/* ========================================
   CSS Variables (Design System)
   ======================================== */
:root {
    /* Primary Colors */
    --primary: #667eea;
    --primary-dark: #764ba2;
    --primary-light: #a8b3ff;
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    /* Accent Colors */
    --accent-yellow: #ffd93d;
    --accent-pink: #ff6b9d;
    --accent-green: #6bcf7f;
    --accent-orange: #ff9f43;

    /* Neutral Colors */
    --white: #ffffff;
    --bg-main: #ffffff;
    --bg-secondary: #f8f9ff;
    --bg-card: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border: #e0e0e0;
    --border-light: #f0f0f0;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(102, 126, 234, 0.15);
    --shadow-lg: 0 10px 30px rgba(102, 126, 234, 0.2);

    /* Typography */
    --font-main: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', sans-serif;
    
    /* Font Sizes */
    --text-4xl: 2.5rem;
    --text-3xl: 2rem;
    --text-2xl: 1.5rem;
    --text-xl: 1.25rem;
    --text-lg: 1.125rem;
    --text-base: 1rem;
    --text-sm: 0.875rem;
    --text-xs: 0.75rem;

    /* Font Weights */
    --font-regular: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;
    --font-extrabold: 800;

    /* Line Heights */
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.75;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 80px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-full: 9999px;

    /* Transitions */
    --duration-fast: 150ms;
    --duration-base: 200ms;
    --duration-slow: 300ms;
    --duration-slower: 500ms;
    
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   Reset & Base Styles
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans KR', sans-serif;
}

body {
    font-family: var(--font-main);
    background: radial-gradient(circle at top, rgba(118, 75, 162, 0.12), transparent 55%),
                radial-gradient(circle at bottom, rgba(102, 126, 234, 0.08), transparent 50%),
                #f9f7ff;
    min-height: 100vh;
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
}

#root, main {
    flex: 1;
}

/* ========================================
   Header Styles
   ======================================== */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--duration-base) var(--ease-out);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.logo {
    display: inline-flex;
    align-items: center;
    font-size: var(--text-xl);
    font-weight: var(--font-extrabold);
    color: var(--primary);
    transition: transform 0.2s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.logo-image {
    height: 32px;
    width: auto;
    display: block;
}

.simple-header .logo-image {
    height: 28px;
}

.footer-logo .logo-image {
    height: 36px;
}

.tagline {
    font-size: var(--text-sm);
    color: var(--text-muted);
    font-weight: var(--font-medium);
    display: none;
}

.header-nav {
    display: flex;
    gap: var(--space-xl);
}

.header-nav a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: var(--font-medium);
    font-size: var(--text-base);
    transition: color var(--duration-base) var(--ease-out);
    position: relative;
}

.header-nav a:hover {
    color: var(--primary);
}

.header-nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--duration-base) var(--ease-out);
}

.header-nav a:hover::after {
    width: 100%;
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: var(--text-2xl);
    cursor: pointer;
    color: var(--primary);
    padding: var(--space-sm);
    line-height: 1;
}

.menu-toggle:hover {
    opacity: 0.7;
}

/* Mobile navigation */
.mobile-menu {
    display: flex;
    flex-direction: column;
    padding: 12px 0;
    border-top: 1px solid var(--border-light);
    animation: slideDown var(--duration-slow) var(--ease-out);
}

.mobile-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: var(--font-medium);
    font-size: var(--text-base);
    padding: 12px 0;
    transition: color var(--duration-base) var(--ease-out);
}

.mobile-menu a:hover {
    color: var(--primary);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Simplified header (test pages) */
.simple-header {
    background: transparent;
    box-shadow: none;
    backdrop-filter: none;
}

.simple-header .header-content {
    height: 60px;
}

.simple-header .logo {
    display: inline-flex;
    align-items: center;
    font-size: var(--text-xl);
    font-weight: var(--font-extrabold);
    color: var(--primary);
    transition: transform 0.2s ease;
}

/* ========================================
   Footer Styles
   ======================================== */
.footer {
    background: var(--text-primary);
    color: var(--white);
    padding: var(--space-2xl) 0 var(--space-lg);
    min-height: 220px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.25fr 1.75fr;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.footer-logo {
    font-size: var(--text-2xl);
    font-weight: var(--font-extrabold);
    color: var(--white);
}

.footer-tagline {
    font-size: var(--text-base);
    color: rgba(255, 255, 255, 0.7);
    line-height: var(--leading-relaxed);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.footer-column h4 {
    font-size: var(--text-base);
    font-weight: var(--font-bold);
    color: var(--white);
    margin-bottom: var(--space-md);
}

.footer-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-column ul li {
    margin-bottom: var(--space-sm);
}

.footer-column ul li:last-child {
    margin-bottom: 0;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: var(--text-sm);
    transition: color var(--duration-base) var(--ease-out);
}

.footer-column a:hover {
    color: var(--white);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--space-md);
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    font-size: var(--text-sm);
    margin-bottom: var(--space-xs);
}

.footer-bottom p:last-child {
    margin-bottom: 0;
}

/* Simplified footer (test pages) */
.simple-footer {
    background: transparent;
    padding: 12px 0;
    margin-top: var(--space-xl);
}

.simple-footer .footer-bottom {
    border-top: none;
    padding-top: 0;
}

.simple-footer .footer-bottom p {
    color: rgba(255, 255, 255, 0.8);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* ========================================
   Header & Footer Responsive
   ======================================== */

/* Tablet & Desktop (768px+) */
@media (min-width: 768px) {
    .tagline {
        display: block;
    }

    .desktop-nav {
        display: flex;
    }
}

/* Mobile (< 1024px) */
@media (max-width: 1023px) {
    .header-nav.desktop-nav {
        display: none;
    }

    .menu-toggle {
        display: block;
    }
}

/* Tablet (768px - 1023px) */
@media (max-width: 1023px) {
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }

    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile (< 768px) */
@media (max-width: 767px) {
    .header-content {
        height: 60px;
    }

    .logo {
    display: inline-flex;
    align-items: center;
    font-size: var(--text-xl);
    font-weight: var(--font-extrabold);
    color: var(--primary);
    transition: transform 0.2s ease;
}

    .footer {
        padding: var(--space-2xl) 0 var(--space-lg);
    }

    .footer-content {
        margin-bottom: var(--space-2xl);
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .footer-column h4 {
        font-size: var(--text-sm);
    }
}

/* Mobile Small (< 640px) */
@media (max-width: 639px) {
    .header-container {
        padding: 0 var(--space-md);
    }

    .footer-container {
        padding: 0 var(--space-md);
    }

    .footer-logo {
        font-size: var(--text-xl);
    }

    .footer-tagline {
        font-size: var(--text-sm);
    }
}