/* calc/assets/css/calculators/quadratic-equation.css */

:root {
    --math-primary: #4F46E5; /* Indigo-600 */
    --math-bg: #EEF2FF;      /* Indigo-50 */
    --math-dark: #1E1B4B;    /* Indigo-950 */
    --math-accent: #6366F1;  /* Indigo-500 */
    --math-danger: #EF4444;  
}

/* --- ВЕРХНЯЯ ЧАСТЬ --- */
.calc-header { margin-bottom: 40px; }
.subtitle { color: var(--text-secondary); margin-top: 12px; font-size: 16px; line-height: 1.5; }

.calc-grid { display: grid; grid-template-columns: 1fr; gap: 32px; align-items: start; }
@media (min-width: 992px) { .calc-grid { grid-template-columns: 1.1fr 0.9fr; gap: 48px; } }

.form-divider { border: none; height: 1px; background: #C7D2FE; margin: 24px 0; opacity: 0.7; }
.group-title-small { font-size: 14px; font-weight: 700; color: var(--math-primary); text-transform: uppercase; letter-spacing: 0.5px; margin: 0 0 16px 0; border-left: 3px solid var(--math-primary); padding-left: 8px; }
.helper-text { font-size: 13px; color: #6B7280; line-height: 1.4; margin-top: 12px; }
.text-center { text-align: center; }

/* Уравнение Builder */
.equation-builder {
    display: flex; align-items: center; justify-content: center; gap: 12px; flex-wrap: wrap;
    background: #fff; padding: 24px 16px; border-radius: 16px; border: 2px solid var(--math-bg);
    box-shadow: 0 10px 20px -5px rgba(79, 70, 229, 0.1);
}

.eq-term { display: flex; align-items: center; gap: 4px; position: relative; }
.eq-inp {
    width: 65px; height: 50px; text-align: center;
    font-size: 20px; font-weight: 800; color: var(--math-primary);
    border: 2px solid #D1D5DB; border-radius: 10px; outline: none; transition: all 0.2s;
    -moz-appearance: textfield; font-family: 'Courier New', Courier, monospace;
}
.eq-inp::-webkit-outer-spin-button, .eq-inp::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.eq-inp:focus { border-color: var(--math-primary); box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.15); transform: scale(1.05); }

.eq-var { font-size: 24px; font-weight: 800; color: #111827; font-family: 'Courier New', Courier, monospace; font-style: italic; }
.eq-sign { font-size: 24px; font-weight: 800; color: #6B7280; font-family: 'Courier New', Courier, monospace;}

/* Быстрые примеры */
.quick-examples { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; justify-content: center; }
.qe-title { font-size: 12px; font-weight: 700; color: #9CA3AF; text-transform: uppercase; width: 100%; text-align: center; margin-bottom: 4px;}
.qe-btn {
    font-size: 14px; font-weight: 600; padding: 8px 16px; border-radius: 99px; font-family: 'Courier New', Courier, monospace;
    background: var(--math-bg); color: var(--math-primary); cursor: pointer;
    border: 1px solid #C7D2FE; transition: all 0.2s; box-shadow: var(--shadow-soft);
}
.qe-btn:hover { background: var(--math-primary); color: #fff; transform: translateY(-2px); }


/* --- ПРАВАЯ ЧАСТЬ: РЕЗУЛЬТАТ (KILLER FEATURE) --- */
@media (min-width: 992px) { .sticky-card { position: sticky; top: 24px; transition: top 0.3s; } }

.math-result-card {
    background: #fff; border: 2px solid var(--math-bg); padding: 32px;
    border-top: 6px solid var(--math-primary); border-radius: 20px;
    box-shadow: 0 20px 40px -10px rgba(79, 70, 229, 0.08);
}

.result-header { text-align: center; margin-bottom: 24px; }
.result-header h2 { font-size: 14px; font-weight: 800; color: #9CA3AF; margin: 0; text-transform: uppercase; letter-spacing: 1px; }

/* Главный ответ */
.final-answer-box {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    min-height: 100px; background: var(--math-bg); border-radius: 16px;
    border: 1px dashed var(--math-primary); padding: 20px; text-align: center;
}
.fab-content { font-size: 36px; font-weight: 800; color: var(--math-dark); line-height: 1.2; font-family: 'Courier New', Courier, monospace; word-break: break-word; }
.fab-sub { font-size: 16px; font-weight: 700; color: var(--math-primary); margin-top: 8px; font-family: 'Courier New', Courier, monospace;}
.text-danger-res { color: var(--math-danger) !important; font-size: 24px !important;}

.summary-divider { height: 2px; background: repeating-linear-gradient(90deg, #D1D5DB 0, #D1D5DB 6px, transparent 6px, transparent 12px); margin: 24px 0; opacity: 0.6; }

/* KILLER FEATURE: Школьная доска (ИСПРАВЛЕНО: Авто-высота и скролл) */
.notebook-wrapper {
    background: #fff; border: 1px solid #D1D5DB; border-radius: 12px; position: relative;
    overflow: hidden; box-shadow: 0 10px 20px rgba(0,0,0,0.05); margin-bottom: 24px;
    height: auto; /* Позволяет блоку тянуться вниз за контентом */
}

/* Полоски тетради в клетку */
.notebook-wrapper::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background-image: 
        linear-gradient(rgba(59, 130, 246, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(59, 130, 246, 0.1) 1px, transparent 1px);
    background-size: 20px 20px; pointer-events: none; z-index: 1;
}
/* Красное поле тетради */
.notebook-wrapper::after {
    content: ''; position: absolute; top: 0; bottom: 0; left: 40px;
    width: 2px; background: rgba(239, 68, 68, 0.4); z-index: 1;
}

.nb-title { font-size: 12px; font-weight: 800; color: #fff; background: var(--math-primary); padding: 8px 16px; text-transform: uppercase; letter-spacing: 1px; position: relative; z-index: 2; }

.nb-content {
    padding: 24px 20px 24px 60px; /* Отступ слева для красного поля */
    font-family: 'Courier New', Courier, monospace; font-size: 16px; font-weight: 600;
    color: #1F2937; line-height: 1.8; position: relative; z-index: 2;
    display: flex; flex-direction: column; gap: 12px;
    max-height: 500px; overflow-y: auto; /* Если решение гигантское - появится скролл внутри доски */
}
/* Стилизация скроллбара внутри тетради */
.nb-content::-webkit-scrollbar { width: 6px; }
.nb-content::-webkit-scrollbar-thumb { background: #D1D5DB; border-radius: 3px; }

/* Элементы формул внутри JS */
.step-row { display: block; margin-bottom: 8px; word-break: break-all; }
.step-desc { font-family: var(--font-main); font-size: 13px; font-style: italic; color: #6B7280; margin-bottom: 4px; font-weight: 500;}

/* Стилизация дробей в ответе */
.frac { display: inline-flex; flex-direction: column; align-items: center; vertical-align: middle; margin: 0 4px; line-height: 1.2; }
.frac-n { border-bottom: 1px solid #1F2937; padding: 0 4px; }
.frac-d { padding: 0 4px; }
.sqrt { white-space: nowrap; display: inline-block;}


/* --- НИЖНЯЯ ЧАСТЬ (SEO, INFO) --- */
.info-wrapper { padding: 80px 0; margin-top: 60px; border-top: 1px solid #E5E7EB; }

.author-badge { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 40px; padding: 20px; background: #F8FAFC; border-radius: 16px; border: 1px solid #E2E8F0; }
.author-avatar { width: 48px; height: 48px; background: var(--math-primary); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 22px; flex-shrink: 0; }
.author-info { display: flex; flex-direction: column; min-width: 0; }
.author-name { font-size: 15px; font-weight: 700; color: #111827; line-height: 1.4; margin-bottom: 4px; }
.author-date { font-size: 13px; color: #6B7280; }

.icon-heading { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 32px; font-size: 26px; font-weight: 800; color: #111827; line-height: 1.25; letter-spacing: -0.02em; }
.header-icon { display: flex; align-items: center; justify-content: center; width: 52px; height: 52px; border-radius: 14px; background: #fff; box-shadow: 0 4px 12px rgba(0,0,0,0.06); flex-shrink: 0; margin-top: -6px; font-size: 26px; }

.indigo-icon { color: var(--math-primary); }
.dark-icon { color: var(--math-dark); }
.text-indigo { color: var(--math-primary); font-weight: 700;}

.formulas-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; margin-bottom: 56px; }
.formula-card { background: #fff; border: 1px solid rgba(0,0,0,0.04); box-shadow: 0 4px 20px rgba(0,0,0,0.03); border-radius: 24px; padding: 32px; transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1); display: flex; flex-direction: column; }
.formula-card:hover { transform: translateY(-6px); box-shadow: 0 12px 32px rgba(79, 70, 229, 0.1); border-color: rgba(79, 70, 229, 0.1); }
.formula-header { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; margin-bottom: 20px; }
.formula-card h3 { margin: 0; font-size: 20px; font-weight: 700; color: var(--text-primary); line-height: 1.3; }

.badge-indigo { background: var(--math-primary); color: #fff; padding: 6px 12px; border-radius: 99px; font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; display: inline-block; }
.badge-dark { background: var(--math-dark); color: #fff; padding: 6px 12px; border-radius: 99px; font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; display: inline-block; }

.formula-card p { font-size: 15px; color: var(--text-secondary); margin: 0; line-height: 1.6; font-weight: 500; }
.math-expression { background: var(--math-bg); border: 1px dashed var(--math-primary); padding: 18px; border-radius: 14px; font-weight: 700; color: var(--math-dark); text-align: center; margin-bottom: 20px; font-size: 17px; font-family: 'Courier New', Courier, monospace; letter-spacing: 0.5px; }

.soft-divider { border: none; height: 1px; background: linear-gradient(90deg, transparent, #E5E7EB, transparent); margin: 56px 0; opacity: 0.7; }
.intro-text { font-size: 16px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 40px; }
.calc-description p { font-size: 17px; line-height: 1.7; color: #4B5563; margin-bottom: 24px; }
.calc-description strong { color: #1F2937; font-weight: 700; }

/* Перелинковка */
.internal-links-box { margin-top: 32px; background: #F3F4F6; padding: 24px; border-radius: 16px; border-left: 4px solid var(--math-primary); }
.internal-links-box h4 { margin: 0 0 12px 0; font-size: 17px; color: #111827; }
.internal-links-box ul { margin: 0; padding-left: 20px; color: #4B5563; }
.internal-links-box li { margin-bottom: 8px; font-size: 15px; }
.internal-links-box a { color: var(--math-primary); text-decoration: underline; font-weight: 600; }

/* SEO Таблица */
.seo-table-wrapper { overflow-x: auto; margin-bottom: 48px; background: #fff; border-radius: 16px; border: 1px solid #E5E7EB; box-shadow: 0 4px 10px rgba(0,0,0,0.02); }
.seo-table-wrapper::-webkit-scrollbar { height: 6px; }
.seo-table-wrapper::-webkit-scrollbar-thumb { background: #D1D5DB; border-radius: 3px; }
.seo-table { width: 100%; border-collapse: collapse; min-width: 500px; text-align: left; }
.seo-table th { background: #F9FAFB; padding: 18px 24px; font-size: 13px; font-weight: 800; color: #6B7280; text-transform: uppercase; border-bottom: 1px solid #E5E7EB; letter-spacing: 0.5px; }
.seo-table td { padding: 18px 24px; font-size: 14px; border-bottom: 1px solid #F3F4F6; color: #374151; vertical-align: top; line-height: 1.5; }
.seo-table tr:last-child td { border-bottom: none; }

.howto-section { margin-top: 48px; }
.howto-step { display: flex; gap: 20px; margin-bottom: 32px; background: #fff; padding: 24px; border-radius: 20px; border: 1px solid #E5E7EB; transition: box-shadow 0.2s, transform 0.2s; }
.howto-step:hover { box-shadow: 0 10px 25px -5px rgba(0,0,0,0.05); transform: translateY(-2px); }
.step-num { width: 36px; height: 36px; background: var(--math-bg); color: var(--math-primary); font-weight: 800; border-radius: 50%; display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-size: 15px; border: 1px solid rgba(79, 70, 229, 0.2); }
.step-content h4 { margin: 0 0 10px 0; font-size: 18px; color: #111827; font-weight: 700; }
.step-content p { margin: 0; font-size: 16px; color: #6B7280; line-height: 1.6; }

.faq-section .faq-item { background: #fff; border: 1px solid #E5E7EB; border-radius: 16px; margin-bottom: 16px; overflow: hidden; transition: all 0.2s ease; }
.faq-section .faq-item:hover { border-color: #D1D5DB; }
.faq-section .faq-item[open] { border-color: var(--math-primary); box-shadow: 0 8px 20px rgba(79, 70, 229, 0.08); }
summary.faq-question { padding: 22px 28px; cursor: pointer; font-weight: 700; color: var(--text-primary); font-size: 17px; list-style: none; position: relative; display: flex; justify-content: space-between; align-items: center; transition: background 0.2s; }
.faq-section .faq-item[open] summary.faq-question { color: var(--math-primary); background: var(--math-bg); border-bottom: 1px solid #C7D2FE; }
.faq-question::after { content: '+'; font-size: 26px; color: #9CA3AF; font-weight: 400; line-height: 1; transition: transform 0.3s; }
.faq-section .faq-item[open] summary.faq-question::after { content: '−'; color: var(--math-primary); }
.faq-answer, .faq-item div[itemprop="text"] { padding: 28px; color: var(--text-secondary); line-height: 1.7; font-size: 16px; background: #fff; }
.faq-answer p { margin: 0; }

@media (max-width: 900px) {
    .calc-header { margin-bottom: 32px; }
    .formulas-grid { grid-template-columns: 1fr; gap: 20px; }
    .icon-heading { font-size: 22px; gap: 12px; }
    .header-icon { width: 44px; height: 44px; font-size: 22px; }
    .formula-card { padding: 24px; }
    summary.faq-question { padding: 18px 20px; font-size: 16px; }
    .faq-answer, .faq-item div[itemprop="text"] { padding: 20px; font-size: 15px; }
    .howto-step { padding: 20px; gap: 16px; flex-direction: column; }
    .step-num { margin-bottom: -8px; }
}

@media (max-width: 480px) {
    .author-badge { padding: 16px; gap: 12px; align-items: flex-start; flex-direction: row; }
    .author-avatar { width: 40px; height: 40px; font-size: 18px; }
    
    .equation-builder { flex-direction: column; gap: 8px; padding: 20px; }
    .eq-sign { display: none; } /* Скрываем плюсики на мобилке */
    .eq-term { width: 100%; justify-content: center; }
    .eq-term::before { content: attr(data-label); position: absolute; left: 10px; font-size: 14px; color: #9CA3AF; font-family: var(--font-main); font-weight: 600;}
    .eq-inp { width: 120px; }
    
    /* Добавляем фейковые переменные (a,b,c) для мобилки */
    .eq-term:nth-child(1)::before { content: "a = "; }
    .eq-term:nth-child(3)::before { content: "b = "; }
    .eq-term:nth-child(5)::before { content: "c = "; }

    .math-result-card { padding: 24px 16px; }
    .fab-content { font-size: 28px; }
    .nb-content { padding: 16px 12px 16px 40px; font-size: 14px; }
    .notebook-wrapper::after { left: 24px; }
}