* {
    box-sizing: border-box;
}

body {
    --background-color: #f0f4f8;
    --text-color: #1a2332;
    --text-muted: #5a6a7e;
    --elements-color: #ffffff;
    --shadow-color: rgba(15, 23, 42, 0.08);
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --accent-soft: rgba(59, 130, 246, 0.12);
    --logo-accent: #0d9488;
    --border-color: rgba(15, 23, 42, 0.08);
    --hero-gradient: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #7c3aed 100%);
    margin: 0;
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
}

body.dark {
    --background-color: #0f172a;
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --elements-color: #1e293b;
    --shadow-color: rgba(0, 0, 0, 0.35);
    --accent-color: #60a5fa;
    --accent-hover: #93c5fd;
    --accent-soft: rgba(96, 165, 250, 0.15);
    --logo-accent: #2dd4bf;
    --border-color: rgba(255, 255, 255, 0.08);
    --hero-gradient: linear-gradient(135deg, #0f172a 0%, #1e40af 50%, #6d28d9 100%);
}

a {
    text-decoration: none;
    color: inherit;
}

.header-container {
    background-color: var(--elements-color);
    border-bottom: 1px solid var(--border-color);
    padding-inline: 24px;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1280px;
    margin-inline: auto;
    padding: 18px 0;
}

.title {
    margin: 0;
}

.site-logo {
    display: inline-flex;
    align-items: baseline;
    gap: 6px;
    font-family: 'Fraunces', Georgia, serif;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    transition: opacity 0.2s ease;
}

.site-logo:hover {
    opacity: 0.85;
}

.logo-primary {
    color: var(--text-color);
}

.logo-accent {
    color: var(--logo-accent);
}

.theme-changer {
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 10px 18px;
    border-radius: 999px;
    background-color: var(--accent-soft);
    color: var(--accent-color);
    transition: transform 0.2s ease, opacity 0.2s ease;
    margin: 0;
}

.theme-changer:hover {
    transform: translateY(-1px);
    opacity: 0.9;
}

.hero {
    background: var(--hero-gradient);
    color: #fff;
    padding: 56px 24px 64px;
    text-align: center;
}

.hero-content {
    max-width: 720px;
    margin-inline: auto;
}

.hero h1 {
    margin: 0 0 12px;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    letter-spacing: -0.02em;
}

.hero p {
    margin: 0;
    font-size: 1.05rem;
    opacity: 0.9;
    line-height: 1.6;
}

main {
    max-width: 1280px;
    margin-inline: auto;
    padding: 0 24px 64px;
}

.controls {
    margin-top: -32px;
    background: var(--elements-color);
    border-radius: 16px;
    padding: 28px;
    box-shadow: 0 8px 32px var(--shadow-color);
    border: 1px solid var(--border-color);
    position: relative;
    z-index: 2;
}

.search-box {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 14px 18px;
    margin-bottom: 24px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-box:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.search-box i {
    color: var(--text-muted);
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    background: transparent;
    font-family: inherit;
    font-size: 1rem;
    color: var(--text-color);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.continent-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.continent-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    background: var(--background-color);
    color: var(--text-color);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.continent-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.continent-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: #fff;
    box-shadow: 0 4px 14px var(--accent-soft);
}

.country-count {
    margin: 20px 0 0;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-muted);
}

.countries-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 28px;
    margin-top: 40px;
}

.country-card {
    display: flex;
    flex-direction: column;
    border-radius: 16px;
    overflow: hidden;
    background: var(--elements-color);
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.country-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 40px var(--shadow-color);
}

.card-flag {
    overflow: hidden;
    aspect-ratio: 16 / 10;
    background: var(--background-color);
}

.country-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.35s ease;
}

.country-card:hover img {
    transform: scale(1.06);
}

.card-text {
    padding: 20px 22px 24px;
}

.card-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin: 0 0 14px;
    color: var(--text-color);
}

.card-text p {
    margin: 0 0 8px;
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--text-muted);
}

.card-text p b {
    color: var(--text-color);
    font-weight: 600;
}

.status-message {
    grid-column: 1 / -1;
    text-align: center;
    padding: 48px 24px;
    font-size: 1rem;
    color: var(--text-muted);
}

.status-message.error {
    color: #ef4444;
}

@media (max-width: 768px) {
    .hero {
        padding: 40px 20px 48px;
    }

    .controls {
        padding: 20px;
        margin-top: -24px;
    }

    .continent-filters {
        gap: 8px;
    }

    .continent-btn {
        padding: 8px 14px;
        font-size: 0.85rem;
    }

    .countries-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    main {
        padding-inline: 16px;
    }
}