/**
 * Mega-Calc - Основные стили
 * Mobile-first, адаптивный дизайн
 * Светлая/тёмная тема
 */

/* ============================================
   CSS Переменные (темизация)
   ============================================ */
:root {
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8f9fa;
    --color-bg-tertiary: #f1f3f4;
    --color-text-primary: #1a1a2e;
    --color-text-secondary: #4a4a5a;
    --color-text-muted: #6c757d;
    --color-border: #e9ecef;
    --color-accent: #4f46e5;
    --color-accent-hover: #4338ca;
    --color-accent-light: #eef2ff;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-share-tg: #229ED9;
    --color-share-vk: #0077FF;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
}

[data-theme="dark"] {
    --color-bg-primary: #0f0f1a;
    --color-bg-secondary: #1a1a2e;
    --color-bg-tertiary: #252542;
    --color-text-primary: #f0f0f5;
    --color-text-secondary: #b0b0c0;
    --color-text-muted: #808090;
    --color-border: #2a2a3e;
    --color-accent: #6366f1;
    --color-accent-hover: #818cf8;
    --color-accent-light: #1e1b4b;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}
a { color: var(--color-accent); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-accent-hover); }
img { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea { font-family: inherit; font-size: inherit; }
ul, ol { list-style: none; }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 var(--spacing-md); }
@media (min-width: 768px) { .container { padding: 0 var(--spacing-lg); } }
@media (min-width: 1024px) { .container { padding: 0 var(--spacing-xl); } }

/* Header */
.header {
    background-color: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color var(--transition-base);
}
.header__container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
}
.header__logo { flex-shrink: 0; }
.logo__text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-accent);
    letter-spacing: -0.025em;
}
.header__nav { display: none; }
@media (min-width: 768px) { .header__nav { display: flex; gap: var(--spacing-lg); } }
.nav__link {
    color: var(--color-text-secondary);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}
.nav__link:hover, .nav__link--active {
    color: var(--color-accent);
    background-color: var(--color-accent-light);
}
.header__actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex: 1;
    justify-content: flex-end;
}

/* Burger menu */
.burger-toggle {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 101;
}
.burger-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}
.burger-toggle--open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}
.burger-toggle--open span:nth-child(2) {
    opacity: 0;
}
.burger-toggle--open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}
@media (min-width: 768px) { .burger-toggle { display: none; } }

/* Mobile nav */
.header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md);
    flex-direction: column;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow-md);
}
.header__nav--open { display: flex; }
@media (min-width: 768px) {
    .header__nav {
        display: flex;
        position: static;
        flex-direction: row;
        background: transparent;
        border: none;
        padding: 0;
        box-shadow: none;
    }
}

/* Search */
.search-form {
    display: flex;
    align-items: center;
    background-color: var(--color-bg-tertiary);
    border-radius: var(--radius-full);
    padding: var(--spacing-xs) var(--spacing-sm);
    flex: 1;
    max-width: 300px;
    border: 1px solid transparent;
    transition: border-color var(--transition-fast);
}
.search-form:focus-within { border-color: var(--color-accent); }
@media (min-width: 768px) { .search-form { max-width: 400px; } }
.search-form__input {
    flex: 1;
    border: none;
    background: transparent;
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
    outline: none;
    min-width: 0;
}
.search-form__input::placeholder { color: var(--color-text-muted); }
.search-form__btn {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    padding: var(--spacing-xs);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}
.search-form__btn:hover { color: var(--color-accent); background-color: var(--color-bg-secondary); }

/* Theme toggle */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
    flex-shrink: 0;
}
.theme-toggle:hover { background-color: var(--color-accent-light); color: var(--color-accent); }
.theme-toggle__icon { display: none; }
.theme-toggle__icon--light { display: block; }
[data-theme="dark"] .theme-toggle__icon--light { display: none; }
[data-theme="dark"] .theme-toggle__icon--dark { display: block; }

/* Breadcrumbs */
.breadcrumbs { display: none; align-items: center; gap: var(--spacing-sm); font-size: var(--font-size-sm); color: var(--color-text-muted); }
@media (min-width: 768px) { .breadcrumbs { display: flex; } }
.breadcrumbs__item { color: var(--color-text-muted); }
.breadcrumbs__item:hover { color: var(--color-accent); }
.breadcrumbs__item--current { color: var(--color-text-primary); font-weight: 500; }
.breadcrumbs__separator { color: var(--color-text-muted); }

/* Main */
.main { flex: 1; padding: var(--spacing-xl) 0; }

/* Hero */
.hero { text-align: center; padding: var(--spacing-2xl) 0; }
.hero__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
}
@media (min-width: 768px) { .hero__title { font-size: var(--font-size-3xl); } }
@media (min-width: 1024px) { .hero__title { font-size: var(--font-size-4xl); } }
.hero__subtitle { font-size: var(--font-size-lg); color: var(--color-text-secondary); margin-bottom: var(--spacing-xl); }
.hero__search {
    display: flex;
    max-width: 500px;
    margin: 0 auto;
    background-color: var(--color-bg-secondary);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: var(--spacing-sm);
    transition: border-color var(--transition-fast);
}
.hero__search:focus-within { border-color: var(--color-accent); }
.hero__search-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
    color: var(--color-text-primary);
    outline: none;
}
.hero__search-btn {
    background-color: var(--color-accent);
    color: white;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-full);
    font-weight: 600;
    transition: background-color var(--transition-fast);
}
.hero__search-btn:hover { background-color: var(--color-accent-hover); }

/* Section */
.section-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}
@media (min-width: 768px) { .section-title { font-size: var(--font-size-2xl); } }

/* Calculators grid */
.calculators-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
}
@media (min-width: 640px) { .calculators-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .calculators-grid { grid-template-columns: repeat(3, 1fr); } }

/* Calculator card */
.calculator-card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}
.calculator-card:hover {
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.calculator-card--link { text-decoration: none; }
.calculator-card--link:hover { color: inherit; }
.calculator-card__icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-accent-light);
    border-radius: var(--radius-md);
    color: var(--color-accent);
}
.calculator-card__title { font-size: var(--font-size-lg); font-weight: 600; color: var(--color-text-primary); margin: 0; }
.calculator-card__description { font-size: var(--font-size-sm); color: var(--color-text-secondary); line-height: 1.5; flex: 1; }
.calculator-card__link { font-size: var(--font-size-sm); font-weight: 600; color: var(--color-accent); margin-top: auto; }

/* SEO section */
.seo-section { margin-top: var(--spacing-2xl); padding: var(--spacing-xl); background-color: var(--color-bg-secondary); border-radius: var(--radius-lg); }
.seo-text { color: var(--color-text-secondary); }
.seo-text h3 { font-size: var(--font-size-lg); font-weight: 600; color: var(--color-text-primary); margin: var(--spacing-lg) 0 var(--spacing-md); }
.seo-text p { margin-bottom: var(--spacing-md); }
.seo-text ul { list-style: disc; padding-left: var(--spacing-lg); }
.seo-text li { margin-bottom: var(--spacing-sm); color: var(--color-text-secondary); }

/* Calculator page */
.calculator-main { padding-top: var(--spacing-lg); }
.page-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}
@media (min-width: 768px) { .page-title { font-size: var(--font-size-3xl); } }
.calculator-wrapper { margin: var(--spacing-xl) 0; }
.calculator-card { max-width: 800px; margin: 0 auto; }

/* Share buttons */
.share-buttons {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
    flex-wrap: wrap;
}
.share-buttons__label { font-size: var(--font-size-sm); color: var(--color-text-secondary); margin-right: var(--spacing-sm); }
.share-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    color: white;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
.share-btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.share-btn--telegram { background-color: var(--color-share-tg); }
.share-btn--vk { background-color: var(--color-share-vk); }

/* SEO content */
.seo-content { max-width: 800px; margin: var(--spacing-2xl) auto; padding: var(--spacing-xl); background-color: var(--color-bg-secondary); border-radius: var(--radius-lg); }
.seo-content h2 { font-size: var(--font-size-xl); font-weight: 700; color: var(--color-text-primary); margin-bottom: var(--spacing-md); }
.seo-content__text { color: var(--color-text-secondary); line-height: 1.8; }
.seo-content__text p { margin-bottom: var(--spacing-md); }

/* Ads */
.ads { margin: var(--spacing-xl) 0; padding: var(--spacing-lg); background-color: var(--color-bg-tertiary); border-radius: var(--radius-md); text-align: center; min-height: 100px; display: flex; align-items: center; justify-content: center; }
.ads--top, .ads--middle, .ads--bottom { border: 1px dashed var(--color-border); }

/* Footer */
.footer {
    background-color: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
}
.footer__container { display: flex; flex-direction: column; gap: var(--spacing-lg); }
@media (min-width: 768px) { .footer__container { flex-direction: row; justify-content: space-between; align-items: center; } }
.footer__content { display: flex; flex-direction: column; gap: var(--spacing-md); }
@media (min-width: 768px) { .footer__content { flex-direction: row; align-items: center; gap: var(--spacing-xl); } }
.footer__brand { text-align: center; }
@media (min-width: 768px) { .footer__brand { text-align: left; } }
.footer__tagline { font-size: var(--font-size-sm); color: var(--color-text-muted); margin-top: var(--spacing-xs); }
.footer__links { display: flex; gap: var(--spacing-md); justify-content: center; }
@media (min-width: 768px) { .footer__links { justify-content: flex-end; } }
.footer__link { color: var(--color-text-secondary); font-size: var(--font-size-sm); }
.footer__link:hover { color: var(--color-accent); }
.footer__bottom { text-align: center; padding-top: var(--spacing-lg); border-top: 1px solid var(--color-border); color: var(--color-text-muted); font-size: var(--font-size-sm); }

/* Search page */
.search-page__form { max-width: 600px; margin: 0 auto var(--spacing-xl); }
.search-page__input-wrapper { display: flex; gap: var(--spacing-sm); }
.search-page__input {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
    transition: border-color var(--transition-fast);
}
.search-page__input:focus { outline: none; border-color: var(--color-accent); }
.search-page__btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--color-accent);
    color: white;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: background-color var(--transition-fast);
}
.search-page__btn:hover { background-color: var(--color-accent-hover); }
.search-results__count { font-size: var(--font-size-sm); color: var(--color-text-muted); margin-bottom: var(--spacing-md); }
.search-no-results, .search-hint { text-align: center; color: var(--color-text-secondary); padding: var(--spacing-2xl); }

/* Error page */
.error-page { display: flex; align-items: center; justify-content: center; min-height: 100vh; }
.error-container { text-align: center; padding: var(--spacing-xl); }
.error-code { font-size: 6rem; font-weight: 700; color: var(--color-accent); line-height: 1; margin-bottom: var(--spacing-md); }
.error-title { font-size: var(--font-size-2xl); font-weight: 600; color: var(--color-text-primary); margin-bottom: var(--spacing-md); }
.error-text { color: var(--color-text-secondary); margin-bottom: var(--spacing-xl); }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
}
.btn--primary { background-color: var(--color-accent); color: white; }
.btn--primary:hover { background-color: var(--color-accent-hover); color: white; }
.btn--secondary { background-color: white; color: var(--color-text-secondary); border: 1px solid var(--color-border); }
.btn--secondary:hover { background-color: var(--color-bg-secondary); }
.btn--sm { padding: var(--spacing-xs) var(--spacing-md); font-size: var(--font-size-sm); }

/* Badges */
.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 9999px;
    font-size: 12px;
    font-weight: 500;
    white-space: nowrap;
}
.badge--primary { background-color: var(--color-accent-light); color: var(--color-accent); }
.badge--success { background-color: #ecfdf5; color: #065f46; }
.badge--danger { background-color: #fef2f2; color: #991b1b; }
.badge--warning { background-color: #fffbeb; color: #92400e; }

/* Utilities */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }