/* --- Стили для Бетона (Concrete/Gray Theme) --- */
:root {
    --accent-concrete: #57534E; /* Stone 600 - Оригинальный серый */
    --accent-concrete-dark: #292524;
    --gradient-concrete-card: linear-gradient(135deg, #78716C 0%, #44403C 100%);
    
    /* Цвета компонентов */
    --col-cem: #A8A29E;
    --col-sand: #FCD34D;
    --col-grav: #71717A;
}

.calc-header { margin-bottom: 32px; }
.subtitle { color: var(--text-secondary); margin-top: 8px; }

/* Сетка */
.calc-grid { display: grid; grid-template-columns: 1fr; gap: 24px; align-items: start; }
@media (min-width: 900px) { .calc-grid { grid-template-columns: 1.2fr 0.8fr; } }

/* Inputs */
.calc-inputs { gap: 16px; }
.input-group { margin-bottom: 16px; }
.input-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; color: var(--text-primary); }

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; }

.input-wrapper { position: relative; display: flex; align-items: center; }

.input-wrapper input {
    width: 100%; padding: 14px 16px; padding-right: 40px;
    font-size: 18px; font-weight: 500;
    border: 1px solid #E5E7EB; border-radius: 12px;
    outline: none; transition: border 0.2s, box-shadow 0.2s;
    font-family: var(--font-main);
}
.input-wrapper input:focus { border-color: var(--accent-concrete); box-shadow: 0 0 0 3px rgba(87, 83, 78, 0.15); }

.suffix { 
    position: absolute; right: 16px; top: 50%; transform: translateY(-50%);
    color: var(--text-secondary); pointer-events: none; font-size: 14px; 
}
.helper-text { font-size: 12px; color: var(--text-secondary); margin-top: 6px; }

.row-2-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.divider { border-top: 1px solid #E5E7EB; margin: 24px 0; }

/* Табы */
.mode-switcher {
    display: flex; background: #F3F4F6; padding: 4px;
    border-radius: 12px; margin-bottom: 24px; gap: 4px;
}
.mode-btn {
    flex: 1; padding: 10px 4px; border: none; background: transparent;
    color: var(--text-secondary); font-size: 13px; font-weight: 600;
    border-radius: 8px; cursor: pointer; transition: all 0.2s; text-align: center;
}
.mode-btn.active { background: #fff; color: var(--text-primary); box-shadow: 0 2px 8px rgba(0,0,0,0.05); }

/* Сетка марок */
.mark-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px;
}
.mark-option { cursor: pointer; }
.mark-option input { display: none; }
.mark-option span {
    display: flex; align-items: center; justify-content: center;
    height: 40px; border: 1px solid #E5E7EB; border-radius: 8px;
    font-size: 13px; font-weight: 700; color: var(--text-secondary);
    transition: all 0.2s; background: #fff;
}
.mark-option input:checked + span {
    background: var(--accent-concrete); color: #fff; border-color: var(--accent-concrete);
    box-shadow: 0 2px 6px rgba(87, 83, 78, 0.3);
}

/* Результаты (Concrete Card) */
.card--concrete { background: var(--gradient-concrete-card); color: #fff; border: none; }
.card--concrete h2 { color: rgba(255,255,255,0.9); margin-bottom: 20px; font-size: 16px; }
@media (min-width: 900px) { .sticky-card { position: sticky; top: 24px; } }

.big-result {
    font-size: 56px; font-weight: 800; line-height: 1; margin-bottom: 32px;
    display: flex; align-items: baseline; gap: 12px; white-space: nowrap;
}
.big-result small { font-size: 24px; font-weight: 600; opacity: 0.8; }

/* Визуализация состава */
.mix-visual { 
    background: rgba(0,0,0,0.2); 
    border-radius: 12px; 
    padding: 16px; 
    margin-bottom: 24px; 
}
.mix-title { font-size: 12px; opacity: 0.8; margin-bottom: 12px; text-align: left; }

.mix-bar { 
    display: flex; 
    height: 54px; 
    border-radius: 12px; 
    overflow: hidden; 
}
.mix-part { 
    display: flex; flex-direction: column; 
    align-items: center; justify-content: center; 
    font-size: 10px; font-weight: 700; 
    color: rgba(0,0,0,0.6); 
    text-transform: uppercase;
    transition: flex 0.5s ease;
    text-align: center;
    line-height: 1.3;
}
.p-name { font-size: 9px; opacity: 0.8; margin-bottom: 2px; }
.p-val { font-size: 14px; font-weight: 800; }

.part-cem { background: var(--col-cem); }
.part-sand { background: var(--col-sand); }
.part-grav { background: var(--col-grav); color: rgba(255,255,255,0.8); }

.summary-divider { height: 1px; background: rgba(255,255,255,0.2); margin: 24px 0; }

/* Список материалов */
.materials-list { display: flex; flex-direction: column; gap: 16px; margin-bottom: 24px; }
.mat-row { display: flex; align-items: flex-start; gap: 12px; }
.mat-icon { 
    width: 32px; height: 32px; flex-shrink: 0;
    display: flex; align-items: center; justify-content: center;
    background: rgba(255,255,255,0.15); border-radius: 8px;
    color: #fff;
}
.mat-icon svg { width: 20px; height: 20px; }

.mat-info { display: flex; flex-direction: column; line-height: 1.2; flex-grow: 1; }
.mat-info span { font-size: 12px; opacity: 0.8; margin-bottom: 4px; }
.mat-val-row { display: flex; align-items: baseline; gap: 6px; flex-wrap: wrap; }
.mat-info strong { font-size: 18px; font-weight: 700; }
.mat-info small { font-size: 13px; opacity: 0.7; font-weight: 400; }

.tip-box {
    font-size: 13px; line-height: 1.4; color: #ffffff !important;
    background: rgba(0, 0, 0, 0.3) !important; padding: 16px; border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.15);
}
.tip-box p { margin: 0; color: #ffffff !important; }


/* --- НОВЫЕ ИНФОРМАЦИОННЫЕ БЛОКИ --- */

.info-wrapper {
    padding: 60px 0 60px 0;
    margin-top: 60px;
    border-top: 1px solid rgba(0,0,0,0.06);
    margin-bottom: 20px;
}

.info-wrapper .container {
    max-width: 800px;
    margin: 0 auto;
}

/* Заголовки с иконками */
.icon-heading {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
    font-size: 24px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.3;
}

.header-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 14px;
    background: #fff;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    flex-shrink: 0;
    margin-top: -4px;
}

.header-icon svg { width: 24px; height: 24px; stroke-width: 2px; }

/* Цвета иконок (Фиксированные для семантики) */
.blue-icon svg { color: #2563EB; }
.orange-icon svg { color: #F97316; }
.green-icon svg { color: #10B981; }
.red-icon svg { color: #EF4444; }

/* Маленькие подзаголовки */
.small-heading {
    margin-top: 40px;
    margin-bottom: 16px;
    font-size: 20px;
}
.small-heading .header-icon { width: 40px; height: 40px; }
.small-heading .header-icon svg { width: 20px; height: 20px; }

.intro-text {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.6;
}

/* --- Секция Формул --- */
.formulas-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 48px;
}

.formula-card {
    background: #fff;
    border: 1px solid rgba(0,0,0,0.04);
    box-shadow: var(--shadow-soft);
    border-radius: var(--radius-lg); 
    padding: 24px;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    display: flex;
    flex-direction: column;
    text-align: center; /* Центрируем для ПК и Мобайла */
    align-items: center;
}
.formula-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }

/* Вертикальный хедер (бейдж сверху) */
.formula-header {
    display: flex;
    flex-direction: column;
    align-items: center; /* Центр */
    gap: 12px;
    margin-bottom: 16px;
    width: 100%;
}

.formula-card h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
}

/* Бейджи */
.badge-blue {
    background: #2563EB; color: #fff;
    padding: 6px 12px; border-radius: 99px;
    font-size: 11px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.05em;
    display: inline-block;
}
.badge-green {
    background: #10B981; color: #fff;
    padding: 6px 12px; border-radius: 99px;
    font-size: 11px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.05em;
    display: inline-block;
}

.formula-card p {
    font-size: 14px; color: var(--text-secondary);
    margin: 0; line-height: 1.5; font-weight: 500;
}

.math-expression {
    background: #F5F5F4; /* Светло-серый */
    border: 1px solid #E7E5E4;
    padding: 12px 16px;
    border-radius: 12px;
    font-weight: 700;
    color: var(--accent-concrete); /* Серый акцент */
    text-align: center;
    margin-bottom: 16px;
    font-size: 15px;
    width: 100%;
}

/* Разделитель */
.soft-divider {
    border: none; height: 1px;
    background: linear-gradient(90deg, transparent, #E5E7EB, transparent);
    margin: 48px 0;
}

/* Описание */
.calc-description p {
    font-size: 16px; line-height: 1.7;
    color: var(--text-secondary); margin-bottom: 24px;
}
.calc-description strong { color: var(--text-primary); }

/* FAQ (Стиль Concrete) */
.faq-concrete-style .faq-item {
    background: #fff; border: 1px solid #E5E7EB;
    border-radius: 12px; margin-bottom: 12px;
    overflow: hidden; transition: all 0.2s ease;
}

.faq-concrete-style .faq-item[open] {
    border-color: var(--accent-concrete); 
    box-shadow: 0 4px 20px rgba(87, 83, 78, 0.15); /* Каменная тень */
}

.faq-concrete-style summary.faq-question {
    padding: 16px 20px; cursor: pointer;
    font-weight: 600; color: var(--text-primary);
    list-style: none; position: relative;
    display: flex; justify-content: space-between;
    align-items: center; transition: background 0.2s;
}

.faq-concrete-style summary.faq-question:hover { background-color: #F9FAFB; }

.faq-concrete-style .faq-item[open] summary.faq-question {
    color: var(--accent-concrete-dark);
    background: #F5F5F4; /* Светло-серый */
}

.faq-question::after {
    content: '+'; font-size: 20px;
    color: var(--text-secondary); font-weight: 400; line-height: 1;
}
.faq-question .icon-plus { display: none; }

.faq-concrete-style .faq-item[open] summary.faq-question::after {
    content: '−'; color: var(--accent-concrete);
}

.faq-answer {
    padding: 20px; color: var(--text-secondary);
    line-height: 1.6; font-size: 15px;
}

/* --- МОБИЛЬНАЯ АДАПТАЦИЯ --- */
@media (max-width: 900px) {
    /* Сетка в 1 колонку */
    .formulas-grid { grid-template-columns: 1fr; gap: 16px; margin-bottom: 32px; }
    
    /* Уменьшаем шрифты */
    .icon-heading { font-size: 20px; gap: 12px; margin-bottom: 20px; }
    .header-icon { width: 40px; height: 40px; border-radius: 12px; }
    .header-icon svg { width: 20px; height: 20px; }
    
    /* Центрирование контента карточки уже задано глобально для .formula-card */
    
    .math-expression {
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

    .info-wrapper { margin-top: 40px; padding-top: 40px; }
}