:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    --hover-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    background: linear-gradient(180deg, #f8f9ff 0%, #fff 100%);
    min-height: 100vh;
}

.navbar-brand {
    font-size: 1.4rem;
    letter-spacing: -0.5px;
}

.card {
    transition: all 0.3s ease;
    border-radius: 16px !important;
}

.card:hover {
    box-shadow: var(--hover-shadow);
}

.input-group .form-control {
    border-radius: 12px 0 0 12px;
    border: 2px solid #e0e0e0;
    padding: 0.8rem 1.2rem;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.input-group .form-control:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.input-group .btn-primary {
    border-radius: 0 12px 12px 0;
    background: var(--primary-gradient);
    border: none;
    padding: 0.8rem 2rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.input-group .btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.input-group .btn-primary:active {
    transform: translateY(0);
}

.badge {
    font-weight: 500;
    padding: 0.5em 0.8em;
    border-radius: 8px;
    font-size: 0.85rem;
}

.accordion-button:not(.collapsed) {
    background-color: rgba(102, 126, 234, 0.08);
    color: #667eea;
}

.accordion-button:focus {
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

#coverImage {
    width: 100%;
    border-radius: 12px;
}

.btn-outline-primary {
    border-color: #667eea;
    color: #667eea;
}

.btn-outline-primary:hover {
    background: var(--primary-gradient);
    border-color: transparent;
}

.spinner-border {
    width: 3rem;
    height: 3rem;
}

.toast {
    border-radius: 12px;
}

footer {
    border-radius: 0;
}

@media (max-width: 768px) {
    .display-5 {
        font-size: 1.8rem;
    }

    .input-group .form-control {
        font-size: 0.9rem;
        padding: 0.6rem 0.8rem;
    }

    .input-group .btn-primary {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }

    #coverSection {
        text-align: center;
    }

    #coverImage {
        max-height: 200px;
    }
}