/* Base Styles */
:root {
    /* Base размеры */
    --header-height: clamp(3rem, 4vw, 3.5rem);
    --header-padding: clamp(0.375rem, 0.75vw, 0.625rem);
    --logo-size: clamp(1.5rem, 2vw, 2rem);
    --title-size: clamp(0.875rem, 1.25vw, 1.25rem);
    --text-size: clamp(0.688rem, 0.875vw, 0.813rem);
    --nav-size: clamp(0.75rem, 0.875vw, 0.875rem);
    --icon-size: clamp(0.875rem, 1vw, 1rem);
    --gap-size: clamp(0.25rem, 0.5vw, 0.75rem);
    --mobile-side-padding: 1.25rem;
    
    /* Отступы */
    --logo-gap: clamp(0.5rem, 0.75vw, 1rem);
    --separator-gap: clamp(0.375rem, 0.625vw, 0.875rem);
    --button-height: clamp(1.75rem, 2vw, 2rem);
    --button-padding-x: clamp(0.5rem, 0.625vw, 0.75rem);
    --button-padding-y: clamp(0.25rem, 0.375vw, 0.438rem);
    
    /* Фиксированные значения */
    --header-bg: rgba(255, 255, 255, 0.98);
    --header-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --primary: #034F83;
    --primary-light: #1071B3;
    --primary-dark: #02406a;
    --text-main: #222;
    --text-secondary: #666;
    --transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --depth-shadow: 0 8px 24px rgba(2, 64, 106, 0.12);
}

/* Header Structure */
header {
    position: static;
    width: 100%;
    background: var(--header-bg);
    box-shadow: var(--header-shadow);
    backdrop-filter: blur(8px);
    z-index: 1000;
}

.header-wrap {
    max-width: 1920px;
    width: 99.5%;
    margin: 0 auto;
    padding: var(--header-padding);
    display: flex;
    align-items: center;
    gap: var(--gap-size);
    min-height: var(--header-height);
}

/* Logo Section */
.header-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-main);
    transition: var(--transition);
    min-width: 0;
    margin-right: auto;
}

.logo {
    width: var(--logo-size);
    height: var(--logo-size);
    flex: 0 0 auto;
}

.logo svg {
    width: 100%;
    height: 100%;
    transition: transform var(--transition);
}

.logo-info {
    display: flex;
    align-items: center;
    margin-left: var(--logo-gap);
    min-width: 0;
    flex: 1;
    overflow: hidden;
}

.logo-title {
    font-size: var(--title-size);
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    white-space: nowrap;
    margin-right: var(--separator-gap);
    flex: 0 0 auto;
}

.logo-separator {
    width: 1.5px;
    height: calc(var(--header-height) * 0.4);
    background: linear-gradient(to bottom, var(--primary-light), var(--primary));
    margin: 0 var(--separator-gap);
    border-radius: 2px;
    opacity: 0.7;
    flex: 0 0 auto;
}

.university-name {
    color: var(--text-secondary);
    font-size: var(--text-size);
    line-height: 1.3;
    transition: color var(--transition);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    min-width: 0;
    max-width: min(1000px, 65vw);
}

/* Navigation */
.header-menu {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.top-nav {
    display: flex;
    align-items: center;
    gap: clamp(0.5rem, 0.75vw, 1rem);
    margin: 0;
    padding: 0;
    list-style: none;
    font-weight: 600;
}

.top-nav a {
    color: var(--text-main);
    text-decoration: none;
    white-space: nowrap;
    transition: color var(--transition);
    position: relative;
    padding: 0.375rem 0;
    font-size: var(--nav-size);
}

.top-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 1.5px;
    background: var(--primary-light);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition);
}

.top-nav a:hover {
    color: var(--primary-light);
}

.top-nav a:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

/* Tools Section */
.header-tools {
    display: flex;
    align-items: center;
    gap: calc(var(--gap-size) * 0.75);
    margin-left: auto;
}

.tool-item,
.lang-btn {
    display: flex;
    align-items: center;
    gap: clamp(0.25rem, 0.375vw, 0.438rem);
    height: var(--button-height);
    padding: var(--button-padding-y) var(--button-padding-x);
    border-radius: 0.5rem;
    color: var(--primary);
    text-decoration: none;
    font-size: var(--text-size);
    background: rgba(16, 113, 179, 0.05);
    transition: all var(--transition);
    white-space: nowrap;
    border: none;
    cursor: pointer;
}

.tool-item svg,
.lang-btn svg {
    width: var(--icon-size);
    height: var(--icon-size);
    fill: currentColor;
    transition: transform var(--transition);
}

/* Language Switcher */
.lang-switch {
    display: flex;
    gap: calc(var(--gap-size) * 0.5);
}

.lang-btn svg {
    width: calc(var(--icon-size) * 1.4);
    height: var(--icon-size);
    border-radius: 0.25rem;
}

/* Адаптивность */
@media (max-width: 1400px) {
    .university-name {
        white-space: normal;
        display: -webkit-box;
        -webkit-line-clamp: 2;
        -webkit-box-orient: vertical;
        text-overflow: initial;
    }
}

@media (min-resolution: 120dpi) {
    .header-wrap {
        width: 99.75%;
        gap: calc(var(--gap-size) * 0.75);
    }
    
    .university-name {
        max-width: min(1400px, 95vw);
        white-space: normal;
        display: -webkit-box;
        -webkit-line-clamp: 2;
        -webkit-box-orient: vertical;
        text-overflow: initial;
    }
}

@media (min-resolution: 144dpi) {
    .header-wrap {
        width: 100%;
        gap: calc(var(--gap-size) * 0.5);
    }

    .university-name {
        max-width: min(1600px, 98vw);
    }
}

@media (max-width: 991px) {
    .header-wrap {
        flex-wrap: wrap;
        padding: 0;
        width: 100%;
    }

    .header-logo {
        padding: calc(var(--header-padding) * 0.75);
        padding-left: var(--mobile-side-padding);
    }

    .header-tools {
        padding: calc(var(--header-padding) * 0.75);
        padding-right: var(--mobile-side-padding);
    }

    .header-menu {
        flex-basis: 100%;
        order: 2;
        border-top: 1px solid rgba(0, 0, 0, 0.05);
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        padding: calc(var(--header-padding) * 0.75) var(--mobile-side-padding);
        background: var(--header-bg);
    }

    .header-menu::-webkit-scrollbar {
        display: none;
    }

    .top-nav {
        margin: 0 auto;
        justify-content: flex-start;
        gap: 0.875rem;
        min-width: min-content;
        width: 100%;
    }
}

@media (max-width: 768px) {
    .logo-separator,
    .university-name {
        display: none;
    }

    .tool-item span {
        display: none;
    }

    .tool-item,
    .lang-btn {
        padding: var(--button-padding-y);
        aspect-ratio: 1;
        width: var(--button-height);
        justify-content: center;
    }

    .tool-item svg,
    .lang-btn svg {
        margin: 0;
    }

    .top-nav {
        gap: 0.75rem;
    }
}

/* Анимации */
.tool-item:hover,
.lang-btn:hover {
    color: var(--primary-light);
    background: rgba(16, 113, 179, 0.1);
    transform: translateY(-1px);
}

.tool-item:hover svg,
.lang-btn:hover svg {
    transform: scale(1.1) rotate(-5deg);
}

.logo-info:hover .logo-separator {
    transform: scaleY(1.1);
    opacity: 1;
}

.header-logo:hover {
    transform: translateY(-1px);
}

.header-logo:hover .logo svg {
    transform: scale(1.05);
}

.header-logo:hover .university-name {
    color: var(--primary);
}