:root {
    /* Elegant Blue Theme */
    --background: hsl(220, 15%, 97%);
    --foreground: hsl(220, 25%, 15%);
    --card: hsl(0, 0%, 100%);
    --card-foreground: hsl(220, 25%, 15%);
    --primary: hsl(213, 94%, 68%);
    --primary-foreground: hsl(0, 0%, 100%);
    --primary-light: hsl(213, 94%, 85%);
    --primary-dark: hsl(213, 84%, 58%);
    --secondary: hsl(220, 15%, 95%);
    --secondary-foreground: hsl(220, 25%, 15%);
    --muted: hsl(220, 15%, 95%);
    --muted-foreground: hsl(220, 15%, 45%);
    --accent: hsl(213, 94%, 92%);
    --accent-foreground: hsl(213, 84%, 25%);
    --border: hsl(220, 15%, 90%);
    --input: hsl(220, 15%, 90%);
    --ring: hsl(213, 94%, 68%);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, var(--background), hsl(213, 94%, 98%));
    color: var(--foreground);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header Styles */
.header {
    background: var(--card);
    backdrop-filter: blur(8px);
    background-color: hsla(0, 0%, 100%, 0.8);
    box-shadow: 0 2px 15px -3px hsl(213, 50%, 50%, 0.08);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 50;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

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

.logo-icon {
    width: 2rem;
    height: 2rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--foreground);
}

.nav-desktop {
    display: none;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: var(--foreground);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

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

.menu-button {
    display: block;
    background: none;
    border: none;
    color: var(--foreground);
    font-size: 1.125rem;
    cursor: pointer;
    transition: color 0.2s ease;
}

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

.nav-mobile {
    display: none;
    border-top: 1px solid var(--border);
    background: var(--card);
    padding: 0.5rem 0;
}

.nav-mobile.active {
    display: block;
}

.nav-mobile-link {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--foreground);
    text-decoration: none;
    border-radius: 0.375rem;
    margin: 0.25rem 0.5rem;
    transition: all 0.2s ease;
}

.nav-mobile-link:hover {
    color: var(--primary);
    background: hsla(213, 94%, 92%, 0.5);
}

.nav-mobile-link i {
    color: var(--primary);
    margin-right: 0.75rem;
}

/* Main Content Styles */
.main-content {
    padding: 2rem 1rem;
    min-height: calc(100vh - 4rem);
}

.main-card {
    background: var(--card);
    background-image: linear-gradient(145deg, var(--card), hsl(220, 15%, 98%));
    box-shadow: 0 4px 20px -2px hsl(213, 50%, 50%, 0.1);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    min-height: calc(100vh - 8rem);
}

.card-header {
    text-align: center;
    margin-bottom: 2rem;
}

.card-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.card-subtitle {
    color: var(--muted-foreground);
    font-size: 1.125rem;
    max-width: 32rem;
    margin: 0 auto;
}

.title-divider {
    width: 6rem;
    height: 0.25rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    margin: 1rem auto 0;
    border-radius: 9999px;
}

.content-area {
    background: hsla(220, 15%, 97%, 0.5);
    border-radius: 0.75rem;
    padding: 2rem;
    border: 1px solid hsla(220, 15%, 90%, 0.5);
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder-content {
    text-align: center;
}

.placeholder-icon {
    width: 4rem;
    height: 4rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
    font-size: 1.5rem;
}

.placeholder-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.placeholder-text {
    color: var(--muted-foreground);
    max-width: 28rem;
    margin: 0 auto 1.5rem;
}

.loading-dots {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1rem;
}

.dot {
    width: 0.75rem;
    height: 0.75rem;
    background: var(--primary);
    border-radius: 50%;
    animation: pulse 1.5s ease-in-out infinite;
}

.dot:nth-child(2) {
    opacity: 0.7;
    animation-delay: 0.2s;
}

.dot:nth-child(3) {
    opacity: 0.4;
    animation-delay: 0.4s;
}

.card-footer {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid hsla(220, 15%, 90%, 0.3);
    text-align: center;
}

.footer-text {
    font-size: 0.875rem;
    color: var(--muted-foreground);
}

.footer-text i {
    color: var(--primary);
    margin-right: 0.5rem;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.5;
        transform: scale(0.8);
    }
}

/* Responsive Design */
@media (min-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .nav-desktop {
        display: flex;
    }

    .menu-button {
        display: none;
    }

    .main-card {
        padding: 3rem;
    }

    .card-title {
        font-size: 2.5rem;
    }

    .content-area {
        padding: 3rem;
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 1.5rem;
    }

    .main-card {
        padding: 2.5rem;
    }
}

@media (max-width: 768px) {
        .form-group,
        .form-row,
        .row {
            flex-direction: column !important;
            display: flex !important;
            width: 100% !important;
        }
        .form-group > label,
        .form-group > input,
        .form-group > select,
        .form-group > textarea,
        .form-group > .help-block {
            width: 100% !important;
            max-width: 100% !important;
        }
        .form-control,
        .custom-select {
            width: 100% !important;
        }
        .btn {
            width: 100%;
            margin-bottom: 10px;
        }
    }

    .responsive-content {
        width: 100%;
        overflow-x: auto;
    }
    @media (max-width: 768px) {
        .responsive-content {
            padding: 0;
        }
    }