:root {
    --primary-color: #4F46E5;
    --primary-gradient: linear-gradient(135deg, #4F46E5, #7C3AED);
    --bg-color: #F3F4F6;
    --card-bg: #FFFFFF;
    --text-main: #1F2937;
    --text-muted: #6B7280;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

/* Header */
header {
    background: var(--primary-gradient);
    color: white;
    padding: 3rem 1.5rem;
    text-align: center;
    position: relative;
    box-shadow: 0 4px 20px rgba(79, 70, 229, 0.2);
}

header h1 {
    margin: 0;
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
}

header p {
    margin-top: 0.5rem;
    color: #FFFFFF;
    opacity: 1;
    font-weight: 500;
}

/* Language Switcher */
.lang-switch {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    padding: 0.5rem;
    border-radius: 9999px;
    display: flex;
    gap: 0.5rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.lang-btn {
    background: none;
    border: none;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.lang-btn.active {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Container */
.container {
    max-width: 800px;
    margin: -2rem auto 4rem;
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 1.5rem;
    box-shadow: var(--shadow);
    position: relative;
    z-index: 10;
}

@media (max-width: 640px) {
    .container {
        margin: 0;
        border-radius: 0;
        padding: 2rem 1.5rem;
        box-shadow: none;
    }

    header {
        padding: 2rem 1.5rem;
    }

    header h1 {
        font-size: 2rem;
    }
}

/* Content Typography */
h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

h3 {
    font-size: 1.25rem;
    margin-top: 1.5rem;
    color: #374151;
}

p,
li {
    color: #4B5563;
    margin-bottom: 1rem;
}

ul {
    padding-left: 1.5rem;
}

li {
    margin-bottom: 0.5rem;
    position: relative;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

a:hover {
    color: #4338ca;
    text-decoration: underline;
}

/* Alerts / Highlight Boxes */
.alert-box {
    background-color: #FEF3C7;
    border-left: 4px solid #F59E0B;
    padding: 1rem;
    margin: 1.5rem 0;
    border-radius: 0.5rem;
}

.alert-box p {
    margin: 0;
    color: #92400E;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid #E5E7EB;
    margin-top: auto;
}

/* Utility */
.hidden {
    display: none !important;
}

.back-link {
    display: inline-block;
    margin-top: 2rem;
    padding: 0.75rem 1.5rem;
    background-color: #F3F4F6;
    border-radius: 0.5rem;
    color: #4B5563;
}

.back-link:hover {
    background-color: #E5E7EB;
    text-decoration: none;
    color: #1F2937;
}