:root {
    --background: #f6f7fb;
    --foreground: #1f2933;
    --muted-foreground: #5f6c80;
    --border: #d8dde4;
    --accent: #e6ebf1;
    --accent-foreground: #1f2933;
    --primary: #0f62fe;
    --primary-foreground: #ffffff;
    --radius: 16px;
    font-family: "Inter", "Pretendard", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--background);
    color: var(--foreground);
    font-family: inherit;
    -webkit-font-smoothing: antialiased;
    min-width: 1280px;
}

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

a:focus-visible,
input:focus-visible,
button:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.app-shell {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.page-shell {
    flex: 1;
    width: 100%;
    max-width: 1680px;
    align-self: center;
    display: flex;
    gap: 3.5rem;
    padding: 3rem clamp(1.5rem, 5vw, 4rem) 3.5rem;
}

.side-menu {
    position: sticky;
    top: 2.5rem;
    align-self: flex-start;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
    min-width: 220px;
    padding: 0;
}

.brand-block {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    margin-bottom: 1.5rem;
}

.brand-mark {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: linear-gradient(135deg, #0f62fe, #103b9b);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    letter-spacing: 0.08em;
}

.brand-name {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.brand-description {
    margin: 0.25rem 0 0;
    font-size: 0.82rem;
    color: var(--muted-foreground);
}

.side-menu__title {
    margin: 1.1rem 0 0.35rem;
    font-size: 0.72rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted-foreground);
}

.side-menu__title:first-of-type {
    margin-top: 0;
}

.side-menu a {
    display: inline-flex;
    align-items: center;
    padding: 0.45rem 0;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--muted-foreground);
    transition: color 0.2s ease;
}

.side-menu a:hover {
    color: var(--foreground);
}

.side-menu a.active {
    color: var(--primary);
    font-weight: 600;
}

.side-menu a.side-menu__sub-item {
    padding-left: 1.25rem; /* Indent sub-items */
    font-size: 0.9rem;
}


.page-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
    width: 100%;
}