:root {
    --primary-color: #4a4a9e;
    --secondary-color: #2196f3;
    --text-color: #333333;
    --muted-text-color: #666666;
    --border-color: #e7e7ef;
    --background-color: #ffffff;
    --surface-color: #f7f8fc;
    --shadow-sm: 0 2px 8px rgba(18, 25, 38, 0.08);
    --shadow-md: 0 10px 30px rgba(18, 25, 38, 0.12);
    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --content-width: 1200px;
    --nav-height: 80px;
    --footer-height: 64px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: "Segoe UI", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background:
        radial-gradient(circle at top left, rgba(74, 74, 158, 0.08), transparent 28%),
        linear-gradient(180deg, #ffffff 0%, #fbfcff 100%);
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
}

main {
    min-height: calc(100vh - var(--nav-height));
    padding-top: var(--nav-height);
    padding-bottom: calc(var(--footer-height) + 32px);
}

.container {
    width: min(var(--content-width), calc(100% - 32px));
    margin: 0 auto;
}

.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(74, 74, 158, 0.08);
}

.site-nav__inner {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.site-brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--primary-color);
}

.site-brand img {
    width: 42px;
    height: 42px;
    object-fit: contain;
}

.site-nav__links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.site-nav__links a {
    text-decoration: none;
    color: var(--text-color);
    padding: 10px 14px;
    font-weight: 400;
    transition: color 0.2s ease, font-weight 0.2s ease;
}

.site-nav__links a:hover,
.site-nav__links a.is-active {
    color: var(--primary-color);
    font-weight: 700;
}

.page-section {
    padding: 48px 0;
}

.page-title {
    margin: 0 0 12px;
    text-align: center;
    font-size: clamp(2rem, 4vw, 3rem);
    color: var(--primary-color);
}

.page-subtitle {
    max-width: 760px;
    margin: 0 auto 40px;
    text-align: center;
    color: var(--muted-text-color);
}

.hero-banner {
    padding: 72px 0 48px;
    color: #ffffff;
    background: linear-gradient(135deg, #3f4398 0%, #2296f3 100%);
}

.hero-banner h1 {
    margin: 0;
    font-size: clamp(2.6rem, 7vw, 4.8rem);
    line-height: 1.05;
}

.hero-banner p {
    margin: 18px 0 0;
    max-width: 720px;
    font-size: 1.1rem;
}

.card {
    background: var(--background-color);
    border: 1px solid rgba(74, 74, 158, 0.08);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.filter-bar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 32px;
}

.filter-btn {
    border: 0;
    border-radius: 999px;
    padding: 10px 16px;
    background: #edf1f7;
    color: var(--text-color);
    cursor: pointer;
    transition: transform 0.2s ease, background-color 0.2s ease, color 0.2s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: #ffffff;
    transform: translateY(-1px);
}

.empty-state {
    margin: 0;
    padding: 28px;
    text-align: center;
    color: var(--muted-text-color);
    background: rgba(74, 74, 158, 0.04);
    border-radius: var(--radius-md);
}

.site-footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 1rem;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    min-height: var(--footer-height);
    z-index: 999;
}

.site-footer__inner {
    max-width: 1200px;
    margin: 0 auto;
}

.site-footer__inner p {
    margin: 0;
}

@media (max-width: 860px) {
    .site-nav {
        height: auto;
    }

    main {
        padding-top: 130px;
        padding-bottom: calc(var(--footer-height) + 28px);
    }

    .site-nav__inner {
        padding: 14px 0;
        align-items: flex-start;
        flex-direction: column;
    }

    .site-nav__links {
        width: 100%;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(var(--content-width), calc(100% - 24px));
    }

    .page-section {
        padding: 40px 0;
    }
}