* {
    margin: 0;
    padding: 0;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border: #e2e8f0;
    --primary: #22c55e;
    --primary-hover: #16a34a;
    --error: #ef4444;
    --error-bg: #fef2f2;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}
.dark-theme {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border: #334155;
    --primary: #22c55e;
    --primary-hover: #16a34a;
    --error: #ef4444;
    --error-bg: #1f1415;
}
body {
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
}
main {
    padding: 2rem 0;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}
.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.theme-toggle {
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    padding: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
}
.loading-spinner {
    width: 2rem;
    height: 2rem;
    border: 2px solid var(--border);
    border-top: 2px solid var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}
.loading-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow);
}
.error-content {
    background-color: var(--error-bg);
    color: var(--error);
    border: 1px solid var(--error);
    border-radius: 0.5rem;
    padding: 1rem;
    font-weight: 500;
}
.sun-icon,
.moon-icon {
    width: 1.2rem;
    height: 1.2rem;
    color: var(--text-primary);
    position: absolute;
    transition: all 0.3s ease;
}
.search-section {
    max-width: 42rem;
    margin: 0 auto 2rem;
}
.search-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}
.search-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.search-input-group {
    display: flex;
    gap: 0.5rem;
}
.search-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}
.search-icon {
    width: 1rem;
    height: 1rem;
}
.search-button {
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}
.search-button:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}
.welcome-message {
    max-width: 42rem;
    margin: 0 auto;
    text-align: center;
}
.error-message {
    max-width: 42rem;
    margin: 0 auto 2rem;
}
.loading-state {
    max-width: 42rem;
    margin: 0 auto 2rem;
}
.user-card {
    max-width: 42rem;
    margin: 0 auto 2rem;
}
.user-card-content {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}
.user-info {
    display: flex;
    gap: 1.5rem;
}
.user-avatar {
    display: flex;
    justify-content: flex-start;
}
.user-details {
    flex: 1;
    text-align: left;
}
.avatar {
    width: 6rem;
    height: 6rem;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border);
}
.user-name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}
.user-username {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: 1rem;
    display: inline-block;
}
.user-bio {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-style: italic;
}
.user-stats {
    display: flex;
    justify-content: flex-start;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}
.user-meta {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}
.stat-badge {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    font-weight: 500;
}
.stat-number {
    font-weight: 700;
    color: var(--text-primary);
}
.meta-item {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 0.5rem;
}
.hidden {
    display: none !important;
}
.github-icon {
    width: 2rem;
    height: 2rem;
    color: var(--primary);
}
.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}
.welcome-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 2rem;
    box-shadow: var(--shadow);
}
.welcome-icon {
    width: 4rem;
    height: 4rem;
    color: var(--text-muted);
    margin: 0 auto 1rem;
}
.welcome-card h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}
.welcome-card p {
    color: var(--text-secondary);
}

@media (max-width: 640px) {
    .search-input-group {
        flex-direction: column;
    }
    .search-button {
        justify-content: center;
    }
    .user-info {
        flex-direction: column;
        text-align: left;
    }
    .user-avatar {
        justify-content: center;
    }
    .user-details {
        text-align: left;
    }
    .avatar {
        width: 8rem;
        height: 8rem;
    }
    .user-details {
        text-align: center;
    }
    .user-stats {
        justify-content: center;
    }
    .meta-item {
        justify-content: center;
    }
}