/* ══════════════════════════════════════
   Theme Variables — Corporate Dark Style
   ══════════════════════════════════════ */
:root {
    --bg-primary: #111827;
    --bg-card: rgba(31, 41, 55, 0.85);
    --bg-card-border: rgba(255, 255, 255, 0.06);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.6);
    --text-muted: rgba(255, 255, 255, 0.35);
    --accent: #4A8BF7;
    --accent-light: #6BA3FF;
    --accent-glow: rgba(74, 139, 247, 0.3);
    --nav-bg: rgba(17, 24, 39, 0.82);
    --nav-border: rgba(255, 255, 255, 0.06);
    --chip-bg: rgba(255, 255, 255, 0.06);
    --chip-border: rgba(255, 255, 255, 0.08);
    --chip-text: rgba(255, 255, 255, 0.7);
    --banner-border: rgba(74, 139, 247, 0.2);
    --banner-hover: rgba(74, 139, 247, 0.06);
    --hero-overlay: rgba(17, 24, 39, 0.7);
}

[data-theme="light"] {
    --bg-primary: #f3f4f6;
    --bg-card: rgba(255, 255, 255, 0.9);
    --bg-card-border: rgba(0, 0, 0, 0.06);
    --text-primary: #111827;
    --text-secondary: rgba(17, 24, 39, 0.55);
    --text-muted: rgba(17, 24, 39, 0.3);
    --accent: #3B76E1;
    --accent-light: #5A90F0;
    --accent-glow: rgba(59, 118, 225, 0.25);
    --nav-bg: rgba(255, 255, 255, 0.85);
    --nav-border: rgba(0, 0, 0, 0.06);
    --chip-bg: rgba(0, 0, 0, 0.04);
    --chip-border: rgba(0, 0, 0, 0.06);
    --chip-text: rgba(17, 24, 39, 0.65);
    --banner-border: rgba(59, 118, 225, 0.2);
    --banner-hover: rgba(59, 118, 225, 0.05);
    --hero-overlay: rgba(255, 255, 255, 0.65);
}

/* ══ Reset ══ */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background 0.4s ease, color 0.4s ease;
    overflow-x: hidden;
}

/* ══════════════════════════════════════
   Navigation Bar
   ══════════════════════════════════════ */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2.5rem;
    height: 60px;
    background: var(--nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--nav-border);
    transition: background 0.4s ease;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo {
    font-size: 1.4rem;
}

.nav-brand {
    font-size: 1.1rem;
    font-weight: 900;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    transition: color 0.4s ease;
}

.nav-right {
    display: flex;
    align-items: center;
}

.theme-toggle {
    padding: 0.4rem 0.9rem;
    border: 1px solid var(--chip-border);
    border-radius: 2rem;
    background: var(--chip-bg);
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-family: 'Noto Sans KR', sans-serif;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.theme-toggle:hover {
    color: var(--text-primary);
    border-color: var(--accent);
}

/* ══════════════════════════════════════
   Hero Section
   ══════════════════════════════════════ */
.hero {
    position: relative;
    width: 100%;
    min-height: 340px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 60px;
    background: url('https://images.unsplash.com/photo-1556742049-0cfed4f6a45d?w=1200&q=80') center/cover no-repeat;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: var(--hero-overlay);
    backdrop-filter: blur(2px);
    transition: background 0.4s ease;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 3rem 1.5rem;
}

.hero-title {
    font-size: 2.8rem;
    font-weight: 900;
    color: var(--text-primary);
    line-height: 1.3;
    letter-spacing: -0.03em;
    transition: color 0.4s ease;
}

.hero-title .highlight {
    color: var(--accent);
    position: relative;
}

.hero-title .highlight::after {
    content: '';
    position: absolute;
    left: -4px;
    right: -4px;
    top: -2px;
    bottom: -2px;
    border: 2px solid var(--accent);
    border-radius: 50%;
    opacity: 0.35;
    transform: rotate(-3deg);
}

.hero-subtitle {
    margin-top: 1rem;
    font-size: 1.05rem;
    font-weight: 300;
    color: var(--text-secondary);
    letter-spacing: 0.01em;
    transition: color 0.4s ease;
}

/* ══════════════════════════════════════
   Main Section
   ══════════════════════════════════════ */
.main-section {
    flex: 1;
    display: flex;
    justify-content: center;
    padding: 2.5rem 1rem;
}

.content-wrapper {
    width: 100%;
    max-width: 520px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* ══════════════════════════════════════
   Banner Box
   ══════════════════════════════════════ */
.banner-box {
    width: 100%;
    border-radius: 0.75rem;
    background: var(--bg-card);
    border: 1px solid var(--bg-card-border);
    overflow: hidden;
    transition: all 0.4s ease;
}

.banner-upload {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    width: 100%;
    min-height: 100px;
    cursor: pointer;
    border: 2px dashed var(--banner-border);
    border-radius: 0.75rem;
    transition: all 0.3s ease;
    box-sizing: border-box;
}

.banner-upload:hover {
    border-color: var(--accent);
    background: var(--banner-hover);
}

.upload-icon {
    width: 28px;
    height: 28px;
    color: var(--accent);
    opacity: 0.5;
    transition: opacity 0.3s ease;
}

.banner-upload:hover .upload-icon {
    opacity: 1;
}

.banner-placeholder {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.banner-image {
    display: none;
    width: 100%;
    height: auto;
    max-height: 200px;
    object-fit: cover;
}

.banner-box.has-image .banner-upload { display: none; }
.banner-box.has-image .banner-image { display: block; cursor: pointer; }

/* ══════════════════════════════════════
   Footer
   ══════════════════════════════════════ */
.site-footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-muted);
    font-size: 0.75rem;
    border-top: 1px solid var(--bg-card-border);
    transition: color 0.4s ease, border-color 0.4s ease;
}

/* ══════════════════════════════════════
   Responsive — Tablet
   ══════════════════════════════════════ */
@media (max-width: 768px) {
    .top-nav {
        padding: 0 1.2rem;
        height: 52px;
    }

    .hero {
        margin-top: 52px;
        min-height: 240px;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    .hero-content {
        padding: 2rem 1.2rem;
    }

    .main-section {
        padding: 1.5rem 0.75rem;
    }

    .content-wrapper {
        max-width: 100%;
        gap: 1rem;
    }

    .banner-upload {
        min-height: 80px;
    }

    .banner-image {
        max-height: 160px;
    }
}

/* ══════════════════════════════════════
   Responsive — Mobile
   ══════════════════════════════════════ */
@media (max-width: 480px) {
    .top-nav {
        padding: 0 0.8rem;
        height: 48px;
    }

    .nav-logo {
        font-size: 1.2rem;
    }

    .nav-brand {
        font-size: 0.95rem;
    }

    .theme-toggle {
        padding: 0.3rem 0.65rem;
        font-size: 0.72rem;
    }

    .hero {
        margin-top: 48px;
        min-height: 180px;
    }

    .hero-content {
        padding: 1.5rem 1rem;
    }

    .hero-title {
        font-size: 1.6rem;
    }

    .hero-title .highlight::after {
        border-width: 1.5px;
        left: -2px;
        right: -2px;
        top: -1px;
        bottom: -1px;
    }

    .hero-subtitle {
        font-size: 0.82rem;
        margin-top: 0.6rem;
    }

    .main-section {
        padding: 1rem 0.5rem;
    }

    .content-wrapper {
        gap: 0.75rem;
    }

    .banner-box {
        border-radius: 0.5rem;
    }

    .banner-upload {
        min-height: 64px;
        gap: 0.3rem;
        border-radius: 0.5rem;
    }

    .upload-icon {
        width: 22px;
        height: 22px;
    }

    .banner-placeholder {
        font-size: 0.75rem;
    }

    .banner-image {
        max-height: 130px;
    }

    .site-footer {
        padding: 1.2rem 0.8rem;
        font-size: 0.68rem;
    }
}