/* ============================================
   CSS RESET & BASE
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */
.header {
    background: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1a365d;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav a {
    color: #4a5568;
    font-weight: 500;
    transition: color 0.2s;
}

.nav a:hover,
.nav a.active {
    color: #1a365d;
}

/* Mobile menu button */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #333;
    margin: 5px 0;
    transition: 0.3s;
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: #1a365d;
    color: #fff;
    padding: 2rem 1.5rem;
    margin-top: 3rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-copyright {
    opacity: 0.8;
    font-size: 0.875rem;
}

.footer-copyright a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.2s;
}

.footer-copyright a:hover {
    opacity: 1;
    text-decoration: underline;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: #fff;
    text-decoration: none;
    font-size: 0.875rem;
    opacity: 0.8;
    transition: opacity 0.2s;
    font-weight: 500;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

/* ============================================
   ERROR STATE
   ============================================ */
.error-box {
    background: #fed7d7;
    border: 1px solid #fc8181;
    color: #c53030;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.error-box h3 {
    margin-bottom: 0.5rem;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }

    .nav.active {
        display: flex;
    }

    .nav a {
        padding: 0.75rem 1rem;
        border-bottom: 1px solid #e2e8f0;
    }

    .nav a:last-child {
        border-bottom: none;
    }
}

@media (max-width: 600px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .header-inner {
        padding: 0.75rem 1rem;
    }

    .main {
        padding: 1rem;
    }
}