/* --- Oil Mix Theme --- */
:root {
    --oil-bg: #FEF9C3;       /* Light Yellow */
    --oil-card-bg: linear-gradient(135deg, #FACC15 0%, #CA8A04 100%);
    --oil-text: #422006;     /* Dark Brown */
    --oil-liquid: #B45309;   /* Amber Oil Color */
    --gas-liquid: #10B981;   /* Green Gasoline Color */
    --accent-oil: #CA8A04;   /* Основной акцент для текста и границ */
}

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

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

/* Inputs */
.input-group { margin-bottom: 24px; }
.input-group label { 
    font-size: 14px; font-weight: 700; color: #4B5563; 
    margin-bottom: 8px; display: block; 
}

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

.input-wrapper input {
    flex: 1; width: auto; min-width: 0;
    padding: 14px; border: 2px solid #E5E7EB; border-radius: 12px;
    font-size: 18px; font-weight: 600; outline: none; transition: border 0.2s;
    font-family: var(--font-main);
}
.input-wrapper input:focus { border-color: #EAB308; }

.suffix { position: absolute; right: 14px; color: #9CA3AF; font-weight: 500; }
.prefix { margin-right: 12px; font-weight: 700; color: #4B5563; font-size: 16px; white-space: nowrap; }

/* Quick Pills */
.quick-pills { display: flex; gap: 8px; margin-top: 10px; flex-wrap: wrap; }
.pill-btn {
    background: #F3F4F6; border: none; padding: 6px 12px; border-radius: 8px;
    font-size: 13px; font-weight: 600; color: #4B5563; cursor: pointer; transition: all 0.2s;
}
.pill-btn:hover { background: #E5E7EB; color: #000; }

/* Ratio Selector */
.ratio-selector { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; }
.ratio-option { cursor: pointer; }
.ratio-option input { display: none; }
.ratio-card {
    border: 2px solid #E5E7EB; border-radius: 12px; padding: 12px 6px;
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    background: #fff; transition: all 0.2s; text-align: center; height: 100%;
}
.ratio-val { font-weight: 800; font-size: 16px; color: #1F2937; }
.ratio-desc { font-size: 10px; color: #6B7280; margin-top: 2px; }

.ratio-option input:checked + .ratio-card {
    border-color: #EAB308; background: #FEFCE8;
    box-shadow: 0 4px 12px rgba(234, 179, 8, 0.2);
}

.custom-ratio-wrapper { margin-top: 16px; }

.custom-ratio-wrapper .checkbox-simple { 
    display: flex !important; align-items: center; gap: 10px; cursor: pointer; 
    font-size: 14px; font-weight: 600; color: #4B5563; line-height: 1.2; min-height: 24px; margin-bottom: 0;
}
.checkbox-simple input { accent-color: #EAB308; width: 18px; height: 18px; margin: 0; padding: 0; display: block; }

/* --- RESULT CARD --- */
.card--oil {
    background: var(--oil-card-bg); color: #fff; border: none;
    box-shadow: 0 10px 25px rgba(202, 138, 4, 0.4); position: relative; overflow: hidden;
}
.card--oil h2 { color: rgba(255,255,255,0.9); font-size: 16px; margin-bottom: 4px; text-align: center; }

.oil-result { text-align: center; font-size: 56px; font-weight: 800; line-height: 1; margin: 16px 0; text-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.oil-result .unit { font-size: 24px; font-weight: 600; opacity: 0.8; }

/* --- VISUALS --- */
.mix-visual {
    display: flex; align-items: flex-end; justify-content: center; gap: 16px;
    height: 140px; margin: 24px 0; padding: 0 10px;
}
.plus-sign { font-size: 24px; font-weight: 800; color: rgba(255,255,255,0.6); padding-bottom: 30px; }

.jerrycan {
    width: 80px; height: 100px; background: rgba(0,0,0,0.2);
    border-radius: 12px 12px 4px 4px; position: relative; border: 2px solid rgba(255,255,255,0.3);
    display: flex; flex-direction: column; justify-content: flex-end;
}
.jerrycan-handle { position: absolute; top: -12px; left: 15px; width: 50px; height: 12px; background: rgba(255,255,255,0.3); border-radius: 4px 4px 0 0; }
.jerrycan-spout { position: absolute; top: 5px; right: -8px; width: 12px; height: 16px; background: rgba(255,255,255,0.3); border-radius: 0 4px 4px 0; transform: rotate(-45deg); }
.jerrycan-liquid {
    width: 100%; height: 50%; background: var(--gas-liquid); opacity: 0.9;
    border-radius: 0 0 2px 2px; transition: height 0.5s cubic-bezier(0.25, 1, 0.5, 1);
}
.jerrycan-label { position: absolute; width: 100%; text-align: center; bottom: -24px; font-size: 12px; color: rgba(255,255,255,0.8); }

.cup-container { display: flex; flex-direction: column; align-items: center; position: relative; }
.cup {
    width: 40px; height: 80px; background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.4); border-bottom: 2px solid rgba(255,255,255,0.6);
    border-radius: 0 0 8px 8px; position: relative; display: flex; flex-direction: column; justify-content: flex-end; overflow: hidden;
}
.cup-liquid {
    width: 100%; height: 0%; background: #78350F;
    transition: height 0.5s ease-out; box-shadow: inset 0 0 10px rgba(0,0,0,0.2);
}
.cup-lines { position: absolute; top: 0; left: 0; width: 100%; height: 100%; display: flex; flex-direction: column; justify-content: space-evenly; }
.cup-lines span { width: 50%; height: 1px; background: rgba(255,255,255,0.3); }
.cup-label { margin-top: 8px; font-size: 12px; color: rgba(255,255,255,0.8); }

.summary-divider { height: 1px; background: rgba(255,255,255,0.2); margin: 20px 0; }
.result-summary p { font-size: 15px; margin-bottom: 4px; color: #fff; }
.small-tip { font-size: 12px !important; opacity: 0.8; font-style: italic; }


/* --- 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 */
.blue-icon svg { color: #2563EB; }
.orange-icon svg { color: var(--accent-oil); }
.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;
}
.formula-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }

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

.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: #FEFCE8; /* Светло-желтый фон */
    border: 1px solid #FEF08A; /* Желтая граница */
    padding: 12px 16px;
    border-radius: 12px;
    font-weight: 700;
    color: var(--oil-text);
    text-align: center;
    margin-bottom: 16px;
    font-size: 15px;
}

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

.faq-oil-style .faq-item[open] {
    border-color: var(--accent-oil); 
    box-shadow: 0 4px 20px rgba(202, 138, 4, 0.1);
}

.faq-oil-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-oil-style summary.faq-question:hover { background-color: #FEFCE8; }

.faq-oil-style .faq-item[open] summary.faq-question {
    color: var(--oil-text);
    background: #FEF9C3; /* Light Yellow */
}

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

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

.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 */
    .formula-card { 
        padding: 24px; 
        text-align: center; 
        align-items: center; 
    }

    .formula-header {
        align-items: center;
        width: 100%;
    }

    /* Блок с формулой по центру */
    .math-expression {
        width: 100%;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

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