border-box;
}

.how-info-card.is-active {
    display: block;
}

.how-info-card__label {
    display: block;
    margin-bottom: 10px;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.how-info-card p {
    margin: 0;
    font-size: 15px;
    line-height: 1.55;
    color: var(--color-blue-accent);
}

@media (max-width: 767px) {

    @media (min-width: 360px) and (max-width: 450px) {
        .energy-node--inverter {
            margin-inline: -8px;
        }   
    }

    .how_container {
        width: 92%;
        margin: 0 auto;
    }

    .how-it-works {
        margin-bottom: 0px;
    }

    /* Три состояния остаются в одну строку */

    .how-it-works__steps {
    grid-template-columns:
        calc((100% - 12px) / 3)
        calc((100% - 12px) / 3)
        calc((100% - 12px) / 3);
    gap: 6px;
}

    .how-step {
        width: 100%;
        min-width: 0;
        padding: 10px 8px;
        gap: 6px;
        border-radius: 10px;
    }

    .how-step__number {
        flex: 0 0 auto;
        font-size: 10px;
    }

    .how-step__title {
        min-width: 0;
        font-size: 12px;
        line-height: 1.2;
    }

    /* Схема сохраняет десктопную структуру:
       Сеть → Инвертор → Нагрузка
                       ↕
                      АКБ */

    .how-works__diagram {
        grid-template-columns:
            minmax(0, 1fr)
            28px
            minmax(0, 1fr)
            28px
            minmax(0, 1fr);

        grid-template-rows: auto 25px auto;
        gap: 6px;

        padding: 20px 12px;
        min-height: 0;
    }

    .energy-node {
        min-height: 78px;
        padding: 10px 6px;
        border-radius: 10px;
    }

    .energy-node__icon {
        margin-bottom: 5px;
        font-size: 20px;
    }

    .energy-node strong {
        margin-bottom: 3px;
        font-size: 14px;
    }

    .energy-node small {
        font-size: 9px;
        line-height: 1.25;
    }

    .energy-line {
        height: 3px;
    }

    .energy-line--battery {
        width: 3px;
        height: 25px;
    }

    .energy-flow {
        width: 10px;
        height: 10px;
    }

    @keyframes energyFlow {
        from {
            left: 0;
        }

        to {
            left: calc(100% - 10px);
        }
    }

    @keyframes energyFlowDown {
        from {
            top: 0;
        }

        to {
            top: calc(100% - 10px);
        }
    }

    @keyframes energyFlowUp {
        from {
            top: calc(100% - 10px);
        }

        to {
            top: 0;
        }
    }

    .how-works__info {
        margin-top: 18px;
    }

    .how-info {
        padding: 20px 18px;
    }

    .how-info h3 {
        margin-bottom: 8px;
        font-size: 19px;
    }

    .how-info p {
        font-size: 14px;
        line-height: 1.5;
    }

    .how__bottom {
        grid-template-columns: 1fr;
    }
}

/* ---------- STATES ---------- */

/* Сеть есть / Сеть восстановилась:
   энергия идёт от инвертора к АКБ — сверху вниз */

.how[data-state="network"] .energy-line--battery .energy-flow,
.how[data-state="restore"] .energy-line--battery .energy-flow {
    animation-name: energyFlowDown;
}

/* Сеть отключилась:
   поток идёт от АКБ к инвертору — снизу вверх */

.how[data-state="outage"] .energy-line--battery .energy-flow {
    animation-name: energyFlowUp;
}

/* При отключении сети поток Сеть → Инвертор отсутствует */

.how[data-state="outage"] .energy-line--grid .energy-flow {
    display: none;
}


.energy-node--grid .energy-node__icon {
    color: var(--color-blue-dark);
}
.energy-node--load .energy-node__icon {
    color: var(--color-blue-dark);
}
.energy-node--battery .energy-node__icon {
    color: var(--color-blue-dark);
}