:root {
    --color-first: #530899;
    --color-second: #14b8a6;
}

/* Обнуляем только то, что нужно для макета */
.header,
.content,
.grid-cards,
.card,
.how-to-read,
.read-card,
.footer-note,
.hero,
.live-example,
pre,
code,
.lecture-nav,
.lecture-nav * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}


body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.5;
    background-color: #e3e3e3;
    padding: 20px;
    margin: 0;
}

/* ===== ШАПКА ===== */
.header {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.header-top {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 20px 30px 10px 30px;
}

.logo-link,
.title-link {
    text-decoration: none;
}

.logo-image {
    background: url("/images/logo.svg");
    background-size: 80px;
    background-repeat: no-repeat;
    background-position: center;
    width: 80px;
    height: 80px;
    transition: transform 1.3s ease;
}

.logo-image:hover {
    transform: rotate(360deg) scale(1.05);
}

.title h1 {
    font-size: 32px;
    color: var(--color-first);
    letter-spacing: -0.5px;
}

/* ===== ВЫПАДАЮЩЕЕ МЕНЮ ===== */
.main-nav {
    padding: 10px 30px 10px 30px;
    border-top: 1px solid #e5e7eb;
}

.dropdown {
    position: relative;
    display: inline-block;
}

.dropbtn {
    color: var(--color-second);
    padding: 10px 24px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    border-radius: 40px;
    cursor: pointer;
    transition: 0.2s;
    background: transparent;
}

.dropbtn:hover {
    background: rgba(20, 184, 166, 0.1);
    color: #0f7e6e;
}

.dropdown-content {
    display: none;
    position: absolute;
    left: 0;
    top: 100%;
    min-width: 260px;
    background: white;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    border-radius: 16px;
    z-index: 1000;
    padding: 8px 0;
    margin-top: 0;
}

.dropdown-content a {
    color: var(--color-first);
    padding: 5px 20px;
    text-decoration: none;
    display: block;
    font-size: 14px;
    transition: background 0.2s;
}

.dropdown-content a:hover {
    background: #f0eef7;
}

/* Главное правило: меню видно при наведении на кнопку ИЛИ на само меню */
.dropdown:hover .dropdown-content,
.dropdown-content:hover {
    display: block;
}

/* ===== ОСНОВНОЙ КОНТЕНТ ===== */
.content {
    max-width: 1200px;
    margin: 20px auto 0 auto;
    background: white;
    padding: 40px;
    border-radius: 24px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

/* ===== ЗАГОЛОВКИ ===== */
h1 {
    font-size: 32px;
    color: var(--color-first);
    letter-spacing: -0.5px;
}

h2 {
    font-size: 24px;
    color: var(--color-first);
    margin: 40px 0 20px 0;
}

.hero h2 {
    font-size: 28px;
    margin-top: 0;
    margin-bottom: 20px;
}

/* ===== ГЕРОЙ ===== */
.hero {
    background: linear-gradient(135deg, #f5f0ff 0%, #ffffff 100%);
    padding: 30px;
    border-radius: 20px;
    margin-bottom: 30px;
    border: 1px solid #e0d5f0;
}

.hero-text {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.hero-text p {
    background: white;
    padding: 16px 20px;
    border-radius: 16px;
    flex: 1;
    font-size: 16px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    border-left: 4px solid var(--color-second);
}

.hero-button {
    margin-top: 25px;
    text-align: center;
}

.start-button {
    display: inline-block;
    background: var(--color-first);
    color: white;
    padding: 14px 32px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    transition: background 0.2s, transform 0.1s;
    box-shadow: 0 4px 10px rgba(83, 8, 153, 0.3);
}

.start-button:hover {
    background: #3a066b;
    transform: translateY(-2px);
}

.start-button:active {
    transform: translateY(0);
}

/* ===== КАРТОЧКИ ===== */
.grid-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 20px 0 10px;
}

.card {
    background: #f8f8f8;
    padding: 20px;
    border-radius: 16px;
    border-left: 4px solid var(--color-second);
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.card strong {
    display: block;
    font-size: 18px;
    color: var(--color-first);
    margin-bottom: 12px;
}

.card p {
    color: #334155;
    font-size: 15px;
}

/* ===== БЛОК "КАК ЭТО ЧИТАТЬ" ===== */
.how-to-read {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 20px 0 40px;
}

.read-card {
    background: #f0f9f8;
    padding: 20px;
    border-radius: 16px;
    text-align: center;
    font-size: 16px;
    border-left: 4px solid var(--color-second);
}

/* ===== ПОДВАЛ ===== */
.footer-note {
    background: #faf9fe;
    padding: 20px;
    border-radius: 16px;
    text-align: center;
    color: #4a5568;
    font-size: 14px;
    margin-top: 20px;
}

hr {
    border: none;
    border-top: 2px solid #e3e3e3;
    margin: 30px 0;
}

/* ===== ЛЕКЦИИ ===== */
.lecture-nav {
    display: flex;
    justify-content: space-between;
    margin: 20px 0 30px;
}

.lecture-nav .prev,
.lecture-nav .next {
    background: #f0eef7;
    padding: 10px 24px;
    border-radius: 40px;
    color: var(--color-first);
    text-decoration: none;
    font-weight: 500;
    display: inline-block;
    transition: background 0.2s;
    cursor: pointer;
}

.lecture-nav .prev:hover,
.lecture-nav .next:hover {
    background: #e0daf0;
}

.lecture-nav .prev.disabled,
.lecture-nav .next.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.lecture-title {
    font-size: 32px;
    margin-bottom: 15px;
    border-left: 4px solid var(--color-second);
    padding-left: 20px;
}

.lecture-meta {
    color: #6b7280;
    font-size: 14px;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 1px solid #e5e7eb;
}

.lecture-content h2 {
    margin-top: 35px;
    margin-bottom: 15px;
}

.lecture-content p {
    margin-bottom: 20px;
    line-height: 1.6;
}

.lecture-content ul {
    margin: 15px 0 20px 25px;
}

.lecture-content li {
    margin-bottom: 8px;
}

.lecture-note {
    background: #fef9e3;
    padding: 20px;
    border-radius: 16px;
    border-left: 4px solid #f59e0b;
    margin: 30px 0;
}

.lecture-warning {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 15px 20px;
    border-radius: 12px;
    margin: 25px 0;
    font-size: 14px;
    color: #856404;
}

/* Все примеры кода */
pre {
    background: #2d3a3a;
    border-radius: 16px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    border-left: 4px solid var(--color-second);
}

code {
    font-family: 'SF Mono', 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
    color: #e4e4e4;
}

/* Код внутри текста */
p code,
li code,
.lecture-note code,
.lecture-warning code {
    background: #eef2f3;
    color: #d23669;
    padding: 2px 6px;
    border-radius: 6px;
    font-size: 13px;
    border-left: none;
}

/* Живые примеры */
.live-example {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 16px;
    margin: 20px 0;
    border: 1px solid #e2e8f0;
}

.live-example pre {
    background: transparent;
    border-left: none;
    padding: 0;
    margin: 0;
    color: inherit;
    font-family: inherit;
    font-size: inherit;
    overflow: visible;
}

/* Таблица спецсимволов */
.special-chars-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: #f8f9fa;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid #d1d5db;
}

.special-chars-table th,
.special-chars-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid #d1d5db;
}

.special-chars-table th {
    background: #e5e7eb;
    font-weight: 600;
    color: var(--color-first);
}

.special-chars-table .code-cell {
    background: #e5e7eb;
}

.special-chars-table .code-cell code {
    color: #1a1a1a;
    background: transparent;
    padding: 0;
    font-weight: 600;
    font-size: 14px;
}

/* Таблица единиц измерения (лекция 4) */
.units-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: #f8f9fa;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid #d1d5db;
}

.units-table th,
.units-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid #d1d5db;
}

.units-table th {
    background: #e5e7eb;
    font-weight: 600;
    color: var(--color-first);
}

.units-table td code {
    color: #1a1a1a;
    background: transparent;
    padding: 0;
    font-weight: 600;
}

.units-table tr:hover {
    background: #f1f3f5;
}

/* Блок с двумя кнопками выбора пути */
.action-buttons {
    display: flex;
    gap: 30px;
    margin: 40px 0;
    flex-wrap: wrap;
}

.action-card {
    flex: 1;
    background: #f8f9fa;
    padding: 30px;
    border-radius: 24px;
    text-align: center;
    border-left: 4px solid var(--color-second);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.action-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--color-first);
}

.action-card p {
    color: #4a5568;
    margin-bottom: 25px;
    line-height: 1.5;
    flex-grow: 1;
}

.action-btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: 0.2s;
    align-self: center;
}

.action-btn.primary {
    background: var(--color-first);
    color: white;
    box-shadow: 0 4px 10px rgba(83, 8, 153, 0.3);
}

.action-btn.primary:hover {
    background: #3a066b;
    transform: translateY(-2px);
}

.action-btn.secondary {
    background: #f0eef7;
    color: var(--color-first);
}

.action-btn.secondary:hover {
    background: #e0daf0;
    transform: translateY(-2px);
}

/* ===== АДАПТИВ ===== */
@media (max-width: 700px) {
    .content {
        padding: 20px;
    }

    .grid-cards,
    .how-to-read {
        grid-template-columns: 1fr;
    }

    .hero-text {
        flex-direction: column;
    }

    .header-top {
        padding: 15px 20px 8px 20px;
    }

    .main-nav {
        padding: 0 20px 15px 20px;
    }

    .dropbtn {
        padding: 8px 18px;
        font-size: 14px;
    }

    .logo-image {
        background-size: 60px;
        width: 60px;
        height: 60px;
    }

    .title h1 {
        font-size: 24px;
    }

    .hero h2 {
        font-size: 22px;
    }

    h2 {
        font-size: 20px;
    }
    
    .action-buttons {
        flex-direction: column;
    }
}